【作者】 白杨；

【导师】 柳和生；

【作者基本信息】 南昌大学 ， 机械电子工程， 2011， 硕士

【摘要】 随着对注射成型制品的精度要求不断提高,成型工艺参数对制品翘曲变形的影响越来越受到研究人员的关注。目前,研究不同工艺参数对翘曲的影响较多。但是这些研究对因素的影响机理研究较少。由于iPP为结晶性塑料,晶态iPP和非晶态iPP的密度相差可达13%,这对材料的收缩会产生影响,而收缩不均往往会导致制品发生翘曲。本文利用5因素4水平正交试验表安排16组实验,通过对注射成型参数进行调节,研究了iPP制品翘曲变形和结晶度随成型工艺参数发生变化的规律,并对二者之间的关系进行探究。文章得出如下结论。1)对翘曲度影响较大的因素有保压时间和熔体温度,影响中等的为模具温度和注射速度,影响较小的是保压压力。2)对结晶度影响较显著的因素有保压压力,影响较大的是模具温度,熔体温度、保压时间和注射速度的影响则较小。3)通过研究相同工艺参数对翘曲度和结晶度的影响及之间关系的探索,本文认为,在本文研究的工艺参数取值范围内,结晶度变化与翘曲度变化之间没有必然的联系,结晶度的变化不一定是影响制品翘曲的主要因素。更多还原

【Abstract】 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.更多还原