The Injection Pressure that is required to push the molten plastic into an injection mold is similar to the force required to push play-doh through a toy extruder. There are many variables that affect the force required to inject molten plastic into a mold.
As the flow advances, the molten plastic begins to cool. The rate of cooling depends on the temperature of the melt as well as the temperature of the mold (depending on the cooling channels as well). As the plastic cools it begins to solidify onto the walls of the sprue, runners, gates, and cavities. The solidification of the plastic narrows the flow path. A higher pressure […]