Category Archives

I have often encounter confusion on these two terms when talking to molders… Attribute Data Attribute data has two different outcomes. An example of such an outcome would be a GO / NO-GO gauge which is used when testing parts. This test results in only two different outcomes, Pass or Fail. Variable Data Variables are […]

I was discussing polymers with a technician and was asked this question: John I understand how molecular weight affects the process, but how does molecular weight distribution affect the process? My Response Polymer chain mobility is highly dependent on the length, or molecular weight, of the polymer chain. If most of the polymer chains have a similar molecular weight, or smaller […]

I have been asked about the proper use of an open-loop molding machines… Customer When implementing DECOUPLED MOLDINGsm, how should we best incorporate our open-loop molding machines? My Response Basically, open-loop molding machines are not capable of this since open-loop molding machines cannot decouple 1st stage filling from 2nd stage packing. These machines lack closed-loop, injection velocity control and inject using pressure control instead. As […]

I heard a quality technician make the following comment the other day… Technician Mean, Median, Mode… they are all the same. Mean The mean is the average of measurements within a particular sampling. This value equals the sum of all the numbers in a sampling divided by the number of values in the sample. For example: the […]

This question arrived this morning via email… TA We are processing polycarbonate and are having problems with short molding as well as silver streaks. The mold design is a hot runner system with three drops. My Response For the silver streaks, I suggest you ensure the material is properly dried. A dewpoint meter or moisture analyzer should […]