Manufacturing guide for liquid silicone molding based on silicone rubber parts
This article introduces the liquid silicone molding in detail and the main points of silicone rubber parts selection, I hope it will be helpful to industry practitioners to choose a manufacturer specializing in rubber parts, silicone parts, plastic parts molding, if you have related needs, this is very important.
Whether it is a high-end luxury car or an economical ordinary car, the wiring harness is basically the same in the form of wiring, connectors, rubber parts and wrapping tape. This product is a typical application case in silicone rubber parts.
With the improvement of people’s requirements for the safety, comfort, economy and emission of automobiles, automobile wiring harnesses are becoming more and more complex, but the space for wiring harnesses in the body is getting smaller and smaller. This relatively difficult problem encountered by the automotive industry, we often find solutions from silicon rubber parts.
Therefore, how to improve the comprehensive performance design of automotive wiring harnesses has become the focus of attention, and automotive wiring harness manufacturers no longer simply engage in the later design and manufacture of wiring harnesses, and it has become an inevitable trend to cooperate with automotive mainframe manufacturers for early development. And this happens to involve the process related to liquid silicone molding.
1. Types and applications of silicone rubber parts
The rubber part is to ensure that the electrical device is not damaged and maintain the seal of the passing object when the electrical device passes through the body and other objects. In order to play the role of wear resistance, waterproof, sealing and so on.
1.1 Classification of rubber parts
Its structure and fixing method are also different according to the different fixing positions.
According to the structure of rubber parts, it is divided into two types: with skeleton (guide structure, the material is mostly PA66) and without skeleton.
According to the fixing method of rubber parts, it is divided into two types: single-hole fixing and double-hole fixing.
2. Main features of liquid silicone molding
1) Wide operating temperature range and good high and low temperature resistance;
2) The silicone rubber parts have high heat resistance, and the rubber parts in different regions have different temperatures. It can be used for a long time in an environment of 120°C, and the maximum operating temperature is 150°C;
3) It is in direct contact with the atmosphere, and will be eroded by liquids such as rainwater. It needs to be able to withstand the severe cold outside the house in winter, and can be used for a long time in the sun, damp and cold natural environment without cracking; this is exactly what liquid silicone molding does. A very striking feature.
4) Good elasticity, especially good resilience is required; it can withstand multiple fatigue movements, and can recover from multiple deformations in various environments; it can be used for both moving joints and static joints.
5) Precise finished product stability and strict finished product dimensional tolerance control.
In automobiles, wiring harness rubber parts are used as static sealing and dynamic sealing elements.
For the wiring harness rubber parts in the engine compartment, due to the high temperature and humidity in the cabin and the existence of many corrosive gases and liquids, it is necessary to choose high temperature, oil resistant and chemical resistant rubber parts.
From the perspective of silicone rubber parts manufacturing
Liquid silicone molding creates more possibilities for automotive silicone parts. At the same time, in the application of high-power engines in new models, the layout of the front cabin is required to be compact, and the performance requirements of the wiring harness rubber parts are becoming more and more demanding.
The maximum operating temperature of silicone rubber parts is 150°C. Although it can basically meet the requirements at present, silicone rubber (VMQ) can be used for more safety and reliability. Among the rubbers used, silicone rubber has the widest operating temperature range (-59.5 to 316°C).
Excellent resistance to ozone aging, oxygen aging, light aging and weathering aging; excellent electrical insulation properties; excellent oil resistance, combustion resistance and other properties. The high temperature service life of silicone rubber is shown in Table 5. There are many differences in the heat and oil resistance of silicone rubber and other types of rubber.