Method of controlling the film thickness of blown

专利名称：Method of controlling the film thickness of blown and axially, preferably biaxially
stretched tubular films
发明人：FEISTKORN, WERNER, DR. DIPL.-ING.,VOSS, KLAUS-PETER, DIPL.-ING.
申请号：EP90120516.1
申请日：19901025
公开号：EP0432423A1
公开日：
19910619
专利内容由知识产权出版社提供
摘要：For the axial, preferably biaxial stretching of tubular films laid flat after their production on a blown film extruder line, the said films are inflated again to form a tubular film bubble (4) or are expanded to form a film tube. In the inflated or expanded state, these then run through an oven (11), from which they are drawn off, with renewed flattening (12), at a rate which is increased with respect to the running-in rate by an amount corresponding to the desired stretching ratio. In order to ensure that the stretched tubular films have a substantially equal thickness distribution over their circumference, the film thickness of the stretched tubular film emerging from the oven (11) is measured over its circumference before or after its flattening (12) and the thickness distribution over the circumferential profile of the tubular film produced on the blown film extruder line is set according to the measured thicknesses of the circumferential profile in such a way as to compensate substantially for deviations from the average film thickness brought about in the oven during stretching on account of uneven heating and possibly other disturbing influences.
申请人：WINDMOELLER & HOELSCHER
地址：MUENSTERSTRASSE 50; W-4540 LENGERICH,Münsterstrasse 50 D-49525 Lengerich DE
国籍：DE
代理机构：Gossel, Hans K., Dipl.-Ing.
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