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I received this question last week… ATR I am trying to find out why the injection pressure of PP is lower than the injection pressure of PC in terms of its MFI. But the MFI for PC is at a different temperature and for PP is at a different temperature. My Response Essentially, Melt Flow Index […]

There are many rules to good processing, but this one is paramount… Manager What is the most important thing to look for when evaluating a technicians ability to process? My Response The most important factor in good processing is ‘Rule #1 – Make One Process Change at a Time’. When a change is made, it’s imperative […]

Recently a technicians asked me this question… Tech During a gate seal determination (part weight vs. second stage time), we saw the part weight almost stabilize and then it shot up until it finally leveled out. What might have caused this? My Response When doing a gate seal determination, you might see this two-plateau result. Essentially, this is […]

This question arrived as a follow-up to a previous post: More About Back Pressure… Saylan If I have to work with an odd back pressure like 250 bar, does it create any damage to the equipment or machine? My Response Assuming this is the plastic pressure, this would not necessarily cause machine damage. This will consume […]

This question was received earlier this week… CD What should be the minimum pressure during switch over time of injection? My Response If you are switching over through the use of screw position, then you should ensure the maximum pressure setting is significantly higher than injection pressure at transfer. Additional Thoughts It is critical that you have enough pressure […]