Abstract:
In the plastic industry, the rotational molding has been widely used for making the large hollow products such as water tanks, septic tanks, and ice boxes, etc., which used polyethylene powder as raw material in the form a majority. The aims of this research were to examine the alternative materials for the formation of product which requires different specific properties such as higher clarity and better result in some mechanical properties.
The preliminary study found that the materials used in this work can be rotational molded in some cases. Polycarbonate with the higher molecular weight tended to molding more difficult. While the using polycarbonate powder particles size smaller than 250 μm could be molded more difficult than polycarbonates in particle size larger than 250 μm in contrast to that observed in specimens molded from polyethylene. The thickness distribution of polyethylene was better than polycarbonate in all case. Polycarbonate made a difference on the wall thickness distribution more than 2 times on each side when compared with polyethylene. Some mechanical properties of polycarbonate specimens found that the surface hardness of polycarbonates was higher than polyethylene but the resistance to penetration was lower.
It was found that the size and shape of the particles on material formation and molecular weight affect the viscosity. All of these factors were significant within the formation process. Rotation speed affected the wall thickness distribution. The process duration of the rotational molding was longer than the other process as a result in some mechanical changes.