Abstract: A process for producing cork lines which comprises holding a leader or lers with a pair of metal molds having at the junctional surfaces thereof one or more cavities for forming a float or floats and one or more furrows formed so as to pass through said cavity or cavities for holding said leader or leaders, injecting a molten synthetic resin mixed witha foaming agent into said cavity or cavities to effect molding and foaming of said resin, cooling said metal molds and taking out a flat or floats integrally fixed to said leader or leaders from said metal molds.