CPC B29C 48/92 (2019.02) [B29C 48/0018 (2019.02); B29C 48/325 (2019.02); B29C 55/28 (2013.01); B29C 2948/92152 (2019.02); B29C 2948/92428 (2019.02); B29C 2948/92647 (2019.02); B29C 2948/92904 (2019.02)] | 19 Claims |
1. A blown film forming apparatus comprising:
a die including a substantially columnar inner peripheral member and a substantially cylindrical outer peripheral member that surrounds the inner peripheral member, and extruding a resin from a lip formed between the inner peripheral member and the outer peripheral member; and
a plurality of die lip drive mechanisms including a fluid pressure actuator as a drive source and adjusting a lip width by applying a radially outward tensile load to the outer peripheral member,
wherein the outer peripheral member includes a plurality of tensile load receiving portions to each of which a tensile load is applied by the respective die lip drive mechanism, and a stiffness reducing portion that is provided between the plurality of tensile load receiving portions.
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