Abstract: Sheets, strips or filaments of thermoplastic resin are produced by one or more extruders working into a remote shaping die that is movably juxtaposed with a cooling drum around which the hot product issuing from the die mouth is to be wound, the die being connected with the extruder or extruders via one or more flexible ducts having heating elements embedded in their walls. Each duct may comprise an inner hose of Teflon, an outer envelope of reinforced silicone rubber and various intermediate layers including a heating layer in the form of a wire coil or mesh and a surrounding heat barrier of asbestos.