Cooling accounts for 80 percent of the molding cycle and is a crucial phase in successful molding. Critical dimensions, warpage, and surface finish are all affected by cooling conditions, and poorly cooled parts increase cycle time, dimensional problems, and wastage.
The following sections list common cooling problems and their solutions.
The main problem caused by non-uniform cooling is warpage.
The cycle time is the time taken to produce a molded part, which is measured from the start of injection until the end of clamp open time. High cycle times reduce productivity and increase costs.
The heat transfer rate is reduced when the flow is laminar instead of turbulent because of an insufficient pump capacity.