Patent · US Expired

Method and apparatus for preparing thermoplastic sheets, films, and plates

US5639404A · kind A · utility

8Cited by

10References

11Claims

0Family size

Assignee

Roehm GmbH Chemische Fabrik · DE

Inventors

Michael Meier-Kaiser · Pfungstadt, DE
Horst Greb · Reinheim, DE

Key dates

Filing date	Sep 27, 1995
Grant date	Jun 17, 1997
Priority date	—
Expiry date	Sep 27, 2015

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB29C2948/92923
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

The height of the bulge in the glazing roll gap of a supercalender in the extrusion of plates or films of a thermoplastic material smoothed on both sides may be controlled by measuring the location of the edges of the plastic sheet by means of measuring sensors and regulating the speed of the roll or the rate of extrusion of the polymer melt based on the width of the sheet so that the height of the bulge is always kept within tight tolerances.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.