Silicone rubber manufacturer Primasil supplies compound, mouldings, extrusions and tubing for many industries including the medical, pharmaceutical, automotive, aerospace and rail and mass transit industries. Primasil provides information on how silicon is transformed into silicone rubber.. Silicone rubber manufacturer Primasil supplies compound, mouldings, extrusions and tubing for many industries including the medical, pharmaceutical, automotive, aerospace and rail and mass transit industries.