Non destructive testing on small plastic parts.
Non destructive testing on small plastic parts.
(OP)
We need to cut sprues on a small plastic piece without damaging the piece. I need a method to confirm the piece (a medical device) isn't damaged.
Does anyone have experience with or can anyone point me in the direction of resources/references that can help me find an efficent way to do this?
Thanks!
Does anyone have experience with or can anyone point me in the direction of resources/references that can help me find an efficent way to do this?
Thanks!





RE: Non destructive testing on small plastic parts.
RE: Non destructive testing on small plastic parts.
I need to cut those legs without damaging the center neck piece. As my cutting blades or device gets dull or damaged I need to be able to determine if the center neck piece is getting stretched or broken.
RE: Non destructive testing on small plastic parts.
Charlie
www.facsco.com
RE: Non destructive testing on small plastic parts.
I'm already handling the items to cut them, I was hoping to find a vision process or something (xray? ??, sonic?? ) that can see a break or stretch in the plastic at the neck.
The problem is identifying damage on such a small item in an area that's already designed to break.
RE: Non destructive testing on small plastic parts.
Maybe a hot knife, or a vibrating knife, but it's still skill- intensive and needs to be done under magnification, which is itself exhausting. At least buy a television based microscope.
Sellers of ultrasonic machines will mumble sunshine promises. It never worked worth a crap for me; maybe your mileage will vary. Insisting on a money- back performance guarantee for machine and tooling will considerably cool their ardor.
Could you weaken the ends of your pseudo- runners so that you can snap them off at assembly? Or make them flexible enough to leave in place? Yeah, you should be so lucky.
Or, weaken them _away_ from the body and cap, so when you cut them or snap them, you leave a stub on the actual parts? Let me guess; it would be a puncture hazard, or would interfere with some tight clearance.
Sorry; I was in a bad mood _before_ I looked at your problem ... and I don't see a magic bullet anywhere for you.
Mike Halloran
Pembroke Pines, FL, USA
RE: Non destructive testing on small plastic parts.
Changing the part design is out at least short/medium term. Production is already underway.
The problem is from mgmt/corp. committee-think risk mitigation. These things are being cut at the manufacturer, but shipped and handled before they get to us. I've now got to come up with a way to cut these things in house in the event the manufacturer has a problem and the heads start breaking off in shipment. We could get them to stop the cutting and do it in house.
RE: Non destructive testing on small plastic parts.
Here are a couple of ideas:
1) Monitor cutting with ultrasound (say 40 kHz region) to detect abnormal cut or cutter wear/breakage.
2) Assuming the general shape of the object is like a flattened soda bottle, then clamp the bottle head to hold object as a cantilever beam. Apply impact (object or air jet) and measure natural frequency(s). A change in naural frequency would indicate a damaged/miss-shappen structure.
Walt