HDPE BLOW-MOLDED BOTTLE PINCH-OFF WELD STRENGTH AT VARIOUS MOLECULAR WEIGHTS

摘要

This study focused on the weld strength of different materials in the pinch-off area of an extrusion blow-molded bottle. Various materials of different densities were run through an extrusion blow-molding machine. This study determined how weld strength at the pinch off was affected by the density of the material being processed. The pinch off is the portion of the mold that welds the ends, and at times the interior portions, of the parison as well as cut the excess flash to aid in removal. Having a strong weld was extremely crucial to overall bottle quality and was a direct result of pinch off design. The reason the pinch off has an effect on quality is due to the weld probably being the weakest part of the bottle and bottle strength is only as strong as its weakest point. Strength was a key issue in determining overall quality and the research performed allows for a direct correlation between strength and material grade.