Document Abstract
ANTEC Papers: 2002
The Importance of Monitoring Mold Pressure During Rotational Molding
Roy Crawford, Queen’s University Belfast, Northern Ireland, BT9 5AH Maria Clara Cramez, Universidade do Minho, Portugal Maria Jovita Oliveira, Universidade do Minho, Portugal Alvin Spence, Centro Inc, North Liberty, Iowa
During the rotational molding of plastic parts, the pressure inside the mold can become positive or negative depending on a variety of factors such as the size of the vent, the quality of the mold, the heating rate, etc. In commercial molding, the pressure is likely to vary in an arbitrary manner, depending on particular combinations of key variables. This leads to conflicting reports about the causes and cures of problems such as warpage, residual stress and shrinkage. This paper reviews the effects of pressure variations on the quality of rotomoulded parts and using experimental data, demonstrates the importance of monitoring the pressure inside the mold throughout the cycle. Methods of doing this are illustrated and the benefits in terms of reduced cycle times and improved part quality and consistency are demonstrated.