| 摘要 |
The invention relates to an assembly and method for manufacturing a tubular sheath, including an extrusion head (12) and screw (14). The latter includes a barrel (16) connected to said extrusion head (12) and a screw shaft (20) mounted inside said barrel (16), which has an input end (22) for receiving a mixture of a polymer material and flow additive, and an output end (26) connected to the extrusion head (12), while said screw shaft (20) has a free end (21) located near said output end (26), said screw shaft (20) being intended to drive said mixture, while said flow additive migrates towards said screw shaft (20). According to the invention, said screw shaft (20) includes an axial passageway (38) leading to the surface of said free end (21), so as to be capable of extracting the polymer material which is molten and in which the flow additive is concentrated. |
