动态发泡工艺参数对PS微孔塑料泡孔结构的影响

EFFECTS OF DYNAMIC PROCESS PARAMETERS ON CELL STRUCTURE OF PS MICROCELLULAR PLASTICS

以超临界CO2为发泡剂,用振动诱导发泡模拟装置研究了微孔塑料动态成型过程中气体饱和压力、压力释放速率、温度、气体饱和时间、稳态剪切速率、振动等工艺参数对聚苯乙烯(PS)微孔塑料泡孔结构的影响。研究发现,PS微孔塑料试样的泡孔结构随着气体饱和压力和压力释放速率的提高而得到改善,而温度、气体饱和时间、稳态剪切速率则存在一个最佳的操作范围,在此范围内制得的PS微孔塑料试样泡孔密度最大,泡孔尺寸最小。在稳态剪切速率一定的情况下,通过施加振动可以进一步改善泡孔结构。

The effects of some process parameters such as gas saturation pressure, pressure drop rate, temperature, gas mixing time, stable shear rate and mechanical vibration on cell structure of foam samples during the dynamic foaming process for microcellular plastics were studied on vibration-induced foaming simulator by using supereritieal carbon dioxide as blowing agent. It was found that the cell structure of foam samples was improved with the increasing of gas saturation pressure and pressure drop rate, while there was an optimal operating range for temperature, gas mixing time and stable shear rate, in which the minimum average cell diameter and the maximal cell density could be achieved. The cell structure could be improved further by imposing the mechanical vibration at certain stable shear rate.