发明名称 |
Process for extruding a thermoplastic sheath in the form of a tubular film provided with perforations and device for carrying out the process |
摘要 |
The present invention relates to a process for extruding a thermoplastic sheath in the form of a tubular film provided with perforations and to a device for carrying out the process, according to which the extruded film passes over a skirt through which are blown jets of hot air provoking the perforation and formation of openings in the film; in the areas where the film is not to be perforated, air jets are also blown through channels of smaller width, therefore with a reduced pressure, so that the jets do not provoke the perforation of the film but form an air-cushion facilitating the flow of the film on the skirt; the channels are supplied from a pneumatic chamber with interposition of a rotary distributor formed by a ring made of graphite or self-lubricating material. The invention is applicable to the manufacture of partially perforated tubular films with a view to making packings.
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申请公布号 |
US4303609(A) |
申请公布日期 |
1981.12.01 |
申请号 |
US19790107835 |
申请日期 |
1979.12.28 |
申请人 |
HUREAU, JACQUES;HUREAU, JEAN-CLAUDE;GAILLARD, HUBERT |
发明人 |
HUREAU, JACQUES;HUREAU, JEAN-CLAUDE;GAILLARD, HUBERT |
分类号 |
B29C47/12;(IPC1-7):B29C24/00 |
主分类号 |
B29C47/12 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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