I worked in the plastic compounding industry for 10 years and agree with almost all of what 9x19 posted. For those who are not familiar with plastics, compounding is mixing different types of plastic and additives togher to get the desired properties.
I have listed some coments below, based on my past experience and knowledge of plastics.
I wish that I could be more technical, I have been out of this industry for 10 years.
Injection grade nylon 6 is very strong and brittle. If memory serves me correct nylon 6 nas a strength of 10,000 to 15,000 psi. Glock must have an impact modifier, possibly ionomer, to keep the plastic from shattering.
Determing the basic ingredients is not that hard for the informed person. It is more of an art than science. A good DSC and FTIR with a good library of curves will be a good start. The FTIR might not work because of the high carbon black content.
Older dash boards crack because the plasticizer evaporates out of the flexible PVC.
Plastic does stress crack just like metal.
The superior Glock design appears to have eliminated stress cracking. Time will tell.
