| 摘要 |
PURPOSE:To perform the covering of a conductor both in normal and reverse systems with a single cross head by providing a connection pipe port and a reverse flow ring at the bottom of the cross head to enable the connection to other sub extruder than the upper main extruder. CONSTITUTION:A main extruder 1 is set at the top of a cross head 12 while a connection pipe 3 is attached at the bottom thereof 12 to produce an extruded mixture 10 in an outer layer through a reverse ring 4. In the normal double- layer extrusion, a subextruder 2 is placed thereabove and extrudes an inner layer extruded mixture 9 and the outer layer extruded mixture 10 from the main extruder 1 to cover. In the reverse double-layer extrusion, the subextruder 2 is connected to the connection pipe 3 and extrudes an outer layer extruded mixture 11 through the reverse flow ring 4. The arrangement of two subextruders enables the simultaneous extrusion of three layers, i.e. inner, medium and layers to cover. |
