On the contrary, sponge rubber commonly commences with expandable rubber varieties like EPDM or neoprene. The rubber compound is then supplemented which has a chemical blowing agent, which, upon heating, decomposes and releases gases. This method results in the growth of the rubber plus the formation of the sponge-like structure. https://water-proofrubberfoam93604.blogkoo.com/rubber-foam-versus-sponge-rubber-secrets-53225570