Ribs, Bosses And Gusset Deisgn

The location of ribs and gussets can affect the mold design and the flow length of plastic material in injection process, Gate location can work in concert with the position of ribs and gussets to improve workpiece filling, and to avoid the shrink-sink in parts. In this case, the ribs and gusset act as an internal rmner"or flow director, directing flow in a specific direction. However, poorly located or poorly designed ribs and gussets can hinder flow and can also create burn marks in the workpicce as a result of trapping gas in the tool, this occurs when ribs and gusset are isolated where gas can be trapped. The other defeat is sink marks in the workpicce for unreasonable rib or gussets design which resist the flow of material. To avoid the warpage of workpiece with ribs, a few tall, narrow ribs may have good influence on workpiece integrity and rigidity" than that of only one tall thick rib as illustrated in Fig. 2. 13. The advantages of short and narrow ribs are that narrow ribs improve cooling of workpiece, reducing cycle time, and can reduce the chance of sinks marks