Abstract: An extrusion die for the extrusion of continuous hollow sections of plastic materials reinforced with fibers or molecules. Both the outer nozzle and inner mandrel are rotatable and have radial channels within them to allow the extrudate to flow through either the body of the nozzle or through the body of the mandrel in a direction perpendicular to the axis of the extrusion die into the space between them to impart a radial component to the fibers. Likewise, a helical channel formed either inside the nozzle or the mandrel or on a surface of either imparts a tangential component to the fibers. When formed inside the nozzle or mandrel, the helical channel forms a hollow enclosed passageway open at opposite ends through which the extrudate flows. The flow may also be straight through the die which gives the fibers an axial component.

Abstract: A joint between two hollow pipes is formed by inserting the pipes into a sleeve. The sleeve is made of a similar or compatible material to that of the pipes which are to be joined. The inner diameter of the sleeve increases from a middle portion outwardly to two end portions. The sleeve includes a pair of tapered collars which engage each end portion and abut the middle portion. Relative rotation of the pipes and sleeve causes melting and mixing of the pipe and sleeve surfaces. This mixing action eliminates the weld line present in known systems.

Abstract: An extrusion die for the extrusion of continuous hollow sections of plastic materials reinforced with fibers or molecules. Both the outer nozzle and inner mandrel are rotatable and have channels within them to allow the extrudate to flow through either the body of the nozzle or of the mandrel into the space between them to impart a radial component to the fibers. Likewise, a helical channel formed in either the nozzle or mandrel imparts a tangential component to the fibers. The flow may also be straight through the die which gives the fibers an axial component.