How to quickly measure the brittleness of a plastic?
How to quickly measure the brittleness of a plastic?
(OP)
For the plant, when they process the parts off the process parameters, the plastics got degraded and in my case become brittle for nylon. However many times it looks good until you test the product. Is there a quick way to evaluate the brittleness of a plastic? Thanks. The part is quite small and slim, like 5mm in width. And only moiture control seems not good enough.





RE: How to quickly measure the brittleness of a plastic?
RE: How to quickly measure the brittleness of a plastic?
There are two challenges as we internnally discussed: one is that sometimes the impacted area may not represent the brittleness of the whole part; another is that the part is quite small.
Also I was wondering if annealing the parts above the Tg will help reduce the brittleness?
RE: How to quickly measure the brittleness of a plastic?
As molded nylon is stiff with low elongation and impact. Once left in air the modulus halves and the elongation and impact go way up because the water from the air acts as a plasticizer.
So, all as-molded parts will be brittle and the question becomes how can you get the water into your part faster so testing can start? I'd try a pressure cooker for a short time or boil in water for a few minutes (as you said the part is small a short time should work).
Chris DeArmitt
Expert consulting & training
www.phantomplastics.com
RE: How to quickly measure the brittleness of a plastic?
RE: How to quickly measure the brittleness of a plastic?
Chris DeArmitt
Expert consulting & training
www.phantomplastics.com
RE: How to quickly measure the brittleness of a plastic?
But with DAM we are quite aggressive on our QC, as even in desert the RH may never be zero. It is however one way we want to make a better product.
We do have product made of PA12 though, but that one is expensive.
RE: How to quickly measure the brittleness of a plastic?
RE: How to quickly measure the brittleness of a plastic?
RE: How to quickly measure the brittleness of a plastic?
Doesn't solve the moisture issue, but it's a fast way to determine brittleness once your parts are conditioned.
RE: How to quickly measure the brittleness of a plastic?