It is always to avoid running a pressure-limited process. Any process which is pressure limited will have and inconsistent 1st stage injection weights and 1st stage injection times. Question: The company I work for now, wants all injection/boost pressures set at max 2,000 to 2,300 psi. I was told that it insured a more consistent shot and was also […]
Monthly Archives
January 2013
When to Optimize the Rear Zone
The optimal rear zone temperature is specific to each machine and material combination. For this reason, a rear zone temperature study should be performed each time a new material is molded on a particular machine. Question: In my case we have machines from different brand, so a study in the rear zone temperature must be performed. So, in a […]
Always Look for Correlation…
When one process output is inconsistent, check the process data in case there is not correlating data which can help pinpoint the actual cause of the problem. Problem: Screw recovery time variation in PBT material. notes: The questioner sent a screenshot of the SPC data for the past 200+ shots. In this data, it was […]
Checking Your Check Ring Performance
All check rings leak, but over time the check ring will wear and leak more. The most important issue is how consistently it leaks during the velocity-controlled injection phase of the process. Question: I have an issue with a 360 ton machine. Over the last three months, I have had most of my process’ have had […]