Experimental Research The Effect Of Crystallinity And Warpage About IPP Injection Mold Produce By Technological Parameter

With a rapid development of accuracy about injection molding process, an increasing number of researches pay attention to the influence of process parameters on the warp distortion of Injection Molding.Current studies mainly focus on the influence of different process parameters on the wrap. But the factors for its influence are not usually in their concern.The difference of density rate between crystalline iPP and amorphous iPP can be 13%; and this results in shrink nonconformity followed by the warp.This paper is based upon 16 groups of experiments designed by 5-factor/4-level orthogonal test. Through adapting injection molding process parameters, it studies the effect and the relationship between the warp of iPP process and the changes of process parameters on the warp distortion according to the crystallinity. Several conclusions are indicated as follow:1)The packing time and the melt temperature have major influences on the degree of warp; the mold temperature and the injection velocity, medium; the packing pressure, minor.2)The packing time has an outstanding influence on the crystallinity; the mold temperature and the melt temperature, major; the melt temperature, packing time and injection velocity, minor.3)This paper argues, by exploring the effects of the same process parameter on the degree of warp and crystallinity as well as the relations between them, that inevitable connections exist between the change of the crystallinity and that of the degree of the warp, and that the change of the crystallinity is not the main factor of the warp of the process.