Summary of the characteristics of silicone rubber molding

Silicone rubber molding is the manufacturing method of silicone products, which is also called lsr molding. Silicone products due to their superior reliability, longevity and extreme temperature adaptability, and stability and widely used. It will not deformation, and also won’t under extreme temperature exposure and damage. In the production of silicone products to do before die, ready to die to make silicone products. In the production of silicone mold, we according to the selection of silicone mold.

To make a good silicone mold, to make good mold material selection is the whole mold production process a very important link, the good silicone mold can make high-quality silicone products, silicone mold needs what conditions have? clear concept. Silicone is what? The following is a professional production manufacturer of silicone products NEWTOP silicone some analysis.

Silicone characteristics 1:

The heat resistance of heat-resistant silicone in the air is much better than that of organic silicone. Its physical and mechanical properties are basically unchanged at 150℃. It can be used for more than 1000h at 200℃. It can be used for a short time at 380℃. Therefore, silicone is widely used as the silicone parts used on high-temperature occasions. Silicone rubber molding is the process of processing silicone materials by high temperature and high pressure.

Silicone characteristics 2:

The main chain of weather-resistant silicone is saturated, and the Si-O-Si bond is very stable to oxygen, ozone, and ultraviolet light, so without any additives, that is, it has excellent weather resistance. When corona discharge occurs in ozone, organosilicon ages quickly, but the effect on silicone is not serious. The Lsr molding process absorbs this feature of silicone material and gives full play to its advantages. Long time exposure to ultraviolet and wind and rain, its physical and mechanical properties change little, after decades of outdoor exposure test, no cracks or degradation of viscosity and another aging phenomenon. It’s hard not to acknowledge the importance of silicone rubber molding.

Silicone characteristics 3:

In lsr molding, many characteristics of silica gel have been reflected. Among them, Silicone has excellent electrical insulation performance, its volume resistance up to 1x (1014~1016) ω.cm, creepage resistance of 10~30min(special grade up to 3.5kV /6h), arc resistance of 80~100s(special grade up to 420s); Surface resistance is (1~10) x1012 ω.cm; Conductive grade up to 1x (10-3~107) ω.cm; The tangent of dielectric loss Angle (TG6) is less than 10-3, the dielectric constant is 2.7~3.3(50Hz/25°C), and the dielectric strength is 18~36KV/mm, which varies little over a wide range of temperature and frequency. Even immersed in water, the electrical properties are rarely reduced, very suitable for electrical insulation material silicone has an excellent damping effect on corona discharge and arc under high voltage.

Silicone characteristics 4:

Compression deformation is an important performance of silicone used as a gasket under high and low-temperature conditions. The compression deformation of dimethyl silicone is poor, and the deformation value is up to 60% after 22h compression at 150℃. But methyl vinyl silicone, especially the use of alkyl series peroxide sulfide products, has excellent compression deformation, its deformation value can be less than 20%. Silicone rubber molding is very suitable for the production of these silicone parts.

The second stage vulcanization condition also has a great influence on the compression deformation value, that is, the higher the second stage vulcanization temperature, the lower the compression deformation value. In order to improve the compression deformation of vulcanized rubber products, mercury oxide, cadmium oxide, zinc oxide, and other compounds can be added to the rubber. This shows that lsr molding is one of the best manufacturing processes for silicone. Because of its excellent compression and deformation performance, silicone is suitable for o-rings, gaskets, and rubber rollers.

Silicone characteristics 5:

Oil resistance, chemical resistance of general silicone has medium oil resistance, solvent resistance, the performance of the good or bad mainly depends on the type of silicone rubber, filler type and amount, type of additives and crosslinking density silicone into a polar organic solvent, the volume will increase by 10%~15% in ASTM In no. 1 oil and No. 3 oil soaked at 150℃ for 70H, they can expand by 10% and 45% respectively, while in a non-polar solvent and fuel oil , they can expand by 150%~200%. However, they can return to their original state after the solvent is volatile, and have little influence on their physical properties.

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