Extrusion device for rigid polyvinyl chloride sheets used for packaging

Abstract

The invention provides an extrusion device for rigid polyvinyl chloride sheets used for packaging and relates to an extrusion formation processing device for chemical engineering sheets. The extrusiondevice comprises a machine frame, an upper press roll and a lower press roll, wherein the upper press roll and the lower press roll are provided with a heating device capable of raising temperature and holding temperature respectively. The uneven solidification caused by much low surface temperature of the press rolls does not occur. Moreover, the upper press roll and the lower press roll are deflected relative to the central lines of respective axes on the horizontal plane to allow the two axes to enter a crossing state, and the position of the central point is unchanged after the two axes are crossed, so that gaps between both ends of the upper press roll and the lower press roll are widened and the discharging gap is changed. The deflection angles of the upper press roll and the lowerpress roll are the same, so although the linear velocities of the sheets on both sides of the same plane are different, the walking velocity is compensated and the thickness of the sheets 7 is made uniform and consistent because the linear velocities on the opposite plane are different.

Description

technical field [0001] The invention relates to a chemical sheet extrusion molding processing device, in particular to the improvement of the extrusion device. Background technique [0002] Rigid PVC sheets are widely used in packaging and decoration fields, including food packaging, pharmaceutical packaging, tool packaging, clothing and toy packaging, etc. The application of this product puts forward the following parameter requirements for the production of this product. The first is the size requirement, mainly the width and thickness deviation requirements; the second is the appearance requirement; the third is the mechanical and physical properties. Among them, the size requirement seems simple, but in the actual production process, the problem of uneven thickness of the finished sheet material in the lateral direction of the discharge often occurs, that is, thick in the middle and thin on both sides. In this regard, we analyzed and found that the cause of the problem ...

AI Technical Summary

Problems solved by technology

The main reason for the appearance of flow marks is that the temperature of the plastic sheet before entering the pressure roller is about 195°C, and the temperature of the pressure roller is low, which causes the surface of the sheet to cool and solidify rapidly, forming flow lines; even if the pressure roller interacts with the high-temperature plastic sheet After pressing for a period of time, the pressure roller has a certain temperature, but the pressure roller of metal material will still cool down rapidly during the rotation process, resulting in a large temperature difference between the surface of the roller and the surface of the plastic sheet, and there will still be flow marks

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