Process to produce thin film

US5288437A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Guenther Crass · Taunusstein, DE
• Siegfried Janocha · Wiesbaden, DE
• Gisbert Bammert · Oestrich-Winkel, DE

Key dates

• Filing date: May 4, 1992
• Grant date: Feb 22, 1994
• Expiry date: May 4, 2012

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C35/02
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process is described to produce ultra thin biaxially stretched film made of thermoplastic where at least two film webs are superimposed and stretched together in both the longitudinal and transverse directions. The film webs are subjected to a heat treatment before the first draw step. After stretching, the film webs are separated again from each other.