Insulating sheath cable and preparation method thereof

Abstract

The invention provides an insulating sheath cable and a preparation method thereof, and the preparation method comprises the following steps: extruding an insulating material through a first extruder, and coating the surface of a conductor with the extruded insulating material to obtain an insulating layer; then, extruding a sheath material through a second extruder, and coating the sheath material on the surface of the insulating layer to obtain a sheath layer; and then carrying out segmented cooling to obtain the insulating sheath cable. According to the invention, the cable insulation layer obtained by the preparation method has good mechanical properties; basic performance requirements of the cable, such as electrical performance, insulating performance, aging resistance and the like, can be ensured, and meanwhile, the cable does not crack, and is good in appearance quality and high in production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of cable preparation, and in particular relates to an insulating sheathed cable and a preparation method thereof. Background Art

[0002] Port machinery, or "port machinery" for short, is a crane used for loading and unloading operations at the dock. In recent years, due to the vigorous development of the world's shipping industry, the demand for port machinery has also exploded. Among them, American standard cables exported to the United States must be UL certified. They have high quality requirements and are difficult to produce. They usually require advanced manufacturing processes and materials. Therefore, the manufacturing cost is extremely high and the production efficiency is slow.

[0003] At the same time, the current situation of my country's cable industry: overcapacity; but insufficient supply capacity in the field of high-end products, mainly relying on imports. Under this situation, we can actively explore overseas markets and devote ourselves to the innovation and development of export products with higher technical levels. Among them, polyvinyl chloride (PVC) insulated nylon sheathed wires and cables exported to the United States have better electrical and physical properties than ordinary PVC insulated wires and cables: they have better heat resistance, small weight loss when running at high temperatures, can improve the instantaneous heat overload resistance of wires, and can slow down or reduce the escape or migration of PVC components; at the same time, they have the characteristics of corrosion resistance, self-lubrication and oil resistance. In addition to being widely used in port machinery, they are also widely used in residential, commercial and industrial buildings in the United States.

[0004] However, the existing production method of polyvinyl chloride insulated nylon sheathed wires and cables is to first extrude PVC and cool it; then extrude nylon again and cool it, which has extremely low production efficiency; and the obtained product insulation layer has poor mechanical properties, poor appearance quality, and is easy to crack.

[0005] Therefore, developing a method for preparing polyvinyl chloride insulated nylon sheathed cables with high production efficiency and good performance is an urgent problem to be solved in the art. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide an insulating sheathed cable and a preparation method thereof. The cable insulation layer obtained by the preparation method has good mechanical properties; it can not only ensure the basic performance requirements of the cable, such as electrical properties, insulation properties, aging resistance, etc., but also the cable does not crack, has no bubbles on the surface, has good apparent quality, and has high production efficiency.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing an insulating sheathed cable, the preparation method comprising the following steps: extruding an insulating material through a first extruder, coating the insulating material on the surface of a conductor to obtain an insulating layer; extruding a sheathing material through a second extruder, coating the insulating layer surface to obtain a sheathing layer; and then performing segmented cooling to obtain the insulating sheathed cable.

[0009] In the present invention, the preparation method adopts serial production, the insulating material and the sheath material are extruded in different heads, and after the insulating layer is extruded and coated, the sheath layer is immediately extruded without cooling, and then a segmented cooling method is adopted, which can not only improve the production efficiency, but also the obtained cable insulation layer has good mechanical properties, the tensile strength and elongation at break of the insulation layer are high; the sheath layer is not easy to crack, there are no bubbles on the surface, and the product quality is high.

[0010] Preferably, the insulating material comprises polyvinyl chloride insulating material.

[0011] Preferably, the extrusion wire diameter extruded by the first extruder is φ2.0mm~φ21mm, for example, it can be φ2mm, φ3mm, φ4mm, φ5mm, φ6mm, φ8mm, φ10mm, φ12mm, φ14mm, φ16mm, φ18mm, φ20mm, etc.

[0012] In the present invention, the extrusion wire diameter of the first extruder is determined according to the conductor specifications; when the conductor specifications are 18AWG to 8AWG (φ1.2mm to φ3.8mm), the extruder is a φ50 extruder, and the extrusion wire diameter is φ2.0mm~φ5.4mm; when the conductor specifications are 6AWG to 350MCM (φ4.6mm to φ17.4mm), the extruder is a φ90 extruder, and the extrusion wire diameter is φ6.2mm~φ20.8mm.

[0013] Preferably, the temperature of extrusion through the first extruder is 145-195°C, for example, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, etc.

[0014] In the present invention, the first extruder includes a main engine temperature and a die head temperature; the main engine temperature is: 145-155°C in zone 1; 175-185°C in zones 2-4; the die head temperature is: 185-195°C in zone 1; 175-185°C in zones 2-4; 185-195°C in zones 5-7.

[0015] Preferably, the sheath material comprises nylon sheath material.

[0016] Preferably, the extrusion wire diameter extruded by the second extruder is φ2.0mm~φ22mm, for example, it can be φ2mm, φ3mm, φ4mm, φ5mm, φ6mm, φ8mm, φ10mm, φ12mm, φ14mm, φ16mm, φ18mm, φ20mm, φ21mm, φ22mm, etc.

[0017] In the present invention, the extrusion wire diameter of the second extruder is determined according to the conductor specifications; when the conductor specifications are 18AWG to 8AWG (φ1.2mm to φ3.8mm), the extruder is a φ50 extruder, and the extrusion wire diameter is φ2.2mm~φ5.7mm; when the conductor specifications are 6AWG to 350MCM (φ4.6mm to φ17.4mm), the extruder is a φ90 extruder, and the extrusion wire diameter is φ6.5mm~φ21.4mm.

[0018] Preferably, the extrusion temperature through the second extruder is 230-270°C, for example, it can be 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, 265°C, 270°C, etc.

[0019] In the present invention, the specific temperatures of the second extruder are: zone 1 230-245°C; zones 2-4 240-250°C; clamp 1 and clamp 2 260-270°C; side stream 240-250°C; head 260-270°C; eye die 255-265°C.

[0020] Preferably, the segmented cooling method comprises conveying the obtained cable to cooling water of different temperatures for cooling.

[0021] In the present invention, the insulating layer is not cooled by water after extrusion, so as to avoid the situation that the cooling water cannot be completely removed when the speed is too fast, resulting in the sheath layer being covered thereon after extrusion, and volatilizing at high temperature to form bubbles, thereby resulting in poor apparent quality of the cable; after the extrusion is completed, a uniform segmented cooling method is adopted, which can prevent the sheath from being suddenly cooled after extrusion and causing stress cracking, thereby affecting the performance of the cable.

[0022] Preferably, the staged cooling includes a first stage cooling and a second stage cooling performed sequentially.

[0023] Preferably, the temperature of the first cooling stage is 75-125°C, for example, it can be 75°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, 92°C, 94°C, 96°C, 98°C, 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 125°C, etc.

[0024] Preferably, the temperature of the second cooling stage is 25-35°C, for example, it can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, etc.

[0025] Preferably, the speed of the segmented cooling is ≤180 m / min, for example, it can be 10 m / min, 20 m / min, 40 m / min, 60 m / min, 80 m / min, 100 m / min, 120 m / min, 140 m / min, 160 m / min, 180 m / min, etc.

[0026] Preferably, the first stage cooling includes stage A cooling and stage B cooling performed sequentially.

[0027] Preferably, the cooling temperature of section A is 105-125°C, for example, it can be 105°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C, 120°C, 122°C, 124°C, 125°C, etc.; the cooling temperature of section B is 75-95°C, for example, it can be 75°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, 92°C, 94°C, 95°C, etc.

[0028] As a preferred technical solution of the present invention, the preparation method comprises the following steps:

[0029] The polyvinyl chloride insulation material is extruded through a first extruder at a temperature of 145 to 195° C. and an extruded wire diameter of φ2.0 mm to φ21 mm, and coated on the surface of the conductor to obtain an insulation layer; the nylon sheath material is extruded through a second extruder at a temperature of 230 to 270° C. and an extruded wire diameter of φ2.0 mm to φ22 mm, and coated on the surface of the insulation layer to obtain a sheath layer; and the obtained cable is sequentially cooled by cooling water at a temperature of 105 to 125° C., cooling water at a temperature of 75 to 95° C., and cooling water at a temperature of 25 to 35° C. to obtain the insulating sheathed cable.

[0030] In a second aspect, the present invention provides an insulating sheathed cable, wherein the insulating sheathed cable is prepared by the preparation method described in the first aspect.

[0031] Preferably, the insulating sheathed cable comprises a conductor and an insulating layer and a sheath layer sequentially coated on the surface of the conductor.

[0032] Preferably, the conductor comprises a copper conductor, and the single wire diameter of the copper conductor is 0.39-2.69 mm, for example, it can be 0.39 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, etc.; the twisted pitch ratio is 15-20, for example, it can be 15, 16, 17, 18, 19, 20, etc.

[0033] In the present invention, the conductor is a semi-finished conductor formed by twisting a number of annealed soft copper monofilaments.

[0034] Preferably, the thickness of the insulating layer is 0.38-1.78 mm, for example, it can be 0.38 mm, 0.4 mm, 0.42 mm, 0.44 mm, 0.45 mm, 0.48 mm, 0.5 mm, 0.52 mm, 0.55 mm, 0.58 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.75 mm, etc.

[0035] Preferably, the thickness of the sheath layer is 0.1-0.23 mm, for example, 0.1 mm, 0.12 mm, 0.14 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, etc.

[0036] In the present invention, the nylon sheath layer has high mechanical properties, plays a good protective role during installation and laying, and can be used in harsh environments.

[0037] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The preparation method of the insulating sheathed cable provided by the present invention adopts a series production method, wherein the insulating material and the sheathing material are extruded in different machine heads, and after the insulating layer is extruded and coated, the sheathing layer is immediately extruded without cooling, and then a segmented cooling method is adopted, which can not only improve the production efficiency, but also the obtained cable insulating layer has high tensile strength and elongation at break; the sheathing layer is not easy to crack, and there are no bubbles on the surface, and the product quality is high. At the same time, the cable has good electrical properties, aging resistance, insulation properties, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic structural diagram of an insulating sheathed cable obtained by the preparation method provided in Example 1 of the present invention;

[0041] Among them, 1-conductor; 2-insulation layer; 3-sheath layer. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0043] The materials used in the present invention can be purchased from the market or prepared by conventional methods; unless otherwise specified, the materials used in the present invention are as follows:

[0044] Conductor: Copper conductor, specification is 18AWG, single wire diameter is φ0.3mm, and twisted pitch ratio is 15 times.

[0045] Polyvinyl chloride: TEKNOR APEX 80853-C; wherein the polyvinyl chloride is tested according to UL2556 standard, and its tensile strength is 20.6MPa, elongation at break is 200%, and volume resistivity is 3.4×10 16 Ω·cm; Material density 1.31g / cm 3 ; Single vertical combustion qualified; VW-1 qualified.

[0046] Nylon: Delta PA1001-S4-6.

[0047] Example 1

[0048] This embodiment provides a method for preparing an insulating sheathed cable, which specifically includes the following steps:

[0049] The polyvinyl chloride insulation material is extruded through a first extruder (the specific extrusion process is shown in Table 1, and the extrusion wire diameter is φ2.0 mm), and coated on the surface of the conductor to obtain an insulation layer with a thickness of 0.85 mm; then, the nylon sheath material is immediately extruded through a second extruder (the specific extrusion process is shown in Table 2, and the extrusion wire diameter is φ2.2 mm), and coated on the surface of the insulation layer to obtain a sheath layer with a thickness of 0.18 mm; then the obtained cable is sequentially cooled by cooling water at a temperature of 115° C., cooling water at a temperature of 80° C., and cooling water at a temperature of 25° C. to obtain the insulating sheathed cable.

[0050] The structural schematic diagram of the insulating sheathed cable is as follows Figure 1 As shown, it includes a conductor 1 and an insulating layer 2 and a sheath layer 3 which are sequentially coated on the surface of the conductor.

[0051] Table 1

[0052]

[0053] Table 2

[0054] Water Jacket One section Second paragraph Three sections Four sections Clip One Clip II Side Flow Machine head Eye Model Actual temperature ℃ 53 235 245 245 245 265 265 241 262 260 Set temperature ℃ 50 235 245 245 245 265 265 245 265 260

[0055] Example 2

[0056] This embodiment provides a method for preparing an insulating sheathed cable, which specifically includes the following steps:

[0057] The polyvinyl chloride insulation material is extruded through a first extruder (the specific extrusion process is the same as that in Example 1), and coated on the surface of the conductor to obtain an insulation layer with a thickness of 1.5 mm; then, the nylon sheath material is immediately extruded through a second extruder (the specific extrusion process is the same as that in Example 1), and coated on the surface of the insulation layer to obtain a sheath layer with a thickness of 0.1 mm; then the obtained cable is sequentially cooled by cooling water at a temperature of 125° C., cooling water at a temperature of 95° C., and cooling water at a temperature of 25° C. to obtain the insulating sheathed cable.

[0058] Example 3

[0059] This embodiment provides a method for preparing an insulating sheathed cable, which specifically includes the following steps:

[0060] The polyvinyl chloride insulation material is extruded through a first extruder (the specific extrusion process is the same as that in Example 1), and coated on the surface of the conductor to obtain an insulation layer with a thickness of 0.5 mm; then, the nylon sheath material is immediately extruded through a second extruder (the specific extrusion process is the same as that in Example 1), and coated on the surface of the insulation layer to obtain a sheath layer with a thickness of 0.2 mm; then, the obtained cable is sequentially cooled by cooling water at a temperature of 105° C., cooling water at a temperature of 85° C., and cooling water at a temperature of 25° C. to obtain the insulating sheathed cable.

[0061] Example 4

[0062] This embodiment provides a method for preparing an insulating sheathed cable, which differs from Embodiment 1 only in that the segmented cooling includes sequentially cooling the obtained cable through cooling water at a temperature of 135°C, cooling water at a temperature of 100°C, and cooling water at a temperature of 25°C, and the other steps are the same as those in Embodiment 1.

[0063] Example 5

[0064] This embodiment provides a method for preparing an insulating sheathed cable, which differs from Embodiment 1 only in that the segmented cooling includes sequentially cooling the obtained cable through cooling water at a temperature of 100°C, cooling water at a temperature of 70°C, and cooling water at a temperature of 25°C, and the other steps are the same as those in Embodiment 1.

[0065] Example 6

[0066] This embodiment provides a method for preparing an insulating sheathed cable, which differs from Embodiment 1 only in that the segmented cooling includes sequentially cooling the obtained cable through cooling water at a temperature of 80°C and cooling water at a temperature of 25°C, and the other steps are the same as those in Embodiment 1.

[0067] Example 7

[0068] This embodiment provides a method for preparing an insulating sheathed cable, which differs from Embodiment 6 only in that the segmented cooling includes segmentally cooling the obtained cable through cooling water at a temperature of 60°C and cooling water at a temperature of 25°C, and the other steps are the same as Embodiment 6.

[0069] Comparative Example 1

[0070] This comparative example provides a method for preparing an insulating sheathed cable, which differs from Example 1 only in that an integrated die is used, a high temperature zone and a low temperature zone are respectively arranged in the die, polyvinyl chloride insulation material is added to the low temperature zone, and a nylon sheath material is added to the high temperature zone, and then they are extruded from the same die at the same time and coated on the surface of the conductor, the polyvinyl chloride insulation layer is coated on the surface of the conductor, and the nylon sheath layer is included on the surface of the insulation layer, the extrusion temperature is the same as that in Example 1, and the other steps are also the same as those in Example 1.

[0071] Comparative Example 2

[0072] This comparative example provides a method for preparing an insulating sheathed cable, which differs from Example 1 only in that, after obtaining the insulating layer, the obtained cable is sequentially cooled by cooling water at a temperature of 115°C, cooling water at a temperature of 80°C, and cooling water at a temperature of 25°C, and then extrusion coating of the nylon sheath layer is performed. The other steps are also the same as those in Example 1.

[0073] Performance Testing

[0074] The tensile strength and elongation at break of the insulation layer of the cables obtained by the preparation methods provided in Examples 1 to 7 and Comparative Examples 1 and 2 were tested with reference to Table 11 of standard UL83, and the performance of the insulation layer was used to represent the performance of the cable; the higher the tensile strength and elongation at break of the insulation, the better the performance of the cable prepared by the method provided by the present invention.

[0075] The specific test results are shown in Table 3:

[0076] Table 3

[0077] Insulation tensile strength / MPa Insulation breaking elongation / % Example 1 22.86 250 Example 2 22.58 240 Example 3 22.92 250 Example 4 21.05 210 Example 5 21.42 220 Example 6 20.54 210 Example 7 20.32 200 Comparative Example 1 18.45 180 Comparative Example 2 18.96 180

[0078] As can be seen from Table 3, the preparation method provided by the present invention adopts tandem production, the insulating material and the sheath material are extruded in different heads, and after the insulating layer is extruded and coated, the sheath layer is immediately extruded without cooling, and then a segmented cooling method is adopted, which can not only improve the production efficiency, but also the obtained cable insulation layer has high tensile strength and elongation at break; the sheath layer is not easy to crack, there are no bubbles on the surface, and the product quality is high. At the same time, the cable has good electrical properties, aging resistance, insulation performance, flame retardant performance, etc., meets the technical requirements of UL83, and can be used in humid environments; in the present invention, the cable insulation tensile strength obtained by the preparation method is 20.32-22.86MPa, and the insulation elongation at break is 200-250%.

[0079] It can be seen from Comparative Examples 1 and 2 that the cables not obtained by using the specific process of the present invention have lower insulation tensile strength and insulation elongation at break.

[0080] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing an insulating sheathed cable, characterized in that: The preparation method comprises the following steps: The insulating material is extruded through a first extruder and coated on the surface of the conductor to obtain an insulating layer; then, the sheath material is extruded through a second extruder and coated on the surface of the insulating layer to obtain a sheath layer; then, segmented cooling is performed to obtain the insulating sheathed cable.

2. The preparation method according to claim 1, characterized in that: The insulating material comprises polyvinyl chloride insulating material; Preferably, the extrusion line diameter extruded by the first extruder is φ2.0mm~φ21mm; Preferably, the temperature of the extrusion through the first extruder is 145-195°C.

3. The preparation method according to claim 1 or 2, characterized in that: The sheath material comprises nylon sheath material; Preferably, the extrusion line diameter extruded by the second extruder is φ2.0mm~φ22mm; Preferably, the temperature of the extrusion through the second extruder is 230-270°C.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The segmented cooling method includes conveying the obtained cable to cooling water of different temperatures for cooling.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The segmented cooling includes a first segment cooling and a second segment cooling performed sequentially; Preferably, the temperature of the first cooling stage is 75-125°C; Preferably, the temperature of the second cooling stage is 25-35°C; Preferably, the speed of the segmented cooling is ≤180 m / min.

6. The preparation method according to claim 5, characterized in that: The first stage cooling includes stage A cooling and stage B cooling performed sequentially; Preferably, the cooling temperature of the A section is 105-125°C, and the cooling temperature of the B section is 75-95°C.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: The polyvinyl chloride insulation material is extruded through a first extruder at a temperature of 145 to 195° C. and an extruded wire diameter of φ2.0 mm to φ21 mm, and coated on the surface of the conductor to obtain an insulation layer; the nylon sheath material is extruded through a second extruder at a temperature of 230 to 270° C. and an extruded wire diameter of φ2.0 mm to φ22 mm, and coated on the surface of the insulation layer to obtain a sheath layer; and the obtained cable is sequentially cooled by cooling water at a temperature of 105 to 125° C., cooling water at a temperature of 75 to 95° C., and cooling water at a temperature of 25 to 35° C. to obtain the insulating sheathed cable.

8. An insulated sheathed cable, characterized in that: The insulating sheathed cable is prepared by the preparation method described in any one of claims 1 to 7.

9. The insulating sheathed cable according to claim 8, characterized in that: The insulating sheathed cable comprises a conductor and an insulating layer and a sheath layer sequentially coated on the surface of the conductor; Preferably, the conductor comprises a copper conductor, the diameter of a single wire of the copper conductor is 0.39-2.69 mm, and the twisted pitch ratio is 15-20.

10. The insulating sheathed cable according to claim 8 or 9, characterized in that: The thickness of the insulating layer is 0.38 to 1.78 mm; Preferably, the thickness of the sheath layer is 0.1-0.23 mm.

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