The quality of demolding property is an important performance of silicone compound in molding processing. If the demolding property is poor, it is easy to cause defective products, reduce labor productivity, contaminate molds and increase costs.
One of the reasons why the rubber compound adheres to or sucks the mold is that the hydroxyl groups in the rubber compound undergo a chemical reaction with the hydroxyl groups on the metal surface of the mold at high temperatures. Another reason is that there are more low-molecular-weight substances in the rubber compound, more reactive genes, and the internal cross-linking is not sufficient.
In addition to adding internal release agents and other compounding agents, measures to improve demolding properties also include controlling the addition amount of hydroxyl silicone oil, improving the quality of raw rubber, reducing the content of hydroxyl groups and oligomers in raw rubber, and at the same time, strengthening vacuum mixing, appropriately extending the mixing time, and reducing the content of low-molecular-weight substances in the mixed rubber