Fracture toughness of LLDPE parts using rotational moulding technology

Rotational moulding is a process of producing hollow plastic products. Linear low density polyethylene (LLDPE) is widely used in rotational moulding process. Many rotationally moulded LLDPE products are widely used in outdoor applications such as boats, automobile fuel tanks, body armours etc. From quality characterisation point of view, fracture properties are considered to be critical for rotationally moulded products. Therefore, it is essential to optimise process parameters for rotational moulding process to yield maximum fracture toughness. In this paper, experimental investigations are carried out by planning and performing trials based on design of experiments (DOE). Experimental runs and design of experiments (DOE) analysis revealed non-linear effects of process parameters on fracture toughness. From the experimental investigation, optimum process parameters are proposed which yields maximum fracture toughness for rotationally moulded products. The optimum process parameters are oven temperature: 210°C, oven time: 32 minutes, and cooling medium: water.