EFFECTS OF CALCINED BALL CLAY FILLER ON MECHANICAL PROPERTIESOF HIGH-DENSITY POLYETHYLENE COMPOSITE USED FOR MAKING AUTOMOBILE PARTS

Abstract

The thesis describes the preparation of the composite materials of high density polyethylene (HDPE) and raw ball clay, HDPE and ball clay calcined at 700◦C under the same percentage weight variation using injection moulding machine operated at a temperature of 160◦C. Some mechanical properties vital in automobile parts- impact strength and tensile strength at yield were determined at different weight fraction of filler (0%, 5%, 10%, 15%, 20% 25%, 30%) in accordance with ASTM D256 and ASTM D638 method respectively. The virgin HDPE used was sourced from Indorama Eleme petrochemical Ltd along with the technical data sheet containing its mechanical properties. The X-ray diffraction (XRD) analysis was carried out to investigate the phase composition, crystalline structure and the degree of disorderliness of raw ball clay and calcined ball clay. The Raw ball clay and calcined ball clay were subjected to scanning electron microscope (SEM) to obtain more understanding on the structures and size distributions of the samples. The results for Thermogravimetric analysis (TGA) curves for pure HDPE, HDPE-calcined ball clay (CBC) composite and HDPE-raw ball clay (RBC) composite for the temperature range 0-600°C shows some weight losses. It was deduced that weight loss in sample 100HDPE begins at 360°C while for 95%HDPE/5%CBC, 85%HDPE/15%CBC and 70%HDPE/30%CBC weight lose starts at 430°C. This indicate that calcination of ball clay improves the TGA of the matrix material. Weight loss for various weight fraction of HDPE-RBC begin around 150°C. This show that calcination of ball clay improves the TGA of HDPE-Ball clay composite. Results showed that there was an improvement on the mechanical properties as the filler content increases. Calcined ball clay produces better mechanical properties than raw ball clay. As the filler loadings were increased to a significant amount, the mechanical properties started to reduce. Reinforcing High Density Polyethylene (HDPE) with Raw and Calcined ball clay significantly improves the Tensile strength at yield, and Impact strength of HDPE. Calcined Ball clay-HDPE composite produces better mechanical properties than raw ball clay-HDPE composite. 75% HDPE/25%CBC and 70%HDPE/30%CBC produces has the highest impact and tensile strength of 119.5 J/m and 68.9 Mpa respectively and can be used in the manufacture of automobile parts like car bumper.