Tie-wrap pull test to verify contact retention

[Vthouta]

Hi,

Did anyone execute tie-wrap pull test to verify contact retention???
If yes, Could anyone let me know on how to conduct cable-tie wrap pull test??

Recently, we had a rejection on one of the PCB board that has a ty-wrap installed to one of the inductor.

Ty-wrap: http://www.amazon.com/TY24M-Stainless-Military-Specified-MS3367-5-9/dp/B00B2EYBDK

http://www.tnb.com/ps/fulltilt/index.cgi?part=ty24m

Data sheets and technical specifications are available at the above links.

Thanks in advance

Vik

 

[Miner]

Did the tie wrap slip loose, or was it never cinched tight when it was installed?

 

[Vthouta]

I'm not sure on how it was installed, but they have reported it as tie-wrap broken. We manufactured 400 units in the same way and our customer reported only one broken tie-wrap in the entire lot. Couldn't deduce whether it was an operator error or had a nick on the wire during installation which led to broke during shipping.

 

[Sean Kelley]

Can the customer provide more detail such as a photo or maybe even return the failed part? From your description I interpret it as a broken tie meaning there was something weak such as a void in molding perhaps or some other reason that could make it break under load.

 

[Miner]

The most likely cause was that the wrap was nicked when the excess was cut off. The strength of these wraps are high enough to damage your PCB and components if cinched too tight.

 

[Vthouta]

Sean - Unfortunately, we didn't get any picture and when the board was send to troubleshooting our team has scrapped the tie-wrap and fixed it with new one. It was so late that I couldn't get the broken tie-wrap to my desk.

Miner- Right now, I've been trying to document the CA for this issue. As part of the corrective action, I wanted to test a few samples by conducting the pull test and make sure we are getting right parts sourced to us. In this way, out customer would have more confidence instead of stating human error or probable nick on the tie-wrap might have led to this issue.

I'm assuming pull test data will satisfy the corrective action and gives us more confidence on supplier, trying to be proactive rather than reactive.

I appreciate your quick responses.

 

[somashekar]

I'm assuming pull test data will satisfy the corrective action and gives us more confidence on supplier, trying to be proactive rather than reactive.

There is no meaning in a corrective action without an analysis and finding the root cause...
When you test a locked tie-wrap in a pull test, you may get a very high value at break or stretch, further leading you no where.
When pulled and locked (Perhaps with more force then necessary), the tie-wrap will be in stress, and a small incession from any sharp edge can snap it off.