Full Title

Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor (extrusion blow-moulding B29C49/04) > Component parts, details or accessories; Auxiliary operations > Extrusion nozzles or dies (extrusion characterised by the shape or cross-section of the extruded article B29C48/03) > with annular openings, e.g. for forming tubular articles > Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles