Multilayer plastic strip manufacture with low thickness variation across width by combining streams for outer layers before they are widened for combining with central layer

摘要

Melt for a central layer (62) flows initially through a narrow feed channel (13) of a multichannel die (6) and is then spread out in a broad distribution channel (15). At a point beyond this channel in the flow direction further layers (60,61,63) flow onto the upper and lower sides of the middle layer with at least two on one side, both of which were fed together in a narrow channel (9) before reaching a separate distribution channel (11).