The Effect of Processing Parameters on the Thermal Conductivity of LDPE/UHMWPE Blend Foams

Polymeric foams are used widely as thermal insulator and considerable efforts have been conducted to find out the conditions to minimize the thermal conductivity. In this study the thermal conductivity of low density polyethylene/ultra high molecular weight polyethylene (LDPE/UHMWPE) blend foams was examined by a simple transient method. Dicumyl peroxide (DCP) was used as crosslinking agent and azodicarbonamide (ADCA) was utilized as the chemical blowing agent. The blends were prepared using an internal mixer and the foaming was conducted by compression molding technique via a single stage process. Two group of parameters including: processing variables which can be changed in the internal mixer (DCP and ADCA contents both in 2 levels) and compression molding conditions (foaming temperature and time both in 3 levels) were selected for parametric studies. A Taguchi L9 orthogonal standard array was used for experimental design and the analysis of variance (ANOVA) method was considered for statistical analysis. The effect of the selected variables was investigated on thermal conductivity of specimens. The results revealed that decreasing of the foams’ density decreases their thermal conductivity. Furthermore the ANOVA results indicated that the foaming temperature was the most affective parameter on the foams thermal conductivity

کلیدواژه ها:

LDPE/UHMWPE blend ، Foam ، Thermal conductivity ، Compression molding ، Taguchi method