F.A.Q.s

Failure Analysis:  Why is my part breaking?

After a visual inspection of the failed part and review of the situation, we offer our opinion and recommendation for where to begin.  Our goal is to work with you and proceed as practically as possible.  Generally speaking, the options available for Failure Analysis are Material Identification, Degradation Assessment, Design and Processing Consulting, and End-Use Environment/Chemical Resistivity Consulting.  Failure Analysis often involves both testing and consulting services.

Material Identification:  What kind of plastic is this?  Is my part contaminated?

Material Identification is a 1-3 step process depending on the material and the needs of the customer.  Using FTIR we are able to determine the generic type of plastic.  (for example, nylon, polyester, ABS)  The reactions seen by DSC allow us to comment more specifically on the type of plastic.  (for example, nylon 11 vs. nylon 66 or PET vs. PBT)  TGA is used to quantify some blends, carbon, and noncombustibles such as minerals or glass.

Crystallinity:  My supplier recommends crystallinity testing.  What’s crystallinity?

This is a very specific application that uses DSC to determine the crystallinity of a molded part as processed.  Crystallinity testing is recommended by the material suppliers of PET, PPS, and PPA and is often required by the end-user.  If these materials are processed with low mold heat, they will be less crystalline and actually crystallize during the DSC test allowing us to calculate the relative percent crystallinity.  If these materials are processed with high mold heat, the longer cooling time allows them to “fully” crystallize and we will not see any crystallization during the DSC test.

Receiving Inspection:  Am I getting good materials?

The best time to find out that you have a problem with your raw material is before molding.  If testing all lots of material is not an option we suggest that you consider testing your most troublesome products or use an intermittent program based on lot counts or time intervals.  Most molders experience less problems when their suppliers know they do Receiving Inspection.  (Even if you don’t test, retain!)

Post Processing Inspection:  I think I have a problem.

Here we are looking for contamination and/or degradation in your molded part.  This is usually a pre-failure analysis requested when you suspect there is a problem press side.

Degradation Assessment:  How can I measure the degree of degradation in my parts?

Degradation Assessment is a measure of how much a molded part is different from its virgin material.  Degradation occurs during processing and can occur during subsequent assembly procedures and even in its end-use environment.  This assessment is best performed through comparison of the molded part to the exact lot of virgin material used to produce it.  Melt Flow Rate is the most common measurement technique, however, there are some materials where viscosity is required and we refer you to another lab or outsource the analysis.