Method for extruding an extrusion product and extrusion line
AssigneeCiTEX Holding GmbH
InventorsAndrej Unruh, Jan H. Petermann
Life of this patent
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Abstract
The present disclosure relates to a method and an extrusion line in which an additive content, in particular, a carbon black content, can be determined inline during extrusion of an extrusion product. For this purpose, an initial measurement is carried out in which a layer thickness and a refractive index of the extrusion product are determined, whereupon a continuous in-line measurement of the current additive content is carried out by a stationary radar measuring device. Thus, the layer thickness is set and the additive content is determined directly by the radar measuring device and controlled by setting the additive feed rate, in particular as a close-loop control.
Claims11
A method for extruding an extrusion product, comprising at least the following steps:
- feeding a first bulk material via a feeding device with a first feeding rate to an extruder,
- feeding an additive bulk material via a metering device with an additive feed rate to the extruder,
- melting at least the first bulk material and extruding an extrusion product,
- cooling the extrusion product,
- measuring the extrusion product while determining a layer thickness and a refractive index, wherein a layer transit time of the extrusion product is measured with a radar measuring device,
- determining an additive content of the extrusion product from the refractive index and calibration values,
- comparing the determined additive content with a target additive content and controlling the additive content by controlling the metering device and changing the additive feed rate,
- subsequently, during extrusion, continuous or repeated measurements of the current layer running time with the radar measuring device or a further radar measuring device and determination of the current refractive index, and
- subsequent adjustment or control of the additive content by feedback to the determination of the additive content of the extrusion product,
- wherein the control of the additive content is carried out as a closed loop control and a control of the layer thickness is an external control loop superimposed over the control of the additive content as a superordinate control.
Dependencies are inferred from the claim text.