Metal finishing Q&As since 1989


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Automotive or industry standards for tape to rubber adhesion

I work for an industrial application products rubber manufacturer. We have made a part which uses a pressure sensitive tape on one side, and a heat sensitive tape on the other. This tape is applied at our plant to a EPDM extruded part (heat activated side to the rubber), which we then apply the tape to, send it out, to a sub-supplier who slipcoats the part, which makes it easier to assemble onto the vehicle, upon application. Our part goes onto a plastic CHMSL, which is then attached via the tape, to the metal on the vehicle.

Here's the question. We were recently (this morning) rejected as the tape peeled free, on about 1% of the tape area (1200 mm long x 10 mm wide)from the rubber. We feel that this should not be considered a failure, yet the automotive company is rejecting us. Is there a standard, either automotive, industry (for tape), or government, which would state that as long as the tape adheres on "XX.XX%" it should not be considered a failure? My company has been told by the tape manufacturer, that as long as the tape is 85% adhered, that it will be a functional part, but they are unwilling to put that in writing. I would appreciate any information which will prevent this rejection.

Thank-you in advance, for your assistance in this very important matter.

Marc S. Dulin
Industrial rubber products manufacturer - St. Joseph, Michigan, USA
2004

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Hindsight is easy! This should have been taken care of beforehand so all parties would be in agreement as to what an acceptable % of adhesion would constitute pass/fail.There certainly are ASTM standards that define testing criteria for rating adhesives for their mechanical abilities under certain conditions, but it won't do any good to pull them out now as the damage is already done. This should have been specified at the engineering stage to prevent this kind of surprise. Now it's a game of politics and butt kissing to get back into good graces with the customer. Obviously the auto guys want 100% adhesion and your supplier will only guarantee(?) 85%(verbally) which is a cop out, so that is probably the most important issue you are going to have to deal with.

Good Luck! I hope everything is going well.

Sheldon Taylor
supply chain electronics
Wake Forest, North Carolina
2004