LLDPE/LDPE共混物熔体挤出胀大行为的研究

Research on the Extrudate Swell Behaviour of LLDPE/LDPE Blend Melt

应用毛细管流变仪,考察了实验条件下线性低密度聚乙烯与低密度聚乙烯共混物(LLD-PE/LDPE)熔体挤出胀大行为及其影响因素。结果表明,挤出胀大比B与剪切应力近似呈幂律关系,而随口型长径比的增加呈指数衰减;当共混比为50/50时,B产生局部极小值现象。

The extrudate swell behaviour of linear low density polyethylene and low density polyethylene blend (LLDPE/LDPE) melt is studied by means of a capillary rheometer. The results Show that the power law relationship between the die swell ratio B for the sample melt and shear stress is approximately presented, and the values of B are attenuated in a form of index with Increasing the die length-diamter ratios under the test conditions; a local minimum phenomenon for B is formed when the blending ratio is 50:50.