Systems and methods for forming electrical wires and cables

Abstract

Systems and methods are provided for manufacturing wire and cable products using polymer cable components. The systems and methods include increasing the hardness of the polymer cable components to reduce compression and deformation of the cable components during manufacturing. In some cases, the hardness is temporarily increased before or during the twisted pair fabrication process or during the cable fabrication process. In certain applications, the Young's modulus of the insulated conductive wires is increased during the entanglement process by controlling convective heat transfer.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 408,724, filed September 21, 2022, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE DISCLOSURE This disclosure relates to making communication cables, and more particularly to tailoring the hardness of polymer cable components to make high performance communication cables with reduced crush rates. [Background technology]

[0003] A variety of means are available for transmitting power or signals, and the invention disclosed herein is generally focused on wire and cable products that utilize insulated conductors to transmit electrical current. Summary of the Invention [Problem to be solved by the invention]

[0004] Many factors must be considered when designing wire and cable products. Applications such as Ethernet, CATV, and factory floor-based systems may dictate specific design features such as size, electrical properties, and physical attributes. For size, it may be important that the cable is compatible with standard connectivity, piping, raceways, and conduits. For electrical properties, capacitance, inductance, DC resistance, current, and current-carrying capacity may be design considerations. For certain specialized high-bandwidth cables, additional electrical parameters such as attenuation, velocity of propagation, skew delay, impedance, insertion loss, and noise mitigation may be important. For physical attributes, flame resistance, smoke resistance, chemical resistance, ozone resistance, moisture resistance, and / or tensile strength are common attributes considered. Fortunately, there are many tools and equations available to assist design engineers in considering the best options for building wire and cable products.

[0005] The process for manufacturing wire and cable is typically continuous in nature. A continuous production line typically includes a payout device from which material is paid out or dispensed to start the line process. There may also be an accumulator to store a portion of the payout material and help facilitate a consistent line speed. At the end of the line, there is typically a take-up device, which may also be equipped with an accumulator, to produce the product at a consistent line speed and allow the finished product to be wound into a roll or other form of packaging. Such operations may include, among other things, insulation, entanglement, cable making, braiding, jacketing, and laying up the wire and cable product to a set length. For most wire and cable products, the first step is the insulation process, in which the conductor is coated or covered with a polymeric material to electrically insulate the conductor.

[0006] During and after the insulation process, forces are likely to be generated that can affect the ability of the final product to meet its intended specifications. For example, in the case of coaxial cables, it is desirable to add foil and / or metal braid to protect the inner insulation layer and the electrical signals contained therein. It is well known that metal braid installations can create dents along the surface of the insulation they encase. In other words, because the surface of the insulation is often softer than the metal wires applied to it, the bare wires of the braided shield wire will deform the surface of the insulation underneath. Such insulation deformation can affect the signal transmission capabilities of the final cable by increasing capacitance and insertion loss. To account for these dents, design engineers often add extra insulation material to accommodate the depth of the dents.

[0007] In multi-conductor cables, the various insulated conductors are bundled together through a twisting mechanism, often called a twister, buncher, or cabler. The forces generated by each of these mechanisms can compress and deform the polymer components of the cable. Again, cable designers often add insulation to compensate for the compression, thus increasing the size and cost of the final product. Similar compressive forces can also be generated during jacketing and tensioning operations. To compensate for any deformation due to compression, thicker and / or stiffer jacket layers are sometimes used, which increases both the size and cost of the final product.

[0008] Adverse or compressive forces acting on cable components can be periodic in nature. For example, if a wheel is not properly aligned, it may wobble back and forth as it traverses a circular rotation. This causes a sinusoidal deformation in the material. If this sinusoidal pattern coincides with the intended frequency of the application (or any harmonics thereof), signal integrity can be compromised. Existing methods that help reduce the effects of such forces include slowing down the speed of the production line, whether constant or sinusoidal in nature. Slowing down the speed can mitigate and reduce the compressive forces caused by manufacturing equipment as products are produced. For this reason, it is common to operate the equipment at a fraction of its normal speed. However, this is undesirable because it underutilizes the equipment's capacity.

[0009] Another way compressive forces can potentially cause problems is with regard to capacitance targets. Capacitance is a function of the distance between metal surfaces and the properties of the materials between those surfaces. In the case of wire and cable, conductive surfaces can include, among other things, two conductors in close proximity or a shield and conductor in close proximity. The distance between these conductive surfaces is an important design consideration in manufacturing wire and cable products. Therefore, care is taken to ensure that conductors are spaced apart appropriately.

[0010] In some embodiments, two insulated conductors are formed together to create a twisted pair. Similarly, many insulated conductors can be formed together to create a multi-conductor cable unit. When two insulated conductors are twisted together, a helical pattern is obtained along the length of the twisted pair unit. A twisted pair unit typically consists of a metal conductor, insulating material, and air contained in the gaps between two approximately circular insulated conductors. It is well known that air is a highly desirable dielectric material. For example, materials such as polyolefins have a typical dielectric constant of 2.3 to 2.6, while air has a dielectric constant of 1.0. Therefore, the more air is stored in the gaps between twisted pair units, the better the electrical results. However, when the compressive forces generated during cable construction bring the insulated conductors closer together, insulating material can migrate into these gaps, thus reducing the total air content. This results in higher, generally less desirable, capacitance, which can potentially reduce signal speed and reduce signal propagation capabilities.

[0011] Insulated conductors, such as twisted-pair communication cables, are typically used for high-frequency signal transmission in building plenum areas, raised floors, or conduits. In twisted-pair data cable embodiments, individual conductive wires are insulated using a polymer, and then two such insulated conductors are twisted around each other to form a single twisted pair. Twisted-pair cables are typically composed of multiple twisted pairs contained within a single outer jacket to form a cable. Each twisted pair within a cable may be twisted with a different twist (conventionally measured in mm / turn) to reduce electrical coupling (i.e., crosstalk) between adjacent twisted pairs.

[0012] The process of twisting individual insulated conductors together often compresses the polymer insulation layer. The amount of force compressing the insulation layer varies depending on the twisting equipment and the twist tightness (i.e., turns per inch). The compressive force created by twisting the insulated conductors deforms the insulation layer, reducing the thickness of the insulation layer separating the two conductors. This results in an increase in the capacitance measured between the two conductors and therefore a decrease in the overall impedance of the twisted pair unit. In some cases, the compression results in a loss of air content in the interstices of the twisted pairs or from the foam insulation.

[0013] To compensate for this undesirable loss of insulation thickness, manufacturers of polymer-insulated wire typically increase the thickness of the polymer insulation. The shorter the twist, the tighter the twist and the greater the crushing or compression of the polymer insulation (whether foam or solid). Some twisted pairs are designed to have an impedance of 100 ohms. The center-to-center spacing of the conductors within the twisted pair is a significant factor affecting impedance. Therefore, as the twist length decreases, additional insulation thickness is required to maintain the desired conductor-to-conductor spacing and impedance, because increased compression brings the conductors closer together. Increasing the amount of polymer insulation used increases overall cable weight, cable size, and cost.

[0014] New methods and apparatus are needed to control the deformation of the insulation layer during cable manufacture to create polymer-insulated cables that maintain the desired spacing of the conductors by controlling the amount of compression of the insulated conductors together. Controlling the deformation can help maintain the desired impedance and other electrical and mechanical properties before and after entanglement. Controlling the deformation of the insulation layer caused by mechanical devices such as braids, pulleys (wheels), and winders, as well as non-metallic substrates such as cross inserts, also helps maintain the desired electrical and mechanical properties of the cable.

[0015] What is further needed is a method for adjusting the deformation of the insulation during cable manufacture to obtain desired impedance, electrical, and mechanical properties. Improved control over such properties can be achieved by controlling the hardness and / or stress / strain response of the insulation. The compressive property response of the insulation is often described in terms of Young's modulus.

[0016] It's also important to note that in the case of torsional forces (the type or forces that occur when insulated conductors are twisted together), deformation may not be uniform. This is because the insulation may move unevenly depending on the direction of the torsional force. This condition is particularly undesirable in balanced pair applications. For example, in some applications involving twisted-pair units using two insulated conductors, it is desirable for the signals in each of the two insulated conductors to be mirror images of each other. In this way, electrical noise coupled to each insulated conductor in the twisted unit couples similarly, allowing electronic filtering mechanisms to cancel the noise component. If one insulated conductor in the pair is geometrically unbalanced, it becomes difficult to subtract any noise component from the desired signal. Wire and cable specifications often include near-end and far-end crosstalk specifications to ensure that the amount of noise between the transmitting pair is small enough not to interfere with signal transmission. Unbalanced insulated conductors makes these specifications difficult to meet.

[0017] When cable designers consider how much additional insulation material is needed to offset any displacement or deformation of the insulation resulting from forces generated during the manufacturing process, they must understand the softness of the insulation material. Because these displacements and deformations are generally permanent in nature, it is most appropriate to understand the hardness of the compound. Hardness, often expressed in Pascals, measures a material's resistance to surface deformation. In other words, hardness is the resistance of a surface to localized deformation. Indentation hardness can be measured by a variety of methods, including Brittnell, Mayer, Vickers, Rockwell, and / or Shore durometer. For example, the Shore D hardness scale is commonly used for polymeric materials such as fluorinated ethylene propylene (FEP), polyethylene (PE), polypropylene (PP), polyetheretherketone (PEEK), polyetherketone (PEKK), and polyvinyl chloride (PVC). For other materials, such as rubber, other Shore scales, such as Shore A, can be used. For Shore D, the test protocols are defined in ASTM D2240 and / or ISO 868, which are used herein as the baseline hardness standard.

[0018] It is understood that changes in ambient temperature conditions can affect the softness of a material. For example, in warm climates, temperature control of the manufacturing floor may be necessary during months when ambient temperatures are seasonally high, which may reduce the hardness of any polymeric materials on the manufacturing floor. Additionally, when a cable component is subjected to compression, torsion, or other deformation forces, heat is generated within the cable component. In some applications, the forces involved may cause the component to heat up above the ambient temperature as the component deforms, thereby reducing the hardness of the component and making it more susceptible to deformation during that deformation event and any subsequent deformation events.

[0019] Conversely, the hardness of the compound may increase as the compound cools below ambient temperature. This hardening can make the material more resistant to compressive forces that would cause the material to deform or dent.

[0020] The temperature adjustment does not need to persist beyond the compression event. Because the deformations discussed herein are permanent in nature (i.e., not elastic), the disclosed methods need only be applied before or during the compression event. Once the compression event is over, the material may return to ambient temperature. Other methods described above are more permanent in nature (e.g., slowing down the machine, adding skin layers, or adding harder material to the insulation). Temporarily adjusting the hardness of the material can avoid many of the negative effects of these solutions.

[0021] It is desirable in industry to have a method for hardening compounds or reducing the compressive forces applied to counteract the effects of deforming polymer cable components that is less costly than adding insulation. Any method incorporated to reduce the impact of compressive forces on insulation would also be desirable to fit within the footprint of current machinery with minimal change to the positioning of the equipment itself. One such method is to vary the hardness of the compound by controlling its temperature. It can be seen that harder compounds are less susceptible to compressive forces than softer compounds. When using the Shore D scale, a higher number indicates a harder compound. This assumes that the material type remains the same and only the temperature of the material itself changes.

[0022] As explained earlier, reducing deformation due to forces generated during the manufacturing process can improve performance and reduce costs, and changing the hardness of a material with a temporary temperature change can accomplish both.

[0023] Increasing the hardness of polymeric cable components can reduce deformation of the polymeric insulation layer, cross-web filler, polymeric tube, or other polymeric cable components, which deformation is typically caused by compressive or torsional forces during manufacturing operations such as stranding, braiding, and mechanical devices such as pulleys (wheels) and winders.

[0024] What is needed is a cost-effective method for increasing the harness of the material. What is needed is a method for cooling the insulating material at or near the location where the compressive force is applied. This method can increase the hardness of the material relative to its possible hardness at ambient temperature and reduce any deformation caused by the compressive force. [Means for solving the problem]

[0025] The present disclosure generally relates to the fabrication of wire and cable products that incorporate methods for temporarily changing the stress / strain response, often defined by the material's hardness and / or Young's modulus. The insulation's response to stress and strain forces may be altered by controlling the temperature of a layer of insulation around a conductive wire. Maintaining a low temperature will result in a shift in the Young's modulus response, as will increasing the temperature. This is particularly true for polymeric insulation materials, since most such materials soften at higher temperatures. Some disclosed embodiments relate to methods and devices for increasing the hardness and / or stress / strain response of polymeric insulation that can be used in-line as part of a continuous or semi-continuous manufacturing process. Some disclosed embodiments relate to a method of reducing the effects of compressive forces on a polymer cable component, the method including providing a polymer cable component having a first hardness, the first hardness being the hardness of the polymer cable component under ambient conditions; temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymer cable component; and allowing the polymer cable component to return to the first hardness.

[0026] Some disclosed embodiments relate to a method for forming a twisted pair, the method including providing a first polymer-insulated conductor including a first conductor electrically insulated by a first polymer insulating layer and a second polymer-insulated conductor including a second conductor electrically insulated by a second polymer insulating layer, exposing the first insulated conductor to a cryogenic fluid, and twisting the first and second polymer-insulated conductors around each other to form the twisted pair.

[0027] It has also been found that the temperature of the insulated wire can be effectively controlled during the entanglement process by controlling convective heat transfer. Heat transfer between the wire and the atmosphere (or other fluid) is highly efficient, and if convective heat transfer can be controlled, the temperature of the wire can be controlled. This can be accomplished using little energy by partially or totally shielding the insulated wire from the air or other fluid as it is processed by the spinning bow in the entanglement unit.

[0028] Some disclosed embodiments relate to a method for controlling the effect of a compressive force on a polymeric cable component, the method including: providing a polymeric cable component having a first hardness, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymeric cable component in an entanglement device having a bow, the polymeric cable component being at least partially protected from convective heat transfer while in the bow; and returning the polymeric cable component to the first hardness.

[0029] Some disclosed embodiments relate to a method of manufacturing a communication cable, the method including: providing a polymeric cable component having a first cross-sectional radius and a second cross-sectional radius, wherein the first cross-sectional radius is a maximum distance from a center of the polymeric cable component to an end of the polymeric cable component along the cross section, and the second cross-sectional radius is a minimum distance from the center of the polymeric cable component to an end of the polymeric cable component along the cross section, the first cross-sectional radius being approximately equal to the second cross-sectional radius + / - 3%, and the polymeric cable component having a first hardness, the first hardness being a hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being different from the first hardness; and applying a compressive force to the polymeric cable component in an entanglement unit having a bow, wherein the polymeric cable component is at least partially shielded from convective heat transfer while in the bow, and wherein after the compressive force, the first cross-sectional radius is approximately equal to the second cross-sectional radius + / - 10%.

[0030] Some disclosed embodiments relate to a method of manufacturing a communication cable, the method including: providing a polymer cable component having a first cross-sectional radius and a second cross-sectional radius, wherein the first cross-sectional radius is a maximum distance from a center of the polymer cable component to an end of the polymer cable component along the cross section, and the second cross-sectional radius is a minimum distance from the center of the polymer cable component to an end of the polymer cable component along the cross section, the first cross-sectional radius being approximately equal to ±3% of the second cross-sectional radius, and the polymer cable component having a first hardness, the first hardness being a hardness of the polymer cable component under ambient conditions; temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymer cable component in an entanglement unit having a bow, wherein the polymer cable component is at least partially shielded from convective heat transfer while in the bow; and wherein after the compressive force, the first cross-sectional radius is approximately equal to ±10% of the second cross-sectional radius.

[0031] Some disclosed embodiments relate to a method of manufacturing a communications cable, the method including: providing a polymeric cable component having a first diameter and a second diameter, the first diameter and the second diameter being perpendicular to one another, the first diameter being approximately equal to the second diameter ±3%, the polymeric cable component having a first hardness, the first hardness being a hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymeric cable component at a bow of an entanglement unit, the polymeric cable component being at least partially shielded from convective heat transfer at the bow, and wherein after the compressive force, the first diameter is approximately equal to the second diameter ±10%; and returning the polymeric cable component to the first hardness.

[0032] Some disclosed embodiments include a method of manufacturing a communications cable, comprising the steps of: providing first, second, third, and fourth pairs of polymer-insulated conductors, each pair including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors at ambient conditions; temporarily changing the hardness of the polymer-insulated conductors in the first, second, and third pairs of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; twisting the first pair of polymer-insulated conductors together to form a first twisted pair, the first twisted pair having a first propagation delay over 100 meters; and twisting the second pair of polymer-insulated conductors together to form a second twisted pair, the second twisted pair having a first propagation delay over 100 meters. twisting together a third pair of polymer-insulated conductors to form a third twisted pair, the third twisted pair having a third propagation delay over 100 meters; and twisting together a fourth pair of polymer-insulated conductors to form a fourth twisted pair, the fourth twisted pair having a fourth propagation delay over 100 meters, wherein the first, second, third, and fourth propagation delays over 100 meters differ by within 50 nanoseconds of each other over the 100 meters, and twisting at least one polymer-insulated conductor of the first, second, third, and fourth pairs includes feeding the polymer-insulated conductor to a bow of a twisting unit, wherein the polymer-insulated conductor is at least partially shielded from convective heat transfer at the bow.

[0033] Some disclosed embodiments include a method of manufacturing a communication cable, comprising the steps of: providing a first pair of polymer-insulated conductors and a second pair of polymer-insulated conductors, each pair of polymer-insulated conductors including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors at ambient conditions; temporarily changing the hardness of the polymer-insulated conductors in the first pair of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; and interlacing the first pair of polymer-insulated conductors at a bow of an interlacing unit. twisting together a second pair of polymer-insulated conductors to form a second twisted pair, the second twisted pair having a second propagation delay over 100 meters, wherein the first propagation delay over 100 meters and the second propagation delay over 100 meters are within 25 nanoseconds of each other.

[0034] Some disclosed embodiments relate to a system for manufacturing wire and cable products, the system including: a payout device configured to pay out a polymeric cable component; a cooling vessel configured to receive the polymeric cable component, the cooling vessel containing a chilled fluid; a winding device configured to wind the polymeric cable component; and an entanglement device configured to receive a first polymer-insulated conductor and a second polymer-insulated conductor to form twisted pairs, the entanglement device including a bow in the fluid, the bow including means for protecting the insulated wires from convective heat transfer with the fluid as the bow rotates.

[0035] Some disclosed embodiments relate to a system for manufacturing wire and cable products, the system including: a payout device configured to pay out a polymeric cable component; a winding device configured to wind the polymeric cable component; and an entanglement device configured to receive a first polymer-insulated conductor and a second polymer-insulated conductor to form twisted pairs, the entanglement device including a bow in a fluid, the bow including means for protecting the insulated wires from convective heat transfer with the fluid as the bow rotates.

[0036] Some disclosed embodiments are a method of manufacturing a low fuel load wire and cable product, the method comprising the steps of establishing desired electrical properties of the wire and cable product, the wire and cable product including a polymeric cable component, the polymeric cable component having a first fuel load and a first hardness, the polymeric cable component having a flame travel distance of about 5 feet or less, a peak smoke optical density of about 0.5 or less, and an average optical density of about 0.15 or less when measured according to the Steiner Tunnel Test Method of ASTM E84, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being greater than the first hardness; and applying a compressive force to the polymeric cable component while the polymeric cable component is at the second hardness in an entanglement unit having a bow, thereby causing a first amount of deformation in the polymeric cable component. and forming a wire and cable product using the polymer cable component, wherein the polymer cable component is at least partially protected from convective heat transfer at the bow, and the wire and cable product meets established desired electrical properties when the polymer cable component is deformed by a first deformation amount, but does not meet the desired electrical properties when the polymer cable component is deformed by a second deformation amount, the second deformation amount being an amount that the polymer cable component would deform when subjected to an applied compressive force if the polymer cable component were at a first hardness.

[0037] Some disclosed embodiments relate to a rotating bow for use in a entanglement unit for producing twisted pairs of insulated electrical wire, the rotating bow being used in a fluid and including means for protecting the insulated electrical wire from convective heat transfer with the fluid as the bow rotates.

[0038] Some disclosed embodiments relate to a method of producing a twisted pair of insulated wires with improved crush resistance, the method including cooling a first insulated wire to increase a hardness of the first insulated wire, cooling a second insulated wire to increase a hardness of the second insulated wire, feeding the first insulated wire and the second insulated wire to a bow of an entangler unit in the presence of a fluid, and at least partially shielding the insulated wires from convective heat transfer from the fluid as the bow rotates.

[0039] Some disclosed embodiments relate to a method for producing twisted pairs of insulated electrical wires with improved crush resistance, the method including the steps of cooling an atmosphere within an entangler unit to below ambient temperature, feeding first and second insulated electrical wires to a bow of the entangler unit, and at least partially shielding the insulated electrical wires from convective heat transfer from the cooled atmosphere within the entangler unit as the bow rotates.

[0040] Some embodiments relate to a method of producing a twisted pair of insulated wires having a predetermined impedance, the method including: feeding a first insulated wire and a second insulated wire to a rotating bow that is part of a entanglement device in the presence of a fluid, wherein the first insulated wire includes a first conductor surrounded by a first insulation and the second insulated wire includes a second conductor surrounded by a second insulation; controlling convective heat transfer of the first insulated wire and the second insulated wire from the fluid to control a temperature of the first insulated wire and the second insulated wire to impart a hardness to the first insulated wire and the second insulated wire; and twisting the first insulated wire with the second insulated wire to form the twisted pair, wherein the first insulated wire and the second insulated wire undergo an amount of deformation during twisting that is a function of the hardness, and wherein the impedance of the twisted pair is a function of the degree of deformation.

[0041] Some embodiments relate to a method of producing a twisted pair of insulated wires within a predetermined impedance tolerance, the method including: feeding a first insulated wire and a second insulated wire to a rotating bow that is part of a entangling device in the presence of a fluid, wherein the first insulated wire includes a first conductor surrounded by a first insulation and the second insulated wire includes a second conductor surrounded by a second insulation; controlling convective heat transfer from the fluid to the first insulated wire and the second insulated wire; twisting the first insulated wire with the second insulated wire to form a twisted pair, wherein the first insulated wire and the second insulated wire undergo a deformation during twisting; measuring the impedance of the twisted pair; and adjusting the convective heat transfer from the fluid to the first insulated wire and the second insulated wire if the impedance of the twisted pair is outside the predetermined tolerance.

[0042] Some embodiments relate to a twisted pair of insulated wires with improved resistance to deformation that is the product of any of the above processes.

[0043] Some embodiments relate to a twisted pair of insulated wires having a predetermined impedance that is the product of any of the above processes.

[0044] Some embodiments relate to a twisted pair of insulated wires having an impedance within a predetermined tolerance that is the product of any of the above processes.

[0045] Some embodiments relate to cables that include any of the twisted pairs described above.

[0046] Convection requires the presence of some fluid in contact with the insulated wire. In many embodiments, the fluid in contact with the insulated wire can be air. In some embodiments, the fluid in the entanglement device can include various substitutes, such as cryogenic fluids, inert gases (e.g., helium, N2, argon, krypton, radon, neon, xenon, and combinations thereof). In some embodiments, the fluid in the entanglement device or cooling chamber can include cooled air generated by an air conditioning or refrigeration device, fluorocarbon solutions, brine solutions, gases obtained by vaporizing solid objects or liquids having a vaporization temperature of 0° C. or lower (e.g., dry ice or liquid nitrogen), liquids having a freezing point of 0° C. or lower, chilled acetone, and combinations thereof.

[0047] In some embodiments, the polymer-insulated conductors used in multiple twisted pairs are protected from convective heat transfer or exposed to cryogenic fluid for different periods of time to create a cable with reduced delay skew.

[0048] Some disclosed embodiments relate to methods of manufacturing communication cables to reduce deformation of polymeric cable components and maintain the roundness of insulated conductors and other cable components.

[0049] Some disclosed embodiments relate to system installations for manufacturing wire and cable products with improved electrical properties. Some of these embodiments relate to cooling vessels and / or secondary structures for holding a cooling medium, such as a chilled fluid or a cooled solid surface.

[0050] Some disclosed embodiments relate to methods of manufacturing communication cables with reduced fuel loads, including forming wire and cable products with less total polymer insulation relative to conventional cables, such that the cables with less total polymer insulation have lower total fuel loads and improved flammability and / or smoke generation characteristics.

[0051] Some disclosed embodiments relate to methods of manufacturing communication cables at faster speeds. Some of these embodiments relate to operating an entanglement device at faster speeds, which typically increases the compressive force on the polymer insulation layer. Some of these embodiments relate to curing the polymer insulation prior to entanglement so that the entanglement device can be operated at faster speeds to produce cables with an acceptable amount of deformation and desired electrical properties.

[0052] The disclosed invention may be applied to any form of polymeric cable component or cable structure, including, for example, solid, foam, profile extrusion, insulation layer, hollow tube, cross-web, rod-filler, film, tape, coaxial structures including braided processes, and / or multi-layer insulation.

[0053] In addition to reducing deformation of insulation layers when insulated wires are twisted into twisted pairs, the disclosed invention may be used to reduce deformation of any polymeric material or mechanical system such as a winding device, pulley, or wheel that is exposed to compressive forces, such as braid indentation.

[0054] The foregoing presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key or critical elements of the invention, nor is it intended to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0055] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0056] [Figure 1] 1 is a schematic cross-sectional view of an embodiment of an insulated conductor according to the present disclosure. [Figure 2A] 1 is a schematic cross-sectional view of an embodiment of a twisted pair. [Figure 2B] 1 is a schematic cross-sectional view of an embodiment of a twisted pair. [Figure 3] 1 is a schematic cross-sectional view of an embodiment of an insulated conductor according to the present disclosure. [Figure 4A] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 4B] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 4C] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 5A] 1 is a schematic diagram of an embodiment of a cooling vessel having a secondary structure according to the present disclosure. [Figure 5B] 1 is a schematic diagram of an embodiment of a cooling vessel having a secondary structure according to the present disclosure. [Figure 6] 1 is a graph of crush rate data. [Figure 7] 1 is a graph of surface temperature data and crush rate data versus exposure time. [Figure 8] 1 is a cross-sectional image of a foam-insulated conductor. [Figure 9] 1 is a graph of surface temperature data for foamed and solid polymer insulation versus exposure time. [Figure 10] 1 is a graph showing temperature over time for foamed and solid polymer insulated copper conductors. [Figure 11] 1 is a graph showing temperature over time for foamed and solid polymer insulated copper conductors. [Figure 12] FIG. 1 is a schematic diagram of an embodiment of a twisted pair according to this disclosure. [Figure 13] 1 is a diagram of an embodiment of a cable according to the present disclosure. [Figure 14] 1 is a schematic cross-sectional view of an embodiment of a cable according to the present disclosure. [Figure 15] 1 is a schematic cross-sectional view of an embodiment of a cable according to the present disclosure. [Figure 16] 1 is a schematic cross-sectional view of an embodiment of an insulated conductor according to the present disclosure. [Figure 17] 1 is a schematic cross-sectional view of an embodiment of a cable according to the present disclosure. [Figure 18] 1 is a schematic diagram of an embodiment of a cable according to the present disclosure. [Figure 19A] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 19B] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 19C] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 20A] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 20B] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 20C] 1 is a schematic diagram of an embodiment of a cooling vessel according to the present disclosure. [Figure 21] 1 is a graph of Shore D hardness of solid FEP versus time of exposure to liquid nitrogen. [Figure 22] 1 is a graph of Shore D hardness of solid FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 23A] 1 is a graph of Shore D hardness of solid FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 23B] 1 is a graph of Shore D hardness of solid FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 23C] 1 is a graph of Shore D hardness of solid FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 24] 1 is a graph of Shore D hardness of foamed FEP versus exposure time to liquid nitrogen. [Figure 25] 1 is a graph of Shore D hardness of foamed FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 26] 1 is a graph of Shore D hardness of foamed FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 27] 1 is a graph showing a comparison of Shore D hardness of solid and foam FEP versus time of exposure to liquid nitrogen. [Figure 28] 1 is a graph showing a comparison of Shore D hardness of solid and foam FEP versus exposure time to ambient atmosphere after exposure to liquid nitrogen. [Figure 29] 1 is a graph showing a comparison of the temperature of solid and foam FEP after exposure to liquid nitrogen versus time of exposure to ambient atmosphere. [Figure 30] 10A-10C illustrate embodiments of a bow including a tube to protect polymer cable components from convective heat transfer. [Figure 31] 31 shows a side view of the bow shown in FIG. 30. [Figure 32] 10A-10C illustrate embodiments of a bow including channels to protect polymer cable components from convective heat transfer. [Figure 33] FIG. 31 shows a detail of the embodiment shown in FIG. 30. [Figure 34] FIG. 33 shows a detail of the embodiment shown in FIG. 32. [Figure 35] FIG. 10 shows a detail of an embodiment of a partially covered and partially open flow channel. [Figure 36] 36 shows a side view of the embodiment shown in FIG. 35. [Figure 37] FIG. 36 shows a detail of the embodiment shown in FIG. 35. [Figure 38] 10A-10C show an embodiment of a bow having several air guides to protect the polymer cable from convective heat transfer. [Figure 39] 39 shows a side view of the embodiment of FIG. 38. [Figure 40] 10A and 10B are diagrams showing details of an embodiment of a wind guide; [Figure 41] 10A-10C illustrate an embodiment of a tube for protecting a polymer cable that includes vent openings in an open configuration. [Figure 42] 10A-10C illustrate an embodiment of a partially open flow channel in a bow for protecting a polymer cable including vent openings in an open configuration. [Figure 43] FIG. 42 shows the embodiment of FIG. 41, wherein the vent opening is in a closed configuration. [Figure 44] 43 shows the embodiment of FIG. 42, wherein the vent opening is in a closed configuration. [Figure 45A] 45A-45C show embodiments of a bow including channels to protect polymer cable components from convective heat transfer. Fig. 45A shows an embodiment in which 0% of the channels are covered. [Figure 45B] 45A and 45B show embodiments of a bow including channels to protect polymer cable components from convective heat transfer, and FIG. 45B shows an embodiment in which 25% of the channels are covered. [Figure 45C] 45A-45C show embodiments of a bow including channels to protect polymer cable components from convective heat transfer, and FIG. 45C shows an embodiment in which 50% of the channels are covered. [Figure 45D] 45A-45D show embodiments of a bow including channels to protect polymer cable components from convective heat transfer. Fig. 45D shows an embodiment in which 75% of the channels are covered. [Figure 45E]45A-45E show embodiments of a bow including channels to protect polymer cable components from convective heat transfer. Fig. 45E shows an embodiment in which 100% of the channels are covered. [Figure 46] 1 is a graph showing the results of tests of varying levels of protection on the impedance of a twisted pair. [Figure 47] 1 is a graph showing the results of tests of varying levels of protection on twisted pair delay. DETAILED DESCRIPTION OF THE INVENTION

[0057] The embodiments described below represent the information necessary to enable those skilled in the art to practice the present disclosure and illustrate the best mode of practicing the disclosure. Upon reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not specifically addressed herein. These concepts and applications should be understood to be within the scope of the present disclosure and the appended claims.

[0058] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art of this disclosure. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the specification, and should not be interpreted in an ideal or overly formal sense unless expressly defined in this specification. Well-known functions or structures may not be described in detail for the sake of brevity or clarity.

[0059] The terms "about" and "approximately" generally refer to an acceptable degree of error or variation in the quantity being measured, given the nature or precision of the measurement. Typically, the exemplary degree of error or variation is within 20 percent (%), preferably within 10%, and more preferably within 5% of a given value or range of values. Quantities given in this description are approximate quantities unless otherwise stated, meaning that the term "about" or "approximately" can be inferred if not explicitly stated. Quantities in the claims are exact quantities unless otherwise stated.

[0060] The term "adapted" means designed or constructed to perform a particular purpose, as opposed to merely being able to be made to perform a particular purpose.

[0061] The term "capable of being" means capable of being made to carry out a particular purpose.

[0062] When a feature or element is referred to as being "on" another feature or element, it will be understood that it can be directly on the other feature or element, and that intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. When a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it will be understood that it can be directly connected, attached, or coupled to the other feature or element, and that intervening features or elements may also be present. In contrast, when a feature or element is referred to as being "directly connected," "directly attached," or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or illustrated with respect to one embodiment, the features and elements so described or illustrated can be applied to other embodiments.

[0063] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0064] Terms such as "first," "second," and the like are used herein to describe various features or elements, but these features or elements should not be limited by these terms. These terms are merely used to distinguish one feature or element from another. Thus, a first feature or element discussed below could also be referred to as a second feature or element, and similarly, a second feature or element discussed below could also be referred to as a first feature or element, without departing from the teachings of the present disclosure.

[0065] Terms such as "at least one of A and B" should be understood to mean "A only, B only, or both A and B." The same structure should apply to longer lists (e.g., "at least one of A, B, and C").

[0066] With reference to the use of the words "comprise," "comprises," and "comprising" in the foregoing description and / or in the following claims, unless the context requires otherwise, those words are used with the standard and clear understanding that they are to be interpreted inclusively and not exclusively, and that each of those words is to be so interpreted in giving the meaning of the foregoing description and / or the following claims.

[0067] The term "including" should be construed to mean "including, but not limited to," unless the context clearly indicates otherwise.

[0068] The term "consisting essentially of" means that in addition to the recited elements, what is stated may also contain other elements (steps, configurations, ingredients, components, etc.) that do not adversely affect the operability of what is stated for the intended purposes set forth in this disclosure. This term excludes other elements that adversely affect the operability of what is stated for the intended purposes set forth in this disclosure, even if such elements may enhance the operability of what is stated for some other purpose.

[0069] In some places, reference is made to standard methods, for example, but not by way of limitation, methods of measurement. It should be understood that such standards are revised from time to time and, unless expressly stated otherwise, references to such standards in this disclosure should be construed as referring to the most recently published standard at the time of filing.

[0070] This disclosure describes embodiments of methods and systems for making wire and cable products with improved electrical performance and / or improved manufacturing features. While the disclosed inventions are generally discussed in the context of intertwining polymer-insulated wires to form twisted pairs, it will be understood that the disclosed inventions are applicable to many applications beyond intertwining insulated conductors, including, for example, polymer insulation layers, foam insulation layers, foam skins, cross-webs, polymer tapes, hollow tubes, rod fillers, sheaths, and other polymer cable components. The disclosure below frequently refers to insulated wires, which include a polymer component that acts as an insulator surrounding a conductive component, which is typically a conductive metal wire such as copper or a copper alloy. However, the subject matter described herein may be used for polymer components in other contexts as well.

[0071] According to an exemplary embodiment of the present disclosure, a method for controlling the effect of a compressive force on a polymer cable component is provided. The polymer cable component can have a first hardness, which can be the hardness of the polymer cable component under ambient conditions. The method can include temporarily changing the hardness of the polymer cable component to a second hardness different from the first hardness. In some examples, the polymer cable component can be processed through an entanglement unit having a bow, where a compressive force can be applied to the polymer cable component. During the entanglement unit process, the polymer cable component can be at least partially protected from convective heat transfer while in the bow. The method can include returning the polymer cable component to the first hardness.

[0072] According to another exemplary embodiment of the present disclosure, a method for manufacturing a communication cable is provided. The method can include providing a polymer cable component. The polymer cable component can have a first cross-sectional radius and a second cross-sectional radius. The first cross-sectional radius can be a maximum distance from a center of the polymer cable component to an end of the polymer cable component along the cross-section. The second cross-sectional radius can be a minimum distance from a center of the polymer cable component to an end of the polymer cable component along the cross-section. Under ambient conditions, the first cross-sectional radius can be approximately equal to the second cross-sectional radius ±3%. Under ambient conditions, the polymer cable component can have a first hardness. The method can include temporarily changing the hardness of the polymer cable component to a second hardness. In some examples, the second hardness can be greater than the first hardness. The polymer cable component can be subjected to a process in an entanglement unit having a bow. The process can include applying a compressive force to the polymer cable component within the entanglement unit. During the process, the polymer cable component can be at least partially protected from convective heat transfer at the bow of the entanglement unit. After the compressive force, the first cross-sectional radius is approximately equal to the second cross-sectional radius ±10%.

[0073] In another exemplary embodiment of the present disclosure, a method for manufacturing a communication cable is provided. The method can include providing a polymer cable component having a first diameter and a second diameter. The first diameter can be perpendicular to the second diameter ±3%. The polymer cable component can have a first hardness, the first hardness being the hardness of the polymer cable component under ambient conditions. The method can include temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being greater than the first hardness. The method can include processing the polymer cable component in an entanglement unit having a bow. The process can include applying a compressive force to the polymer cable component. During the process, the polymer cable component can be at least partially shielded from convective heat transfer in the bow. After the compressive force, the first diameter can be approximately equal to the second diameter ±10%. The method can include returning the polymer cable component to the first hardness.

[0074] In another exemplary embodiment of the present disclosure, a method for manufacturing a communication cable is provided. The method can include providing first, second, third, and fourth pairs of polymer-insulated conductors. Each pair of polymer-insulated conductors can include two polymer-insulated conductors. Each polymer-insulated conductor can have a first hardness, which can be the hardness of the polymer-insulated conductors at ambient conditions. The method can include temporarily changing the hardness of the polymer-insulated conductors in the first, second, third, and / or fourth pairs of polymer-insulated conductors to a second hardness, which can be different from the first hardness. The method can include twisting the first pair of polymer-insulated conductors together to form a first twisted pair. The first twisted pair can have a first propagation delay over 100 meters. The method can include twisting the second pair of polymer-insulated conductors together to form a second twisted pair. The second twisted pair can have a second propagation delay over 100 meters. The method can include twisting a third pair of polymer-insulated conductors together to form a third twisted pair. The third twisted pair can have a third propagation delay over 100 meters. The method can include twisting a fourth pair of polymer-insulated conductors together to form a fourth twisted pair. The fourth twisted pair can have a fourth propagation delay over 100 meters. For the first, second, third, and fourth propagation delays over 100 meters, the difference in propagation delay over 100 meters can be within 50 nanoseconds of each other. In some examples, twisting at least the first, second, third, and fourth pairs of polymer-insulated conductors can include feeding the polymer-insulated conductors to a bow of a twisting unit. The polymer-insulated conductors can be at least partially shielded from conductive heat transfer at the bow.

[0075] Another exemplary embodiment of the present disclosure provides a method for manufacturing a communication cable. The method can include providing a first pair of polymer-insulated conductors and a second pair of polymer-insulated conductors. Each pair of polymer-insulated conductors can include two polymer-insulated conductors. Each polymer-insulated conductor can have a first hardness, which can be the hardness of the polymer-insulated conductors at ambient conditions. The method can include temporarily changing the hardness of the polymer-insulated conductors in the first pair of polymer-insulated conductors to a second hardness. The second hardness can be different from the first hardness. The method can include twisting the first pair of polymer-insulated conductors together at a bow of a entanglement unit to form a first twisted pair. The polymer-insulated conductors can be at least partially shielded from convective heat transfer at the bow. The first twisted pair can have a first propagation delay of over 100 meters. The method can include twisting the second pair of polymer-insulated conductors together to form a second twisted pair. The second twisted pair can have a second propagation delay over 100 meters. The first propagation delay over 100 meters and the second propagation delay over 100 meters can be within 25 nanoseconds of each other.

[0076] In another exemplary embodiment of the present disclosure, a system for manufacturing wire and cable products is provided. The system may include a payout device configured to payout a polymer cable component. The system may include a cooling vessel configured to receive the polymer cable component. The cooling vessel may contain a chilled fluid. The system may include a winding device configured to wind the polymer cable component. The system may include an entanglement device configured to receive a first polymer-insulated conductor and a second polymer-insulated conductor to form a twisted pair. The entanglement device may include a bow in the fluid, the bow including means for protecting the insulated wire from convective heat transfer with the fluid when the bow is rotating.

[0077] In another exemplary embodiment of the present disclosure, a system for manufacturing wire and cable products is provided. The system can include a payout device configured to payout a polymer cable component. The system can include a winding device configured to wind the polymer cable component. The system can include an entanglement device configured to receive a first polymer-insulated conductor and a second polymer-insulated conductor to form a twisted pair. The entanglement device can include a bow in a fluid. The bow can include means for protecting the insulated wire from convective heat transfer with the fluid when the bow is rotating.

[0078] In another exemplary embodiment of the present disclosure, a method for manufacturing a low fuel load wire and cable product is provided. The method can include establishing desired electrical properties of the wire and cable product. The wire and cable product can include a polymeric cable component. The polymeric cable component can have a first fuel load and a first hardness. In some examples, the polymeric cable component can have a flame travel distance of about 5 feet or less. In some examples, the polymeric cable component can have an average optical density of about 0.15 or less when measured according to the Steiner Tunnel Test Method of ASTM E84. In some examples, the first hardness of the polymeric cable component can be the hardness of the polymeric cable component under ambient conditions. The method can include temporarily changing the hardness of the polymeric cable component to a second hardness, which can be different from the first hardness. The method can include applying a compressive force to the polymeric cable component in an entanglement unit having a bow, thereby causing a first deformation in the polymeric cable component. In some examples, the polymeric cable component can have the second hardness while the compressive force is applied. In some examples, the polymeric cable component can be at least partially protected from convective heat transfer at the bow during application of a compressive force within or after the bow of the entanglement unit. The method can include forming a wire and cable product using the polymeric cable component. The wire and cable product can meet established desired electrical properties when the polymeric cable component is deformed by a first deformation amount, but does not meet the desired electrical properties when the polymeric cable component is deformed by a second deformation amount. The second deformation amount can be an amount by which the polymeric cable component deforms when a compressive force is applied when the polymeric cable component has a first hardness.

[0079] In at least some examples, the change in hardness between the first and second hardnesses of the polymer cable components and / or polymer insulated conductors can be between about 5% and about 95%. In some examples, the change in hardness between the first and second hardnesses of the polymer cable components and / or polymer insulated conductors can preferably be between about 25% and about 75%. In some examples, the change in hardness between the first and second hardnesses of the polymer cable components and / or polymer insulated conductors can more preferably be between about 35% and about 65%.

[0080] In at least some examples, polymer cable components and / or polymer-insulated conductors may be protected from convective heat transfer with the bow environment by about 5% to about 95%. In this context, percent protection refers to the percentage of the bow length that is covered by the means for protecting the insulated wires to reduce or prevent the flow of air or other fluids within the entanglement device that encases the insulated cable components. For example, if the means is a covered flow passage and 75% of the length of the flow passage is covered, the percent protection is 75%. In another example, if the means is an adjustable air vent along the bow length and the air vent is adjusted to reduce air flow within the bow by 25%, the protection is 25%. In some examples, polymer cable components and / or polymer-insulated conductors may be protected from convective heat transfer by at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. In further embodiments, the polymeric cable components or insulated wires may be protected from convective heat transfer by up to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100%. In other examples, the polymeric cable components and / or polymeric insulated conductors may be protected from convective heat transfer with the bow environment by about 50% to about 80%.

[0081] In some examples, protecting the polymer cable components and / or polymer-insulated conductors from convective heat transfer can be accomplished by including one or more optionally vented tubes in the entangling machine bow. In some examples, protecting the polymer cable components and / or polymer-insulated conductors from convective heat transfer can be accomplished by including one or more partially or completely open flow channels in the entangling machine bow. In yet other examples, protecting the polymer cable components and / or polymer-insulated conductors can be accomplished by one or more windscreens positioned throughout the bow. In some examples, the windscreens can be adjustable so that an optimal level of heat transfer protection can be achieved. The adjustable windscreen can be of any suitable type, including, but not limited to, a windscreen with an adjustable opening to the entangling unit environment and / or an adjustable wind guide that can be adjusted while the bow is rotating.

[0082] Some embodiments of the means for protecting the polymeric component or insulated wire as an insulated conductor from convective heat transfer are adjustable to provide varying degrees of protection. For example, the channel or tube may include an adjustable vent. The vent may be of any suitable form. For example, as shown in Figures 41-44, the vent may include a plurality of rotating slats. Some embodiments of the adjustable vent may be connected to a control unit that transmits signals to open and close the vent. Such a control unit may be used to adjust the amount of convective heat transfer to the polymeric component in response to, for example, measurements of the impedance of the twisted pair. Such a control unit may be used to adjust the amount of convective heat transfer while the bow is rotating.

[0083] In at least some instances, the present disclosure refers to ambient conditions, which refer to the temperature, humidity, and atmospheric pressure conditions that typically occur in an indoor space.

[0084] In at least some examples, a system for manufacturing wire and cable products is disclosed. The system may include components such as, but not limited to, an unwinder and a reeler.

[0085] As used herein, unwinding equipment may refer to a machine that allows an operator to remove or unwind flexible material (such as, for example, polymer insulated conductors and / or polymer cable components) in a controlled manner. Unwinders can provide quality rewinding and coiling, protect the material from damage, and assist operators in the rewinding and coiling process. Unwinders can have different designs based on many parameters, such as the size and type of material used, the size of the reel, the overall weight of the product for coiling and winding, and whether the machine is portable or floor-standing.

[0086] As used herein, a winding device may refer to a machine configured to receive flexible material (e.g., polymer insulated conductors and / or polymer cable components, etc.) and wind the flexible material onto a wheel or reel for rewinding and / or coiling.

[0087] In some examples, certain characteristics of the polymer cable components and / or polymer-insulated conductors may be desirable. For example, it may be desirable for the polymer-insulated conductors and / or polymer cable components to have desired smoke peak optical density, average optical density, and flame travel distance. In some examples, the desired smoke peak optical density for the polymer-insulated conductors and / or polymer cable components may be about 0.5 or less. In some examples, the desired average optical density for the polymer-insulated conductors and / or polymer cable components may be about 0.15 or less, as measured according to the Steiner Tunnel Test Method of ASTM E84. In some examples, the desired flame travel distance for the polymer-insulated conductors and / or polymer cable components may be 0.5 or less. In some examples, the flame travel distance, smoke peak optical density, and / or average optical density may be measured after a compressive force is applied to the polymer-insulated conductors and / or polymer cable components in the bow of the entanglement unit.

[0088] When a compressive force is applied to a polymer-insulated conductor, such as when the wires are intertwined to form a twisted pair, the polymer insulation components may be compressed or otherwise deformed. In polymer insulation layers, this deformation can disrupt the conductor-to-conductor spacing of the conductive wires, affecting the electrical performance of the wire or resulting cable.

[0089] 1 schematically illustrates a cross section of an insulated wire having a polymer insulation layer 110 around a conductor 120. When a compressive force is applied to the insulated wire, the insulation layer 110 may deform. The degree of deformation of the insulation layer 110 can be described by the crush ratio, which is defined as the deformed length / initial OD x 100 and expressed as a percentage.

[0090] Figure 2A is a schematic illustration of a cross section of two insulated wires, each having a polymer insulation layer 210 around a conductor 220. Figure 2A shows the two insulated wires in contact with each other and with undeformed circular polymer insulation layers. The shaded areas of polymer insulation layer 210 in Figure 2A indicate areas that would be deformed by compressive forces if the two wires were intertwined together.

[0091] Figure 2B is a schematic illustration of a cross section of two insulated wires, each having a polymer insulation layer 210 around a conductor 220. Figure 2B shows the two wires in contact with each other after a compressive force has caused deformation of the polymer insulation layer.

[0092] A comparison of the conductor-to-conductor distance between the crushed wire in Figure 2B and the uncrushed wire in Figure 2A shows that deformation of the two insulation layers reduces the distance between the two conductors. This type of compression can occur when twisting wires together or during other compression events. This reduction in conductor-to-conductor distance has a detrimental effect on the electrical performance of the twisted wire and any resulting cable.

[0093] The forces applied to polymer cable components depend on the type and manufacturer of equipment utilized by any particular wire and cable company. For example, there are many different types of cable making machines. Each of these machines will exhibit unique forces on the various elements being cabled. When a wire and cable manufacturer determines how much additional insulation to incorporate into their design to offset deformation, experience, in large part combined with knowledge of the material harness, will ultimately determine how much extra insulation is required.

[0094] Within the industry, the term "wall thickness" is used to capture how much insulation and / or sheathing material is needed to produce a desired product. Most application designs will have an absolute minimum wall thickness, an average minimum wall thickness, a nominal wall thickness, and an absolute maximum wall thickness. When compensating for deformation and recession of the insulation layer, the nominal wall thickness is typically considered.

[0095] The softer the insulation material, the greater the amount of additional wall thickness typically required to compensate for lost wall thickness upon compression under a given set of conditions. FEP, for example, is a softer insulation than HDPE or PP and will require a greater amount of additional insulation. Understanding the hardness of the insulation material is useful in determining the amount of compensation required. With better control over the amount of deformation, the amount of additional insulation required can be reduced, which benefits both the size and cost of the final product. In some embodiments, the amount of additional insulation added to produce a desired cable is reduced by at least about 0.0005 inches, or at least about 0.001 inches, at least about 0.003 inches, at least about 0.005 inches, or at least about 0.01 inches relative to a cable produced under the same conditions but without the cooling techniques described herein.

[0096] Softer insulating polymers, such as fluorinated ethylene propylene (FEP), tend to deform more than insulating layers made of harder polymers when a force is applied to the insulating layer. Foam insulating layers may also be more susceptible to deformation than solid polymers.

[0097] The resistance of an insulating layer to deformation can generally be measured or described in terms of the hardness of the insulating material. As discussed, hardness is a measure of resistance to localized plastic deformation caused by mechanical indentation or abrasion. Different materials generally have different hardnesses. In some embodiments, Young's modulus can affect the degree of deformation that occurs as a result of a compressive force. Young's modulus is a mechanical property that measures the hardness of a solid material. Young's modulus defines the relationship between stress (force per unit area) and strain (proportional deformation) in a material. A higher Young's modulus can result in less elastic deformation of the material under the same force.

[0098] One way to control the hardness and stress / strain response of the polymer insulation layer is to adjust the amount of convective heat transfer during the entanglement process. Another method is to cool the polymer material. This cooling can be accomplished by any reasonable method, such as by directly or indirectly exposing the insulation layer to a chilled fluid, such as a chilled liquid or gas. In some embodiments, the polymer cable components can be exposed to chilled water or aqueous solutions. In some embodiments, the polymer cable components can be exposed to cryogenic or chilled fluids, such as liquid nitrogen. In some embodiments, the polymer cable components can be exposed to chilled gases or vapors. In some embodiments, the polymer cable components can be exposed to one or more chilled wheels, rollers, tubes, or other solid surfaces. In some embodiments, the polymer cable components can be cooled indirectly. For example, the polymer cable components can be passed through the interior of a tube while the exterior of the tube is cooled. The atmosphere within the tube is chilled, thereby cooling the polymer cable components. Although the invention described herein is generally described in the context of cryogenic fluids, it will be understood that any of these methods may be used similarly or interchangeably.

[0099] In some situations, the time required to cool the entire thickness of the polymer insulation layer may make this approach impractical. In one embodiment, the disclosed invention cools the exterior surface of the insulation layer and does not cool the interior bulk of the insulation layer to the same extent. In some embodiments, cooling only the outer portion of the insulation layer helps reduce overall deformation of the insulation layer, since the exterior surface is typically the portion of the insulation layer that experiences the greatest compressive forces during manufacturing.

[0100] FIG. 3 schematically illustrates a cross section of an insulated wire having a polymer insulation layer around a conductor 340. The insulation layer in the embodiment depicted in FIG. 3 is a single homogenous polymer layer, although for clarity, FIG. 3 shows the homogenous insulation layer divided into separate concentric sections. The outer surface 310 of the polymer insulation layer is generally exposed to the external environment and experiences any external compressive forces first. The outer portion 320 of the insulation layer is directly below the outer surface. The inner bulk of the insulation layer 330 surrounds the conductor 340 and is exposed to the least external compressive forces because both the outer surface 310 and the outer portion 320 of the insulation layer must deform before the inner bulk 330 is affected.

[0101] When a polymer-insulated wire is exposed to a chilled liquid or cryogenic fluid, such as liquid nitrogen, the outer surface 310 cools rapidly due to direct contact with the cryogenic fluid. The outer portion 320 of the insulation layer will cool next as heat is drawn from the insulation layer into the cryogenic fluid. The rate at which the outer portion of the insulation layer cools will vary based on the thermal conductivity of the polymer material forming the insulation layer. The inner bulk 330 of the insulation layer will cool after the outer surface and outer portion. It will be appreciated that a temperature gradient, rather than a sharp line, will form, separating the outer portion 320 from the inner bulk 330.

[0102] As the outer surfaces and outer portions of the insulation layer cool, the stress / strain response of these portions of the insulation layer may increase, which in some embodiments creates a hardened "skin" on the outer portions of the insulation layer that surrounds the relatively uncooled or relatively hot inner bulk of the insulation layer.

[0103] If the insulation layer remains in contact with the cryogenic fluid long enough, eventually the entire bulk of the insulation layer can cool, and the hardness of the entire insulation layer can increase. However, wire and cable manufacturing facilities typically produce cables at relatively high speeds. To cool the entire thickness of the insulation layer while the cable is moving at relatively high speeds, the length of the cooling equipment may be required to be longer than desired for certain applications. By using embodiments of the disclosed invention to cool the outer portion of the insulation layer while leaving the inner bulk of the insulation layer at a relatively high temperature, the length of the cooling equipment required may be reduced, and deformation of the insulation layer may be minimized. Creating a hardened skin within the homogeneous polymer insulation layer can reduce the crush rate when insulated wires are intertwined together and when the polymer insulated wire is subjected to other external compressive forces.

[0104] It will be appreciated that when a polymer-insulated conductor is removed from the cryogenic fluid or other cooling medium and exposed to the ambient atmosphere, the polymer insulation begins to return to ambient temperature. As the temperature increases, the hardness and stress / strain response of the polymer insulation decrease, making the polymer insulation more susceptible to deformation due to compressive forces. In some embodiments of the disclosed invention, the polymer insulation layer is cooled just prior to being subjected to a compressive event, such as intertwining to form a twisted pair. In some applications, the speed at which the insulated conductor moves and the distance between the cooling vessel and the intertwining take-up device will determine the amount of time the polymer-insulated conductor is exposed to the ambient atmosphere after cooling but before the application of the compressive force. In some embodiments, the end of the cooling vessel is less than 10 feet from the point at which the polymer-insulated conductor is subsequently subjected to the compressive force. In some embodiments, the end of the cooling vessel is less than 8 feet, 6 feet, 4 feet, or 2 feet from the point at which the polymer-insulated conductor is subsequently subjected to the compressive force.

[0105] It will be understood that the hardness of a given material is determined by the temperature of that material. Thus, as the temperature of a given material increases and decreases, the hardness decreases and increases, respectively. In some embodiments, the material is cooled just prior to the compressive force, thereby increasing its hardness, and then allowed to return to ambient temperature. The increased hardness at the time of the compressive force can help the material resist deformation due to the compressive force, even though the increase in hardness is only temporary.

[0106] It will be appreciated that the disclosed invention does not require modification of the composition of the polymer insulation material. The composition of the polymer insulation layer remains unchanged while the polymer insulation is cooled, thereby modifying its stress / strain response. The composition of the polymer insulation layer remains unchanged when any compressive or deforming force is applied to the insulation and when the polymer insulation is allowed to return to ambient temperature, thereby reducing its hardness.

[0107] In some embodiments, a conductor may be insulated by more than one layer of insulation. In some embodiments, a conductor may be insulated, for example, by a polymer foam layer and also by a solid polymer layer. In some embodiments, the multiple layers of polymer insulation may be made from different polymers. In some embodiments, the multiple layers of polymer insulation may be made from the same polymer. Each layer of insulation may be a different thickness than any other insulation layer, or may be about the same thickness.

[0108] It will be appreciated that thicker polymer insulation layers may require more time to reach a higher hardness relative to thinner polymer insulation layers because the temperature gradient must propagate through the bulk of the thicker polymer insulation layer. In some embodiments, the exposure time for which the insulated conductor is exposed to the cryogenic fluid may be adjusted based on the thickness of the polymer insulation layer.

[0109] In some embodiments, some of the conductors of multiple twisted pairs contained in a single cable may be exposed to the cryogenic fluid for different amounts of time. By controlling the amount of time the conductors are exposed to the cryogenic fluid, the degree of collapse and the resulting electrical properties of the twisted pairs can be adjusted.

[0110] In some embodiments, increasing the hardness of the polymer-insulated conductors causes the conductors to maintain a generally circular cross-section rather than deforming under compressive forces, which can reduce the amount of surface-to-surface contact between two polymer-insulated conductors and reduce friction or twisting forces between the insulated conductors.

[0111] In some embodiments, the polymer insulated conductor or other polymer cable component is cooled to increase its hardness before being subjected to the compressive force. In some embodiments, the temperature of the polymer cable component is reduced to offset any heat generated within the polymer cable component by the compressive force. In some embodiments, the temperature of the polymer cable component during or immediately after the compressive event is at or below ambient temperature.

[0112] In some embodiments, the disclosed invention can be utilized to intertwine polymer-insulated wires to form a twisted pair. Twisted pair wires are typically formed by twisting two polymer-insulated wires around each other using a machine called an intertwining machine. The process of intertwining the wires to form a twisted pair creates a compressive force between the two wires at their contact points. This compressive force increases as the pitch or twisting speed of the twisted pair increases.

[0113] The purpose of intertwining wires to form a twisted pair is to improve the wires' electromagnetic compatibility. Twisting wires reduces electromagnetic radiation from the pair and reduces crosstalk and electromagnetic interference between adjacent twisted pairs compared to untwisted wires. A single twisted pair can be used to form a single-pair Ethernet cable, or multiple twisted pairs can be combined to form various other forms of cabling, including Ethernet cabling. It is desirable for each insulated conductor in a twisted pair to be an equal mirror image of the other insulated conductor in the twisted pair. When the two insulated conductors in a twisted pair are mirror images of each other, this achieves improved noise cancellation between the insulated conductors and creates a balanced pair system. Often, the insulation layers around the conductors contained in a twisted pair are affected differently by compressive forces. This can create a difference between the two insulated conductors, resulting in an imbalance and reduced noise cancellation, which can be undesirable in the end product.

[0114] In one embodiment, the polymer insulated wire is passed through a cooling vessel before being fed into the entanglement machine. In some embodiments, the cooling vessel exposes the insulated wire to a cryogenic fluid, which increases the hardness of at least the outer surface of the polymer insulation layer. In some embodiments, the cooling vessel contains a pool of cryogenic fluid, such as liquid nitrogen. In some embodiments, the cooling vessel contains a spray of cryogenic fluid. It will be understood that the cooling vessel can be used to expose any polymer cable component to any form of cooling medium. For clarity, the disclosed invention is described in the context of a cryogenic fluid, but chilled air, or any other gas or vapor, and chilled water, or any other chilled liquid, or a chilled solid surface can be used.

[0115] 4A shows a schematic diagram of a cooling vessel 410 according to one embodiment. As shown in FIG. 4A, an insulated wire 420 may enter the cooling vessel 410 through a hole 440 in the cooling vessel that is below the surface of the cryogenic fluid 430, causing the insulated wire to sink into a pool of cryogenic fluid 430. The cooled insulated wire 420 may exit the cooling vessel 410 through a similar hole 440 in the side of the cooling vessel. In some embodiments, a flexible gasket, membrane, or valve may be used to restrict the flow of cryogenic fluid out of the cooling vessel.

[0116] 4B shows another schematic diagram of a cooling vessel 411 according to one embodiment. In some embodiments, insulated electrical wires 421 are fed downward into a pool of cryogenic fluid 431 using wheels, rollers, or wire guides 441. This allows the cooling vessel to maintain a pool of liquid without leaking. In some embodiments, the cooling vessel includes a perforated top or lid (not shown) that allows the electrical wires to enter the cooling vessel and reduce overall loss of cryogenic fluid due to evaporation or dissipation.

[0117] 4C shows another schematic diagram of a cooling vessel 412 according to one embodiment. In some embodiments, the cooling vessel 412 includes one or more nozzles 432 that spray cryogenic fluid or another chilled liquid or gas onto the insulated wire 422. In some nozzle embodiments, the insulated wire 422 does not physically contact the cooling vessel or associated equipment, thereby avoiding any compressive forces prior to cooling. In some embodiments, the insulated wire enters and exits the cooling chamber through small holes 442 and is sprayed with the cryogenic fluid. In some nozzle embodiments, there is no permanent pool of cryogenic fluid, so loss of cryogenic fluid is less of a concern.

[0118] It will be appreciated that some embodiments include combinations of the cooling vessels described above. In some embodiments, multiple cooling vessels may be used in series to achieve a particular desired effect. In some embodiments, a single cooling chamber may allow one, two, or multiple insulated conductors to pass through the cooling chamber simultaneously. In some embodiments, a single cooling chamber may be used to cool two wires to be formed into a single twisted pair. In some embodiments, a single cooling chamber may be used to cool multiple insulated wires that may be used to form multiple twisted pairs.

[0119] In some embodiments, the cooling vessel can be at least about 2 feet long, or about 4 feet long, or about 6 feet long, or about 10 feet long, or about 15 feet long. In some embodiments, the cooling vessel can be up to about 20 feet long, or about 15 feet long, or about 10 feet long, or about 8 feet long, or about 6 feet long. In some embodiments, one or more pulleys, wheels, capstans, and / or rollers within the cooling vessel can be used to redirect the path of the polymer cable component within the cooling vessel. This arrangement allows the polymer cable component to remain within the cooling vessel for a longer period of time without increasing the length of the cooling vessel or slowing the linear velocity of the component. In some embodiments, the polymer cable component enters the cooling vessel in a vapor region at the top of the vessel, where evaporated cryogen rises above the liquid cryogen, and is subsequently redirected through a liquid region of the vessel, where the liquid cryogen remains. This arrangement allows heat to be transferred from the polymer cable components to the cryogenic vapor first before contacting the cryogenic liquid, thereby reducing the overall heat load transfer to the cryogenic liquid and increasing the total residence time of the polymer cable components within the cooling vessel.

[0120] The length of time the insulated wire is exposed to the cryogenic fluid will depend on the length of the cooling vessel and the speed at which the insulated wire is moving. In some embodiments, the wire is exposed to the cryogenic fluid for a time period of at least about 1 second, or at least about 2 seconds, or at least about 4 seconds, or at least about 6 seconds, or at least about 8 seconds, or at least about 10 seconds. In some embodiments, the wire is exposed to the cryogenic fluid for a time period of up to about 30 seconds, or up to about 20 seconds, or up to about 10 seconds, or up to about 8 seconds, or up to about 6 seconds, or up to about 4 seconds.

[0121] In some embodiments, after exiting the cooling vessel, the insulated wire enters a entanglement device where it is twisted around a second cooled insulated wire to form a twisted pair with minimal deformation of the two insulation layers. In some embodiments, the insulated wire enters the entanglement device within about 1 second of exiting the cooling vessel, or within about 2 seconds, or within about 4 seconds of exiting the cooling vessel. In some embodiments, the cooling vessel is positioned relative to the entanglement device or other device that applies a compressive force to the insulated wire such that the polymer-insulated wire is subjected to a subsequent compressive force before the elevated stress / strain response of the polymer-insulated wire decreases by more than about 10%, or by more than about 20%, or by more than about 30%. In other words, in some embodiments, the cooling vessel is positioned such that the polymer-insulated wire exiting the cooling vessel is subjected to any subsequent compressive force before the polymer-insulated wire significantly warms and thereby decreases in hardness.

[0122] In some embodiments, one or more secondary structures may be positioned around the polymer-insulated conductors after they exit the cooling chamber to maintain an atmosphere cooler than ambient temperature. FIG. 5A illustrates an example of a cooling vessel 510 with a secondary structure 550 positioned around the polymer-insulated conductors 520 as they leave the cooling vessel. In some embodiments, the secondary structure 550 is a hollow tube positioned to maintain a chilled atmosphere around the polymer-insulated wires before applying a compressive force to the wires as part of the entanglement process. The secondary structure 550 may be made of any thermally conductive material, including, for example, metal and / or polymer. In some embodiments, the secondary structure 550 may be a larger tube positioned to surround the multiple wires as they exit the cooling chamber to maintain an increased hardness before the wires are subjected to any compressive or deforming forces. In some embodiments, the secondary structure 550 may be a tube with an adjustable length that can expand and / or contract to adjust the residence time of the polymer cable components within the tube. In some embodiments, the secondary structure includes a portion, such as a top or lid, that can be removed or opened. In such an embodiment, the secondary structure can be opened to allow for the initial treading or lacing of the wire or cable line, and then closed to seal out the ambient atmosphere and maintain a cooler atmosphere within the secondary structure.

[0123] In some embodiments, the secondary structure is arranged to receive the cryogenic fluid from a cooling vessel. In one example, the secondary structure may be arranged to receive cold nitrogen vapor from a pool of evaporated liquid nitrogen contained within the cooling vessel. By maintaining an atmosphere at a cooler temperature than ambient around the wires leaving the cooling vessel, the secondary structure can help maintain increased hardness and Young's modulus as the wires move from the cooling vessel to an intertwining device or during other subsequent processes involving compressive forces. In some embodiments, any cryogenic fluid that leaks out of the cooling vessel is received by the secondary structure. In the case of a cryogenic liquid, the cryogenic liquid received by the secondary structure may evaporate within the secondary structure, thereby creating a chilled atmosphere within the secondary structure and preventing any leakage of the cryogenic liquid onto the manufacturing floor.

[0124] In some embodiments, the secondary vessel may be connected to the cooling vessel, the entanglement device, or both. In some embodiments, the secondary structure may direct cryogenic vapor expanding or evaporating from the cooling vessel through the secondary structure and into the entanglement device. In such embodiments, the atmosphere within the entanglement device may be maintained at a lower temperature than the ambient atmosphere surrounding the entanglement device.

[0125] Although the present invention is generally described in the context of exposing polymer cable components to cryogenic fluids, it will be understood that other methods of cooling polymer cable components, thereby increasing their hardness and stress / strain response, may be used.

[0126] In some embodiments, polymer cable components may be passed through a chilled tube. The exterior of the tube may be exposed to a cooling medium, such as a chilled or cryogenic fluid, which reduces the temperature of the tube itself. In such embodiments, the atmosphere within the chilled tube is indirectly cooled by the chilled or cryogenic fluid as heat is drawn from the tube into the chilled or cryogenic fluid. The polymer cable components may be cooled by exposure to the chilled atmosphere within the tube, which increases the stiffness and stress / strain response of the polymer cable components. In some embodiments, the tube is only slightly larger than the polymer cable components passing through it. The degree of cooling of the polymer cable components can be controlled by reducing the distance between the inner surface of the tube and the polymer cable components. In some embodiments, the tube may have a removable or hinged lid that can open the tube to facilitate initial lacing of the polymer cable components through the tube. Once the tube is closed, the exterior of the tube can be exposed to a chilled or cryogenic fluid to establish a cooled internal atmosphere within the tube. In some embodiments, the tube may be telescoping or modular components may be used to increase or decrease the tube length during continuous operation, which in some embodiments allows operators to adjust the total residence time of the polymer cable components within the tube cooling atmosphere without stopping production to change the tube, tube length, and / or tube components.

[0127] FIG. 5B schematically illustrates the chilled tube embodiment described above. In the illustrated embodiment, a tube 610 passes through a chilled material 620, which creates a chilled atmosphere within the tube 610. A polymer cable component 605 passes through the chilled tube 610 and is exposed to the chilled atmosphere within the tube 610. In the illustrated embodiment, a heat exchanger 630 may be used to control the temperature of the chilled material 620. In some embodiments, the temperature of the chilled material 620 may be adjusted depending on the temperature of the atmosphere within the tube 610. In some embodiments, the chilled material 620 may be a chilled liquid circulated around the tube 610. If the atmosphere within the tube 610 increases beyond a desired range, the chilled liquid may be circulated faster or the temperature of the chilled liquid may be reduced until the temperature of the atmosphere within the tube 610 is within the desired range.

[0128] In some embodiments, the chilled tube contains intake holes or slits configured to allow a certain amount of chilled material to move into the tube. The size, shape, and number of these holes or slits may be configured differently depending on the expected conditions. In some embodiments, the chilled material is a cryogenic liquid that can enter the tube through the holes or slits. This reduces the temperature within the tube and also allows for some direct contact between the polymer cable component and the cryogenic fluid. In some embodiments, the amount of cryogenic fluid allowed into the tube can be adjusted so that under operating conditions, all of the cryogenic fluid entering the tube evaporates within the tube. This prevents the cryogenic liquid from leaking out of the cooling device and allows for faster and / or greater cooling of the polymer cable component.

[0129] In some embodiments, chilled wheels, rollers, or pulleys may be used to increase the hardness and stress / strain response of polymer cable components. Wire and cable manufacturing is generally a continuous process involving a number of wheels, rollers, and / or pulleys for a variety of different purposes, such as guiding the process, controlling tension, and / or gathering the components for cable construction. When the polymer cable components contact these wheels, at least some compressive force is applied to the cable components. In some embodiments, chilled or cryogenic fluid may be passed through the interior of the wheels, thereby cooling the wheels. Because the solid surface of the wheels rotates, polymer cable components in contact with the rotating surface can be cooled without incurring significant additional deformation forces. When the polymer cable components contact the wheels, they are at least slightly cooled, resulting in greater hardness. In some embodiments, a series of chilled wheels, rollers, or pulleys may be used to increase the exposure time between the cable components and the chilled surface, allowing the cable components to reach a desired degree of hardness before being subjected to subsequent compressive forces.

[0130] In some embodiments, rather than using a liquid or solid cooling medium, chilled air or another chilled gas or vapor can be used to reduce the temperature of polymer cable components and increase their hardness and stress / strain response. The medium or fluid in the entanglement device can include various alternatives, such as cryogenic fluids, inert gases (e.g., helium, N2, argon, krypton, radon, neon, xenon, and combinations thereof). In some embodiments, the fluid in the entanglement device or cooling chamber can include chilled air generated by an air conditioning or refrigeration device, fluorocarbon solutions, brine solutions, gases obtained by vaporizing solid objects or liquids with a vaporization temperature of 0°C or lower (e.g., dry ice or liquid nitrogen), liquids with a freezing point of 0°C or lower, chilled acetone, and combinations thereof. Seasonal variations in wire and cable manufacturing are a known phenomenon. During warmer months, manufacturing facilities may have higher ambient temperatures. This can result in an increase in temperature and a corresponding decrease in hardness of the polymer cable components used in a particular facility. To address this seasonal variation, some manufacturing facilities utilize standard air conditioning to maintain a relatively constant temperature within the facility. However, maintaining a moderate temperature throughout the manufacturing facility is not required to improve the electrical performance of the cables produced.

[0131] In some embodiments, air conditioning equipment can be used to direct cool air directly to the entanglement equipment or cooling chamber surrounding the polymer cable components. Lowering the temperature of the atmosphere surrounding the polymer cable components can increase the hardness and Young's modulus of the polymer just prior to or during a compression event. In some embodiments, air conditioning equipment can be used to generate air at temperatures lower than would be adequately tolerated throughout a manufacturing facility. In some embodiments, the air conditioning system can be configured to direct air at temperatures below about 60°F to the polymer cable components. In some embodiments, the air conditioning or refrigeration system can be configured to direct air at temperatures below about 50°F, or below about 40°F, or below about 30°F, or below about 20°F, or below about 10°F, or below about 0°F to the polymer cable components. In some embodiments, the air conditioning or refrigeration system may be configured to direct air below about 10°C, or below about 5°C, or below about 0°C, or below about -5°C, or below about -10°C, or below about -15°C to the polymer cable components.

[0132] In some embodiments, a structure may be used to contain a cooler atmosphere around the polymeric cable components before or during a compression event. In some embodiments, a chamber may be used around the entanglement winding device to contain a cooler atmosphere than the ambient. It will be appreciated that for some applications, dedicated refrigeration equipment may be required to generate large volumes of very cold air. It will also be appreciated that cold air may be applied to the polymeric cable components at any step in the manufacturing process where increased hardness would help reduce deformation due to compression forces.

[0133] In one illustrative example, multiple twisted pairs of fluorinated ethylene propylene (FEP) insulated wire were produced at a line speed of 19 m / min, or approximately 63 ft / min. The entanglement machine parameters were set at 3,000 twists / min and a twist length of 6.2 mm. Before feeding the insulated wire into the entanglement machine, the wire was passed through a cooling vessel and submerged in liquid nitrogen for various lengths of time. The crush rate of the resulting twisted pairs was examined using computed tomography (CT) scans.

[0134] Table 1 below shows a table of data collected over three trials. Each trial included four samples that were passed through cooling vessels of varying lengths. The cooling vessel lengths varied from zero feet (control) to two feet, four feet, and six feet. The entanglement parameters listed above, including linear speed, were kept constant throughout all trials.

[0135] [Table 1]

[0136] As can be seen from Table 1, the average crush rate decreased as the length of the cooling vessel increased. Since a linear velocity of 19 meters / minute is approximately 1 foot / second, the length of the cooling vessel in feet is approximately equal to the time the wire was exposed to liquid nitrogen, measured in seconds.

[0137] Figure 6 shows a graph of the data presented in Table 1. As can be seen from the graph in Figure 6 and Table 1, the average crush rate decreased from 6.74% when the FEP insulated wire was not exposed to liquid nitrogen to 1.09% when the FEP insulated wire was exposed to liquid nitrogen for approximately 6 seconds, which corresponds to a reduction in the crush rate of approximately 83% in approximately 6 seconds.

[0138] Table 2 (below) shows the surface temperatures of samples of FEP insulated wire exposed to liquid nitrogen over various lengths. A temperature probe was used to measure the surface temperature while the FEP insulated wire was entangled after passing through the cooling chamber. The entanglement parameters, including wire speed, were consistent with those listed above.

[0139] [Table 2]

[0140] Figure 7 shows the data presented in both Tables 1 and 2 presented on a single graph. As can be seen from Figure 7, the surface temperature of the FEP-coated wire decreases significantly after about 2 seconds of exposure to liquid nitrogen and then continues to decrease at a slower rate. The crush rate of the FEP-insulated wire decreases after about 2 seconds of exposure to liquid nitrogen and continues to decrease as the length of the cooling vessel and the time the wire is exposed to liquid nitrogen increase.

[0141] The reduction in the surface temperature of the insulated wire and the corresponding decrease in the crush rate demonstrates that it is not always necessary to expose the insulated wire to a cryogenic fluid for an extended period of time to reduce the crush rate. In some embodiments, it is not necessary to reduce the temperature through the thickness of the insulation layer to dramatically reduce the crush rate. The outer skin of the insulation layer can be cooled, which increases the hardness of the outer portion of the insulation layer and reduces the amount of crush caused by entangling the insulated wire.

[0142] Without being bound by theory, it is believed that the decrease in crush rate is due to an increased stress / strain response and hardness of the outer portion of the FEP insulated wire. As the insulated wire is exposed to liquid nitrogen for an extended period of time, the thickness of the outer portion of the insulation layer, which has an increased stress / strain response, increases. The degree of increased hardness and increased stress / strain response at the outer surface of the polymer insulation layer may also increase as the wire is exposed to liquid nitrogen for an extended period of time.

[0143] By briefly exposing a polymer-insulated wire to liquid nitrogen or another cryogenic fluid, a "harder" polymer skin can form within the homogeneous polymer layer. This hardened layer of polymer with an increased stress / strain response reduces deformation of the polymer insulation layer when the wire is exposed to external forces. Reduced deformation of the polymer insulation can more consistently maintain conductor-to-conductor distance. In some embodiments, the disclosed methods can be used to reduce the total amount of polymer insulation used while maintaining the same conductor-to-conductor distance. In some examples, reducing deformation of the polymer insulation layer increases the electrical performance of the wire and resulting cable. The reduced amount of deformation also helps maintain the shape of each insulated conductor, improving the electrical integrity between the two insulated conductors of a twisted pair and maintaining balance in the twisted pair.

[0144] In some embodiments, the exterior surface of the polymeric insulation layer drops below 0° C., while the interior portion of the polymeric insulation layer remains above about 5° C. In some embodiments, less than half the thickness of the polymeric insulation layer will have a temperature below about 5° C.

[0145] In some embodiments, the polymer insulation layer, or portions of the polymer insulation layer, may be foamed polymer. In such embodiments, the foamed polymer insulation contains many small pockets of air that are created during the manufacturing process. Air is known to be an excellent electrical insulator, so incorporating air pockets throughout the polymer insulation layer reduces the dielectric constant of the insulation layer. This is because air has a dielectric constant of 1.0, which is favorable compared to the dielectric constants of other materials, such as FEP (2.0), polyethylene (2.3), and polyvinyl chloride (3.5).

[0146] While air has excellent dielectric properties, it does not provide mechanical hardness. Therefore, foamed materials or other polymeric components incorporating air will have lower hardness than similar components without air. Air can be incorporated into polymeric cable components in multiple ways (small bubbles, large bubbles, cavities, etc.), ultimately resulting in reduced strength depending on the percentage of air substituted for solid polymer and the size of the air cavities utilized. In some embodiments, the methods for increasing hardness described herein are useful for increasing the hardness of the remaining polymeric material not replaced by air. Foamed polymers are more susceptible to deformation than solid polymers, requiring increased amounts of additional material to inhibit deformation. In some embodiments, the Shore D hardness of a foamed polymeric material increases by at least about 10% before or during a compression event relative to a similar material at 20°C.

[0147] Figure 8 shows a cross-sectional image of a foam-insulated conductor with multiple air pockets distributed throughout the insulation layer. It will be appreciated that these air pockets are closed and do not allow air or any other fluid to migrate through the insulation layer.

[0148] In some instances, single wires insulated with foamed FEP (rather than solid FEP) were entangled in a Setic entangler and analyzed for crush rate and electrical impedance. Samples of foamed FEP insulated wire were exposed to cryogenic fluid for various lengths of time. The exposed samples were compared to identical foam insulated wire samples that were not exposed to cryogenic fluid.

[0149] In one example, a pair of intertwined wires was used as a control and was not exposed to any cryogenic fluid, while a similar pair of foamed polymer insulated wires was exposed to a liquid nitrogen bath for 5.6 seconds before being intertwined. The twist length of the intertwined pair made using both sets of wires was 8.5 mm. For this analysis, a 6-inch sample of each of the two intertwined pairs was imaged at three separate locations along its length using X-ray / CT.

[0150] As can be seen in Table 3 below, the average crush rate for the foam-insulated twisted wires decreased from an average of 17.75% when the wires were not exposed to liquid nitrogen to an average of 12.92% when the twisted wires were exposed to liquid nitrogen for 5.6 seconds. This represents an improvement of 27.21%. Crush rate analysis was performed using X-ray / CT. Table 3 shows the crush rate data for each of the three locations analyzed for both the control and treated wires. The electrical impedance of the cryogenically cooled twisted pairs also increased from 136 ohms to 146 ohms, a 10 ohm, or 7.4%, increase over the control twisted pairs.

[0151] [Table 3]

[0152] In another example, a second pair of FEP foam insulated intertwined wires was used as a control and was not exposed to any cryogenic fluid, while a similar pair of wires was exposed to a liquid nitrogen bath for 9.1 seconds before intertwining. The twist length of the intertwined pairs made using these wires was 8.5 mm. Again, for this analysis, a 6-inch sample of each intertwined pair was imaged at three separate locations along its length using X-ray / CT.

[0153] As can be seen in Table 4 below, the average crush rate of the intertwined wires decreased from an average of 18.84% when the wires were not exposed to liquid nitrogen to an average of 9.74% when the wires were exposed to liquid nitrogen for 9.1 seconds. This represents a 48.3% improvement. Crush rate analysis was performed using X-ray / CT. Table 4 shows the crush rate data for each of the three locations analyzed for both the control and treated wires. The electrical impedance of the cryogenically cooled twisted pairs also increased from 142 ohms to 154 ohms, an increase of 12 ohms, or 8.5%, over the control twisted pairs.

[0154] [Table 4]

[0155] One benefit of the disclosed invention is the ability to create twisted pairs and / or other cable designs with improved electrical properties by increasing their hardness and reducing the amount of deformation that occurs during the entanglement, cable fabrication, and / or manufacturing process. One source of deformation of the insulation layer in twisted pairs is the entanglement process, which twists two insulated conductors around each other. The degree of deformation that occurs during the entanglement process is affected by several factors, including, for example, twist length, wire tension, insulation material, insulation hardness, and / or the amount of heat generated within the polymer insulation during the entanglement process. To minimize deformation, it may be desirable to increase the hardness of the insulation material during the entanglement process, when the insulated conductors are subjected to the greatest deformation forces. As discussed, one way to temporarily increase the hardness of the insulation layer is to reduce its temperature. In some embodiments, it is desirable to reduce the temperature of the insulation layer while the wires are being entangled.

[0156] In several examples, the relationship between cryogenic fluid exposure time, surface temperature, and crush rate was further investigated for both solid and foamed polymer insulated conductors. In the example below, a pair of FEP insulated conductors was exposed to a cryogenic fluid and then entangled at a speed of 19 m / min. The surface temperature of the insulation layer was measured by direct contact with a temperature probe placed at the first contact point of the two insulated conductors.

[0157] Both the foam FEP insulated wire and the solid FEP insulated wire were exposed to cryogenic fluid (liquid nitrogen) for various lengths of time and the surface temperatures were measured. Table 5 shows the results of this example. Figure 9 shows a graph of these results.

[0158] [Table 5]

[0159] Table 5 and Figure 9 show that there is a significant difference in the surface temperatures of foamed and solid polymer insulated conductors, even when exposed to cryogenic fluid for the same amount of time. After a 6-second exposure to liquid nitrogen, the foam insulated wire maintained a significantly lower surface temperature than the solid polymer insulated conductor.

[0160] The surface temperature of the insulated conductor was measured approximately 1 second after the conductor was removed from the liquid nitrogen. Without being bound by theory, it is believed that the surface of the solid polymer insulation warms faster than the surface of the foam insulation layer. The foam insulation layer contains multiple enclosed air pockets. The air trapped in these air pockets cools while the foam-insulated wire is immersed in liquid nitrogen, and the cooled air can then slow the warming of the surrounding insulation layer. In other words, the cooled air pockets within the foam insulation layer can help maintain a lower surface temperature of the foam insulation layer compared to the solid polymer insulation layer. Over time, both the solid polymer insulation layer and the foam insulation layer will warm to the ambient temperature, but the foam insulation layer may maintain a significantly cooler temperature for a longer period of time.

[0161] In some embodiments, cables are fabricated without significantly deforming the polymer cable components incorporated therein. Many polymer cable components have generally circular cross sections, and many have approximately equal diameters. Similarly, the generally circular cross sections of many polymer cable components will have many radii that are all approximately equal to one another before the cable is compressed or deformed. For clarity, before the polymer cable component is compressed or deformed, the radius with the largest length is approximately equal to the radius with the smallest length. While there are some natural deviations in the wall thickness of polymer cable components, the maximum and minimum radii are generally within 3% of each other. In some polymer cable components, the initial maximum and minimum radii may be within 5% of each other before being compressed or deformed.

[0162] In some embodiments, the generally circular cross-section of a polymeric cable component is preserved after the polymeric cable component is subjected to a compressive or deforming force. Increasing the hardness of a polymeric cable component, as described herein, may cause the polymeric component to deform less, thereby maintaining the generally circular cross-section. In some embodiments, after the polymeric cable component is subjected to a compressive force, the maximum and minimum major radii are within about 10% of each other. In some embodiments, the maximum and minimum major radii are within about 8% or about 5% of each other. In some embodiments, the maximum and minimum major radii are within about 15% or about 12% of each other. It will be appreciated that the more similar the maximum and minimum major radii are to each other, the more circular the cross-section and, generally, the less the polymeric cable component will deform.

[0163] In some embodiments, cooling the cable component for a time of less than about 10 seconds can increase the hardness of the polymer cable component, thereby causing the polymer component to deform less after being subjected to a compressive or deforming force. In some embodiments, after the polymer cable component is subjected to a compressive force, the maximum and minimum major diameters are within about 10% of each other. In some embodiments, the maximum and minimum major diameters are within about 8% or about 5% of each other. In some embodiments, the maximum and minimum major diameters are within about 15% or about 12% of each other. It will be appreciated that the more similar the maximum and minimum major diameters are to each other, the more circular the cross section and, generally, the less the polymer cable component will deform.

[0164] Intertwining the insulated conductors while they are still cooled and therefore have a high hardness is one way to reduce the amount of deformation during the intertwining process. In some embodiments, this results in a lower crush rate and improved electrical properties of the resulting twisted pair. In some embodiments, the amount of time the insulated conductors are exposed to the cryogenic fluid and / or the amount of time the cooled insulated conductors are exposed to ambient temperature before intertwining may be adjusted to adjust the electrical properties of the resulting twisted pair.

[0165] In some embodiments, the crush ratio and / or associated electrical properties of the individual conductors or twisted pairs may be tailored to create multiple twisted pairs with approximately the same propagation delay. In some embodiments, twisted pairs with shorter twist lengths may be intertwined while the individual insulated conductors are cooler and therefore have a higher hardness to create twisted pairs with reduced propagation delay compared to twisted pairs with longer twist lengths. In some embodiments, twisted pairs with longer twist lengths may be intertwined while the individual insulated conductors are hotter than twisted pairs with shorter twist lengths to create twisted pairs with increased propagation delay compared to twisted pairs with shorter twist lengths. In some embodiments, the surface temperature of the insulated conductors comprising the first twisted pair may be adjusted relative to the surface temperature of the insulated conductors comprising the second twisted pair to create first and second twisted pairs having approximately equal propagation delays over 100 meters, or within 10 nanoseconds of each other over 100 meters, or within 15 nanoseconds of each other over 100 meters, or within 25 nanoseconds of each other over 100 meters, or within 50 nanoseconds of each other over 100 meters. It will be appreciated that the surface temperature of the insulated conductors may be adjusted by adjusting the time interval for which the insulated conductors are exposed to the cryogenic fluid or by adjusting the time interval after the insulated conductors are removed from the cryogenic fluid but before entangling or applying other compressive force to the conductors. It will also be appreciated that other cooling methods may be used besides exposure to a cryogenic fluid, as described herein. In all forms of cooling, the overall degree of cooling may be adjusted by controlling the temperature of the cooling material and / or the time the polymer cable components are exposed to the cooling material. Similarly, regardless of the cooling method used, the temperature of the polymer cable component when subjected to a compressive or deforming force can be controlled by adjusting the amount of time the polymer cable component is exposed to the ambient atmosphere after cooling and before being subjected to the force.

[0166] In some embodiments, the first, second, third, and / or fourth pairs of polymer-insulated conductors, each pair including two polymer-insulated conductors, are temporarily cooled to increase the hardness of each pair to a certain degree. In some embodiments, the degree of hardness increase may vary for each pair. Once the pairs of polymer-insulated conductors have the desired hardness, the pairs are twisted together to form the first, second, third, and / or fourth twisted pairs. Each twisted pair has a propagation delay over 100 meters. In some embodiments, the first, second, third, and fourth propagation delays over 100 meters have a difference in propagation delays within 50 nanoseconds of each other. In some embodiments, the propagation delays are all within 25 nanoseconds of each other. In some embodiments, the first, second, third, and fourth propagation delays over 100 meters have a difference in delay time of less than about 25 nanoseconds.

[0167] In some embodiments, the first, second, third, and / or fourth pairs of polymer-insulated conductors are cooled for different periods of time to allow each pair to individually reach a desired hardness. In some embodiments, the cooling periods are all less than about 20 seconds, or all less than about 15 seconds, or all less than about 10 seconds. In some embodiments, the first period is between about 8-10 seconds, the second period is between about 6-8 seconds, and the third period is between about 4-6 seconds. In some embodiments, the fourth period is less than about 4 seconds, or even zero seconds, indicating that one of the four pairs may not be significantly cooled at all.

[0168] In some embodiments, the cooling time and / or hardness increase of a polymer-insulated conductor is related to the expected twist length of a twisted pair made from that polymer-insulated conductor. Generally, shorter twist lengths require a longer cooling period and / or a greater hardness increase before entanglement than other pairs of conductors.

[0169] In some embodiments, the first, second, third, and / or fourth twisted pairs have first, second, third, and / or fourth twist lengths, respectively. The first twist length is shorter than the second twist length, which is shorter than the third twist length. In some embodiments, the first cooling time is longer than the second cooling time, which is longer than the third cooling time.

[0170] In some embodiments, the first, second, third, and / or fourth twisted pairs have first, second, third, and / or fourth collapse ratios, respectively, and in some embodiments, the first collapse ratio is less than the second collapse ratio, and the second collapse ratio is less than the third collapse ratio.

[0171] In some embodiments, the first, second, third, and fourth twisted pairs have first, second, third, and fourth signaling rates, respectively, and in some embodiments, the first signaling rate is greater than the second signaling rate, and the second signaling rate is greater than the third signaling rate.

[0172] In some embodiments, the first, second, third, and / or fourth pairs of polymer-insulated conductors each have a different increased hardness, in some embodiments, the increased hardness of the first pair of polymer-insulated conductors is greater than the increased hardness of the second pair of polymer-insulated conductors, which is greater than the increased hardness of the third pair of polymer-insulated conductors.

[0173] It will be appreciated that when two insulated conductors are intertwined together, the generally circular cross-section of each insulated conductor is at least slightly deformed. The more circular the cross-section of each insulated conductor, the greater the amount of air retained in the gaps between the two insulated conductors. If more air is retained in the gaps, the overall dielectric constant of the twisted pair of conductors decreases, and the speed of propagation increases. By cooling the polymer-insulated conductors to increase their hardness while the conductors are intertwined to form the twisted pair, the polymer insulation will deform less and maintain a more circular cross-section. It will be appreciated that the dielectric constant of the insulating material itself does not increase or decrease. However, if the insulation layer maintains a generally circular cross-section and more air is incorporated into the interstices of the twisted pair, the dielectric constant of the resulting twisted pair may decrease. In some embodiments, the purpose of cooling the polymer-insulated conductors is to retain more air in the interstices of the resulting twisted pair.

[0174] In some examples, the temperature of the conductors in the twisted pairs was analyzed both during and after exposure to a cryogenic fluid (e.g., liquid nitrogen). This analysis was based on the electrical resistance of the conductors using the equation shown below. Equation 1:

number

[0175] In one example, the a of copper at 20°C is 0.00393K -1 It is known that R refwas determined to be 1.25 ohms based on the calculations described below. To analyze the conductor temperature, the twisted pair was connected to a handheld cable analyzer that recorded the conductor's resistance in real time. The insulated conductor was immersed in a liquid nitrogen bath and the resistance was recorded over time. Equation 1 (above) was then solved for T.

[0176] In this example, a 24' 9" length of FEP insulated copper wire was used. The resistance of 24' 9" wire is known to be 1.51 ohms. The resistance of 6" wire is known to be 0.26 ohms. R ref To calculate the value of R, subtract the resistance of 6 inches of copper wire from the resistance of 24 feet 9 inches of copper wire to subtract the approximate resistance of any other components in the circuit that are not insulated conductors. R ref Once R is determined to be 1.25 ohms, the measured value of R can be used to solve Equation 1 for T.

[0177] The calculated temperature of the copper conductor over time is shown in Figures 10 and 11. Figure 10 shows the first 20 seconds after immersion in liquid nitrogen in more detail. Figure 11 shows the temperature of the conductor as it was immersed and after removal from liquid nitrogen. The conductor was placed in the liquid nitrogen bath at time = 0. During the first 5 to 10 seconds, the conductor temperature rapidly decreased before leveling off at approximately -176°C. The cable remained in the liquid nitrogen bath for 120 seconds. As shown in Figure 11, when the conductor was removed from the liquid nitrogen bath at 120 seconds, the conductor temperature began to warm up again. Both the solid-insulated and foam-insulated conductors reached approximately 0°C approximately 40 seconds after removal from liquid nitrogen. As can be seen from Figures 10 and 11, the solid-insulated and foam-insulated conductors maintained generally similar temperatures relative to each other when cooling in liquid nitrogen and warming after removal from liquid nitrogen.

[0178] The disclosed invention is generally described in terms of intertwining twisted pairs, but is applicable to a wide variety of other applications.

[0179] In some embodiments, when two insulated conductors are joined together to form a twisted pair, additional tape, filler, or hollow tube may be added to or incorporated into the twisted pair. In the case of tape, the tape may be added between the insulated conductors, on the exterior of the twisted pair unit, and / or surrounding the twisted pair unit.

[0180] FIG. 12 shows a schematic diagram of a twisted pair incorporating tape, according to one embodiment. As shown in FIG. 12, a tape 930 may be placed between two insulated conductors 920 of a twisted pair 910. The tape 930 is subjected to forces during twisting of the twisted pair. As a result of these forces, the tape 930 may be compressed or otherwise deformed during the entanglement process. Deformation of the tape 930 may result in increased capacitance, increased insertion loss, decreased electrical impedance, and / or other undesirable effects on the electrical properties of the resulting twisted pair. By increasing the stress / strain response of the tape 930 just prior to applying the entanglement process forces to the tape, deformation of the tape may be reduced, preserving or enhancing the electrical properties of the resulting twisted pair. As described elsewhere herein, the stress / strain response (and thus the hardness) of the tape may be increased by exposing the tape to a cryogenic fluid.

[0181] FIG. 13 schematically illustrates an embodiment in which tape is wrapped around twisted pairs. In some embodiments, one or more twisted pairs 1010 can be surrounded by tape 1020. Each twisted pair 1010 may contain two conductors 1030 surrounded by an insulating layer 1040. In some cables, multiple twisted pairs 1010 are surrounded by an outer jacket 1050. The tape 1020 can be tightly formed around the twisted pairs 1010, which can cause deformation, increasing capacitance, decreasing impedance, and / or increasing insertion loss. In some embodiments, the tape 1020 can include a combination of metal and polymer insulating material. As described, polymer materials can be susceptible to compression or other forms of deformation. In some embodiments, before wrapping the tape around the twisted pairs, the tape is passed through a cooling chamber where it is immersed in, sprayed with, or otherwise exposed to a cryogenic fluid or other cooling medium. By exposing the tape to a cryogenic fluid to increase the polymer's stress / strain response and hardness, the tape becomes more rigid and able to withstand deformation. It is believed that the amount of air trapped between the twisted pairs and the layer of tape surrounding them can be increased through higher stiffness (i.e., increased stiffness) of the tape. This is because a stiffer tape, by itself, will not conform more tightly around the insulated conductors and will maintain a larger amount of air space within the wrapped tape than a polymer tape with a lower hardness. Increasing the amount of air trapped between the tape and the twisted pairs will improve the electrical performance of the wire or resulting cable. Air is a ferroelectric material. Increasing the volume of air within a cable or insulation layer generally has a positive impact on the electrical performance of the resulting wire and / or cable.

[0182] FIG. 14 schematically illustrates a cross section of an embodiment in which a hollow tube is incorporated into a twisted pair cable. FIG. 14 shows a cable including two conductors 1110, each surrounded by an insulation layer 1120. The insulated conductors are positioned within an outer sheath 1130. In some embodiments, the twisted pair may be combined with a hollow tube 1140 and / or filler positioned between the two insulated conductors to create additional air space 1150 within the outer sheath 1130. These hollow tubes 1140 are typically made from a polymeric material and may compress or otherwise deform when compressed against the insulated wires of the twisted pair during the entanglement process. If the hollow tube or filler deforms, the amount of air contained within the hollow tube and / or within the outer sheath may be reduced. Additionally, if the hollow tube or filler deforms, the spacing between twisted pairs may decrease or become inconsistent, which increases the amount of crosstalk between different twisted pairs. In some cases, reduced spacing between twisted pairs may also increase the capacitance, increase insertion loss, decrease impedance, and / or otherwise degrade the electrical performance of the resulting cable.

[0183] Exposing the hollow tubes 1140 or filler to cryogenic fluid increases their stress / strain response, thereby increasing their hardness, allowing them to withstand deformation and collapse into the gaps between the twisted pairs, thereby maintaining air spaces 1150 and improving electrical performance. The air pockets formed between the hollow tubes 1140 and the gaps between the pairs are beneficial for electrical performance because air has a dielectric constant of 1.0, which is favorable compared to the dielectric constants of other materials, such as FEP (2.0), polyethylene (2.3), and polyvinyl chloride (3.5). In some embodiments, maximizing air content is beneficial for the electrical performance of wire and cable.

[0184] 15 schematically illustrates a cross section of an embodiment using protrusions to increase air space, reduce material costs, and / or reduce weight. In some embodiments, the outer jacket 1210, twisted pairs 1220, and / or hollow tube 1230 include protrusions 1240 or striations on the inner and / or outer surfaces to create additional air space 1250. In some embodiments, the protrusions 1240 and / or striations are susceptible to deformation. In such embodiments, increasing the stress / strain response and stiffness of the striations and / or hollow tube 1230, including the protrusions 1240, to prevent deformation or collapse of the protrusions 1240 can help maintain and / or maximize the air space 1250 within the cable.

[0185] In some embodiments, protrusions from the hollow tube, insulation layer, or armor layer are formed during profile extrusion of the cable component. In some embodiments, the protrusions can be easily compressed or deformed. Hardening the surface (i.e., increasing the stress / strain response) by exposing the material to a cryogenic fluid can help reduce the effect of forces on the protrusions, thereby maintaining the volume of air that would be present if the protrusions were not compressed or deformed.

[0186] It will be appreciated that not only may polymer insulated wires be exposed to cryogenic or chilled fluids to increase stress / strain response and stiffness, but hollow tubes, filler tubes, tapes, sheaths, and / or other polymer cable construction components may be exposed to cryogenic or chilled fluids or another cooling medium. By reducing deformation of cable components, the volume of air within the cable can be maintained or increased, improving the electrical performance of the cable over similar cables that are compressible or deformable.

[0187] FIG. 16 schematically illustrates a cross section of an embodiment in which a conductor is insulated by multiple layers of insulation. In some embodiments, multiple layers of different insulating materials may be used to surround the conductor. In some embodiments, an outer layer of material with a high inherent hardness may be used, which may help reduce compression of a softer inner layer of material. In some embodiments, a layer of foam insulation 1320 may be used to insulate the conductor 1310. Because foam insulation contains many separate air pockets, the Young's modulus and hardness of the foam insulation layer may be significantly lower than a solid insulation layer of the same polymer material. As a result, the foam insulation layer may be more susceptible to compression during manufacturing. A skin layer 1330, which is a harder material with a higher Young's modulus than the underlying foam insulation 1320, may be used to reduce compression of the foam insulation 1320. To reduce compression or deformation of the insulation layer during the manufacturing or cable-making process, the stress / strain response and hardness of the outer portion of the insulation material may be temporarily increased by exposing the insulated conductor (including the foam insulation and foam skin) to a cryogenic fluid. It will be understood that the entire thickness of the inner foam insulation layer may not need to be cooled for the outer portion of the foam insulation layer to have a temporary elevated stress / strain response and hardness to withstand compression during the cable fabrication process. It will be understood that the skin 1330 may or may not be a foam itself. In some embodiments, the skin will be a solid polymer designed to protect the underlying foam insulation. In some embodiments, the skin layer will comprise a different polymer than the foam insulation layer.

[0188] In some cable embodiments, separator tapes, cross webs, and / or star fillers are utilized between twisted pair units to separate them from one another. Due to the forces experienced during the cable fabrication process, deformation of these separators can occur, thereby reducing the air volume within the cable and adversely affecting the electrical performance of the cable.

[0189] Figure 17 is a schematic cross-sectional view of an embodiment in which multiple twisted pairs are separated by cross-webs. In the embodiment shown in Figure 17, twisted pairs 1410 are separated from each other by polymer cross-webs 1420. This reduces the amount of electromagnetic interference between the twisted pairs 1420. The cross-webs 1420 and the twisted pairs are encased in an outer sheath 1430.

[0190] In some embodiments, the separator tape, cross-web, and / or star filler are extruded polymer shapes without the benefit of a metal backing or rigid internal elements. The polymer separator may be made of a high dielectric constant material (3.0 or higher). In some embodiments, the separator may be made of a foamed material, which improves dielectric properties and increases susceptibility to deformation. During the cable fabrication process, cable components are typically subjected to multiple compressive or deforming forces. Exposing the separator tape, cross-web, or star filler to a cryogenic fluid before or during the cable fabrication process temporarily increases its stress / strain response and hardness, reducing compression or deformation of the separator or other components, thereby increasing the air volume within the cable and improving the electrical performance of the resulting cable.

[0191] In some embodiments, the polymer cable components may be cured before being compressed to reduce the degree of deformation to the polymer cable components. In some embodiments, the polymer cable components may be cured before being compressed so that the polymer cable components can withstand greater compressive forces while remaining nearly as compressible as if the cable had not been cured before being compressed.

[0192] In some embodiments, a first twisted pair is produced by operating a twinning apparatus or twinner at a first line speed. The resulting first twisted pair has a specific first crush rate. Another twisted pair can be produced by cooling the polymer-insulated conductors to increase the hardness of the polymer insulation layer and then operating the cable twinning apparatus at a second, faster speed to twine the polymer-insulated conductors and produce a second twisted pair having a second crush rate. In some embodiments, the second twisted pair is produced at a second, faster speed and has approximately the same crush rate as the first twisted pair. In some embodiments, the second crush rate is within about 10% of the first crush rate. In some embodiments, the second crush rate is less than the first crush rate. In some embodiments, the second speed is at least about 15% faster than the first speed. In some embodiments, the second rate is at least about 25% faster than the first rate.

[0193] In some embodiments, the twinner or twinning apparatus used will have a rated speed for a particular type of wire and cable product. In some embodiments, the first speed listed above is the rated speed for a given twinner and cable product, and the second speed is at least about 10% faster than the rated speed for the same product. In some embodiments, the first linear speed is about 60 feet / minute and the second speed is about 70 feet / minute. In some embodiments, the first linear speed is about 160 feet / minute and the second speed is about 180 feet / minute. In some embodiments, the first linear speed is about 220 feet / minute and the second speed is about 275 feet / minute.

[0194] FIG. 18 schematically illustrates a cross section of an embodiment in which an electrical wire includes a metal braid. In some embodiments, a conductor 1510 is insulated by a polymer insulation layer 1520, and a wire braid 1530 is constructed on top of the insulation layer 1520. The wire braid 1530 may be made of a metal such as copper and may be plated with silver or tin. The wire braid 1530 may contain multiple metal strands woven together. When the braid is applied to the polymer insulation layer 1520, the individual metal strands that make up the braid may create indentations on the surface and / or compress the polymer insulation layer 1520, which may adversely affect the electrical properties of the cable. In some embodiments, multiple polymer cable components, such as insulated conductors and hollow tubes, are cabled together using the metal braid. In such embodiments, each of the polymer cable components in contact with the metal strands may be deformed by the compressive force of the metal strands, which may adversely affect the electrical properties of the resulting cable.

[0195] In some instances, the indentations of the braid on the polymer insulation layer are repeated at regular intervals, which can adversely affect periodic electrical signals that repeat at approximately the same regular intervals or frequencies, or any harmonics thereof. Increasing the stress / strain response and hardness of the polymer insulation layer before applying the braid or metal strands can reduce indentations, compression, and other deformations of the braid on the polymer insulation layer.

[0196] In some embodiments, the cooling chamber or other structure containing the cooling medium located immediately prior to the braiding machine is less than about 5 feet in length, or less than about 3 feet in length, or less than about 1 foot in length. Due to the relatively slow linear speeds of most braiding machines, the cooling chamber footprint can be reduced without reducing the residence time of the polymer cable components within the cooling chamber.

[0197] In one non-limiting embodiment, uninsulated copper conductor wire was used to simulate the indentations made in polymeric cable components during the metal braiding process. Metal braids are typically applied over polymeric cable components by weaving or braiding multiple individual metal strands together over the polymeric component. As these individual strands are braided together, they compress and deform the underlying polymer component. To simulate this deformation process, a entanglement machine was used to entangle one foam FEP insulated conductor with one uninsulated copper conductor wire. The uninsulated copper conductor wire was twisted around the foam FEP insulation, allowing inspection of the indentations left in the foam FEP insulation layer. The bare copper wire was 24 AWG wire, and the FEP foam insulated conductor had an outer diameter of approximately 82.68 mils, or approximately 2.1 mm.

[0198] Samples were prepared using a 6.2 mm twist length and a entanglement machine operating at 30 ft / min with 1400 twists / min. Samples were collected after exposing the FEP foam insulation to liquid nitrogen for 10 seconds, and a control sample without a cooling chamber. The depth of the impression left by the copper conductor in the foam insulation was analyzed using a laser microscope.

[0199] Upon initial visual inspection, the polymer insulation layer that was not exposed to liquid nitrogen deformed into a generally spiral shape when intertwined with the exposed copper wire. The polymer insulation exposed to liquid nitrogen for 10 seconds appeared to have increased hardness and become generally straight, with the copper wire spirally wrapped around the straight foam insulation layer. The foam FEP insulation layer appeared unaltered by the intertwining process with the exposed copper wire.

[0200] The depth of the indentation caused by the exposed copper wire penetrating the FEP foam insulation layer was measured three times at each of three locations: before winding on the entanglement machine, inside the bow, and on the entanglement take-up reel. The data are presented in Table 6 below.

[0201] [Table 6]

[0202] As the intertwined pair moves from pre-wind, to the bow interior, to the take-up reel, the amount of force and the number of total compression events increases and the lay length decreases. The distance and time since the polymer insulation left the cooling chamber also increases, which decreases the hardness of the polymer insulation as it returns to ambient temperature.

[0203] As can be seen in Table 6, at all locations, samples exposed to liquid nitrogen for 10 seconds showed a significant reduction in the indentation made by the copper wire. Therefore, it can be expected that a metal braid armor layer applied over a polymer insulation layer will cause less deformation of the polymer insulation layer if the polymer is cured by cooling the polymer before applying the braid. Wire and cable products with less deformation of the polymer insulation layer generally have improved electrical properties over wire and cable products with compressed or otherwise deformed polymer insulation layers.

[0204] In some embodiments, compression and / or deformation can occur when individual insulated conductors and / or other cable components are bundled together during the cable fabrication process. This deformation can push the insulated conductors into the cross-web or other separator, resulting in compression of the insulation layers and / or collapse of the armor layer. During the cable fabrication process, twisting of the current twisted pairs can increase the twisting speed of the twisted pairs, which creates additional compressive forces within the current twisted pairs. Stiffening the cable components by temporarily increasing their stress / strain response and hardness during the cable fabrication process can help reduce or avoid deformation of the various cable components, both individually and relative to each other. Exposing the cable fabrication components to a cryogenic fluid before and / or during the cable fabrication process can maintain the desired cable configuration. Avoiding deformation maximizes air space within the cable, improving electrical performance. Allowing deformation of the cable's physical configuration can have a negative impact on the cable's electrical performance.

[0205] As described herein, air is a preferred dielectric material, but it does not provide physical support or prevent conductors from contacting each other. Therefore, insulating materials are used to prevent contact between conductors and reduce interference. To improve the electrical performance of the insulating layer, air may be introduced into the insulating material via air channels (profile extrusion) or foaming (creating bubbles within the insulating material). Because air itself has no physical strength, introducing air into the insulating layer reduces the overall stress / strain response and hardness of the insulating material. A lower Young's modulus and hardness result in greater compression or deformation as a result of the same external force. Exposing the insulating element to a cryogenic fluid can temporarily increase the stress / strain response and hardness of the insulating layer, thereby mitigating deformations that occur during the manufacturing process. In some embodiments, introducing air into the insulating layer allows the cryogenic fluid to cool any enclosed air pockets. This may help maintain the insulating layer at a lower temperature for a longer period of time than a solid insulating layer without any air pockets. This may also allow the cryogenic fluid to penetrate deeper into the insulating layer for the same exposure time and / or provide a larger surface area for the cryogenic fluid to act upon.

[0206] During the process of forming twisted pairs from the individual insulated conductors, the compressive force generally increases as the twist of the twisted pairs increases. In some embodiments, the foamed insulation layers are exposed to a cryogenic fluid before being intertwined to create the twisted pairs.

[0207] In some embodiments, increasing the stress / strain response and hardness of polymer cable components before or during manufacturing can create lighter, smaller, and / or more useful cables. If the cable components are not compressed or otherwise deformed, less overall insulation material may be required to achieve the same electrical performance. If the insulation layers are less compressed due to increased stress / strain response and hardness during manufacturing, the total thickness of the insulation layers may be reduced.

[0208] In some embodiments, untwisted wires may benefit from a temporary increase in the stress / strain response and hardness of the polymer insulation layer. For example, the polymer insulation layer of a single polymer-insulated conductor may deform if the wire contacts rollers, guide bars, or other equipment during the manufacturing process. The polymer insulation layer may also deform when two wires join to form an untwisted pair.

[0209] Many cables contain two or more twisted pairs. To reduce electrical interference between the twisted pairs, each twisted pair in a cable can have a different twist length or number of twists per meter. Differences in twist length and other differences in twisted pairs can lead to a particular twisted pair having a faster or slower signal speed. One factor that determines whether a twisted pair has a faster or slower signal speed is the amount of air between the two insulated conductors of the twisted pair. The more the conductors in the twisted pair are deformed by the compressive force of intertwining, the less air remains in the gap. The less the conductors in the twisted pair are deformed by the compressive force of intertwining, the more air remains in the gap, resulting in a lower dielectric constant and a higher signal speed for the twisted pair. In addition to the air contained in the gaps between the twisted pairs, air may also be contained between various components within the cable. In some cable embodiments, air pockets may form between the twisted pairs, between the twisted pairs and the cross members, between the twisted pairs and the filler tube, and / or within the hollow tube. Generally, the more air contained within a cable, the better the electrical properties of the cable.

[0210] Certain applications may use multiple twisted pairs within a single cable to transfer data. For that data to be properly processed, it must be sent over and received from each of the twisted pairs at a specific time. In some embodiments, different twist lengths are used to reduce electrical noise between different twisted pairs. It is common for four pairs to be used to transmit a signal. By using different twist lengths for each of these four pairs, the conductor path of one twisted pair may be shorter or longer than another twisted pair. For example, a twisted pair with a longer twist length and fewer twists per inch will have a shorter conductor path than a twisted pair with a shorter twist length and more twists per inch.

[0211] In many applications, it is important that the signals on each twisted pair arrive at approximately the same time. Different conductor lengths can cause the signals to arrive at different times. This can cause an effect called differential delay. In some embodiments, it is beneficial to slow down or not modulate the first-arriving signal (shortest conductor pair path) and naturally speed up the last-arriving signal (longest conductor pair path).

[0212] The difference between the signal received from the fastest twisted pair and the slowest is called the delay skew. A delay skew of less than 25 ns is desirable. In some applications, a delay skew of less than 50 ns is acceptable.

[0213] As discussed, deformation of the polymer insulation layer in a twisted pair can affect the electrical performance of the twisted pair, including signal speed. The tighter the twist or the shorter the twist length of the twisted pair, the greater the compressive force applied during entanglement, which typically results in a greater degree of deformation of the polymer insulation layer and a subsequent reduction in the air dielectric between the insulated conductors.

[0214] In some embodiments, multiple twisted pairs can be exposed to the cryogenic fluid for different lengths of time to adjust the signal speed and reduce the delay skew of the resulting cable. By exposing the polymer-insulated conductor to the cryogenic fluid for different lengths of time, a desired amount of deformation can be introduced into the polymer layer. Controlling the degree of polymer deformation can control the desired amount of air in the gaps between the twisted pairs. While deformation generally adversely affects the electrical properties of the resulting twisted pairs, being able to control the degree of this adverse effect can standardize the signal speed between the multiple twisted pairs and create a cable with reduced delay skew across the multiple twisted pairs.

[0215] In one non-limiting example, four twisted pairs are fabricated to be incorporated into a single Ethernet cable. The polymer-insulated conductors forming each of the four twisted pairs can be exposed to a cryogenic fluid before being intertwined. The polymer-insulated conductors forming the twisted pair with the longest twist length can be exposed to the cryogenic fluid for, for example, about 2 seconds to reduce deformation of the polymer insulation layer. The polymer-insulated conductors forming the twisted pair with the shortest twist length can be exposed to the cryogenic fluid for, for example, about 10 seconds to reduce deformation of the polymer insulation layer and preserve most of the air dielectric between the insulated conductors. The polymer-insulated conductors forming the twisted pair with a medium twist length can be exposed to the cryogenic fluid for 2 to 10 seconds. By exposing the wires forming different twisted pairs to the cryogenic fluid for different lengths of time, the signal speed of the resulting twisted pairs can be adjusted and the delay time difference of the resulting cable can be reduced.

[0216] While the dielectric constant of a given polymer may be known, the total amount of insulating material and air gap surrounding the conductors in a twisted pair is a function of the original polymer-insulated conductors, the cable design, and the degree of deformation of the various cable components introduced during the manufacturing process. In the case of foamed polymer insulation, the amount of air gap around the conductor is closely related to the degree of deformation of the polymer insulation.

[0217] For a given conductor, the dielectric constant is inversely related to the propagation velocity. Therefore, the time it takes a signal to travel a given length of twisted pair is also related to the dielectric constant. The higher the total dielectric constant (the sum of the insulation and air gap) surrounding the conductor, the longer the signal will take to travel through the twisted pair. For example, controlling the degree of deformation of various cable components, such as the insulation, twisted pairs, hollow tube, feed tube, and / or jacketing, can tailor the electrical performance of the twisted pair and / or cable. This is due in part to the amount of air surrounding or retained within the cable components. Combining twisted pairs with known or controlled signal speeds can produce cables with reduced delay skew.

[0218] The velocity of propagation in a twisted pair can be measured directly using commercially available instruments. The velocity measurement can be used to determine the coupling permittivity (ε) using the following equation:

[0219] [Table 7]

[0220] By directly measuring the propagation velocity, it is possible to calculate the combined dielectric constant (ε), which takes into account the dielectric effects of both the polymer insulation and the air gap surrounding the conductor.

[0221] In one non-limiting example, based on the equation above, if the propagation velocity of a twisted pair is measured to be 68%, the coupling permittivity is calculated to be 2.16. Using the same time delay calculations shown above, the time delay for signals traveling down this twisted pair corresponds to approximately 1.5 nanoseconds per foot. Fabricating a second twisted pair and exposing it to a cryogenic fluid before twisting the polymer-insulated wires together can increase the amount of air gap surrounding the conductors and improve the propagation velocity. If the improved propagation velocity is 70%, a 2% increase, the resulting coupling permittivity is calculated to be 2.04, and the calculated time delay is 1.45 nanoseconds per foot. For twisted pairs longer than 330 feet, a difference of 0.05 nanoseconds per foot between two twisted pairs results in a total difference of 16.5 nanoseconds in signal delay. Exposing the polymer-insulated conductor to a cryogenic fluid for a specific time can control the coupling permittivity and propagation velocity. This will enable the development of faster twisted pairs and the creation of cables with reduced delay time skew.

[0222] By exposing the polymer-insulated conductor to cryogenic fluids for various lengths of time, a desired amount of deformation can be introduced into the polymer layer. While deformation generally has a negative effect on the electrical properties of the resulting twisted pair, the ability to control the degree of this effect allows for standardization of signal speeds among multiple twisted pairs, resulting in cables with reduced delay skew.

[0223] In some embodiments, the entanglement device can be adjusted to operate at a faster or slower line speed to control the time the insulated conductor is exposed to the cryogenic fluid. In some embodiments, multiple cooling vessels of different lengths may be used to expose the polymer-insulated conductor to the cryogenic fluid for different times. In some embodiments, a displacement block or adjustable divider can be used to control which portion of the cooling vessel actually contains the cryogenic fluid, thereby allowing a single cooling vessel to expose the polymer to the cryogenic fluid for different times. By using a displacement block or adjustable divider, portions of the cooling vessel can be left free of cryogenic fluid, allowing for the functional creation of cooling vessels of variable lengths.

[0224] In some embodiments, one or more pulleys, wheels, capstans, and / or rollers can be used within the cooling vessel to redirect the path of the polymer cable component within the cooling vessel. This arrangement can allow the polymer cable component to remain in the cooling vessel for a longer period of time without increasing the length of the cooling vessel or slowing the linear velocity of the component. In some embodiments, the polymer cable component enters the cooling vessel at an upper vapor region of the vessel, where evaporated cryogenic vapor rises above the cryogenic liquid, and is then redirected through a liquid region of the vessel where the liquid cryogenic fluid remains. This arrangement can allow the polymer cable component to first transfer heat to the cryogenic vapor before contacting the cryogenic liquid, thereby reducing the total heat load transferred to the cryogenic liquid and increasing the total residence time of the polymer cable component within the cooling vessel. In some embodiments, the redirecting wheels can be adjustable to control the total residence time of the polymer cable component within the cooling vessel.

[0225] It will be appreciated that the cable can be made with one or more twisted pairs, for example, 2, 3, 4, 6, or 8 twisted pairs. Each twisted pair in the cable can be exposed to the cryogenic fluid for a specific predetermined time to adjust the signal speed. Adjusting the signal speed can reduce the delay time skew of the resulting cable.

[0226] In some embodiments, the cable jacket is formed around the twisted pairs or other cable components using an extruder with a profile die. The cable components are passed through the extruder die, and a polymer is extruded around the cable components to form the jacket. In some embodiments, to avoid deformation of the cable jacket, the cable jacket is exposed to a cryogenic fluid after being extruded around the cable components.

[0227] In some embodiments, a polymer may be exposed to a cryogenic fluid after being extruded to form a polymer shape, including, but not limited to, a hollow tube, a solid tube, a rectangular shape, an irregular shape, a shape with protrusions, depressions, or cavities, or any other profile design. By exposing the extruded polymer shape to a cryogenic fluid after the polymer shape is extruded, the stress / strain response and hardness of the extruded shape can be increased over a relatively short distance. In some embodiments, exposure to a cryogenic fluid may be used to tailor the crystalline structure of the extruded shape and / or control the physical properties of the resulting polymer shape. In some embodiments, the extruded polymer may be exposed to a water bath before being exposed to a cryogenic fluid. By exposing the extruded polymer shape to a cryogenic fluid, the resulting polymer may be easier to handle, grind, machine, or cut. The resulting polymer may be able to withstand deformation and / or produce less shavings, dust, chips, or unusable material during processing. In some embodiments, improved tensile and elongation properties can be achieved by tailoring the crystalline structure of the polymer cable components.

[0228] In some embodiments, a cryogenic cooling vessel may be incorporated into an in-line continuous or semi-continuous process. In some embodiments, an entanglement machine may be configured to incorporate a cryogenic cooling chamber before, during, and / or after the entanglement machine pairs the polymer-insulated conductors to form twisted pairs. In some embodiments, a cable fabrication machine may be configured to incorporate a cryogenic cooling chamber before, during, and / or after the cable fabrication machine gathers and / or twists the cable components to form a cable core.

[0229] In some embodiments, the cryogenic cooling vessel includes a vessel configured to contain a cryogenic liquid, a liquid level sensor, such as a float switch, and an inlet arrangement for supplying the cryogenic liquid and / or an exhaust arrangement for removing vaporized cryogenic liquid. In some cryogenic cooling vessels, the inlet is configured to allow a polymer component, such as a polymer-insulated conductor, to enter the cooling vessel, and the outlet is configured to allow the polymer component to exit the cooling vessel. In some embodiments, the inlet and outlet each have a diameter less than 0.3 mm larger than the diameter of the polymer sample. In some embodiments, the inlet and / or outlet are configured with a shape that corresponds to the shape of the polymer sample to accommodate various shaped polymer samples, such as cross-web. In some embodiments, the cooling vessel incorporates sensors and / or labeling devices to maintain consistent wire or cable quality during operation and / or line shutdown.

[0230] In some embodiments, the cooling vessel is positioned to expose the polymer-insulated conductors entering the entanglement machine to the cryogenic fluid before the initial contact between the polymer-insulated conductors. The point of initial contact may be several feet before the polymer-insulated conductors actually enter the take-up device of the entanglement machine. At the point of initial contact, a compressive force between the polymer-insulated conductors exists, but may be weak against the peak compressive force that occurs when the polymer-insulated conductors are entangled together. In some embodiments, the cooling vessel is positioned to expose the polymer-insulated conductors to the cryogenic fluid after the point of initial contact and before the polymer-insulated conductors enter the entanglement machine.

[0231] In some embodiments, the automated cryogenic exposure system may be utilized as part of an in-line continuous or semi-continuous process. The automated cryogenic exposure system may be used in conjunction with entanglement lines, cable making lines, jacketing lines, and / or any other process where polymeric members may be compressed or deformed.

[0232] In some embodiments, the cryogenic temperature exposure system includes a cooling vessel having one or more sensors positioned to determine variable length, variable component paths, multiple component paths, wires, twisted pairs, cable cores, and / or cable diameters, and / or a machine automation controller.

[0233] In one non-limiting example, an optical sensor can be used to measure the diameter of one or two polymer-insulated conductors being unwound at the beginning of the twisted pair entanglement process. As described herein, the polymer-insulated conductors may be passed through a cooling vessel containing a cryogenic fluid, such as liquid nitrogen, to increase the stress / strain response and hardness of at least a portion of the polymer insulation layer. After passing through the cooling vessel, the two polymer-insulated conductors are twisted together to form the twisted pair. A second optical sensor can also be used to measure the width of the final twisted pair.

[0234] By measuring the diameter of both polymer-insulated conductors before they contact each other, and assuming no crushing or deformation of the polymer insulation layers, the two diameters can be combined to determine the potential width of the resulting twisted pair. In some embodiments, the potential zero-deformation width may also be determined by measuring the diameter of one of the polymer-insulated conductors at the start of the intertwining process and doubling it.

[0235] When measuring the width of the resulting twisted pair, the optical sensor may measure the width of the twisted pair as it passes through a beam, such as a photon beam emitted by the optical sensor. It will be understood that the peak width measurement is used to represent the width of the twisted pair when the individual conductors are oriented in a plane perpendicular to the optical sensor's beam. If two conductors of the twisted pair are stacked in alignment with the optical sensor's beam, the measured width may be approximately equivalent to the width of a single insulated conductor and is not representative of the width of the twisted pair. By comparing the measured twisted pair width to a theoretical zero-collapse width, the collapse rate of the twisted pair can be determined in real time.

[0236] As part of the twisted pair cable design, a desired crush rate can be established to achieve desired electrical properties. If the measured crush rate is determined to be higher than the desired crush rate setting, the cooling vessel can be adjusted to extend the length the polymer-insulated conductors are exposed to the cryogenic fluid. Increasing the length of the cooling vessel containing the cryogenic fluid can increase the exposure time of the polymer-insulated conductors, increasing their stress / strain response and hardness before they are exposed to the compressive forces of the entanglement process. Increasing the stress / strain response and hardness of the polymer-insulated conductors prior to entanglement can reduce the crush rate of the resulting twisted pair. In some embodiments, the speed of the entanglement device can be adjusted to help increase or decrease both the residence time of the insulated conductors in the cryogenic fluid and / or the compressive forces created by the entanglement process.

[0237] In some embodiments, the optical sensor and variable-length cooling vessel may be connected to one or more processors or machine automation controllers to create an automated quality control process. If the measured collapse rate deviates from a desired collapse rate setpoint, the controller may cause the variable-length cooling vessel to respond by adjusting the position of the diverting wheels to extend or contract the length of the portion of the cooling vessel containing the cryogenic fluid and / or the length of the component path within the cooling vessel. Automatically adjusting the length of the portion of the cooling vessel containing the cryogenic fluid can adjust the exposure time of the polymer-insulated conductor to the cryogenic fluid and, therefore, the stress / strain response and hardness of the polymer insulation layer. Adjusting the stress / strain response and hardness of the polymer insulation layer can control the collapse rate of the twisted pair.

[0238] In some embodiments, minor modifications to the variable length cooling vessel may be made continuously. Having granular and / or automatic control over the length of the cooling vessel, and therefore the exposure time of the polymer-insulated conductor to the cryogenic fluid, allows for the collapse rate to be controlled and maintained regardless of many potentially complex factors, including, but not limited to, ambient temperature, ambient sunlight, relative humidity, line speed, twist length, entanglement device parameters, entanglement device design, the type of polymer insulation used, whether the polymer insulation is foamed or solid and / or the degree to which the polymer insulation is foamed, variations in polymer-insulated conductor from reel to reel, and many others.

[0239] In some embodiments, multiple cooling vessels can be used to control the total exposure time of the polymer-insulated conductor to the cryogenic fluid. By using multiple separate cooling vessels, different methods of applying cryogenic fluid to the polymer insulation can be used on the same polymer insulation. For example, a first cooling vessel can immerse the polymer conductor in a cryogenic fluid bath, while a second cooling vessel can use a cryogenic fluid spray. It will be appreciated that any number of cooling vessels can be used in any of a number of configurations. By varying the configuration of some or all of the multiple cooling vessels, the exposure time of the polymer-insulated conductor and the temperature of the polymer-insulated conductor during entanglement or application of other compressive forces can be adjustable.

[0240] Previously, achieving the desired degree of crush required a trial-and-error process of fabricating a reel of twisted pairs and testing the resulting reel for electrical properties. If the electrical properties were not within the predetermined specifications, the reel was labeled nonconforming and one of many variables was changed. Another reel of twisted pairs was then fabricated and its electrical properties tested. This trial-and-error process was time-consuming and resulted in material loss. Because the physical properties of polymer-insulated conductors and the resulting twisted pairs are known to affect their electrical properties, controlling the degree of crushing of the twisted pairs can also control the electrical properties of the twisted pairs. The disclosed continuous and / or automated processes can be used to achieve desired physical properties, and therefore desired electrical properties, with less time and less wasted material.

[0241] 19A-C show schematic diagrams of a variable-length cooling vessel according to one embodiment. As shown in FIG. 19A, the variable-length cooling vessel may include a partition 1630 arranged to move back and forth to change the length of the cooling vessel containing the cryogenic fluid 1620. The partition 1630 may be controlled by a motor 1650 connected to a threaded rod or screw drive 1660. As shown in FIG. 19A, the polymer-insulated conductor 1610 can enter the cooling vessel through a hole 1640. After passing through a portion of the cooling vessel that does not contain the cryogenic fluid 1620, the polymer-insulated conductor may pass through the partition 1630 through a similar hole 1640. After passing through the partition 1630, the polymer-insulated conductor 1610 can be exposed to the cryogenic fluid 1620. As shown in FIGS. 19B and 19C, the position of the partition 1630 can be controlled using the motor 1650 and / or screw drive 1660 to extend or reduce the portion of the cooling vessel containing the cryogenic fluid 1620. By adjusting the length of the portion of the cooling vessel containing the cryogenic fluid, the time the polymer-insulated conductor is exposed to the cryogenic fluid can be controlled. By controlling the time the polymer-insulated conductor is exposed to the cryogenic fluid, the crush rate and therefore the electrical performance of the twisted pair or cable can be controlled.

[0242] In some embodiments, a motor, screw drive, or other mechanism for controlling the position of the partition within the variable-length cooling vessel may be operably connected to a machine controller. In some embodiments, the machine controller may be used to control the position of a diverting wheel within the cooling vessel to adjust the length of the component path within the cooling vessel. This dynamic component path may be controlled to adjust the residence time of the polymer cable component within the cooling vessel. The machine controller may be in data communication with one or more processors that are in data communication with a first sensor for determining the diameter of the polymer-insulated conductor and a second sensor for determining the width of the twisted pair. The processor and machine controller may compare the diameter of the polymer-insulated conductor and the resulting width of the twisted pair to determine a crush rate and compare the determined crush rate to a predetermined desired crush rate setpoint. The machine controller may then command the motor and / or screw drive to adjust the exposure time of the polymer-insulated conductor to the cryogenic fluid until the determined crush rate is approximately equal to the desired crush rate setpoint. Although the cryogenic exposure system described above is described in the context of an entanglement system, it will be understood that the system may also be applied to any other process in which a polymer component may be compressed or deformed.

[0243] In some embodiments, the cooling vessel includes nozzles configured to spray the cryogenic fluid onto the polymeric component. In some embodiments, rather than changing the physical size of the cooling chamber containing the cryogenic fluid, some of the nozzles may be closed, bypassed, or prevented from spraying the cryogenic fluid. This allows for control of the exposure time of the polymeric component and the resulting rate of collapse of the polymeric component, as described above.

[0244] 20A-C show schematic diagrams of a variable spray cooling vessel according to one embodiment. As shown in FIG. 20A, a polymer-insulated conductor 1710 can enter the cooling vessel through a hole 1730. Cryogenic spray nozzles 1720 can be activated to expose the polymer-insulated conductor 1710 to the cryogenic fluid. As shown in FIG. 20A, all of the multiple spray nozzles 1720 can be activated to maximize the exposure of the polymer-insulated conductor to the cryogenic fluid. As shown in FIG. 20B, some of the multiple cryogenic spray nozzles 1720 can be deactivated to reduce the exposure time of the polymer-insulated conductor to the cryogenic fluid. As shown in FIG. 20C, more of the spray nozzles 1720 can be deactivated to reduce the exposure time of the polymer-insulated conductor to the cryogenic fluid. In some embodiments, the flow rate of the cryogenic fluid through one or more nozzles can also be adjusted to tailor the stress / strain response and hardness of the polymer component passing through the cooling vessel. In some embodiments, all of the spray nozzles can be deactivated, preventing the polymer component from being exposed to the cryogenic fluid at all. By adjusting the flow of at least one of the plurality of cryogenic nozzles, the exposure time of the polymer-insulated conductor to the cryogenic fluid can be adjusted. In some embodiments, the flow of the cryogenic fluid through the nozzles of the cooling vessel may be adjusted in response to the measured collapse rate to precisely control the collapse rate of the twisted pairs or deformation of any other polymer component passing through the cooling vessel.

[0245] In some embodiments, reducing the crush or deformation of polymer-insulated conductors, cables, cable jackets, and other cable components allows those components to be manufactured using less polymer material while maintaining or improving electrical performance. By using less polymer material, the resulting cable has less flammable material and a lower fuel load. Cables with lower fuel loads are more likely to pass the UL 910 Steiner Tunnel test.

[0246] In some embodiments, the process of adding additional insulation and / or jacketing material to compensate for expected deformation introduces a new set of problems. For example, many cables must pass certain flame and smoke standards that ensure the cable is safe for use within a building or dwelling. One factor in a cable's propensity to propagate flame and generate smoke is the amount of material contained within the cable, commonly referred to as the "fuel load." Generally, the greater the amount of fuel (here, polymer insulation or jacketing material), the greater the smoke generation and flame propagation from the cable under test.

[0247] An example of a fuel load test is the UL 910 Steiner Tunnel test, which is related to ASTM E84, NFPA 255, UL 723, and ULC S102. In this test, a flame is applied to a cable bundle placed inside a 24 ft x 1.8 ft x 1 ft noncombustible horizontal box or tunnel. The flame intensity is set at 89 kilowatts, and air is forced through the tunnel to simulate plenum ceiling conditions. Materials tested to these standards are required to exhibit a maximum flame spread distance of 5 ft, a maximum peak optical density of 0.5, and a maximum average optical density of 0.15.

[0248] Design engineers typically select materials optimized for cost and to meet required fuel load specifications. Potential problems arise when extra material is added to compensate for cable deformation due to forces generated during cable manufacturing. This extra material increases fuel loads, driving up costs and limiting the types of materials that can be employed. For example, some Cat6A cables have shorter lay lengths that generate higher compressive forces during manufacturing. These cables typically use FEP and PVC resins for insulation due to the greater than normal deformations encountered during the manufacture of these products. Cat6 cables, on the other hand, utilize longer lay lengths and experience relatively reduced compressive forces during manufacturing. As a result, these cables require less additional insulation to compensate for deformation. This lower fuel load allows for the use of other, less costly materials and / or components.

[0249] In some embodiments, cables are manufactured by temporarily increasing the hardness of polymer cable components before or during a compression event. The increased hardness reduces the degree of deformation that occurs during the compression event, and therefore less additional insulating material is required to achieve the desired electrical performance. In some embodiments, increasing the hardness of the polymer cable components can reduce the total fuel load of the resulting cable, allowing the cable to pass the UL 910 Steiner Tunnel test, whereas a similar cable without the increased hardness and including additional polymer material to offset the increased sag would not pass the UL 910 Steiner Tunnel test.

[0250] In some embodiments, cables with lower fuel loads of more cost-effective materials can be developed that would not have passed the UL 910 Steiner Tunnel test without the reduced fuel load. In some embodiments, cables manufactured using the disclosed technology contain reduced fuel loads and are less likely to propagate flame or smoke.

[0251] In some embodiments, cables made using the disclosed technology may have smaller outer diameters, which may allow existing buildings to be retrofitted with modern, high-performance cables that have similar or smaller diameters than the lower-performance cables previously used.

[0252] In some embodiments, the wire and cable product has a certain amount of polymeric insulation and / or other polymeric cable components that contribute to its fuel load. In some embodiments, the fuel load is designed to produce a flame travel distance of about 5 feet or less, a peak smoke optical density of about 0.5 or less, and / or an average smoke optical density of about 0.15 or less, when measured according to the Steiner Tunnel Test Method of ASTM E84, UL 910, NFPA 255, UL 723, or ULC S102.

[0253] In some embodiments, the polymer cable components are cooled and / or hardened prior to undergoing the compression event, which can provide desirable electrical properties because the polymer cable components do not deform as much as if the polymer cable components had not cooled and / or hardened prior to compression.

[0254] In some embodiments, polymer cable components deform less after being cured, so less overall polymer is incorporated into the wire and cable product, which may reduce the total fuel load of the wire and cable product. In some embodiments, reduced fuel load wire and cable products have capacitance values ​​of less than about 20 pf / ft. In some embodiments, reduced fuel load wire and cable products have impedance values ​​of between about 50 ohms and 150 ohms, or between about 75 ohms and 125 ohms, or equal to about 100 ohms. In some embodiments, reduced fuel load wire and cable products have a velocity of propagation of between about 62% and 80%, or between about 66% and 70%.

[0255] In some manufacturing facilities, there is ample space to slowly cool very hot insulated conductors or other polymer cable components after they are extruded. In some facilities, this initial cooling step involves prolonged exposure of the recently extruded polymer components to ambient air or water contained in a trough. Because wire and cable manufacturing is generally a continuous process in which cable components move at high speeds, each of these cooling methods can require a significant amount of space, e.g., greater than about 40 feet. The long distances required to cool the extruded polymer components require a large amount of manufacturing floor space. Furthermore, these cooling methods generally do not reduce the temperature of the polymer cable components to below ambient temperature.

[0256] In some embodiments, a faster temperature drop is advantageous for both saving time and reducing the footprint of the extruder manufacturing run. In some embodiments, a cooling chamber with chilled or cryogenic fluid can be used to rapidly cool the polymer cable component immediately after it is extruded. In some embodiments, the cooling chamber after the extruder is less than about 10 feet long, or less than about 8 feet long, or less than about 5 feet long, or less than about 3 feet long.

[0257] In one non-limiting example, the Shore D hardness of solid FEP plaques was measured as described below. Injection-molded plaques of solid FEP polymer were used throughout this example. The plaques were 61 mm long, 61 mm wide, and 2 mm high. The Shore D hardness of the solid FEP plaques was measured at an ambient temperature of approximately 20° C. The plaques were then exposed to liquid nitrogen for different lengths of time by submerging them in a pool of liquid nitrogen. The Shore D hardness of the plaques was measured after the different exposure times. The data is shown in FIG.

[0258] As can be seen in Figure 21, the Shore D hardness of the FEP plaque increases from about 60 to about 83 after about 10 seconds of exposure to liquid nitrogen. After about 10 seconds of exposure to liquid nitrogen, the FEP plaque reached a maximum hardness of about 83. Continuing exposure to liquid nitrogen beyond 10 seconds did not cause the hardness of the FEP plaque to continue to increase.

[0259] In the examples that follow, the Shore D hardness of solid FEP plaques was measured upon returning to ambient temperature after exposure to liquid nitrogen for a set period of time. The plaques were immersed in liquid nitrogen for either 6, 10, or 30 seconds and then removed from the liquid nitrogen. For each of the three tests, the Shore D hardness of the plaques was measured at set intervals until the plaques returned to ambient temperature.

[0260] Figure 22 shows the Shore D hardness of the plaques as they return to ambient temperature after immersion in liquid nitrogen for 6, 10, or 30 seconds. As shown in Figure 22, there is relatively little difference in hardness over time between the samples exposed to liquid nitrogen for 10 seconds and those exposed to liquid nitrogen for 30 seconds. This correlates with the data shown in Figure 21, which suggests that the FEP plaques reached maximum hardness after approximately 10 seconds of exposure to liquid nitrogen. The plaques exposed to liquid nitrogen for 6 seconds likely reached a lower initial Shore D hardness of approximately 76, which decreased as the plaques were exposed to ambient conditions.

[0261] In subsequent examples, solid FEP plaques were immersed in liquid nitrogen for 10 seconds and then removed. The Shore D hardness and temperature (°C) of the plaques were measured as they returned to ambient temperature. Figures 23A-23C show this data over different time periods.

[0262] Figure 23A shows the Shore D hardness decrease and temperature increase of a solid FEP plaque over approximately 390 seconds. Figure 23B shows the Shore D hardness decrease and temperature increase of a solid FEP plaque over approximately 180 seconds. Figure 23C shows the Shore D hardness decrease and temperature increase of a solid FEP plaque over approximately 30 seconds. Note that in Figures 23A-C, the temperature data below -60°C is a prediction, not a direct measurement.

[0263] In another non-limiting example, the Shore D hardness of foamed FEP was measured. To create a foamed FEP sample, an FEP foam-insulated wire was tightly wrapped around a plaque of solid FEP. The Shore D hardness of the foamed FEP wire was measured at an ambient temperature of about 20°C. The FEP foam-insulated wire was then exposed to liquid nitrogen for different lengths of time by submerging it in a pool of liquid nitrogen. The Shore D hardness of the foamed FEP was measured after the different exposure times. The data is shown in Figure 24.

[0264] As shown in Figure 24, the Shore D hardness of FEP foam is about 29 at ambient temperature and increases to about 63 after about 15 seconds of exposure to liquid nitrogen. Once the foam FEP reaches a Shore D hardness of about 63, the Shore D hardness plateaus and does not increase significantly after additional exposure times to liquid nitrogen.

[0265] Figure 25 shows the Shore D hardness of an FEP foam insulated wire after a 10-second immersion in liquid nitrogen and upon returning to ambient temperature. As the foam FEP is exposed to ambient temperature for longer periods of time, the Shore D hardness decreases until it reaches a Shore D hardness of approximately 29 at ambient temperature.

[0266] In the following examples, foam FEP insulated wires were immersed in liquid nitrogen for 10 seconds and then removed. The Shore D hardness and temperature of the foam FEP insulated wires were measured as the foam FEP returned to ambient temperature. Figure 26 shows this data over a period of time.

[0267] Figure 26 shows the decrease in Shore D hardness and increase in temperature of a solid FEP plaque over a period of about 390 seconds. Note that no initial temperature data was collected below about -55°C.

[0268] Figure 27 shows the Shore D hardness for both solid and foam FEP as they are exposed to liquid nitrogen over time. As can be seen from Figure 27, the Shore D hardness of the solid FEP generally stops increasing after about 10 seconds. The Shore D hardness of the foam FEP generally stops increasing after about 15 seconds.

[0269] Figure 28 shows the Shore D hardness of both solid and foam FEP when exposed to liquid nitrogen for 10 seconds and then to ambient conditions. Notably, the Shore D hardness of the foam FEP decreased more slowly, taking over 3 minutes longer than the solid FEP to return to its Shore D hardness at ambient temperature.

[0270] Figure 29 shows the temperatures of solid and foam FEP when exposed to liquid nitrogen for 10 seconds and then to ambient conditions. The temperature of the foam FEP rose more slowly and took over 10 minutes longer than the solid FEP to return to ambient temperature.

[0271] Without being bound by theory, it is believed that the air pockets within foam FEP change temperature more slowly than solid FEP. Therefore, foam FEP insulation takes longer to reach its minimum temperature and associated increased hardness when exposed to liquid nitrogen. After being removed from the liquid nitrogen, foam FEP also takes longer to return to ambient temperature and associated hardness.

[0272] While the above examples are described in terms of solid and foam FEP, it will be understood that similar data can be easily collected for any form and polymer type. Understanding the rate at which the polymer hardness returns to ambient hardness allows the hardness of a polymer cable component when subjected to a compression event to be controlled by adjusting the amount of time the polymer component is exposed to ambient temperature after exiting the cooling vessel. In some embodiments, the distance between the cooling vessels and / or the linear speed of the production line can be adjusted to reach the desired hardness of the polymer cable component at the time of compression or deformation.

[0273] It will also be appreciated that the amount of cooling time (e.g., exposure time to cryogenic fluid or other cooling medium) can alternatively or additionally be adjusted to reach a desired hardness of the polymer cable component upon being subjected to a compressive or other deforming force.

[0274] In some embodiments, the methods described herein for increasing hardness result in an increase in Shore D hardness of the polymeric cable component of at least about 10% compared to a similar component at ambient temperature before the polymeric cable component is subjected to a compressive force or at the time the polymeric cable component is subjected to a compressive force.

[0275] In some embodiments, the hardness increasing methods described herein result in at least about a 10% increase in Shore D hardness of the polymer cable component relative to a similar component made of the same polymer at 20° C. In some embodiments, the hardness increasing methods described herein result in at least about a 10% increase in Shore D hardness of the polymer cable component relative to a similar component at 20° C. and reduce the deformation caused by a compression event by at least about 0.0005 inches.

[0276] In some embodiments, a cooling chamber less than about 10 feet in length is used to produce at least about a 10% increase in Shore D hardness relative to a similar component at ambient temperature.

[0277] In all cases, it will be understood that a 10% increase in Shore D hardness can be converted to other hardness tests such as Britnell, Meyer, Vickers, Rockwell, and other Shore durometer scales, e.g., Shore A.

[0278] For reference, the Shore D durometer test is described in ASTM D2240 and ISO 868. Hardness values ​​are determined by penetrating the specimen with the tip of a durometer indenter. Shore hardness measurements are dimensionless and range between 0 and 100. The higher the Shore hardness number, the harder the material is and the more resistant it is to deformation. In some embodiments, the disclosed methods for increasing hardness are most advantageous for substrates exhibiting a Shore hardness between 40 and 80.

[0279] The methods, systems, and embodiments described herein generally relate to tailoring the stress / strain response and / or hardness of polymeric components. Polymers contemplated herein include, but are not limited to, thermoplastics, thermosets, rubbers, and / or elastomers, each of which may be foams or solids and may contain various additives and / or flame retardants. Specific polymers contemplated include linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polyethylene-PE, perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), tetrafluoroethylene perfluoromethyl vinyl ether (MFA), polyphenylene sulfide (PPS), polyetherketone (PEEK), polyetherketone (PEK), polyethyleneimine (PEI), fluorinated ethylene propylene (FEP), ethylene propylene tetrafluoroethylene (ETFE), and ethylene propylene tetrafluoroethylene (ETFE). Examples of suitable materials include, but are not limited to, polyethylene-ETFE, ethylene fluoroethylene propylene-EFEP, polypropylene-PP, nylon-PA, polyvinyl chloride-PVC, polycarbonate-PC, acrylonitrile butadiene styrene-ABS, polystyrene-PS, polyesters such as polyethylene terephthalate (PET), polyimide-PI, polyamide, polyimide, polyamideimide-PAI, natural rubber, synthetic rubber, fluoroelastomer-FKM, silicones (such as dimethylpolysiloxane), PVdF, PEBA, foams thereof, blends thereof, and alloys thereof.

[0280] The conductivity of an electrical wire is measured using one or more characteristics of the wire, such as impedance. As discussed above, the impedance of a twisted pair of insulated conductor wires depends on the hardness or softness of the polymer insulation. For example, the impedance of a twisted pair of insulated conductor wires increases with increasing hardness of the polymer insulation. The harder the polymer insulation layer, the greater the amount of air that will be trapped within the gaps of the twisted pair.

[0281] In another embodiment, foamed polymer insulation may be used to insulate the conductive wires of the twisted pairs. Foaming the polymer may be achieved by techniques such as, but not limited to, extrusion, compression molding, injection molding, reaction injection molding, solid-state methods, or adding a foaming agent to a molten polymer, where the foaming agent decomposes to release a gas, and the polymer is then foamed by pressing and heating. Foaming introduces air pockets or gaps into the polymer insulation at the time it insulates the conductive wires. The air pockets or gaps contribute to increasing the effectiveness of the insulation layer for a given thickness. Because foamed insulation provides better electrical insulation than solid insulation, thinner layers of insulation may be used.

[0282] A twisted pair of insulated conductors may be created by twisting two insulated conductors together to intertwine them in a helical configuration. Other means for twisting insulated conductors, such as SZ twisting, in which the twist direction of the pairs changes, such as from left to right, may be available. A twisted pair of insulated conductors, or twisted pair, includes two individual insulated conductors twisted together at a level of looseness or tightness desired for the purpose for which they are used. For example, some twisted pairs may be used for higher-speed data communications than others. When the individual insulated conductors are twisted together, the polymer insulation on each insulated conductor is pressed against the polymer insulation on the other insulated conductor to a certain level of tightness. The pressure resulting from this twisting action results in deformation of the polymer insulation layer, known as collapse. The greater the degree of deformation or collapse, the shorter the distance between the conductors. This causes a reduction in impedance between the twisted pair. The goal is to control the amount of collapse of the polymer insulation.

[0283] The crushing of the polymer insulation that occurs when the individual insulated conductors are twisted together is proportional to the level of hardness of the polymer insulation. The crushing or deformation is higher when the polymer insulation is softer. The polymer insulation becomes softer when heat is applied to it. As discussed above, the impedance of the twisted pair is determined by the level of hardness of the polymer insulation during crushing.

[0284] In another embodiment, several twisted pairs may be used to form a single cable. In a cable, each twisted pair may have a different delay, or the time it takes for an electrical signal to travel a given length of the twisted pair. Delay is typically measured in nanoseconds per 100 meters. The difference in delay for multiple twisted pairs in a cable is the delay skew. To minimize delay skew, the delay per 100 meters for each twisted pair in the cable must be similar. A delay skew of less than 50 ns or less than 25 ns is preferred. For twisted pairs with tighter twists, the total distance an electrical signal must travel is longer than for twisted pairs with looser twists. This is because the individual insulated conductors that make up a twisted pair with a tighter twist must be longer than the individual insulated conductors that make up a twisted pair with a looser twist. Therefore, it is desirable to have faster signal transmission in twisted pairs with tighter twists compared to twisted pairs with looser twists. One method for achieving the desired differential delay of the twisted pairs in the cable is by precise control of the temperature of the polymer insulation during twisting.

[0285] A twisting device or twisting unit may be used in twisting insulated conductors into twisted pairs. The twisting of individual insulated conductors is typically done at high speed using a twisting device having a bow. The bow is a curved device into which the individual conductors can be fed. The bow is set to rotate or spin at high speed so that the bow receives the individual conductors and performs a twisting action on them, thus creating twisted pairs of insulated conductors.

[0286] In another embodiment, adjusting the temperature of the polymer insulation may also be achieved by shielding the polymer components of the insulated wire from convective heat transfer in addition to or as an alternative to adjusting the temperature of the fluid surrounding the bow or immersing the polymer components in a cryogenic or chilled fluid.

[0287] In some embodiments, the spinning bow may be used at standard atmospheric conditions, i.e., the air surrounding the bow is not temperature-controlled. If the fluid is warmer than the polymer components, convective heat transfer from the fluid may soften the polymer insulation, leading to increased deformation or collapse. If the fluid is cooler than the polymer components, convective heat transfer to the fluid may harden the polymer insulation, leading to decreased deformation or collapse. In some embodiments, the spinning bow may be used in a temperature-controlled atmosphere, where the temperature may be warmer or colder than ambient conditions. For example, the air in the entanglement unit may be cooled by a refrigeration unit. In some embodiments, the atmosphere in the entanglement unit may be cold nitrogen vapor or another vapor at a cooler temperature than ambient.

[0288] In some embodiments, the bow may include means for shielding the insulated wire from convective heat transfer with the fluid as the bow rotates or spins. In other embodiments, the rotating or spinning bow may be shielded from convective heat transfer from the surrounding fluid by shielding the insulated wire in a longitudinal tube sized to contain the insulated wire. The longitudinal tube may be made of any suitable material, such as a polymeric insulating material, which in turn reduces the amount of heat transferred to the insulated conductor.

[0289] In some embodiments, the spinning bow may be protected from convective heat transfer from the surrounding fluid by shielding the insulated wire in longitudinal grooves on the bow designed to contain the insulated wire. In other embodiments, the rotating or spinning bow may employ a means to shield the insulated conductors from convective heat transfer from the surrounding fluid by the use of a wind guide on the windward side of the bow.

[0290] In other embodiments, the rotating or spinning bow may use means for protecting the insulated conductors from convective heat transfer from the fluid, including one or more adjustable vents as described above.

[0291] Also described herein are methods for producing twisted pairs of insulated conductors having a predetermined impedance. Such methods may include feeding two individual insulated conductors to a rotating or spinning bow that is part of a entanglement device in the presence of a fluid. Convective heat transfer from the fluid to the insulated conductors is then controlled to control their temperature, thereby achieving a specific level of hardness. The insulated conductors are then twisted together using the bow to form a twisted pair, where the insulated conductors undergo an amount of deformation during twisting based on the level of hardness of the polymer insulation for a given set of entanglement device parameters. Also described are methods for producing twisted pairs of insulated conductors having an impedance within a predetermined tolerance range. One method includes feeding a pair of insulated conductors to a rotating bow in the presence of a fluid, controlling convective heat transfer from the fluid to the insulated conductors, and twisting them together to form the twisted pair. Once the twisted pair is fabricated, the method includes measuring the impedance of the twisted pair and, if necessary, adjusting the amount of convective heat transfer from the fluid to the insulated conductor based on the measured impedance of the twisted pair compared to a predetermined tolerance. [Example]

[0292] In the examples, multiple twisted pairs were made using FEP insulated conductors. For all trials, the copper conductor diameter was approximately 0.0216 inches and the FEP insulated conductor outer diameter was approximately 0.0419". The twist length for all twisted pairs in this example was 6.20 mm / twist. Samples were twisted at approximately 2750 twists per minute (TPM) with an 18% back twist. A control trial was run without any temperature or hardness manipulation. An unprotected bow was used to twist the control single wires at ambient temperature. For the remaining trials, the insulated single wires were exposed to liquid nitrogen before being twisted together. Each sample was twisted using a modified bow that was 0%, 25%, 50%, 75%, or 100% protected from convective heat transfer as shown in Figures 45A-E. In this embodiment, the bow was protected by a single continuous section rather than separated sections. The bow could be in a single continuous section or by a series of separate sections such as that shown in Figure 35. It will be appreciated that multiple separate sections may be used to provide the same percentage of protection. Bow embodiments with a single protected section may include a protected section covering the most upstream entrance to the bow, the most downstream exit from the bow, or any intermediate portion of the bow. Each such device may have a different effect on the degree of convective heat transfer between the twisted pairs in the bow and the atmosphere of the entanglement device, allowing for greater control over the degree of heat transfer. In this example, two twisted pair samples were made for each trial. The impedance of each twisted pair was measured for each sample. As shown in the data below, the impedance increases as the degree of bow protection increases. Additionally, twisted pairs exposed to liquid nitrogen and entangled using a 0% protected bow had a higher impedance than control samples made without any temperature or hardness adjustment.

[0293] [Table 8]

[0294] The above data (shown in Figure 46) indicates that impedance can be adjusted by controlling the degree to which the bow is shielded from convective heat transfer during the intertwining process.

[0295] In another example, multiple twisted pairs were made using FEP insulated conductors. For all trials, the copper conductor diameter was approximately 0.0216 inches and the FEP insulated conductor outer diameter was approximately 0.0419". The twist length for all twisted pairs in this example was 6.20 mm / twist. Samples were twisted at approximately 2750 twists per minute (TPM) with an 18% back twist. A control trial was run without any temperature or hardness manipulation. An unprotected bow was used to twist the control single wires at ambient temperature. The remaining trials were exposed to liquid nitrogen before being twisted together. Each sample was twisted using a modified bow that was 0%, 25%, 50%, 75%, or 100% protected from convective heat transfer. Two twisted pair samples were made for each trial. The delay (time for an electrical signal to travel 100 meters) was measured for each twisted pair. As shown in the data below (and in Figure 47), delay increases as the degree of bow protection increases.

[0296] [Table 9]

[0297] Disclosed embodiments include a method of reducing the effect of compressive forces on a polymer cable component, the method comprising: providing a polymer cable component having a first hardness, the first hardness being the hardness of the polymer cable component under ambient conditions; temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymer cable component; and allowing the polymer cable component to return to the first hardness. In some embodiments, the polymer cable component is exposed to the compressive force while the polymer cable component has the second hardness. In some embodiments, the compressive force causes less deformation in the polymer cable component at the second hardness than in the polymer cable component at the first hardness. In some embodiments, the second hardness is greater than the first hardness. In some embodiments, temporarily changing the hardness of the polymer cable component comprises cooling the polymer cable component. In some embodiments, cooling the polymer cable component comprises exposing the polymer cable component to a chilled fluid. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a chilled solid surface. In some embodiments, the chilled solid surface rotates. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a cryogenic fluid. In some embodiments, the polymer cable component is exposed to the cryogenic liquid for about 10 seconds or less. In some embodiments, the polymer cable component is exposed to the cryogenic liquid for between 6 and 10 seconds. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a chilled gas. In some embodiments, the chilled gas is between 15°C and -10°C. In some embodiments, the polymer cable component includes an exterior surface, an interior bulk, and an interior surface, and cooling the polymer cable component includes cooling the exterior surface of the polymer cable component.In some embodiments, the polymer cable component is a polymer insulation surrounding the conductor. In some embodiments, the polymer cable component is a fluoropolymer insulation surrounding the conductor. In some embodiments, the polymer cable component is not cooled for 10 seconds or less before being subjected to the compressive force. Some embodiments further include stopping cooling of the polymer cable component for 5 seconds or less before being subjected to the compressive force.

[0298] Additional disclosed embodiments include a method of manufacturing a communications cable, comprising: providing a polymeric cable component having a first cross-sectional radius and a second cross-sectional radius, wherein the first cross-sectional radius is the maximum distance from the center of the polymeric cable component to an end of the polymeric cable component along the cross section, and the second cross-sectional radius is the minimum distance from the center of the polymeric cable component to the end of the polymeric cable component along the cross section, the first cross-sectional radius being approximately equal to the second cross-sectional radius + / - 3%; the polymeric cable component having a first hardness, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being greater than the first hardness; and applying a compressive force to the polymeric cable component, wherein after the compressive force, the first cross-sectional radius is approximately equal to the second cross-sectional radius + / - 10%. In some embodiments, the compressive force causes less deformation in the polymeric cable component at the second hardness than in the polymeric cable component at the first hardness. In some embodiments, temporarily altering the hardness of the polymer cable component comprises cooling the polymer cable component. In some embodiments, cooling the polymer cable component comprises exposing the polymer cable component to a chilled fluid. In some embodiments, cooling the polymer cable component comprises exposing the polymer cable component to a cryogenic fluid. In some embodiments, cooling the polymer cable component comprises exposing the polymer cable component to a chilled gas. In some embodiments, the polymer cable component is allowed to cool for 10 seconds or less before the compressive force is applied. Some embodiments further comprise stopping cooling of the polymer cable component for 5 seconds or less before the polymer cable component is exposed to the compressive force. In some embodiments, the polymer cable component is a polymer insulation surrounding a conductor. In some embodiments, the polymer cable component is a fluoropolymer insulation surrounding a conductor.Additional disclosed embodiments include a method of manufacturing a communications cable, comprising: providing a polymeric cable component having a first diameter and a second diameter, the first diameter and the second diameter being perpendicular to one another, the first diameter approximately equal to the second diameter + / - 3%, the polymeric cable component having a first hardness, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness greater than the first hardness; applying a compressive force to the polymeric cable component, wherein after the compressive force, the first diameter approximately equals the second diameter + / - 10%; and allowing the polymeric cable component to return to the first hardness. In some embodiments, the polymeric cable component is subjected to the compressive force while the polymeric cable component is at the second hardness. In some embodiments, a compressive force causes less deformation in a polymer cable component at a second hardness than in a polymer cable component at a first hardness. In some embodiments, the second hardness is greater than the first hardness. In some embodiments, temporarily altering the hardness of the polymer cable component includes cooling the polymer cable component. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a chilled solid surface. In some embodiments, the chilled solid surface rotates. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a cryogenic fluid. In some embodiments, cooling the polymer cable component includes exposing the polymer cable component to a chilled gas. In some embodiments, the chilled gas is between 15°C and -10°C and can include various alternatives to the cryogenic fluid, such as an inert gas (e.g., helium, N2, argon, krypton, radon, neon, xenon, and combinations thereof).In some embodiments, the fluid in the entanglement device or cooling chamber can include chilled air generated by an air conditioning or refrigeration device, a fluorocarbon solution, a brine solution, a gas obtained by vaporizing a solid object or liquid having a vaporization temperature of 0° C. or lower (e.g., dry ice or liquid nitrogen), a liquid having a freezing point of 0° C. or lower, chilled acetone, and combinations thereof.

[0299] An additional disclosed embodiment is a method of manufacturing a communications cable, comprising the steps of: providing first, second, third, and fourth pairs of polymer-insulated conductors, each pair of polymer-insulated conductors including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors under ambient conditions; temporarily changing the hardness of the polymer-insulated conductors in the first, second, and third pairs of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; twisting the polymer-insulated conductors of the first pair together to form a first twisted pair, the first twisted pair having a first propagation delay over 100 meters; and twisting the polymer-insulated conductors of the second pair together. The method includes twisting together a first pair of polymer-insulated conductors to form a second twisted pair, the second twisted pair having a second propagation delay over 100 meters; twisting together a third pair of polymer-insulated conductors to form a third twisted pair, the third twisted pair having a third propagation delay over 100 meters; and twisting together a fourth pair of polymer-insulated conductors to form a fourth twisted pair, the fourth twisted pair having a fourth propagation delay over 100 meters, wherein the first, second, third, and fourth propagation delays over 100 meters have a difference in propagation delay time of less than about 25 nanoseconds. In some embodiments, temporarily altering the hardness of the polymer-insulated conductors includes cooling the polymer-insulated conductors. In some embodiments, temporarily modifying the hardness of the polymer-insulated conductors in the first, second, third, and fourth pairs of polymer-insulated conductors includes cooling the polymer-insulated conductors in the first, second, third, and fourth pairs for first, second, third, and fourth periods, respectively. In some embodiments, the first period is longer than the second period, and the second period is longer than the third period. In some embodiments, the first period is between about 8-10 seconds, the second period is between about 6-8 seconds, and the third period is between about 4-6 seconds.In some embodiments, the first, second, third, and fourth twisted pairs have first, second, third, and fourth twist lengths, respectively, where the first twist length is shorter than the second twist length and the second twist length is shorter than the third twist length. In some embodiments, the first, second, third, and fourth twisted pairs have first, second, third, and fourth twist lengths, respectively, where the first twist length is shorter than the second twist length and the second twist length is shorter than the third twist length, the first time is longer than the second time, and the second time is longer than the third time. In some embodiments, the polymer-insulated conductors of the first, second, third, and fourth twisted pairs have first, second, third, and fourth crush ratios, respectively. In some embodiments, the first crush ratio is less than the second crush ratio and the second crush ratio is less than the third crush ratio. In some embodiments, the first, second, third, and fourth twisted pairs have first, second, third, and fourth signaling rates, respectively. In some embodiments, the first signaling rate is greater than the second signaling rate, which is greater than the third signaling rate. In some embodiments, the first, second, third, and fourth pairs of polymer-insulated conductors each have a different second hardness. In some embodiments, the second hardness of the polymer-insulated conductors of the first pair is greater than the second hardness of the polymer-insulated conductors of the second pair, which is greater than the second hardness of the polymer-insulated conductors of the third pair.An additional embodiment is a method of manufacturing a communications cable, comprising the steps of providing a first pair of polymer-insulated conductors and a second pair of polymer-insulated conductors, each pair of polymer-insulated conductors including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors under ambient conditions; temporarily changing the hardness of the polymer-insulated conductors in the first pair of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; and 1. A method for connecting a first pair of polymer-insulated conductors to a second pair of polymer-insulated conductors, the first pair having a first propagation delay over 100 meters, and the second pair having a second propagation delay over 100 meters, the first propagation delay over 100 meters and the second propagation delay over 100 meters being within 25 nanoseconds of each other. 2. The method for connecting a first pair of polymer-insulated conductors to a second pair of polymer-insulated conductors, the first pair having a first propagation delay over 100 meters and the second propagation delay over 100 meters being within 25 nanoseconds of each other.

[0300] Some disclosed embodiments relate to a system for manufacturing wire and cable products, the system including: a payout device configured to payout a polymer cable component; a cooling vessel configured to receive the polymer cable component, the cooling vessel containing a chilled fluid; and a winding device configured to wind the polymer cable component. In some embodiments, the cooling vessel contains liquid nitrogen. Some embodiments further include a secondary structure configured to receive the polymer cable component, the interior of the secondary structure being in fluid communication with the interior of a cooling chamber. In some embodiments, the cooling vessel contains liquid nitrogen, and nitrogen vapor migrates from the interior of the cooling vessel to the interior of the secondary structure. In some embodiments, the secondary structure is a hollow tube. In some embodiments, the atmosphere within the cooling vessel is below ambient temperature. In some embodiments, the cooling vessel is thermally insulated. Some embodiments further include refrigeration equipment, the refrigeration equipment configured to supply chilled air to the cooling vessel. In some embodiments, the polymer cable component is a polymer-insulated conductor, and the system further includes a entanglement device configured to receive a first polymer-insulated conductor and a second polymer-insulated conductor to form a twisted pair. In some embodiments, the atmosphere within the entanglement device is below ambient temperature. Some embodiments further include a secondary structure configured to receive the polymer cable component, wherein an interior of the secondary structure is in fluid communication with an interior of the cooling chamber, and wherein the secondary structure is in fluid communication with an interior of the entanglement device. Additional embodiments relate to a system for manufacturing wire and cable products, the system including a payout device configured to pay out the polymer cable component and a take-up device configured to take up the polymer cable component. Some embodiments further include a plurality of chilled rollers.

[0301] Still more disclosed embodiments include a method for manufacturing a low fuel load wire and cable product, the method comprising establishing desired electrical properties of the wire and cable product, the wire and cable product including a polymer cable component, the polymer cable component having a first fuel load and a first hardness, and a polymer cable component conforming to ASTM the polymeric cable component has a flame travel distance of about 5 feet or less, a peak smoke optical density of about 0.5 or less, and an average optical density of about 0.15 or less when measured according to the Steiner Tunnel Test Method of E84, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being greater than the first hardness; applying a compressive force to the polymeric cable component while the polymeric cable component is at the second hardness, thereby causing a first amount of deformation in the polymeric cable component; and forming a wire and cable product using the polymeric cable component, wherein the wire and cable product meets established desired electrical properties when the polymeric cable component is deformed by the first amount of deformation but may not meet the desired electrical properties when the polymeric cable component is deformed by the second amount of deformation, the second amount of deformation being the amount the polymeric cable component deforms when exposed to the compressive force when the polymeric cable component is at the first hardness. In some embodiments, the polymeric cable component is a polymeric insulation layer around the conductive wires. In some embodiments, the wire and cable product is a twisted pair. In some embodiments, the wire and cable product produces a flame travel distance of less than 4 feet when measured using the Steiner Tunnel Test Method of ASTM E84. In some embodiments, the wire and cable product produces a peak smoke optical density of less than 0.4 when measured using the Steiner Tunnel Test Method of ASTM E84. In some embodiments, the wire and cable product produces an average optical density of less than 0.15 when measured using the Steiner Tunnel Test Method of ASTM E84. In some embodiments, the desired electrical property of the wire and cable product is a capacitance value of less than about 20 pf / ft.In some embodiments, the desired electrical property of the wire and cable product is an impedance value between about 75 ohms and 125 ohms. In some embodiments, the desired electrical property of the wire and cable product is a velocity of propagation between about 62% and 80%.

[0302] Additional disclosed embodiments relate to a method for forming twisted pairs, the method comprising: operating a cable entanglement device at a first speed to produce a first twisted pair of a first collapse ratio; providing a first polymer-insulated conductor comprising a first conductor electrically insulated by a first layer of polymer insulation; providing a second polymer-insulated conductor comprising a second conductor electrically insulated by a second layer of polymer insulation; exposing at least the first polymer-insulated conductor to a cryogenic fluid; and operating the cable entanglement device at a second speed to produce a second twisted pair of a second collapse ratio, the second twisted pair comprising the first and second polymer-insulated conductors, the second speed being faster than the first speed. In some embodiments, the second collapse ratio is within 10% of the first collapse ratio. In some embodiments, the second collapse ratio is less than the first collapse ratio. In some embodiments, the second speed is at least 15% faster than the first speed. In some embodiments, the second speed is at least 25% faster than the first speed. In some embodiments, the first speed is the rated speed of a cable entanglement device for wire and cable products, and the second speed is at least 10% faster than the first speed. In some embodiments, the second speed is at least 10% faster than the first speed, and the second crush rate is less than the first crush rate. In some embodiments, the first speed is at least 60 feet / minute and the second speed is at least 70 feet / minute. In some embodiments, the first speed is at least 160 feet / minute and the second speed is at least 180 feet / minute. In some embodiments, the first speed is at least 220 feet / minute and the second speed is at least 275 feet / minute. In some embodiments, the cryogenic fluid is liquid nitrogen.

[0303] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. It will be understood that any given element of the disclosed embodiments of the present invention may be embodied in a single structure, a single step, a single material, etc. Likewise, a given element of the disclosed embodiments may be embodied in multiple structures, steps, materials, etc.

[0304] The foregoing description and accompanying drawings illustrate and describe certain processes, machines, manufactures, and compositions of matter, some of which embody the present invention. Such descriptions or illustrations are not intended to limit the scope of what may be claimed, but are provided as an aid in understanding the claims, enabling the making and use of the claimed items, and teaching the best mode of use of the invention. If this description and accompanying drawings are construed as disclosing only certain embodiment or embodiments, they should not be construed as limiting what may be claimed to the embodiment or embodiments. Any example or embodiment of the invention described herein is not intended to indicate that what is claimed must be of the same scope as such example or embodiment. If the invention or an embodiment thereof is stated to achieve one or more objectives, it is not intended to limit what may be claimed to adaptations capable of achieving all such objectives. Any statements in this description criticizing the prior art are not intended to limit what is claimed to exclude any aspect of the prior art.

[0305] Additionally, while this disclosure illustrates and describes certain particular embodiments of the disclosed processes, machines, manufacture, compositions of matter, and other teachings, it should be understood that the teachings of this disclosure are capable of use in various other combinations, modifications, and environments, and are capable of changes or modifications within the scope of the teachings as expressed herein.

[0306] Any section headings herein are provided solely for consistency with the proposed U.S. Patent No. 1,597,111, and to otherwise provide organizational cues. These headings in no way limit or characterize the invention described herein.

Claims

1. 1. A method for producing a twisted pair of insulated wires having improved crush resistance, the method comprising: cooling a first insulated wire to increase a hardness of the first insulated wire; cooling a second insulated wire to increase a hardness of the second insulated wire; feeding the first insulated wire and the second insulated wire to a bow of an entangler unit in the presence of a fluid; and at least partially shielding the insulated wires from convective heat transfer from the fluid as the bow rotates.

2. 1. A method for producing a twisted pair of insulated wires having a predetermined impedance, comprising: a) feeding a first insulated wire and a second insulated wire to a rotating bow that is part of an entanglement device in the presence of a fluid, the first insulated wire including a first conductor surrounded by a first insulation, and the second insulated wire including a second conductor surrounded by a second insulation; b) controlling convective heat transfer from a fluid through the first insulated wire and the second insulated wire to control the temperature of the first insulator and the second insulator to impart hardness to the first insulator and the second insulator; c. twisting a first insulated wire with a second insulated wire to form a twisted pair, the first insulated wire and the second insulated wire undergo an amount of deformation during twisting that is a function of their hardness, and the impedance of the twisted pair is a function of the degree of deformation; A method comprising:

3. 1. A method for producing a twisted pair of insulated wires having an impedance within a predetermined tolerance, comprising: a) feeding a first insulated wire and a second insulated wire to a rotating bow that is part of an entanglement device in the presence of a fluid, the first insulated wire including a first conductor surrounded by a first insulation, and the second insulated wire including a second conductor surrounded by a second insulation; b. controlling convective heat transfer from a fluid to the first insulated wire and the second insulated wire; c. twisting a first insulated wire with a second insulated wire to form a twisted pair, the first insulated wire and the second insulated wire undergoing deformation during twisting; d. Measuring the impedance of the twisted pair; e. adjusting convective heat transfer from the fluid to the first insulated wire and the second insulated wire if the impedance of the twisted pair is outside a predetermined tolerance; A method comprising:

4. The fluid is air, N ２ , CO ２ 4. The method of claim 1, wherein the gas is selected from the group consisting of argon, helium, neon, krypton, xenon, and radon.

5. 10. A twisted pair of insulated electrical wire having improved resistance to deformation, the product of the process of claim 1.

6. 3. A twisted pair of insulated wires having a predetermined impedance, the product of the process of claim 2.

7. 4. A twisted pair of insulated wires having impedance within a predetermined tolerance, the product of the process of claim 3.

8. 8. A twisted pair according to any one of claims 5 to 7, having an impedance of at least 101.8 ohms.

9. 8. A twisted pair according to any one of claims 5 to 7, having an impedance of at least 102 Ω.

10. 8. A twisted pair according to any one of claims 5 to 7, having an impedance of at least 103 Ω.

11. 8. A twisted pair according to any one of claims 5 to 7, having a delay of at least 491.5ns / 100ft.

12. 8. A twisted pair according to any one of claims 5 to 7, having a delay of at least 492ns / 100ft.

13. A cable comprising a twisted pair according to any one of claims 5 to 12.

14. 1. A method for reducing the effect of compressive forces on a polymeric cable component, the method comprising: providing a polymeric cable component having a first hardness, the first hardness being the hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymeric cable component to a second hardness, the second hardness being different from the first hardness; applying a compressive force to the polymeric cable component at a bow of an entanglement unit, the polymeric cable component being at least partially protected from convective heat transfer at the bow; and returning the polymeric cable component to the first hardness.

15. 1. A method for reducing the effects of compressive forces on a polymer cable component, comprising: a. providing a polymeric cable component having a first hardness, the first hardness being a hardness of the polymeric cable component under ambient conditions; temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being different from the first hardness; b. applying a compressive force to the polymeric cable component at a bow of the entanglement unit, the polymeric cable component being at least partially protected from convective heat transfer at the bow; c. returning the polymer cable component to a first hardness; A method comprising:

16. 1. A method of manufacturing a communications cable, comprising: providing a polymer cable component having a first cross-sectional radius and a second cross-sectional radius, the first cross-sectional radius being a maximum distance from a center of the polymer cable component to an end of the polymer cable component along the cross section, the second cross-sectional radius being a minimum distance from a center of the polymer cable component to an end of the polymer cable component along the cross section, the first cross-sectional radius being approximately equal to ±3% of the second cross-sectional radius, the polymer cable component having a first hardness, the first hardness being a hardness of the polymer cable component under ambient conditions; b. temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being greater than the first hardness; c. applying a compressive force to the polymeric cable component at a bow of the entanglement unit, the polymeric cable component being at least partially shielded from convective heat transfer at the bow, and wherein after the compressive force, the first cross-sectional radius is approximately equal to ±10% of the second cross-sectional radius; A method comprising:

17. 1. A method of manufacturing a communications cable, comprising: a. providing a polymeric cable component having a first diameter and a second diameter, the first diameter and the second diameter being perpendicular to one another, the first diameter being approximately equal to the second diameter ±3%, the polymeric cable component having a first hardness, the first hardness being a hardness of the polymeric cable component under ambient conditions; b. temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being greater than the first hardness; c. applying a compressive force to the polymeric cable component at a bow of the entanglement unit, the polymeric cable component being at least partially shielded from convective heat transfer at the bow, and wherein after the compressive force, the first diameter is approximately equal to the second diameter plus or minus 10%; d. Returning the polymer cable component to the first hardness; A method comprising:

18. 1. A method of manufacturing a communications cable, comprising: a. providing first, second, third, and fourth pairs of polymer-insulated conductors, each pair of polymer-insulated conductors including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors at ambient conditions; b. temporarily changing the hardness of the polymer-insulated conductors in the first, second, third, and fourth pairs of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; c. twisting a first pair of polymer insulated conductors together to form a first twisted pair, the first twisted pair having a first propagation delay over 100 meters; d. twisting a second pair of polymer insulated conductors together to form a second twisted pair, the second twisted pair having a second propagation delay over 100 meters; e. twisting a third pair of polymer insulated conductors together to form a third twisted pair, the third twisted pair having a third propagation delay over 100 meters; f. twisting a fourth pair of polymer insulated conductors together to form a fourth twisted pair, the fourth twisted pair having a fourth propagation delay over 100 meters, wherein the first, second, third, and fourth propagation delays over 100 meters differ in propagation delay over 100 meters within 50 nanoseconds of each other; the step of twisting the polymer-insulated conductors of at least one of the first, second, third, and fourth pairs includes the step of supplying the polymer-insulated conductors to a bow of a twisting unit, the polymer-insulated conductors being at least partially shielded from convective heat transfer at the bow; method.

19. 1. A method of manufacturing a communications cable, comprising: a. providing a first pair of polymer-insulated conductors and a second pair of polymer-insulated conductors, each pair of polymer-insulated conductors including two polymer-insulated conductors, each polymer-insulated conductor having a first hardness, the first hardness being a hardness of the polymer-insulated conductors at ambient conditions; b. temporarily changing the hardness of the polymer-insulated conductors in the first pair of polymer-insulated conductors to a second hardness, the second hardness being different from the first hardness; c. twisting a first pair of polymer-insulated conductors together at a bow of the interlacing unit to form a first twisted pair, the polymer-insulated conductors being at least partially shielded from convective heat transfer at the bow, the first twisted pair having a first propagation delay over 100 meters; d. twisting a second pair of polymer-insulated conductors together to form a second twisted pair, the second twisted pair having a second propagation delay over 100 meters, wherein the first propagation delay over 100 meters and the second propagation delay over 100 meters are within 25 nanoseconds of each other; method.

20. 1. A system for manufacturing wire and cable products, the system including: a payout device configured to pay out a polymer cable component; a cooling vessel configured to receive the polymer cable component, the cooling vessel containing a chilled fluid; a winding device configured to wind the polymer cable component; and an entanglement device configured to receive a first polymer insulated conductor and a second polymer insulated conductor to form a twisted pair, the entanglement device including a bow in the fluid, the bow including means for protecting the insulated wires from convective heat transfer with the fluid as the bow rotates.

21. 1. A system for manufacturing wire and cable products, the system including: a payout device configured to pay out a polymer cable component; a cooling surface configured to contact the polymer cable component; a winding device configured to wind the polymer cable component; and an entanglement device configured to receive a first polymer insulated conductor and a second polymer insulated conductor to form a twisted pair, the entanglement device including a bow in a fluid, the bow including means for protecting the insulated wires from convective heat transfer with the fluid as the bow rotates.

22. 1. A method for manufacturing a low fuel load wire and cable product, comprising: a) establishing desired electrical properties of a wire and cable product, the wire and cable product comprising a polymeric cable component, the polymeric cable component having a first fuel load and a first hardness, the polymeric cable component having a flame travel distance of about 5 feet or less, a peak smoke optical density of about 0.5 or less, and an average optical density of about 0.15 or less, when measured according to the Steiner Tunnel Test Method of ASTM E84, wherein the first hardness is the hardness of the polymeric cable component under ambient conditions; b. temporarily changing the hardness of the polymer cable component to a second hardness, the second hardness being greater than the first hardness; c) applying a compressive force to the polymeric cable component at a bow of the entanglement unit while the polymeric cable component has a second hardness, thereby causing a first amount of deformation in the polymeric cable component, wherein the polymeric cable component is at least partially shielded from convective heat transfer at the bow; d. forming a wire and cable product using the polymeric cable component, wherein the wire and cable product meets established desired electrical properties when the polymeric cable component is deformed by a first deformation amount, but does not meet the desired electrical properties when the polymeric cable component is deformed by a second deformation amount, the second deformation amount being an amount that the polymeric cable component would deform when subjected to an applied compressive force if the polymeric cable component were at a first hardness; A method comprising:

23. A rotating bow for use in a entanglement unit for producing twisted pairs of insulated wire, the rotating bow being used in a fluid and including means for protecting the insulated wire from convective heat transfer with the fluid as the bow rotates.

24. 24. The rotating bow of claim 23, wherein the means for protecting the insulated wire from convective heat transfer is a longitudinal tube sized to at least partially contain the insulated wire.

25. 24. A rotating bow as defined in claim 23, wherein the means for protecting the insulated wire from convective heat transfer is a longitudinal groove on the bow sized to at least partially contain the insulated wire.

26. 24. The rotating bow of claim 23, wherein the means for protecting the insulated wire from convective heat transfer is a plurality of wind guides positioned on the windward side of the insulated wire.

27. 24. The rotating bow of claim 23, wherein the means for protecting the insulated wire from convective heat transfer includes adjustable sized ventilation openings.

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