Drop Test on PVC Profiles

So, the test sample passes the test and the parts still fail? What is your end product? Who imposed this test? The more meaningful information you give, the better answer you will get.

No, the production parts dont fail either. We're trying to develop an impact test for QC purposes, however, if we keep droping without ever finding the limit of when failure will occur, what good is the test, so we're looking to do something more qualitative, although we could calculate the energy. Anyway, the end product is fence profiles. Thanks.

PVC greatly changes characteristics with temperature. It is better to do the test at the service temperatures. The new REACH specs have issues with phthalates. May need checking.

bioramani

Typically, drop dart impact testing is done in foot pounds per mil (so two different wall thickness samples from the same materials would be subjected to different pass/fail criteria) - and is used to determine the limits of acceptable ductile or brittle failure modes - you say that "only a few are failing" - actually at the maximum for acceptable failure mode - none should fail - perhaps you are testing at too high a standard to be appropriate (you are just beyond what would be "acceptable") or your testing isn't destructive enough if you are hoping for failure more often?

Too many questions come to mind given your information - how long is the product resting between production and testing; is an annealing process involved to relax stress, how thick is the product in mils? what tup shape are you using? Are you testing for ductile or brittle failure. After the drop dart testing, are you giving it more "real life" type 'whammo' testing - the kind of test when a worker drops it from the truck, or off a roof, in hot and more importantly cold weather?

Also, assuming that dimensions and aesthetics are acceptable at current run conditions - aka you should be doing this testing to failure to parts that are in all other ways acceptable - if not, and you make additional changes, your test results may be suspect or worse, value-less

As stated before, more info equals better answers -

Just my two cents -

Jim Wilson

How did this question ever work out?

thanks