Retaining Defects…

I was recently visiting a molder who was having a specific problem… Supervisor We are having trouble with our employees properly identifying and naming part defects… any suggestions as to how we can improve this? note: After a couple questions, it was determined that they do not retain defective parts as they are all discarded, reworked, or reground. My Response It […]

The Affect of Moisture on Injection Pressure…

The other week, I received a multiple part question regarding many aspects of materials, this is one part… Nathan Although the 1st stage injection time is the same, the virgin PC/ABS (<0.06% moisture) has a 1RMPa higher peak injection pressure than virgin PC/ABS (0.08% moisture). Is this change in pressure common? My Response Moisture in the polymer causes hydrolysis to occur. As […]

Determining Intensification Ratio Using Specifications…

I was asked this question during an on-site visit earlier this week… Technician I know this machine is rated with a maximum injection pressure of 38,000psi, but I am not sure how to convert this to an intensification ratio. note: The intensification ratio is a factor which is used to convert the hydraulic pressure being applied to the […]

The Importance of Consistency…

Many processors often experiment in training without a clear-cut goal. One year, they might send some people to a seminar, another year, they might buy some products or try making something themselves.  Develop a Structured Approach Although most industry training has some merit, you need to develop a structured approach. For instance, if one form of training turns out to […]

Attribute Data vs. Variables Data…

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 […]