Pressure Setting During Mold Open and Close

The molding machine does it’s best to achieve the set mold open and close speed as long as there is enough pressure available. Question: What is the pressure and speed relation for clamp open and close? How can I make sure that I have enough pressure to satisfy the set speed? Answer: During clamp movement, […]

Watch Your Back Pressure

The fun of molding PP is that it can take a significant amount of abuse during molding and end use, but only if it has been melted properly. Concern: In the past week, two different customers consulted us for assistance in troubleshooting failures with their molded parts. They were both running PP and were both […]

Burn Marks & Weld Line Issues

It is always critical to check your first stage short shot since it affects both mold filling and part packing. Request: Please provide reasons & remedies of burn-mark or weld line problems in plastic (HDPE) moulded product during the injection moulding process. My Response: There are many possible causes, but injection should be checked first: […]

Cavitation Reduction Concerns

Cavitation reduction is not as simple as blocking off a couple cavities and continuing to run. The process should be as close as possible to the original process, but this will require an adjustment to the process inputs. Question: Do you have a good process for blocking cavities? My Response: The process is almost identical […]

PVC Packing vs. Thin Wall Molding

Thin wall molding is a relative term that implies the flow length is long with respect to the part thickness and material viscosity… Question: Our thick PVC parts require a higher packing pressure than the injection pressure, yet the training states this is typically the case for thin-wall molding. In our case, the parts are […]