The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1995
Filed:
Sep. 07, 1993
Andreas Rutz, Lindau, DE;
Lindauer Dornier GmbH, Lindau, DE;
Abstract
A thermoplastic film web is subjected to a defined shrinking in a treatment apparatus with two mirror-symmetrically arranged tentering chains. For this purpose, each chain is equipped with tentering clamps that have a variable on-center spacing or pitch in the travel direction of the tentering chains, and which additionally are position adjustable in a direction other than the travel direction. The entire clamp body or clamp elements may be position variable in a direction other than the travel direction. In operation, the pitch is first reduced in the inlet and/or heating zone of the treatment apparatus. Simultaneously, the clamping position of the individual clamps or clamping element is changed, e.g. by tilting or lifting. The clamp position change takes up extra film web length resulting from the pitch change, whereby the film web assumes throughout its width a corrugated configuration. Then, the film web is cross-stretched. Then the position of the clamps or clamp elements is changed in the setting zone of the apparatus so that the film web is plane again, whereby the shrinking takes up the corrugations. Then, the clamps release the film web and thereafter the original longer pitch is restored.