公开(公告)号：US20040207130A1

公开(公告)日：2004-10-21

申请号：US10845307

申请日：2004-05-12

Applicant: Addex, Inc.

Inventor： William Randolph ,  Robert E. Cree

IPC: B29C047/88

CPC classification number: B29C47/92 ,  B29C47/0026 ,  B29C47/883 ,  B29C47/8835 ,  B29C2947/92152 ,  B29C2947/92314 ,  B29C2947/92428 ,  B29C2947/926 ,  B29C2947/92647 ,  B29C2947/92809 ,  B29C2947/92904 ,  B29C2947/92923

Abstract: A plastic resin extrusion line for the production of blown film includes an external thickness control device that provides a controllable amount of air from an inlet side through an annular region to one or two sets of lips. Barriers that can be manually or automatically controlled are provided in the annular region for localized control of air flow and thus for localized thickness control. The pressure drop across the barriers is significant relative to that in the lips.