Electrically heated and cooled rollers

Abstract

A method and system for electrically heating and cooling a roller is described. The system may include one or more rollers with one or more electric heating elements and one or more air channels. The one or more electric heating elements may be integrated with a power source and control circuitry via electrical contacts at at least one end of the roller. The control circuitry may further receive input from one or more temperature sensors.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 275,845, filed November 4, 2021, the disclosure of which is incorporated by reference in its entirety herein. [Technical field]

[0002] The present disclosure relates to an integrated roller device, and more particularly, to a roller that can maintain precise dimensions through precise temperature control.

[0003] In the fields of forming products such as sheets, films, and webs, handling such products, calendering, and the like, there is often a need to precisely manufacture these products to minimize thickness variations. However, some rollers are large in overall size, which, combined with thermal expansion associated with the roller material, can cause the rollers to vary in size, affecting the thickness and other dimensions of the product. Thus, there is a long-standing need to provide a device for adjusting a roll nip that will ensure a uniform thickness of the material web passing through the roll nip. This means that the roll nip must be kept constant regardless of load and external environment, such as by maintaining a precise and uniform temperature throughout the roll nip.

[0004] The exact thickness of the film profile is also important, especially in the field of manufacturing electrochemical cells such as lithium ion cells. The thickness of the film must be uniform throughout its length. This is because during the manufacturing of lithium ion cells, such as cylindrical, prismatic, or pouch type cells, the entire endless laminate film is cut to a predetermined length after the electrode film is manufactured and laminated to other layers such as separators and current collectors. The cut laminate film is then wound to form the lithium ion. Any deviation in the thickness of the film throughout its length may result in a change in the size of the wound layers of the film resulting from the above process, resulting in an incomplete winding that cannot be used to form a cylindrical, prismatic, or pouch type cell. For the above reasons, there is a need for improved systems, methods, and apparatus to ensure the accuracy of the film thickness.

[0005] Additionally, precise temperatures are important when forming electrochemical cells such as Li-ion batteries. The components that form the electrodes of dry electrode Li-ion batteries must be processed at the correct temperature and pressure to form electrode layers that meet stringent specifications for thickness and uniformity. These specifications must be maintained across the full width (transverse direction) of a particular roller to impart uniform thickness and properties to the film formed. These specifications must also be maintained as the roller rotates in the machine direction to impart uniform thickness and properties to the film formed.

[0006] Conventional structures and techniques for maintaining the temperature of a roller or roll nip are varied. For example, a roller may include internal channels, holes, or passages suitable for circulating a heated fluid, such as oil, through the roller or roll nip. This has drawbacks, such as the need for complex flow paths to ensure uniform heating, the loss of temperature of the fluid as it passes through the roller and loses thermal energy, and delays associated with changing rollers that need to be used during production. Improved structures and techniques are needed for rollers, including nip rollers, and for controlling the temperature of such rollers. Summary of the Invention

[0007] A roller is provided that includes one or more temperature control elements, which are electrical devices for maintaining a consistent temperature within the roller.

[0008] In some embodiments, the technology described herein relates to a system including a roller including one or more electric heating elements integrated inside the roller, one or more contacts electrically interfaced to the one or more electric heating elements, and one or more air channels, and a control circuit configured to control the one or more electric heating elements.

[0009] In some embodiments, the roller is divided longitudinally into a series of zones.

[0010] In some embodiments, each zone includes an electric heating element that has a unique electrical interface to the control circuitry.

[0011] In some embodiments, the heating characteristics of the electric heating element vary in each zone.

[0012] In some embodiments, the system further includes one or more temperature sensors.

[0013] In some embodiments, at least one of the one or more temperature sensors is external to the roller.

[0014] In some embodiments, at least one of the one or more temperature sensors is integrated inside the roller.

[0015] In some embodiments, the system further includes one or more active components, the one or more active components including at least one of a fan, a blower, a pump, or a compressor, the one or more active components interfaced to the control circuitry, the one or more active components configured to move at least one of a gas or a liquid through the one or more air channels.

[0016] In some embodiments, the electrical heating element is resistive.

[0017] In some embodiments, the electric heating element is inductive.

[0018] In some embodiments, the technology described herein relates to a method of manufacturing a roller, the method including providing a roller, providing at least one electric heating element integrated within the roller, providing at least one electrical contact on at least one end of the roller, electrically interfacing the at least one electric heating element and the at least one electrical contact, and providing at least one air channel inside the roller.

[0019] In some embodiments, each of the at least one electric heating element has a unique electrical contact.

[0020] In some embodiments, the method further includes providing at least one temperature sensor integrated within the roller.

[0021] In some embodiments, the method further includes electrically interfacing the at least one temperature sensor and the at least one electrical contact. In some embodiments, the technology described herein relates to a method of maintaining temperature control within a roller, the method including determining a temperature of at least one of the rollers by at least one temperature sensor integrated within the roller and in operative communication with a processor, comparing, by the processor, the temperature of the at least one of the rollers to a desired temperature, activating an external cooling system interfaced to at least one channel within the roller in response to the temperature of the at least one of the rollers being above the desired temperature, and activating an electric heating element integrated within the roller in response to the temperature of the at least one of the rollers being below the desired temperature. [Brief description of the drawings]

[0022] Aspects, features, benefits, and advantages of the embodiments described herein will become apparent with reference to the following description, the appended claims, and the accompanying drawings.

[0023] [Figure 1] 1 illustrates an integrated roller bending device, according to an embodiment.

[0024] [Diagram 2] 1 illustrates a roller with an integrated heating element, according to an embodiment.

[0025] [Diagram 3] 13 shows a roller with an integral heating element according to another embodiment.

[0026] [Figure 4] 1 shows a roller divided into heating / cooling zones, according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The disclosure is not limited to the particular systems, devices, and methods described, which may vary, and the terminology used herein is for the purpose of describing particular variations or embodiments only, and is not intended to limit the scope.

[0028] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Nothing in this disclosure should be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term "including" means "including, but not limited to."

[0029] This disclosure describes an apparatus for maintaining the alignment of integral nip rollers to ensure that the film produced by the nip rollers has a uniform thickness. Precise temperature control of each roller eliminates undesirable changes in the nip due to thermal expansion.

[0030] FIG. 1 shows an integrated roller bending device, according to an embodiment. In some embodiments, the rollers produce a nip accurate to about 1 μm. In this way, it is possible to configure the rollers with a crown as needed. In some embodiments, the crown ensures that the contact footprint, and therefore the film profile and film thickness, remain flat and accurate even as the rollers deflect or undergo different operations. The amount of crown is not limited and is selected based on the requirements of the particular film and the deflection selected for each roller. In some embodiments, the crown of the nip rollers is about 3 μm, about 4 μm, about 5 μm, about 6 μm, about 7 μm, about 8 μm, about 9 μm, about 10 μm, or any range of the above values, such as about 3 μm to about 10 μm, about 4 μm to about 9 μm, or about 4 μm to about 8 μm. If the temperature is not controlled, thermal expansion in the system may exceed these precise tolerances.

[0031] FIG. 2 illustrates a roller 200 with an integrated heating element 201, according to an embodiment. The heating element 201 is configured to maintain a known operating temperature of the roller 200. The known operating temperature allows the roller to perform with a known thermal expansion. In some embodiments, the heating element 201 is resistive. In a further embodiment, the heating element 201 is a resistive coil. In an alternative embodiment, the heating element 201 is inductive. In yet another embodiment, the separate heating element 201 is omitted and the entire roller is configured to be an inductive heating element. Those skilled in the art will recognize that multiple types of heating elements may be combined to maintain a predetermined temperature within the roller 200. In some embodiments, the heating element 201 is embedded into the roller 200 at a certain depth to uniformly heat the body of the roller 200. In yet other embodiments, the heating element 201 is provided on the central axis of the roller 200 or within a cavity surrounding the central axis of the roller 200.

[0032] The arrangement of the heating elements 201 includes, but is not limited to, a spiral shape, a straight rod shape, a loop shape forming a cylinder in the middle, a zigzag shape, or any other physical shape that allows for a desired temperature profile within the roller.

[0033] In some embodiments, the heating element 201 is coated with an electrical insulator 201 to ensure that electrical current remains within the heating element 201 and is not conducted through the roller 200. The electrical insulator needs to be electrically resistive but also thermally conductive. Examples of electrical insulators include ceramics such as silica, alumina, steatite (a magnesium silicate mineral), cordierite (a mineral containing iron, magnesium, aluminum, and silicon, but excluding iron in synthetic form), and polymers. Polymers, if used, can contain components that are thermally conductive but electrically insulating, such as alumina or boron nitride. In embodiments where the roller has consistent cyclic bending during operation, the insulator needs to be flexible, such as fiberglass or polymer, or omitted if induction heating elements 201 can be used.

[0034] In certain embodiments, the roller includes a core that is constructed of a different material than the roller's casing. In further embodiments, the core is hollow and contains a gas, such as air. In some embodiments, an electric heating element is within the core. In yet other embodiments, the core is centered on the central axis of the roller. In some embodiments, the core may include one or more openings 202 that allow for the circulation of a gas or fluid to manage the temperature of the roller 200.

[0035] In some embodiments, the heating element 201 is electrically interfaced to a power source external to the roller 200. In further embodiments, the interface is electrical contacts at both ends of the roller 200. In an alternative embodiment, there is only one electrical contact at one end of the roller 200.

[0036] In certain embodiments, the roller 200 may further include one or more air cooling channels. In some embodiments, the channels include a core. In other embodiments, the channels are in addition to the core. A portion of the channels may extend the length of the roller 200 with openings at both ends, extend only a portion of the length of the roller 200 and return to the same end, and / or extend a portion of the length of the roller 200 and terminate. The channels may follow any path through the roller 200, including but not limited to straight, spiral, curved, or any combination thereof. These channels may be passively or actively cooled by a cooling gas or liquid, such as forced air, nitrogen, or other substance, using a system external to the roller 200. In some active cooling embodiments, the active components of the cooling system are activated only prior to removal of the roller 200 during the roller replacement process. In certain embodiments, the active components are fans, blowers, pumps, or compressors. In certain embodiments, the cooling gas further controls the temperature of the roller as it circulates during operation. The cooling gas can be supplied at ambient temperature (eg, about 18° C. to about 24° C., or about 20° C.), at a temperature greater than ambient temperature, or at a temperature less than ambient temperature.

[0037] In certain embodiments, the roller 200 may further include one or more sensors for measuring temperature. In further embodiments, the temperature sensor may be a resistive temperature sensor. In some embodiments, a single temperature sensor may be located either centrally within the roller 200 or near the running surface of the roller 200. Alternatively, in some embodiments, a temperature sensor is located external to the roller 200 and measures the temperature radiating from the roller 200. One skilled in the art will recognize that multiple types of temperature sensors may be integrated herein.

[0038] In certain embodiments, the heating element 201, active cooling element, and / or temperature sensor may be integrated into control circuitry external to the roller 200. The control circuitry may include one or more processors, a storage medium for storing data and programming instructions / settings, and a communication interface.

[0039] 3, a roller 300 is shown with a resistive heating element 301 according to an embodiment. In this illustrated embodiment, the resistive heating element 301 is configured as a helix that is inserted into a hollow central core (not shown) of the roller 300. However, it will be understood that the exact configuration of the resistive heating element 301 is not particularly limited and other shapes that provide the desired temperature profile are suitable.

[0040] 4 shows a roller divided into heating / cooling zones, according to embodiments. In some embodiments, roller 400 may vary in thickness or density at different locations across the span of roller 400. Additionally or alternatively, in some embodiments, roller 400 may have uneven running contact across its surface. As a result of this uneven running contact, the surface temperature of roller 400 may also be uneven. To accommodate these scenarios, in some embodiments, roller 400 may include multiple temperature control zones 401 / 402 / 403 to ensure uniform temperature across the roller.

[0041] In certain embodiments, each zone 401 / 402 / 403 includes one or more heating elements that do not overlap with other zones. In some embodiments, the individual heating elements are manufactured to generate different temperatures based on a single electrical input. As a result, the individual heating elements may be wired in series within the roller. As a non-limiting example, the resistive elements may change material properties, such as increasing or decreasing the resistance between two zones. Alternatively, each zone 401 / 402 / 403 may include separate heating elements with unique signal contacts. Each of the zones shown can have different heat densities depending on the required temperature profile, or profile and performance of the roller. For example, in one embodiment according to the present disclosure, the amount of heating, and therefore the number of coils provided in the central portion of the roller.

[0042] In certain embodiments, each zone may include a unique set of one or more temperature sensors. In some embodiments, the temperature sensors for each zone may be internal to roller 400. In alternative embodiments, the temperature sensors for each zone may be external to roller 400.

[0043] In the above detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like symbols typically identify like components unless otherwise indicated by context. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a wide variety of configurations, as expressly contemplated herein.

[0044] The present disclosure is not limited to the specific embodiments described in this application, but is intended as an illustration of various aspects. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from the spirit and scope thereof. Functionally equivalent methods and apparatuses that are within the scope of the present disclosure, as well as those recited herein, will be apparent to those skilled in the art from the above description. Such modifications and alterations are intended to be included within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims, and the full scope of equivalents to which such claims are entitled. It is to be understood that the present disclosure is not limited to specific methods, reagents, compounds, compositions, or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of merely describing specific embodiments, and is not intended to be limiting.

[0045] With respect to the use of substantially any plural and / or singular term herein, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. For clarity, various singular / plural permutations may be explicitly set forth herein.

[0046] Those skilled in the art will understand that the terms used in the specification, in general, and in the claims, in particular (e.g., the body of the claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including but not limited to," etc.). While various components, methods, and devices are described in terms of "comprising" (interpreted as meaning "including but not limited to") various components or steps, compositions, methods, and devices may also "essentially comprise" or "consist of" various components and steps, and such terms should be interpreted as defining an essentially closed collection of elements. Those skilled in the art will further understand that if a specific number of claim recitations are intended to be introduced, such intent will be explicitly recited in the claim, and the absence of such recitation is not an indication that such intent is not presented.

[0047] For example, as an aid to understanding, the following appended claims may include the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that introducing a claim recitation with the indefinite article "a" or "an" limits any particular claim that includes such an introduced claim recitation to embodiments that include only one such recitation, even when that same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim recitations.

[0048] In addition, when a specific number of claim recitations is explicitly recited, one of ordinary skill in the art will understand that such recitation should be interpreted to mean at least the recited number (e.g., a minimum recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations). Furthermore, when a rule similar to "at least one of A, B, and C, etc." is used, such an interpretation is generally intended in the sense that one of ordinary skill in the art would understand the rule (e.g., "a system including at least one of A, B, and C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In cases where a rule similar to "at least one of A, B, or C, etc." is used, such an interpretation is generally intended in the sense that one of skill in the art would understand the rule (e.g., "a system including at least one of A, B, or C" includes, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Furthermore, one of skill in the art will appreciate that virtually any disjunction and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" is understood to include the possibilities of "A" or "B" or "A and B."

[0049] Additionally, when features or aspects of the disclosure are described in a Markush group, one of skill in the art will understand that the disclosure is also thereby described in terms of any individual component or subgroup of components of that Markush group.

[0050] It will be appreciated by those of skill in the art that for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges of that range. Any range listed can be readily recognized as fully descriptive and capable of dividing the same range into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range described herein can be easily broken down into a lower third, middle third, upper third, etc. Also, as will be appreciated by those of skill in the art, all words such as "up to," "at least," etc. refer to ranges that are inclusive of the recited numbers and can then be subdivided into subranges as described above. Finally, it will be appreciated by those of skill in the art that a range includes each of the individual elements. Thus, for example, a population having 1-3 batteries refers to a population having 1, 2, or 3 batteries. Similarly, a population having 1-5 batteries refers to a population having 1, 2, 3, 4, or 5 batteries.

[0051] Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements thereof, each of which are intended to be encompassed by the disclosed embodiments, may subsequently be made by those skilled in the art.

Claims

1. A roller, one or more electric heating elements integrated inside said roller; one or more contacts electrically interfaced to the one or more electric heating elements; one or more air channels; the roller, a control circuit configured to control the one or more electric heating elements; Including, the system.

2. The system of claim 1 , wherein the roller is divided longitudinally into a series of zones.

3. The system of claim 2 , wherein each zone includes a respective electric heating element of the one or more electric heating elements having a unique electrical interface to the control circuit.

4. The system of claim 3 , wherein the heating characteristics of each electric heating element vary within each zone.

5. The system of claim 1 further comprising one or more temperature sensors.

6. The system of claim 5 , wherein at least one of the one or more temperature sensors is external to the roller.

7. The system of claim 5 , wherein at least one of the one or more temperature sensors is integrated inside the roller.

8. 10. The system of claim 1, further comprising one or more active components, the one or more active components comprising at least one of a fan, a blower, a pump, or a compressor, the one or more active components interfaced to the control circuitry, and the one or more active components configured to move at least one of a gas or a liquid through the one or more air channels.

9. The system of claim 1 , wherein the one or more electric heating elements are resistive.

10. The system of claim 1 , wherein the one or more electric heating elements are inductive.

11. 1. A method of manufacturing a roller, comprising: Providing a roller; providing at least one electric heating element integrated within said roller; providing at least one electrical contact on at least one end of the roller; electrically interfacing the at least one electric heating element and the at least one electrical contact; forming at least one air channel inside the roller; The method comprising:

12. The method of claim 11 , wherein each electric heating element has its own electrical contact.

13. The method of claim 1 further comprising providing at least one temperature sensor integrated within the roller.

14. The method of claim 13 , further comprising electrically interfacing the at least one temperature sensor and the at least one electrical contact.

15. 1. A method of maintaining temperature control within a roller, comprising: determining a temperature of at least one of the rollers by at least one temperature sensor integrated within the roller and in operative communication with a processor; comparing, by the processor, the at least one temperature of the roller to a desired temperature; activating an external cooling system interfaced to at least one channel in the roller in response to the at least one temperature of the roller exceeding the desired temperature; activating an electric heating element integrated within the roller in response to the at least one temperature of the roller falling below the desired temperature; The method comprising:

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