Why cushion is critical for your injection molding process

摘要

You might ask the question, why bother with cushion if you monitor peak shot volume? Although it's important to monitor peak shot volume to ensure you're injecting the same amount of material into the mold every time, cushion can be just as critical to make sure you're running the same process. The reason is, without having a cushion, you can't transmit pressure into the cavity - once the screw bottoms out, it no longer has anything to push on, which will cause the actual cavity pressure to fluctuate, making it difficult to overcome viscosity shifts. But why does it matter what the cushion size is as long as we make sure there is one?