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. 27, 1990
Filed:
Nov. 25, 1988
Hans Reifenhauser, Troisdorf, DE;
Wilhelm Predohl, Hennef-Bool, DE;
Reifenhauser GmbH & Co. Maschinenfabrik, Troisdorf, DE;
Abstract
The process for making a thermoplastic foil involves the use of a wide-outlet or long-slit die which has at least one outlet-gap-defining adjustable die lip, an opposing gap-bounding lip and a group of piezotranslators distributed over the length of the outlet-gap-defining adjustable die lip, each of which is part of a control loop, acts as a positioning member and is associated with an individual section of an outlet-gap-defining adjustable die lip. At least one actual value of the foil thickness of the thermoplastic foil formed is measured with a measuring device and is fed to a controlling processor. Each of the piezotranslators is controlled by a controlling processor with a controlling variable. In the controlling processor a distribution control variable which is generated by a thickness variation or error is generated by a control variable deviating from a setpoint value and the distribution control variable is fed to individual piezotranslators from the controlling processor according to a distribution function which distributes the thickness errors over the length of the adjustable outlet-gap-defining adjustable die lip.