Document Abstract
ANTEC Papers: 2003
Effects Of Particle Morphology On The Processability Of Ethylene Copolymers For Rotational Molding Applications
Mark Weber, Celine Bellehumeur, Wen Lin
Rotational molding is used to manufacture hollow plastics parts. The degree of coalescence achieved will directly influence the production cycle time and the mechanical properties of the final parts. The resins used in rotational molding are normally in powder form. The pulverization conditions imposed on the material in the preparation of powder will affect its main characteristics (size, shape), as well as the crystalline structure of the material and possibly the physical and chemical structure of the particle surface. Moreover, the resin formulation (additives formulation and molecular structure) can be modified so the end product has adequate properties. The presence of additives will also affect characteristics of the particles such as morphology and surface energy. The resin formulation and the conditions imposed on the material during the pulverization process will play a significant role in determining the materials procesability. The approach undertaken in this work consists of imposing different thermal treatments on ethylene copolymers and conducting microscopic coalescence experiments under controlled conditions. To date, experimental work has been conducted on cylindrical particles produced by hot pressing powder into a perforated plate, which is subsequently cooled at different rates. Results show that the thermal treatment imposed on the material has an effect on the polymer coalescence. The addition of a nucleating agent to the material also has an impact on the coalescence process. The presence of the nucleating agent was found to affect the morphology of the particles and the surface energy of the material. Further work will be conducted to establish the impact of these changes on the rotational molding cycle and the molded part properties.