Rules for the use and assembly of heat-shrinkable pipes in cars  

Heat shrink tubes are widely used in automobiles, and depending on their characteristics, they can be divided into bundle systems, pipe systems and other systems. What specific application? Let's take a look together.

01 Linear system

Let's talk about the bundle system, which is generally divided into connecting bundles, bundle clamps, cable connectors, battery lines, connecting bundles and so on. It connects air conditioning, ABS brakes, signal lights and other important functions. It places high demands on insulation and sealing. Generally, double wall heat shrink tubing is used to cover wires and cables to prevent moisture, dust, oil stains, etc. to ensure the normal operation of wires and cables.

At the same time, double wall heat shrink tubes correspond to different bundles depending on the level of heat resistance and adhesion properties. For example:

Bundle connection:  In the process of double wall heat shrink tube processing, the internal thermomelt must be completely flowed into the gap between multiple wires, cooled and molded to achieve sealing. Therefore, it is necessary to select double-wall heat shrink tube with good fluidity and high thermoplastic shrinkage. This not only ensures efficient packaging, but also provides greater adhesion, making it easier to fill gaps in the bundle with hot melt adhesive.

In addition, with the advent of new energy vehicles, Y-cups used in high-voltage cable runs of new energy vehicles can provide insulation and sealing protection while being easy to install, providing a strong and reliable insulation and seal.

Bundle terminals:  Generally, the combination of bundles on one side of the wire is relatively simple, heat shrink tubes are easy to seal, and the gap between metal joints is larger and not easy to seal. It is recommended to use heat shrink tubing with sufficient adhesive content and good flowability of hot melt adhesive, which promotes full flow of hot melt adhesive during heating and filling the front gap.

Cable connections:  Cable connections are suitable for selecting double-wall heat shrink pipes with low fluidity to prevent slipping when heated.

Battery cables:  Battery cables are suitable for sealing with double-wall heat-shrinkable tubes with low fluidity and good adhesion to metal.

02 Pipe system

In a piping system, the area where heat shrink pipes are used typically includes brake pipes, air conditioning pipes, high pressure pipes and cooling pipes. In most cases, single wall heat shrink tubing is selected for packaging, providing mechanical protection, insulation and friction resistance. In some cases, double wall heat shrink tubing can be used. Below is an example of PVC heat shrink tubing specifically designed for capacitors.

Air conditioner pipe:  When shrinking the heat shrink tube, it should be well connected with the air conditioner pipe and should not wrinkle when bent and molded. At the same time, it plays the role of shock absorption and noise protection between components.

Automotive brake and fuel pipes:  It is necessary to use heat shrink pipes with seismic resistance, wear resistance, oil resistance, corrosion resistance and low temperature to protect automobile brakes and fuel pipes from mechanical damage and moisture, which may cause corrosion.

Air conditioner pipe:  When shrinking the heat shrink tube, it should be well connected with the air conditioner pipe and should not wrinkle when bent and molded. At the same time, it plays the role of shock absorption and noise protection between components.

Automotive brake and fuel pipes: It is necessary to use heat shrink pipes with seismic resistance, wear resistance, oil resistance, corrosion resistance and low temperature to protect automobile brakes and fuel pipes from mechanical damage and moisture, which may cause corrosion.

03  Other uses

Other application levels are mainly engine systems and identification systems.

High temperature heat shrink tubes are often used in engine systems, such as diesel elastomer heat shrink tubes, PVDF heat shrink tubes and PTFE heat shrink tubes, which operate in the engine compartment with a temperature resistance of more than 150°C and have excellent characteristics such as high wear resistance, sharpness and corrosion resistance.

In addition, high-pressure copper core polyolefin heat shrink tubing used in electric vehicle batteries has the characteristics of high shrinkage, wear resistance and no suffocation. It can connect and stick to different tires, effectively protecting tires in confined spaces.

Identification systems generally use printed text heat shrink tubes, which have the characteristics of halogen-free, low smoke, soft and smooth surface and excellent ink adhesion. It can be used for cable recognition, easy installation, and after-sales separation and identification.

Thermal capacitors also play an important role in the installation and maintenance of automotive electronics.

For example, in car audio systems, heat shrink tubing can be used to insulate and protect connectors from noise and interference. In automotive lighting system, heat shrink tubing can be used to seal and waterproof lamps, improving the reliability and service life of lighting equipment.

In addition, heat shrink tubing can also be used to protect car sensors, maintain car dashboards and other aspects, providing a good guarantee for the normal operation of the car.

04 Rules for assembling wires

Connection bundle

Before heat shrinking, check the condition of the wire, make sure there are no individual wires with poor wiring or bulging copper wires. After thermal compression, the thermomelt must overflow from both ends of the heat shrink tube and must satisfy the following points:

1.Copper wire should not pierce the heat shrink pipes;

2.Single end wrapped in metal shell of heat shrink tubes should be ≥1.5cm, and multi-pole end should be ≥2cm.

Heat shrink tubing should shrink evenly and bond to the outer layer of the wire. After heat shrinking there should be no visible gap between the glued surface, the heat shrink tube and the wire; Heat shrink pipes and pipes should not burn or shrink enough.

If single-sided wire is used, at least 1cm should be reserved at the wireless end of the heat shrink tube after connection;

Bundle clamp

After heat shrinking, the heat shrink tubing should be wrapped around all copper wires, and the visible copper wire at the end of the clamp should be completely covered with heat shrink tubing or thermoplastic. At the same time, the following criteria must be met:

1.Copper wire should not pierce the heat shrink pipes;

2.The area of the lining of the winding of heat-shrinkable pipes must be at least 1 cm;

Dot adhesive should not interfere with the normal use of assembly or assembly fastening tools;

Heat shrink tubing should shrink evenly and adhere to the wires and clamps. After heat shrinking, there should be no visible gap between the glued surface, heat shrink tube, clamp and wire; Heat shrink pipes and pipes should not burn or shrink enough.

三、Analysis of factors affecting the application of heat shrink pipes

1.Product consistency:Select heat shrink pipes that meet customer's performance requirements, such as single and double wall, shrinkage, heat resistance, material, pipe diameter, length and so on.

2.uniformity of parameters: time, temperature, heat shrink interval, temperature tolerance, etc. during the thermal compression process.

3.Equipment consistency: It is necessary to ensure that the models of each batch of equipment match and the operating condition is stable.

4.Build Consistency: correspondence between the position of the heat-shrinkable tube relative to the end of the assembly and the position of the bundle in the heat-shrinkable equipment.

5.Terminal structure:The specific design of the terminal requires targeted selection and technical and economic assessment.

6.Environmental factors:Since bundle suppliers have different seasonal or inventory conditions, heat shrink parameters must be adjusted accordingly and performance testing must be conducted to reflect the appropriate changes.