Investigating the influence of peak internal air temperature (PIAT) on material characteristics of linear low-density polyethylene (LLDPE) during rotational moulding

Abstract

In present study, six samples of ICORENE 1613 LLDPE fuel tank with homogeneous composition were analysed for six different PIAT values of 165 °C, 170 °C, 180 °C, 190 °C, 195 °C and 200 °C in the first stage. In the second phase of the study, the samples with optimum PIAT values were considered for the Tensile and Flexural strength study at different temperatures. Peak Internal Air Temperature (PIAT) values were obtained using the rotolog instrument, while the tensile and flexural tests were performed utilizing the Universal Testing Machine for accurate characterization of the material properties. The tensile and flexural strength were carried out at three different operating temperatures considering the tank will be subjected to variable operating conditions in real world exercise. The maximum value for both all the process parameters studied were observed at PIAT value of 195 °C, the same has been chosen for the further investigation. The failure data obtained from these two destructive testing will be helpful to mitigate the defects during the process. The tensile test results indicate that the LLDPE sample exhibits the maximum tensile strength of 17.3 MPa at 23 °C and the highest elongation percentage at failure, which is 182.7% at 80 °C. Moreover, the sample shows a remarkable flexural strength of 75.97 MPa at 23 °C, which is indicative of its superior ability to resist deformation under applied bending stresses.