Damaged Dies
Damaged Dies
(OP)
Here's one for you: We have an injection process where we have 600+ part numbers with 1000+ dies running on 50+ presses. We had a die get damaged and we let some bad parts escape to the customer. We have instructions in place for the dies to be inspected for damage/wear at the beginning of every shift (these are very intricate parts). Still, we missed this one. The customr is demanding a preventive action- and rightfully so- but we will have to implement this plant wide and not just on this one part. Revising instructions and retraining employees has been deemed "not good enough." We have an already overtasked technician running a 3-D scanner but if we had him scan every running die every day or every few days we would a)never see the dies again and b)probably never see the 3D guy again.
Suggestions on how to satisfy the customer? We are at our wit's end.
Suggestions on how to satisfy the customer? We are at our wit's end.





RE: Damaged Dies
RE: Damaged Dies
Permanently laser made with barcode or whatever-code to permanently identify the die. Set up a simple hierachal computer (PLC?) system at each machine that requires (1) machine recipe & (2) matching proper die number and (3) production schedule number. Dies are inspected and if damaged, then (4) are coded "BAD" for the entire plant and therefore not allowed to run at any machine until repaired and (5) coded "GOOD". Approaching the problem in this manner would require some administrative work, perhaps can somehow tie it into MRP and/or PLM systems.
Just a thought.
TygerDawg
RE: Damaged Dies
{ Loudly and publicly fire the operator who ran the bad parts, and everyone who touched them on the way to the customer, and their supervisors, and _their_ supervisors. }
Probably not.
Like your customer, I'm having a hard time believing that _no_one_ noticed the screwed up parts somewhere along the way, unless the aberrant features require microscopy to detect.
Like your customer, I suspect that someone _did_ notice, and chose to say nothing about it, because of your culture. With your 600+ part numbers, 1000+ molds, 50+ machines, you're clearly a production house, and your culture is oriented toward getting _anything_ out the door.
Production workers don't choose to ship scrap. Someone at a higher station clearly does, and has been deciding to do so for long enough that the issue is no longer presented to him or her as a question, because the answer is known.
To change your culture, you have to _at_least_ identify and publicly fire that person, even if it's the President ... especially if it's the President.
Don't know who it is? Your documented malcontents do.
Mike Halloran
Pembroke Pines, FL, USA
RE: Damaged Dies
This incident has reminded me of why I got out of quality engineering: No matter whose fault it really is, it's your fault.
RE: Damaged Dies
Mike Halloran
Pembroke Pines, FL, USA
RE: Damaged Dies
Basically someone who just walks around and randomly inspects parts either visually or with the aid of simple fixtures, go/ nogo gauges for critical features for example.
You could also consider training operators to do this say every one hundred parts. However as has been said if someone over rules them and sends the parts out anyway you are back to square one.
RE: Damaged Dies
Thanks to all who replied.
RE: Damaged Dies
You can do this by automating the inspection process. They do this with injection molded medical parts all the time. Barcoding each part, Cognex type Visual Inspection, Air go/no-go gauges, limit switch touch gauges, laser point inspections, etc.
Elliminate the human component from the inspection as much as possible...it prevents bordom, repetitive stress, personality conflicts and man power costs. You can have the PLC do real time process control. You track number of errors, type of errors, and what parts (barcodes) are coming from which dies to watch for wear patterns, etc. automatically printing out an inspection report for each part is not much more trouble either.
Ingenious automation is the only way the US is going to stay competitive in manufacturing world wide. Work smart, not hard.