模压发泡扩散理论模型及其实验分析

Diffusion Theoretical Model and Experimental Analysis of Moulded Foaming

在模压发泡的苯乙烯-丙烯腈共聚物(SAN)母板上预先开设气体扩散通道可以缩短饱和时间,提高生产效率。通过分析计算、对比发现,当扩散通道的布置方式按照等边三角形分布时,不仅可得到较高的扩散效率,而且还能减少制品缺陷的产生几率。建立了饱和时间与扩散通道孔径、扩散通道中心距之间的理论模型,并通过实验验证了该模型的可靠性。同样工艺条件下,采用扩散通道可以明显提高模压发泡效率;随着孔间距的增大,同样条件下的CO_2吸附量减小,因而在不影响制品质量的前提下,应尽可能地缩短扩散孔中心距。

By means of designing diffusion paths on the motherboard of styrene-acrylonitrile copolymer（SAN） in advance, could shorten the saturated time and enhance the productivity of moulded foaming. The holes were punched and distributed in the way of equilateral triangle after deduction and contrasting. This method not only could reduce consumption of resources, but also could reduce the likelihood of product defects. The diffusion model of gas into polymer sheet with holes was established, and the reliability of the model was verified by experiment. Using the method of punching obviously improved the efficiency of the moulded foaming. The less the distance from one hole to another, the more the adsorption. Therefore, the distance of the holes should be shortened as much as possible, in order not to affect the quality of the products.