Post curing for LSR

[ivyliu]

Dear experts,
I understand that liquid silicone rubber (LSR) requires secondary curing at 200°C for 4 hours. However, if the LSR has already bonded to the substrate, high-temperature treatment may cause warping.

Are there alternative methods for removing VOCs from LSR without exposing it to such high temperatures?

 

[Compositepro]

Silicone is a condensation cure polymer. It releases methanol or acetic acid during cure. The post cure is intended to complete the cure reaction, which releases these volatile materials. After the reaction is complete it still takes time for volatiles to diffuse to the surface and evaporate. The silicone will not have its full properties until you have done this. Your customer will have to deal lower properties and volatiles in his process, which may or may not be acceptable. This is why some products are cheaper and lesser quality than others. Time is money. Warping on post curing means that you did not get adequate cure during initial cure in the mold. Cure in the mold longer before demolding or fixture the part during post cure.