Why does AB two-component liquid silicone rubber need vacuum treatment? Before answering this question, we first know what types of silicone rubber AB two-component liquid silicone rubber contains. Food grade silicone rubber, human silicone rubber, pad printing silicone rubber and foaming silicone rubber are ab two-component liquid silicone rubber; After these AB silicone rubbers are mixed, the way to eliminate the bubbles generated by crosslinking and stirring is vacuuming.

Although AB silicone rubber can discharge bubbles by itself after mixing and stirring, it will affect its smoothness and product integrity; In particular, food grade silicone rubber is not recommended to be cured by self foaming. Vacuum treatment is required to ensure the integrity and smoothness of the finished silicone rubber mold.

Two component liquid silicone rubber

The vacuumizing time of mold silicone rubber needs to reasonably grasp the bubble discharge time according to the viscosity of liquid silicone rubber and climate temperature factors. Silicone rubber is relatively thin and produces fewer bubbles. Generally, bubbles can be completely removed in 3-5 minutes; It is relatively thick. In the case of high hardness and density, the vacuum pumping time can be controlled within 7-8 minutes, not more than 10 minutes. A long time will affect the fluidity of silicone rubber, resulting in agglomeration and viscosity of silicone rubber, which is not suitable for operation and production.

Someone will ask, if there is no vacuum pumping machine, how to deal with bubble discharge? If the mold requirements are not very high, the method of naturally eliminating bubbles at room temperature can be selected, but it can not guarantee the complete discharge of bubbles. Silicone rubber mold requires fine and high smoothness. It is recommended to use vacuum rod to pump bubbles, so as to avoid the unsmooth and flatness effect of silicone rubber mold.

Therefore, it is necessary to vacuum the two-component liquid silicone rubber. Do you understand?