Influence Factor Analysis Of Warpage And Optimization In Plastic Injection Molding Of Thin-wall Parts

Thin-walled injection molding technology is different from traditionalinjection molding, and due to the thinner wall thickness of parts, it is much moredifficult to fill the cavity and prone to product defect because the melt is frozenmuch quickly. As one of the primary product quality defects, warpage has been paidmore and more attention by product researchers and interrelated customers. It isimportant research direction by way of optimizing injection molding processparameters and die structure design to reduce the thin-walled product warpage.Based on the thin-walled refrigerator decoration parts as the research object, theCAE technology and intelligent optimization method were applied to research theeffects of the injection molding process parameters on warpage, and actualproduction verification is also performed. Meanwhile, injection mold coolingsystem design and gate location is optimized by use of thermal analysis module ofthe ANSYS software and CAE technology. The main work of this thesis are listedbelow:On the basis of CAE technology and orthogonal experiments, the influence ofprocess parameters on warpage is obtained by using range analysis and ANOVAanalysis. The sequence of influence extent is packing time, packing pressure, moldtemperature, cooling time, injection time and melt temperature, from largest tosmallest. Meanwhile, the optimum parameters combination is got, and thecorresponding warpage by CAE simulation confirmation test is2.238mm, which isthe least among all the orthogonal samples.Artificial Neural Network model is developed to map the complex non-linearrelationship between warpage and process parameters, and GA is used to optimizeparameters in the selected range of parameters. CAE verification and actualproduction verification are carried out with the optimum parameters, and thewarpage in vertical plastic plane is, respectively,1.962mm and2.10mm.The quantitative research of the entire cooling process is done through thethree-dimensional heat transfer analysis, with the aim to reduce warpage throughoptimizing channels parameters (diameter and location). By way of CAEtechnology the gate location and type are adjusted to optimize the packing process,and thus to reduce uneven shrinkage and warpage. After the optimization, the warpage result is reduced to1.583mm.