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, […]
Category Archives
Plastics Technology
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 […]