| 摘要 |
<p>PURPOSE: To enable economical manufacture of all multilayer tubular structures by a method wherein an inner core ring and an inner wall of an outer nozzle ring define not only annular passages between the lower and upper portions thereof but also the flows of two annular passages forming a bottom face opposite to a jacket and multilayer tubular structures as well. CONSTITUTION: A seven-layer structure formed by an annular passageway inside a jacket 1a comprises inner and outer carrier layers formed on passageways 10 and 11, a recycling material layer on passageways 12 and 13, an adhesive layer formed on passageways 14 and 15, and an intermediate barrier layer formed on a passageway 16. The foregoing layers are combined and joined in an annular passageway 17 inclined downward. A bottom coupling region 17a is enclosed by an inner core ring 18 and an outer nozzle ring 19. Two rings 18 and 19 have head portion segments 20 and 21, respectively, each of which segment inclination is parallel to the bottom section of the jacket surface. Between the core ring 18 and the nozzle ring 19, the multilayer tubular structures are introduced to a flow aperture 22 of a nozzle 23 to be extruded.</p> |
