CRK was established in 1963 in gunma prefecture northern part of Tokyo. Since then, we offer various kinds of rubber materials such as rubber compound, molded rubber, and tapes. One of our main products are graphite based intumescent rubber materials applied for variety of through-penetration wall parts. They expand more than 10 times in case of fire and prevent further passage of flame. We can provide these fire-proof materials at various kinds of tapes, putty, and sponges. Also, ...