An investigation into the relationship between the impact performance of rotationally molded polyethylene products and their dynamic mechanical properties

Abstract

In this paper, a study of the relationship between the impact performance of rotationally molded polyethylenes and their dynamic mechanical properties is carried out. A wide range of conventional linear low density polyethylene powders and met‐allocene catalyzed linear low density polyethylene powders were rotationally molded and tested. Instrumented falling weight impact tests were carried out over a temperature range of −60°C to 20°C. Dynamic Mechanical Thermal Analysis (DMTA) tests were also carried out between −100°C and 90°C, at a frequency of 100 Hz. Comparisons between the impact performance of metallocene catalyzed LLDPEs and Ziegler‐Natta LLDPEs are made. The transitions evident in the DMTA results are related to changes in impact performance with temperature. The beta transition is found to fall in the transition region between high impact performance at low temperatures and lower impact performance at ambient temperatures.

Effect of mould pressurisation on impact strength of rotationally moulded polyethylenes

“…11,12 Dynamic mechanical thermal analysis tests were therefore carried out on samples from each of the mouldings to determine if similar correlations could be obtained in the present work. The loss modulus and tan d traces of the mouldings pressurised to 1 bar are shown in Figs.…”

A New Approach for Resin Selection in Rotational Molding

“…It is calculated as: where A i corresponds to the area under the diagram (spider or line diagram) for a resin i, while A B represents the area under the diagram for a positive benchmarking resin. The positive benchmarking values are obtained using Equation (8). A resin with the highest value of coefficient of similarity is ranked higher.…”

Parametric and mechanical characterization of linear low density polyethylene (LLDPE) using rotational moulding technology

“…Author also observed that the suppression of crystallization occurs during the degradation of polyethylene whereas change in the appearance and the level of birefringence of spherulites occurs during the degradation of polypropylene. An experimental study to establish the relationship between the impact performances of rotationally moulded polyethylene over a range of temperatures from −60 to 20 • C is reported by Pick & Harkin-Jones (2003a). Three samples of conventional LLDPE and metallocene catalysed LLDPE is tested for every 10 • C rise in temperatures between −60 and 20 • C. The result showed that the metallocene catalysed LLDPE has better impact properties than conventional LLDPE.…”