Process for producing a small diameter nylon jacketed electrical wire

Abstract

This application provides a method for preparing small-diameter nylon-coated wires. The method includes the following steps: an extrusion step: preheated nylon-coated raw material is output through the screw of an extruder to a self-centering die head for heating under a first preset condition, and preliminary extrusion is performed; a forming step: the pre-extruded nylon-coated raw material is heated under a second preset condition through a die, and final extrusion is performed to form small-diameter nylon-coated wires. The preparation method of this application adopts an extrusion production method. By combining a self-centering die head, a flat-mouth pressure-reducing outer die, and high extrusion temperature and fast screw speed, the thickness of the nylon coating is ensured to be uniform, and the pressure during rubber production is reduced. This solves the problem that the small diameter of the nylon coating wire is not suitable for production using large machines, and improves the utilization rate of small machines.

Description

Technical Field

[0001] This invention relates to the field of wire technology, and in particular to a method for preparing a small-diameter nylon-coated wire. Background Technology

[0002] The widespread adoption of electric vehicles has led to the booming development of electric vehicle charging cables. For ease of use, lightweight and miniaturized electric vehicle charging cables are reasonable pursuits for home use. To reduce the outer diameter of home electric vehicle charging cables, the core wire of the charging cable is made by extruding a layer of nylon inner sheath, which can reduce the total outer diameter of the wire by about 25% while ensuring electrical performance.

[0003] Traditional nylon-coated wires are typically extruded using a tube-extrusion process. This is because the nylon coating is thin, only about 0.15mm thick, and the tube-extrusion process ensures uniform thickness of the nylon layer and reduces extrusion pressure, preventing the core wire and conductor from being pulled thin.

[0004] However, the traditional extrusion production method generally uses an adjustable die head to adjust the eccentricity. However, adjustable die heads are generally configured on machines with a diameter of 70mm or more, and the glue output is much greater than the needs of producing small diameter nylon, which can lead to problems such as nylon glue sticking and burning. Summary of the Invention

[0005] In view of the above problems, embodiments of the present invention are proposed to provide a method for preparing a small-diameter nylon-insulated wire that overcomes or at least partially solves the above problems.

[0006] To address the aforementioned problems, this invention discloses a method for preparing a small-diameter nylon-coated wire, the method comprising the following steps:

[0007] Extrusion step: The preheated nylon intermediate material is output to the centerless die head of the extruder through the screw of the extruder for heating under the first preset conditions and preliminary extrusion is carried out. The first preset conditions are heating temperature of 270±5℃ and heating time of 1 to 10 minutes.

[0008] Molding steps: The nylon inner material that has been initially extruded is heated under the second preset conditions through an eye mold to perform final extrusion and form a small-diameter nylon inner wire. The second preset conditions are a heating temperature of 275±5℃ and a heating time of 1 to 10 minutes.

[0009] Furthermore, prior to the extrusion step, a preheating step is included, in which the nylon inner material is preheated by sealing the feed hopper; wherein the preheating temperature is 175±5℃~260±5℃ and the preheating time is 8-10min;

[0010] Furthermore, the preheating step includes:

[0011] The nylon inner material is preheated in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon inner material is 175±5℃, the temperature of the second stage is 220±5℃, the temperature of the third stage is 250±5℃, and the temperature of the fourth stage is 260±5℃; the preheating time of the first stage of the nylon inner material is 1-2 min, the preheating time of the second stage is 2 min, the preheating time of the third stage is 2-3 min, and the preheating time of the fourth stage is 3 min;

[0012] Furthermore, the temperature of the first stage of the four-stage preheating of the nylon raw material is 175°C, the temperature of the second stage is 225°C, the temperature of the third stage is 250°C, and the temperature of the fourth stage is 255°C.

[0013] Furthermore, extrusion production is carried out using a flat-mouth pressure-reducing outer die and an extrusion inner die;

[0014] Furthermore, the diameter of the extruder's screw is ≤50mm;

[0015] Furthermore, the speed of the extruder is 1500 rpm;

[0016] Furthermore, the ratio of the screw speed of the extruder to the speed of the extruder is greater than 9:10;

[0017] A small-diameter nylon-coated wire as described above, wherein the small-diameter nylon-coated wire is prepared by the method for preparing small-diameter nylon-coated wire as described in any one of the above claims, comprising: a conductor, an insulated core wire, and a nylon sheath, arranged sequentially from the inside out.

[0018] Furthermore, the diameter of the nylon inner lining is 1.2 to 6.0 mm, and the thickness of the nylon inner lining is 0.10 to 0.20 mm.

[0019] This application has the following advantages:

[0020] This application provides a method for preparing small-diameter nylon-coated wires. The method includes the following steps: an extrusion step: preheated nylon-coated raw material is output through the screw of an extruder to a self-centering die head for heating under a first preset condition, and preliminary extrusion is performed; a forming step: the pre-extruded nylon-coated raw material is heated under a second preset condition through a die, and final extrusion is performed to form small-diameter nylon-coated wires. The preparation method of this application adopts an extrusion production method. By combining a self-centering die head, a flat-mouth pressure-reducing outer die, and high extrusion temperature and fast screw speed, the thickness of the nylon coating is ensured to be uniform, and the pressure during rubber production is reduced. This solves the problem that the small diameter of the nylon coating wire is not suitable for production using large machines, and improves the utilization rate of small machines. Attached Figure Description

[0021] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart of the steps in a method for preparing a small-diameter nylon-coated wire according to this application;

[0023] Figure 2 This is a schematic diagram of the structure of a small-diameter nylon-insulated wire according to this application;

[0024] Figure 3 This is a schematic diagram of the internal and external mold structure used in the existing tube extrusion production method;

[0025] Figure 4 This is a schematic diagram of the inner and outer mold structure used in the preparation method of a small-diameter nylon wire according to this application.

[0026] The reference numerals in the accompanying drawings are as follows:

[0027] 21. Conductor; 22. Insulated core wire; 23. Nylon inner lining. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] One of the core concepts of this application is the extrusion step: the preheated nylon inner material is output to the centerless die head of the extruder through the screw of the extruder for heating under the first preset conditions and for preliminary extrusion; the molding step: the pre-extruded nylon inner material is heated under the second preset conditions through the die and for final extrusion to form a small-diameter nylon inner wire.

[0030] Reference Figure 1 The flowchart illustrates the steps of a method for preparing a small-diameter nylon wire according to this application, which may specifically include the following steps;

[0031] S100, Extrusion Step: The preheated nylon intermediate material is output through the extruder screw to the centerless die head for heating under the first preset conditions and for initial extrusion.

[0032] S200, Molding Step: The nylon inner material that has been initially extruded is heated under a second preset condition through an eye die, and then finally extruded to form a small-diameter nylon inner wire.

[0033] In one embodiment of this application, the extrusion step involves: preheating the nylon inner coating material and outputting it through the extruder screw to a self-centering die head for heating under first preset conditions, thus performing preliminary extrusion; the forming step involves heating the pre-extruded nylon inner coating material through a die under second preset conditions, thus performing final extrusion to form a small-diameter nylon inner coating wire; the preparation method of this application adopts an extrusion production method, which, by combining a self-centering die head, a flat-mouth pressure-reducing outer die, and high extrusion temperature and fast screw speed, ensures uniform thickness of the nylon inner coating and reduces the pressure during rubber production; it solves the problem that the nylon inner coating wire diameter is not suitable for production using large machines, and improves the utilization rate of small machines.

[0034] The method for preparing a wire coated with small-diameter nylon in this exemplary embodiment will now be further described.

[0035] In one embodiment of this application, as described in step S100, the preheated nylon intermediate material is output to the centerless die head of the extruder through the extruder screw for heating under the first preset conditions and preliminary extrusion is performed. The first preset conditions are a heating temperature of 270±5℃ and a heating time of 1 to 10 minutes.

[0036] To reduce the outer diameter of the charging cable, the core wire is extruded with a layer of nylon sheath. While maintaining the performance of the wire, the total outer diameter of the wire is reduced by about 25%. The extrusion of the nylon sheath involves extruding a thin layer of nylon outside the insulated core wire to form a sheath. The screw diameter of the extruder is selected to be ≤50mm to address the current production situation of small-diameter nylon-sheathed wires, improve the utilization rate of small machines, and at the same time increase the screw speed to ensure smooth extrusion of the nylon sheath material, preventing backflow and compression inside the screw, and reducing the pressure during rubber production.

[0037] The die head is designed to be centerless to ensure uniform thickness of the nylon inner liner. The centers of the inner and outer dies are aligned with the die head on a horizontal axis, ensuring that the nylon inner liner material has the same thickness in all directions after passing through the outer die. The heating temperature at the die head is set to 270±5℃ to ensure that the nylon inner liner material is in a molten state, allowing it to enter the die head evenly and be extruded stably, resulting in more stable output.

[0038] In one embodiment of this application, as described in step S200, the nylon inner material that has been initially extruded is heated under a second preset condition through an eye mold to perform final extrusion and form a small-diameter nylon inner wire. The second preset condition is a heating temperature of 275±5℃ and a heating time of 1 to 10 minutes.

[0039] The nylon core material that was initially extruded was reheated at the eye die. The heating temperature was set to 275±5℃. The reason for setting the temperature higher was to ensure that the nylon core material remained in a molten state when it entered the eye die, thereby reducing the pressure of the nylon core material and thus reducing the pressure of the rubber compound. If the temperature is low, the surface of the rubber compound will be rough and the mechanical properties will be poor after it exits the die.

[0040] In one embodiment of this application, the preheating step is included before step S100, wherein the nylon inner material is preheated by sealing the feed hopper; wherein the preheating temperature is 175±5℃~260±5℃ and the preheating time is 8-10min; during sealed preheating, exhaust is carried out through a predetermined exhaust channel to prevent the work area from emitting material odor, and the moisture-sensitive material is dried by preheating baking so that bubbles will not be generated due to the moisture in the material during heating, thereby resulting in defective products.

[0041] In one embodiment of this application, the preheating step includes: preheating the nylon inner coating material in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon inner coating material is 175±5℃, the temperature of the second stage is 220±5℃, the temperature of the third stage is 250±5℃, and the temperature of the fourth stage is 260±5℃; the preheating time of the first stage of the nylon inner coating material is 1-2 min, the preheating time of the second stage is 2 min, the preheating time of the third stage is 2-3 min, and the preheating time of the fourth stage is 3 min; the four-stage preheating allows the material to gradually heat up, avoiding the problem of uneven heating of the material due to one-time heating, thereby preventing uneven density of the extruded material.

[0042] Specifically, the first stage is the feeding stage, where the temperature of 175±5℃ preheats the rubber compound. This ensures the nylon inner material is granular during feeding. If the temperature is too high, the nylon inner material will melt, increasing the difficulty of its forward movement, or even preventing it from moving forward at all. The second stage is the transition between the feeding and plasticizing stages, where the temperature of 220±5℃ further preheats and softens the nylon inner material. Therefore, the temperature of the second stage is slightly higher than the first stage. The third stage is the plasticizing stage, where the temperature of 250±5℃ fully melts the nylon inner material. Therefore, the temperature of the third stage is relatively high. The fourth stage is the homogenization stage, where the temperature of 260±5℃ is higher than the third stage, which is beneficial for stable extrusion of the rubber compound. The shallow screw thread in the fourth stage facilitates the even entry of the nylon inner material into the die head, resulting in a stable output.

[0043] In one specific embodiment, the nylon is preheated in four stages: the first stage temperature is 175°C, the second stage temperature is 225°C, the third stage temperature is 250°C, and the fourth stage temperature is 255°C. By gradually increasing the temperature from 175°C to 255°C, the material is kept in a relatively stable state, thereby improving the yield during extrusion.

[0044] Reference Figure 2 The diagram shows a structural schematic of a small-diameter nylon-insulated wire of the present application, which is prepared by the above-described method and includes, from the inside out, a conductor 21, an insulating core wire 22 and a nylon sheath 23.

[0045] Conductor 21 is the conductive part of the wire, used to transmit electrical energy. It uses optical fiber as the conductive core and is made of non-ferrous metals with excellent conductivity, such as copper, aluminum, copper-clad steel, and copper-clad aluminum. Insulated core wire 22 is a high-performance insulated wire with a core wire in the middle and an insulation layer covering the core wire. It electrically isolates the conductor from the ground and conductors of different phases, ensuring the transmission of electrical energy. Nylon sheath 23 is formed by extruding a thin layer of nylon on the outside of the insulated core wire to form a sheath. While ensuring the performance of the wire, it reduces the total outer diameter of the wire by about 25%.

[0046] In one embodiment of this application, the wire diameter of the nylon inner sheath 23 is 1.2 to 6.0 mm, preferably 1.2 mm, 2.8 mm, 3.6 mm, 4.2 mm, 5.0 mm or 6.0 mm.

[0047] In one embodiment of this application, the thickness of the nylon inner layer 23 is 0.10 to 0.20 mm, preferably 0.10 mm, 0.13 mm, 0.15 mm, 0.18 mm or 0.20 mm.

[0048] Reference Figure 3 The diagram shows the internal and external mold structure of the existing extrusion production method. Specifically, the external mold of the traditional extrusion production method consists of a pressure external mold and a pressure gallery section. The pressure gallery section is provided at the mold opening of the external mold. The internal mold of the traditional extrusion production method has an internal mold tube at the front end.

[0049] The extrusion production method can ensure uniform thickness of the nylon layer and reduce extrusion pressure, preventing the core wire and conductor from being stretched thin. However, the extrusion production method generally uses an adjustable die head to adjust the eccentricity. The adjustable die head is generally configured on a machine with a diameter of 70mm or more. The amount of glue produced is much greater than the needs of producing small diameter nylon, which can lead to problems such as nylon glue sticking and burning.

[0050] Reference Figure 4 This paper shows a schematic diagram of the inner and outer mold structure used in a method for preparing a small-diameter nylon-coated wire according to this application. It adopts an extrusion production method, which is different from the traditional tube extrusion production method. The extrusion production is carried out by a flat-mouth pressure-reducing outer mold and an extrusion inner mold. The outer mold of the extrusion production method of this application is a flat-mouth pressure-reducing type, and the pressure corridor is eliminated at the outer mold opening. The inner mold is an extrusion type, and there is no inner mold tube at the front end of the inner mold.

[0051] The extrusion production method uses a centerless die head during extrusion, with the centers of the inner and outer dies aligned with the die head on a horizontal axis. The nylon inner liner material has the same thickness in all directions after passing through the outer die, ensuring uniform thickness of the nylon inner liner and reducing the pressure of the rubber material during production. At the same time, the extrusion production method solves the problem that the nylon inner liner wire diameter is not suitable for production on large machines, thus improving the utilization rate of small machines.

[0052] Example 1

[0053] In specific embodiment 1, the method for preparing the small-diameter nylon-coated wire includes: preheating the nylon-coated raw material in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon-coated raw material is 175°C, the temperature of the second stage is 225°C, the temperature of the third stage is 250°C, and the temperature of the fourth stage is 255°C; the preheating time of the first stage of the nylon-coated raw material is 2 minutes, the preheating time of the second stage is 2 minutes, the preheating time of the third stage is 2 minutes, and the preheating time of the fourth stage is 3 minutes; the material is gradually heated through the four-stage preheating to maintain a relatively stable state, thereby obtaining the preheated nylon-coated raw material; the preheated nylon-coated raw material is then passed through the screw of an extruder. The extruder output is heated to a centerless die head under first preset conditions for preliminary extrusion. The first preset conditions are a heating temperature of 270°C and a heating time of 8 minutes, with a screw diameter of 50 mm. The ratio of the screw speed to the extruder's overall speed is 9:10, and the screw speed is 1350 rpm. The pre-extruded nylon inner material is then heated through a die under second preset conditions for final extrusion, forming a small-diameter nylon inner wire. The second preset conditions are a heating temperature of 280°C and a heating time of 10 minutes, with a wire diameter of 1.2 mm and a thickness of 0.15 mm.

[0054] Example 2

[0055] In specific embodiment 2, the method for preparing the small-diameter nylon-coated wire includes: preheating the nylon-coated raw material in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon-coated raw material is 170℃, the temperature of the second stage is 220℃, the temperature of the third stage is 245℃, and the temperature of the fourth stage is 260℃; the preheating time of the first stage of the nylon-coated raw material is 1 min, the preheating time of the second stage is 2 min, the preheating time of the third stage is 2 min, and the preheating time of the fourth stage is 3 min; the material is gradually heated through the four-stage preheating to maintain a relatively stable state, thereby obtaining the preheated nylon-coated raw material; the preheated nylon-coated raw material is then fed into the extruder through the screw of the extruder. The material is heated to a centerless extruder head under first preset conditions for preliminary extrusion. The first preset conditions are: heating temperature 265℃, heating time 10 minutes, extruder screw diameter 40mm; extruder screw speed to extruder speed ratio 9.2:10, extruder screw speed 1380rpm; the pre-extruded nylon inner material is then heated through a die under second preset conditions for final extrusion, forming a small-diameter nylon inner wire. The second preset conditions are: heating temperature 280℃, heating time 8 minutes, nylon inner wire diameter 3.6mm, nylon inner wire thickness 0.18mm.

[0056] Example 3

[0057] In specific embodiment 3, the method for preparing the small-diameter nylon-coated wire includes: preheating the nylon-coated raw material in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon-coated raw material is 180℃, the temperature of the second stage is 215℃, the temperature of the third stage is 255℃, and the temperature of the fourth stage is 265℃; the preheating time of the first stage of the nylon-coated raw material is 1 min, the preheating time of the second stage is 2 min, the preheating time of the third stage is 3 min, and the preheating time of the fourth stage is 3 min; the material is gradually heated through the four-stage preheating to maintain a relatively stable state, thereby obtaining the preheated nylon-coated raw material; the preheated nylon-coated raw material is then passed through an extruder. The screw output is heated to a centerless die head under first preset conditions for preliminary extrusion. The first preset conditions are a heating temperature of 270℃ and a heating time of 7 minutes. The screw diameter of the extruder is 35mm. The ratio of the screw speed to the extruder's overall speed is 1, and the screw speed is 1500rpm. The pre-extruded nylon inner material is then heated under second preset conditions through a die for final extrusion, forming a small-diameter nylon inner wire. The second preset conditions are a heating temperature of 275℃ and a heating time of 6 minutes. The wire diameter of the nylon inner wire is 5.0mm, and the thickness of the nylon inner wire is 0.10mm.

[0058] Example 4

[0059] In specific embodiment 4, the method for preparing the small-diameter nylon-coated wire includes: preheating the nylon-coated raw material in four stages using a heating device; wherein the temperature of the first stage of the four-stage preheating of the nylon-coated raw material is 175°C, the temperature of the second stage is 215°C, the temperature of the third stage is 250°C, and the temperature of the fourth stage is 260°C; the preheating time of the first stage of the nylon-coated raw material is 2 minutes, the preheating time of the second stage is 2 minutes, the preheating time of the third stage is 3 minutes, and the preheating time of the fourth stage is 3 minutes; the material is gradually heated through the four-stage preheating to maintain a relatively stable state, thereby obtaining the preheated nylon-coated raw material; the preheated nylon-coated raw material is then fed into the extruder through the screw of the extruder. The material is heated to a centerless extruder head under first preset conditions for preliminary extrusion. The first preset conditions are: heating temperature 275℃, heating time 5 minutes, extruder screw diameter 20mm; extruder screw speed to extruder speed ratio 9.8:10, extruder screw speed 1470rpm; the pre-extruded nylon inner material is then heated through a die under second preset conditions for final extrusion, forming a small-diameter nylon inner wire. The second preset conditions are: heating temperature 270℃, heating time 7 minutes, nylon inner wire diameter 6.0mm, nylon inner wire thickness 0.20mm.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0061] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0062] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0063] The above provides a detailed description of a method for preparing a small-diameter nylon-coated wire according to this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing a small-diameter nylon-coated wire, characterized in that, The diameter of the nylon sheath is 1.2-6.0 mm, the thickness of the nylon sheath is 0.10-0.20 mm, the method adopts a flat pressure-reducing outer mold and an extruding inner mold for extrusion production, the center of the inner and outer molds and the head are on a horizontal axis, and the preparation method comprises the following steps: a preheating step: the nylon sheath raw material is preheated in four stages through a feed bin seal; the first-stage temperature of the four-stage preheating is 175±5℃, the second-stage temperature is 220±5℃, the third-stage temperature is 250±5℃, and the fourth-stage temperature is 260±5℃; the first-stage preheating time of the nylon sheath raw material is 1-2 min, the second-stage preheating time is 2 min, the third-stage preheating time is 1-3 min, and the fourth-stage preheating time is 3 min; wherein the first-stage temperature of the four-stage preheating is 175℃, the second-stage temperature is 225℃, the third-stage temperature is 250℃, and the fourth-stage temperature is 255℃; an extruding step: the preheated nylon sheath raw material is output to a center-free head through the screw rod of the extruder for heating under the first preset condition for preliminary extrusion, wherein the first preset condition is a heating temperature of 270±5℃ and a heating time of 1-10 min; a molding step: the preliminary extruded nylon sheath raw material is heated under the second preset condition through an eye mold for final extrusion to form a small-diameter nylon sheath wire, wherein the second preset condition is a heating temperature of 275±5℃ and a heating time of 1-10 min.

2. The method of claim 1, wherein the step of applying the coating is performed by a method selected from the group consisting of: dip coating, spray coating, and spin coating. The diameter of the screw rod of the extruder is ≤50 mm.

3. The method of claim 1, wherein the step of applying the coating is performed by a process selected from the group consisting of: dip coating, spray coating, and spin coating. The speed of the extruder is 1500 rpm.

4. The method for preparing a small-diameter nylon-coated wire according to claim 1, characterized in that, The ratio of the rotation speed of the screw rod of the extruder to the speed of the extruder is greater than 9:

10.

5. A small diameter nylon jacketed electrical wire as defined in Claim 1, wherein, The small-diameter nylon sheath wire is prepared by the small-diameter nylon sheath wire preparation method according to any one of claims 1-4, and comprises, from inside to outside, a conductor, an insulating core wire, and a nylon sheath.

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