| 摘要 |
The apparatus includes at least one additional cylinder (2, 2) and plug (1, 1) which can be connected to an additional extruder for another polymer material. - An extrusion apparatus for producing a polymer film comprises a casing with a cylinder (2) having a first inlet (l1) connectable to a first extruder for a first polymer and a second inlet (l2) connectable to a second extruder for a second polymer. A first plug (1) located inside or insertible into the cylinder has first and second passages (P1, P2) in communication with the first inlet and second and third passages (P3, P4) in communication with the second inlet. A means is provided for moving the plug relative to the inlets. When the plug is in a first position between the inlets and a first end of the passages, a flow path is present between the first inlet, the first end of the first passage and a film-forming nozzle via a second end of the first passage, whilst at the same time another flow path is present between the second inlet, the first end of the third passage and an outlet (10) via a second end of the third passage, the outlet being connected to a bypass or an inlet to another cylinder. When the plug is in a second position between the inlets and a first end of the passages, a flow path is present between the second inlet, the first end of the fourth passage and a film-forming nozzle via a second end of the fourth passage, whilst at the same another flow path is present between the first inlet, the first end of the second passage and outlet via a second end of the second passage, the outlet being connected to a bypass or an inlet to another cylinder. The apparatus or casing also includes one or more, preferably at least two, additional cylinders which can be connected together via the four passages and contain plugs or can have plugs inserted into them. The additional cylinders and plug are all of the same type as the first cylinder and plug. The additional cylinders can be connected to at least one additional extruder for another polymer material. |
