A Dynamic Adjustment Method for Plastic Injection Molding Pressure Switching

Abstract

The invention discloses a dynamic adjustment method for plastic injection moulding pressure-keeping switchover. The dynamic adjustment method comprises the following steps: executing a plastic injection moulding process for at least one mould order before formally processing so as to obtain a plurality of sampling points, wherein the sampling points comprise a start point when injection pressure is converted from fluctuation to stability and a switchover point corresponding to a pressure-keeping switchover position, and simultaneously, recording corresponding injection screw position and injection pressure; calculating a product filling index FI; starting normal processing, collecting a plurality of sampling points in real time, wherein the sampling points comprise sampling points corresponding to the screw position and the start point, and then, calculating a current filling index FI*; and comparing the product filling index FI as a pressure-keeping switchover index with the current filling index, and executing dynamic adjustment of pressure-keeping switchover. By means of the dynamic adjustment method disclosed by the invention, the weight fluctuation problems of plastic products, caused by fluctuation of production factors, are obviously alleviated on the premise of not adding extra equipment; and simultaneously, the dynamic adjustment method has the advantages of being convenient to operate and control, high in precision, good in stability and the like.

Description

technical field [0001] The invention belongs to the related field of injection molding control, and more specifically, relates to a dynamic adjustment method for pressure-holding switching of plastic injection molding. Background technique [0002] Plastic products are mainly produced by injection molding process, and injection molding machine is the main production equipment. Injection molding includes six processes of mold closing, injection, pressure holding, cooling, melting, mold opening, and ejection. Pressure holding switching means that when the mold cavity is about to be full, the injection molding machine switches from the speed control of the injection stage to Pressure control in the pressure holding stage, the movement of the screw is switched from speed control to pressure control. This switching point is the so-called pressure holding switching point (V / P switching point), and constitutes one of the very important process parameters in the entire injection mol...

AI Technical Summary

Problems solved by technology

However, further studies have shown that the above-mentioned existing technologies are all based on cavity pressure information to perform control, and correspondingly need to install cavity pressure sensors on injection molding machines or molds, which not only increases equipment costs, but also increases the cost of installing cavity pressure sensors. It also puts forward higher requirements on the mold and the parts themselves, thus greatly restricting the application of this method in actual production.

Images