Preparation process of novel automobile wire harness with high tensile strength

Abstract

The invention discloses a preparation process of a novel automobile wire harness with high tensile strength, which comprises the following steps: carrying out acid pickling, activation, coupling agent coating and other pretreatment on a carbon nanotube, blending with modified polyaryletherketone, and granulating to obtain a novel PAEK-CNT nano composite material with high tensile strength, high temperature resistance, chemical corrosion resistance and low impedance. And finally performing extrusion molding on the nano composite material and a conductive wire core through a double-screw extruder to obtain the novel automobile wire harness with high tensile strength. The jacket is prepared by mixing modified polyaryletherketone (PAEK) with carbon nanotubes (CNT), is superior to a traditional rubber jacket, is resistant to high temperature and chemical corrosion, good in mechanical property and high in tensile strength, is integrally adaptive to current new energy automobile wire harness deployment and control, and meets the lightweight design requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile wiring harnesses, and in particular relates to a novel preparation process for automobile wiring harnesses with high tensile strength. Background Art

[0002] The automotive wiring harness is the network backbone of the vehicle's electrical circuits; without it, there would be no automotive circuits. A wiring harness is a component that connects electrical wires and cables, formed by pressing contact terminals (connectors) stamped from copper, and then plastic-molded with insulators or metal casings to form a bundled wiring harness. The wiring harness industry chain encompasses wires and cables, connectors, processing equipment, wiring harness manufacturing, and downstream application industries. Wiring harnesses are widely used in automobiles, home appliances, computers and communications equipment, and various electronic instruments and meters. The vehicle body wiring harness connects the entire vehicle body.

[0003] In actual use, existing automotive wiring harnesses are prone to entanglement and are not fixed, resulting in short circuits between the wiring harnesses, which in turn affects the entire use of the car. In addition, they have poor tensile strength and are prone to breakage. They also have poor high-temperature resistance, which results in damage to the cables due to the flow of current and the increase in external temperature during use. Therefore, in order to solve this series of problems, we have proposed a new automotive wiring harness with high tensile strength to solve the problem. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a new automotive wiring harness preparation process with high tensile strength, avoiding the troubles of conventional wiring harnesses being coated with ordinary rubber, which has poor mechanical properties, is easy to wear, and has low tensile strength.

[0005] In order to solve the above technical problems, the present invention discloses a novel process for preparing automotive wiring harnesses with high tensile strength, comprising: Step a. The CNTs were acidified by ultrasonic shaking in concentrated H2SO4 / HNO3 for 2 hours, wherein the concentrated H2SO4 / HNO3 ratio was 3:1; Step b. The acidified CNTs were fed into a plasma activation device and bombarded with Ar plasma at a power of 300 W for 5 minutes to enhance surface activity; the CNTs were then removed and impregnated with an ethanol solution of a silane coupling agent; Step c. providing a PAEK particle size of 3 mm and 0.2 wt% -1.5 wt% of the impregnated CNT dry mix, and put into a twin-screw extruder, after cooling, cut into 2 × 2 mm particles, vacuum dried to obtain a PAEK-CNT nanocomposite material; Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion.

[0006] According to one embodiment of the present invention, in the above step b, the CNT aspect ratio is greater than 1000, the purity is greater than 95%, and the size of the agglomerates after acidification is less than 1 μm.

[0007] According to one embodiment of the present invention, the twin-screw extruder in the above step c has a length-to-diameter ratio of 40:1 and is temperature-controlled in sections, wherein the feeding end temperature is 280°C, the melting end temperature is 320°C, the die end temperature is 300°C, and the screw speed is 200 rpm.

[0008] According to one embodiment of the present invention, the mass percentages of PAEK particles and CNTs in the above step c are 98.5% and 1.5% respectively.

[0009] According to one embodiment of the present invention, the mass percentages of PAEK particles and CNTs in the above step c are 99% and 1% respectively.

[0010] According to one embodiment of the present invention, the mass percentages of PAEK particles and CNTs in the above step c are 99.8% and 0.2% respectively.

[0011] According to one embodiment of the present invention, the wire harness body extruded in the above step e is cooled in a graded water cooling tank, and the graded water cooling tank is divided into 60°C section, 30°C section, and 15°C section.

[0012] According to one embodiment of the present invention, in the above step e, after cooling, irradiation cross-linking is performed using an irradiation device, wherein the electron beam energy is 10 MeV and the dose is 50 kGy, so that the cross-linking degree of the insulating layer reaches more than 70%.

[0013] According to one embodiment of the present invention, the outer side of the wiring harness body obtained after radiation cross-linking in step e is further covered with a metal shielding mesh and a wear-resistant insulating sleeve.

[0014] Compared with the prior art, the present invention can achieve the following technical effects: The jacket is prepared by modifying polyaryletherketone (PAEK) mixed with carbon nanotubes (CNT), which is superior to traditional rubber jackets. It is also resistant to high temperature and chemical corrosion, has good mechanical properties and high tensile strength.

[0015] Of course, any product implementing the present invention does not necessarily need to achieve all of the above-mentioned technical effects at the same time. DETAILED DESCRIPTION

[0016] The following will describe the embodiments of the present invention in detail with reference to examples, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0017] The present invention discloses a novel process for preparing a high-tensile-strength automotive wiring harness, comprising: Step a. The CNTs were subjected to an acidification treatment by ultrasonic oscillation in concentrated H2SO4 / HNO3 for 2 hours, wherein the ratio of concentrated H2SO4 / HNO3 was 3:1; thereby introducing -COOH groups to enhance dispersibility.

[0018] Step b. The acidified CNTs are fed into a plasma activation device and bombarded with Ar plasma at 300W for 5 minutes to increase surface activity. The CNTs are then removed and impregnated with an ethanol solution of a silane coupling agent, KH-550, to improve interfacial bonding with PAEK. The CNTs must have an aspect ratio greater than 1000, a purity greater than 95%, and agglomerate size less than 1μm after dispersion.

[0019] Step c. 3mm PAEK particles and 0.2wt%-1.5wt% impregnated CNTs are dry-blended and fed into a twin-screw extruder. After cooling, the mixture is cut into 2x2mm pellets and vacuum-dried to produce a PAEK-CNT nanocomposite. The modified polyaryletherketone (PAEK) exhibits high-temperature resistance (200°C long-term, 300°C short-term), surpassing conventional PVC / XLPE. It is also chemically resistant (resistance to fuel oil, coolant, and salt spray), low-smoke, and non-toxic, meeting electric vehicle fire safety standards (e.g., UL94 V-0). The carbon nanotubes (CNTs) enhance electrical conductivity (reducing impedance and signal transmission loss) and mechanical strength (increasing tensile strength by over 30%). The twin-screw extruder has a length-to-diameter ratio of 40:1 and uses segmented temperature control, with feed-end temperatures of 280°C, melt-end temperatures of 320°C, and die-end temperatures of 300°C. The screw speed is 200 rpm.

[0020] Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion.

[0021] The extruded wire harness body is cooled in a graded water cooling tank, which is divided into 60°C, 30°C and 15°C sections. After cooling, it is irradiated and cross-linked using an irradiation device, with an electron beam energy of 10MeV and a dose of 50kGy, so that the cross-linking degree of the insulation layer reaches more than 70%. The outer side of the wire harness body obtained after irradiation and cross-linking continues to be covered with a metal shielding mesh and a wear-resistant insulating sleeve. Example 1

[0022] Step a. The CNTs were subjected to an acidification treatment by ultrasonic oscillation in concentrated H2SO4 / HNO3 for 2 hours, wherein the ratio of concentrated H2SO4 / HNO3 was 3:1; thereby introducing -COOH groups to enhance dispersibility.

[0023] Step b. The acidified CNTs are fed into a plasma activation device and bombarded with Ar plasma at 300W for 5 minutes to increase surface activity. The CNTs are then removed and impregnated with an ethanol solution of a silane coupling agent, KH-550, to improve interfacial bonding with PAEK. The CNTs must have an aspect ratio greater than 1000, a purity greater than 95%, and agglomerate size less than 1μm after dispersion.

[0024] Step c. providing 98.5% PAEK particles with a particle size of 3 mm and 1.5% impregnated CNTs to dry mix, and feeding them into a twin-screw extruder. After cooling, cutting them into 2×2 mm particles, vacuum drying, and obtaining a PAEK-CNT nanocomposite material.

[0025] Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion. Example 2

[0026] Step a. The CNTs were subjected to an acidification treatment by ultrasonic oscillation in concentrated H2SO4 / HNO3 for 2 hours, wherein the ratio of concentrated H2SO4 / HNO3 was 3:1; thereby introducing -COOH groups to enhance dispersibility.

[0027] Step b. The acidified CNTs are fed into a plasma activation device and bombarded with Ar plasma at 300W for 5 minutes to increase surface activity. The CNTs are then removed and impregnated with an ethanol solution of a silane coupling agent, KH-550, to improve interfacial bonding with PAEK. The CNTs must have an aspect ratio greater than 1000, a purity greater than 95%, and agglomerate size less than 1μm after dispersion.

[0028] Step c. providing 99% PAEK particles with a particle size of 3 mm and 1% impregnated CNTs for dry mixing, feeding the mixture into a twin-screw extruder, cooling the mixture, cutting the mixture into 2×2 mm particles, and vacuum drying the mixture to obtain a PAEK-CNT nanocomposite material.

[0029] Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion. Example 3

[0030] Step a. The CNTs were subjected to an acidification treatment by ultrasonic oscillation in concentrated H2SO4 / HNO3 for 2 hours, wherein the ratio of concentrated H2SO4 / HNO3 was 3:1; thereby introducing -COOH groups to enhance dispersibility.

[0031] Step b. The acidified CNTs are fed into a plasma activation device and bombarded with Ar plasma at 300W for 5 minutes to increase surface activity. The CNTs are then removed and impregnated with an ethanol solution of a silane coupling agent, KH-550, to improve interfacial bonding with PAEK. The CNTs must have an aspect ratio greater than 1000, a purity greater than 95%, and agglomerate size less than 1μm after dispersion.

[0032] Step c. providing 99.8% PAEK particles with a particle size of 3 mm and 0.2% impregnated CNTs to dry mix, and feeding into a twin-screw extruder, and cutting into 2×2 mm particles after cooling, and vacuum drying to obtain a PAEK-CNT nanocomposite material.

[0033] Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion.

[0034] Experimental measurements show that when PAEK is less than 98%, processability deteriorates, and when CNT is greater than 2%, brittleness increases significantly. Therefore, the ratio is controlled to 98.5% to 99.8% PAEK and 0.2% to 1.5% CNT. In the above three embodiments, the electrical conductivity (in compliance with LV 112-1 standard) is: 0.5% CNT: reaches the percolation threshold, volume resistivity drops to 10 4 Ω·cm (meets the requirements of low-voltage signal lines).

[0035] 1.0% CNT: Resistivity 10² Ω·cm, can replace some copper wires (applicable to high-voltage wiring harnesses).

[0036] At 1.5%, the marginal effect of conductivity improvement is significantly reduced.

[0037] Mechanical properties (ISO 527 test): Tensile strength: 1% CNT increases the strength of PAEK from 90MPa to 135MPa (+50%).

[0038] Impact toughness: When CNT>1.2%, the notched impact strength decreases (due to stress concentration due to CNT agglomeration).

[0039] Processing performance: Melt Flow Index (MFI): Pure PAEK (340°C / 5kg): 28g / 10min At 1% CNT, it drops to 15g / 10min (still suitable for injection molding / extrusion).

[0040] 1.5% CNT results in MFI <10g / 10min, requiring special screw design.

[0041] Therefore, Example 2 is the most preferred and has the best mechanical properties. At the same time, compared with traditional PAEK, the volume resistivity is reduced to 10²Ω·cm and the tensile strength is increased to 135MPa by adding 1% CNT. 6 Ω·cm, and the tensile strength is only 90MPa.

[0042] In summary, the present invention prepares a jacket by modifying polyaryletherketone (PAEK) mixed with carbon nanotubes (CNT), which is superior to traditional rubber jackets and is resistant to high temperature and chemical corrosion, has good mechanical properties and high tensile strength.

[0043] The foregoing description shows and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the inventive concept described herein by the teachings above or by techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be within the scope of the appended claims.

Claims

1. A new type of automobile wiring harness preparation process with high tensile strength, characterized in that: include: Step a. The CNTs were acidified by ultrasonic shaking in concentrated H2SO4 / HNO3 for 2 hours, wherein the concentrated H2SO4 / HNO3 ratio was 3:1; Step b. The acidified CNTs were fed into a plasma activation device and bombarded with Ar plasma at a power of 300 W for 5 minutes to enhance surface activity; the CNTs were then removed and impregnated with an ethanol solution of a silane coupling agent; Step c. providing a PAEK particle size of 3 mm and 0.2 wt% -1.5 wt% of the impregnated CNT dry mix, and put into a twin-screw extruder, after cooling, cut into 2 × 2 mm particles, vacuum dried to obtain a PAEK-CNT nanocomposite material; Step d. providing a conductive core, removing the surface oxide layer by plasma cleaning, and then coating the conductive core with a silane coupling agent to enhance the bonding strength with the polymer; Step e. Using a dual extruder, pass the wire core through the die at a speed of 50 m / min; the PAEK-CNT melt is coated on the wire core through the annular die with a thickness control accuracy of ±0.02 mm, and the wire harness body is obtained by synchronous co-extrusion.

2. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: In the step b, the CNT aspect ratio is greater than 1000, the purity is greater than 95%, and the size of the agglomerates after acidification is less than 1 μm.

3. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: The twin-screw extruder in step c has an aspect ratio of 40:1 and segmented temperature control, wherein the feeding end temperature is 280°C, the melting end temperature is 320°C, the die end temperature is 300°C, and the screw speed is 200 rpm.

4. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: In step c, the mass percentages of PAEK particles and CNTs are 98.5% and 1.5% respectively.

5. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: In step c, the mass percentages of PAEK particles and CNTs are 99% and 1% respectively.

6. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: The mass percentages of PAEK particles and CNTs in step c are 99.8% and 0.2% respectively.

7. The novel automobile wiring harness preparation process with high tensile strength according to claim 1 is characterized in that: The wire harness body extruded in step e is cooled in a graded water cooling tank, which is divided into 60°C section, 30°C section and 15°C section.

8. The novel process for preparing a high tensile strength automotive wiring harness according to claim 8, characterized in that: In step e, after cooling, irradiation cross-linking is performed using an irradiation device, wherein the electron beam energy is 10 MeV and the dose is 50 kGy, so that the cross-linking degree of the insulating layer reaches more than 70%.

9. The novel process for preparing a high tensile strength automotive wiring harness according to claim 8, characterized in that: The outer side of the wiring harness body obtained after radiation cross-linking in step e is further covered with a metal shielding mesh and a wear-resistant insulating sleeve.