EFFECTS OF PROCESS CONDITIONS ON SHRINKAGE AND WARPAGE IN THE INJECTION MOLDING PROCESS

摘要

Polymer density increases when it cools down in the cavity. In the injection molding process, without proper packing to provide extra material to fill the void due to the density change, parts will shrink and even warp. Reducing shrinkage and warpage of injection molded parts in order to improve quality is one of the top priorities in the manufacturing process. Part design, material properties and process conditions are factors that affect part quality most significantly. In this paper, the effects of process conditions on shrinkage and warpage will be discussed. They include packing pressure, packing time, fill time and mold wall temperature. Two tools, CAE software and design of experiment, will be used in this investigation. This paper will show that these two can be used together effectively to design the process window.