Why does the surface of the silicone mold remain sticky?
All addition curing silicone elastomers are susceptible to inhibition of crosslinking when in contact with certain materials and chemicals. Inhibition occurs when the elastomer is only partially cross-linked after 24 hours or when the contact surface with another material is tacky. Materials containing amines or sulfur compounds and non-ferrous metals have a particularly strong inhibiting effect, as do organotin compounds in condensation-curing silicone rubbers. It is advisable to examine mixing containers, molding boxes, originals and release agents for inhibiting effects before processing.