with means connecting the layers, e.g. tie layers or undercuts

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) > Articles comprising two or more components, e.g. co-extruded layers > the components being layers > with means connecting the layers, e.g. tie layers or undercuts