选用等规聚丙烯为实验材料，基于正交实验设计方法进行微注射成型实验，制备了微注塑拉伸试样，并选取拉伸弹性模量和拉伸屈服应力作为力学性能指标。采用直观分析和方差分析法对拉伸实验的结果进行分析，研究工艺参数对厚度为1.0 mm和0.2 mm试样拉伸性能的影响规律及重要性，并分析了尺度效应对试样力学性能的影响。结果表明，微注塑实验的拉伸弹性模量和拉伸屈服应力都随着试样尺寸的减小而增大，且不同试样尺寸下，各工艺参数对拉伸弹性模量和拉伸屈服应力的影响规律和重要性也不同。对于厚度为1.0 mm的试样，其拉伸弹性模量受保压压力的影响最大，随保压压力增加呈现先增后减的趋势；其屈服应力受保压时间的影响最大，随保压时间增加呈现先增后减的趋势。对于厚度为0.2 mm的试样，拉伸弹性模量和拉伸屈服应力受熔体温度的影响最大，且两者均随着熔体温度的升高而减小。%Using isotactic polypropylene as experimental materials,the micro injection molded isotactic polypropylene tensile specimens were prepared and the influence laws and significance of processing conditions on the on the elasticity modulus and yield stress of the specimens with thickness of 1.0 mm and 0.2 mm were analyzed based on DOE method. The scale effects on the tensile properties of the specimens were also investigated. The results show that the modulus and yield stress of the specimens increase with the specimen thickness decreasing,the significance and influence laws of the processing conditions on the modulus and yield stress are changed at different specimen thickness. The significance of holding pressure on the modulus of the specimen with thickness of 1.0 mm is largest,and the modulus increases first and then decreases with the holding pressure increasing. The influence of holding time on the yield stress is most significant,and the yield stress increases first and then decreases with the holding time increasing. The effects of melt temperature on the modulus and yield stress of the specimens with thickness of 0.2 mm are most significant,and the elastic modulus and yield stress both decrease with the melt temperature increasing.
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