the invention relates to a process for bonding a silicone or silicone based material to a polyurethane and use of the bonded silicone - polyurethane in the manufacture of biomaterials , devices , articles or implants , in particular long term implantable medical devices in the fields of cardiology , orthopedics , plastic surgery and gastroenterology . the process involves the steps of flame treating a surface of the silicone or silicone based material and bonding the polyurethane to the flame treated surface of the silicone or silicone based material .