US 6,152,720 AGranted

Device for stable widthwise regulation of bulb angle in extrusion of sheets of heat-sensitive plastics through a calender opening formed by intake rollers

AssigneeRoehm GmbH Chemische Fabrik

InventorsHorst Greb, Erhard Haun, Karl Funk

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Abstract

A process and device for the stable widthwise regulation of the bulb angle in connection with the extrusion of sheets of heat-sensitive plastic (2) in an extrusion device with a calender opening formed by two intake rollers (3, 2) and a traversing measuring device (7) provided according to the calender slot by altering positioning elements on the extrusion device. At least two traversing measurements of a parameter correlating with the bulb angle are started consecutively on the heat-sensitive plastic sheet synchronously with the positioning of one of the two calender rollers. Like measurement conditions therefore exist and the deviation of the measured values obtained on the basis of the measurements in relation to specified expected values is used to regulate the bulb angle over its width by altering a setting element on the extrusion device.

Claims8

Dependent claims

A device for stable widthwise regulation of a bulb angle in extrusion of sheets of heat-sensitive plastic using an extrusion device having a calender opening formed by rotatable intake rollers, said device for stable widthwise regulation comprising:

a sensor positioned to sense an angular position of one of the rotatable intake rollers;
a measuring device constructed and positioned for measuring a parameter of the sheets of heat-sensitive plastic which correlate with the bulb angle, wherein said measuring device is triggered for movement in a widthwise direction of the sheets of heat-sensitive plastic in response to the angular position of the one of the intake rollers which was sensed by said sensor;
means for altering positioning elements of the extrusion device in accordance with the measured parameter of the sheets of heat-sensitive plastic said measuring device;
and
means for synchronizing a position through which said measuring device moves with the angular position of the one of the intake rollers sensed by said sensor.

2 more elements

Dependencies are inferred from the claim text.