How to choose the right injection molding machine? (2)

1. Determine the required injection volume by the weight of the finished product and the number of mold cavities and select the appropriate "screw diameter"
To calculate the weight of the finished product, the number of mold cavities should be considered; for the sake of stability, the injection volume must be more than 1.35 times the finished product weight, that is, the finished product weight must be within 75% of the injection volume;
2. The conditions of "screw compression ratio" and "injection pressure" are determined by the plastic.
Some engineering plastics require higher injection pressure and appropriate screw compression ratio design to have better molding effects. Therefore, in order to make the finished product shot better, the needs of injection pressure and compression ratio should also be considered when selecting the screw. .
3. Some finished products require high injection rate and rapid injection to form stable molding, such as ultra-thin finished products. In this case, it may be necessary to confirm whether the injection rate and rate of injection of the machine are sufficient, and whether it needs to be equipped with pressure accumulators, closed loop control and other devices . Generally speaking, under the same conditions, a screw that can provide a higher injection pressure usually has a lower rate of fire. On the contrary, a screw that can provide a lower injection pressure usually has a higher rate of fire. Therefore, when selecting the screw diameter, injection volume, injection pressure and injection rate (injection speed) need to be cross-considered and selected.
4. In addition, a multi-loop design can also be used to shorten the molding time with synchronized compound actions.
After the above steps, in principle, an injection molding machine that meets the needs can be determined, but there are some special issues that must be considered.