Experimental Study On Effects Of Rapid Heat Cycle Molding Process Parameters On Surface Quality Of Plastic Products

Rapid Heat Cycle Molding(RHCM) is a new injection molding technology, which can eliminate defects such as weld line, fiberglass revealed, mark, craze and so on. Meanwhile, it can also improve surface gloss. However, RHCM contains complicated technology and demanding high requirement of technology control, surface quality will be influenced significantly by process parameters. Generally speaking, in the process of RHCM, through the effective control of process parameters to improve the surface quality is extremely important.In this dissertation, the effect of RHCM process parameters on surface quality of plastic products was studied. The main works and achievements are as follows.1. The experiment platform of RHCM was built. The evaluation system of RHCM’s products was established. Several important evaluation projects on RHCM and the way to figure it was pointed out.2. Surface gloss, weld line and surface hardness were chosen as the surface quality evaluation targets. Single factor experiments and orthogonal experiments were chosen to study the rules of process parameters’influence on surface quality of HDPE and ABS plastic products. The result showed that increasing mold heating temperature can increase the surface gloss and surface hardness, reduce the weld line of HDPE and ABS products significantly on condition that ensuring the forming quality.3. The influence of mold heating temperature on RHCM products’ structure was studied. The relationship between organization structure and surface quality was discussed. The influence on surface quality from a micro-angle was explored by polarization microscope, scanning electron microscope and X-ray diffraction. The result showed that increasing mold heating temperature can increase the quantity of grain on surface significantly, reduce the creation of weld line and adverse combination of layer, which improved product’s surface quality.Through the research of Rapid Heat Cycle Molding process parameters’influence on surface quality, rules and levels of process parameters’influence on surface gloss, weld line and surface hardness were cleared, for providing experimental basis to control surface quality more effective. How mold heating temperature influence the RHCM products’structure was investigated from micro-angle. The rules of RHCM influence quantity of grain on surface, weld line and adverse combination of layer were obtained. An intensive and deeper study on effects of RHCM process parameters on surface quality of plastic products was made, for providing theoretical basis to control surface quality more effective. The best parameters combination of surface gloss and weld line were made for engineering applications.