A method for controlling the individual layer thicknesses of a coextruded multilayer plastic web

摘要

PCT No. PCT/EP93/00301 Sec. 371 Date Jul. 23, 1994 Sec. 102(e) Date Jul. 23, 1994 PCT Filed Feb. 9, 1993 PCT Pub. No. WO93/15897 PCT Pub. Date Aug. 19, 1993.A method for regulating the thickness of several individual layers of an extruded multilayered plastic web involves melting at least two currents of molten plastic in different extruders and bringing the individual molten currents together in an adapter wherein the currents are superimposed into a laminated extruded multilayer stream. The extruded multilayer stream is supplied to a die slot. Devices are provided for controlling the flow of individual currents of molten plastic by modifying their sections before the currents are brought together in the adapter. In order to regulate the thickness distribution, the thickness of the individual layers of the multilayered extruded stream, which correspond to the different currents of molten plastics, is determined before the stream leave the die slot; that is, while the currents are still in a plastic state.