Silicone products, production, processing and matters needing attention
When processing production of silicone products, in order to shorten the cycle time, as far as possible for silica gel, peroxide can choose relatively high curing temperature.
According to different wall thickness of the silicone products, mold temperature generally choose between 180 ℃ to 230 DHS C.
But often in the course of processing and production of silicone products appear some problems, will pay attention to the following points.
If the temperature is too high, will produce cracks around the parting surface, especially for large workpiece thickness phenomena.
This is in the process of sulfide caused by excessive expansion of internal stress.
In this case you should lower the temperature of the mold.
The temperature of the injection unit should be set at 80 ℃ to 100 ℃.
If the production is relatively long cycle time of vulcanization time or artifacts, the temperature will be a little bit lower.
For platinum silicone, it is recommended to use a lower temperature.
The injection unit is generally not more than 60 ℃ temperature.
Relative to natural rubber, solid silica gel can be quickly filled cavity.
But in order to avoid and reduce the formation of bubbles and other impurities, should reduce the injection speed.
The holding process should set up a relatively short time and low pressure.
Pressure too high or too long will back concave joint around the gate.
Peroxide vulcanization system of silicon rubber, 3-20 equivalent of fluorine rubber vulcanization time or three yuan, and for platinum silicone, can shorten curing time higher 70%.
Release agent containing silica gel composition is strictly prohibited.
Otherwise, even slight pollution of silica gel, can also cause sticking later.