A Study on the Blends of HDPE and LLDPE for Rotomolding Applications

摘要

This paper examines the technical feasibility of using blends of high-density polyethylene (HDPE) with linear-low density polyethylene (LLDPE) for rotational molded underground water tanks application. Various blending ratios were investigated to determine the most optimum stiffness, reasonable toughness and low warpage, properties required in underground water tanks. Mechanical properties were characterized and determination of miscibility by different methods, including zero shear viscosity study, DSC analysis and Crystallization rate measurement were done in order to find the suitable ratio of blending. Rotomoldability was checked for this ratio to using vacuum tests. It was found that HDPE/LLDPE blends are miscible in all compositions and that the ratio 70:30 (HDPE:LLDPE) has the most optimum mechanical properties for underground water tanks and also for any load-bearing applications. The resulting warpage after vacuum tests confirmed mechanical characterization. The grade 70:30 with LLDPE MI 1 (g/10 min) can be used for underground water tank applications to increase mechanical properties and to reduce warpage.