The injection amount refers to the amount of melt injec […]
The injection amount refers to the amount of melt injected into the mold by the injection molding machine screw at the time of injection molding.
The injection volume is equal to the screw propulsion volume multiplied by the injection material density multiplied by C
C is 0.85 for crystalline polymer and 0.93 for amorphous polymer.
Injection molding machines are not designed to process products that are less than 1/10 of the shot size or 70% of the shot size.
After each injection procedure is terminated. The screw is at the foremost end of the barrel. When the pre-plasticing program arrives, the screw starts to rotate and the material is sent to the head of the screw. The screw retreats under the reaction of the material and hits the limit switch. This process is a metering process.
The amount of injection is related to the accuracy of the metering stroke: too small, insufficient injection volume; too large, so that the residual material is too large after each injection in the front of the barrel, so that the melt temperature is uneven or overheated.