工艺参数对沉降斑影响的实验研究

采用实验方法考察工艺参数对沉降斑的影响。基于一个带凸台的平板模具,采用L27(313)正交矩阵进行实验,研究了几何尺寸、熔体温度、注射时间、保压压力及保压时间对厚度突变处沉降斑形成的影响,同时还考虑了熔体温度和注射时间以及保压压力和注射时间之间的交互作用影响;通过性噪比分析和F检验优化成型工艺条件并对工艺参数的影响进行显著性分析。结果表明,对于厚度突变的平板制品,厚度突变的程度对其沉降斑形成的影响最大,其次为熔体温度,保压压力,保压时间等;采取减小厚度变化,降低熔体温度或增加保压压力和保压时间等措施,可以减小厚度突变处沉降斑,从而减少其对外观质量的影响;因素之间的交互作用对制品沉降斑的形成有一定的影响,熔体温度B和注射时间C之间的交互作用影响较为明显,而保压压力D和注射时间C之间的交互作用对该质量指标的影响最小,可以并入误差。

Research on Influences of Processing Parameter on Sink Marks Based on Experiments

The influence of process parameters on sink marks depth was considered based on experiments. Based on a plane mould with a boss, L27(313) orthogonal array was conducted to investigate the significance of each factors (boss, melt temperature, injection time, packing pressure, packing time) on sink mark depth. The two-way interaction influences between melt temperature and injection time, between packing pressure and injection time were also considered. The influence of process parameters was analyzed by means of S/N and the F-test. The results showed for the plate product with a thickness mutation, the effect of the degree of the thickness mutation was the most significant, melt temperature, packing pressure and packing time came second. The decrease of the changes of the thickness, the lowerinng of the melt temperature and the increases of the packing pressure and packing time could all decrease the sink marks at the area of thickness mutation, reducing the effect on the apperance of the product. The two-way interaction of the parameters had effects on the formation of the sink marks. The effect of the interaction between melt temperature B and injection time C was obvious, but that of packing pressure D and injection time C was the minimum, which could be incorporated in error.