TPE/Nylon jersey laminate discoloration and speckled

[CarolM]

hello all,

We are manufacturing kids backpacks in Taiwan. The material we are using is a TPE foam 2mm thick laminated with nylon or polyester jersey on both sides. (similar to a wet-suit).
The material becomes discolored and speckled with brown spots over time. We suspect that it is the glue the factory is using to laminate the materials. We have switched to a white glue and this has helped but still getting the discoloration. We think it is from UV and or heat.
Our short term solution is using a thicker fabric which masks the glue. Some of the cut rubber edges are exposed and the brown glue and TPE looks bad.

Any ideas how to stop the discoloration?

Thank-you
C

 

Visit the factory and inspect their processes from start to finish. Determine which stage of production the problem appears and you should have your answer.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[CarolM]

Thank-you. The discoloration is happening 2-3 months after production. We are fairly certain it is caused by UV light but we have had speckling occur on bags straight out of the carton.

 

[EdStainless]

You need to do some analysis and figure out which component is breaking down.
Then you can attack the stability of that one.
Accelerated UV testing is fairly easy.
It could be an interaction between the glue and the TPE (or a processing aid/curative in it).
The supplier should have some grasp of this situation.

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P.E. Metallurgy, Plymouth Tube

 

[CarolM]

Thank-you.
It has been frustration working with the supplier. It is a small factory. We order a small amount and do not meet the moq of a larger supplier.

 

[itsmoked]

Clear close up photos might help someone here identify the issue.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Compositepro]

Nylon film is used for vacuum bagging of composite parts. The nylon film will often turn brown when exposed to contact with numerous different resins at elevated temperature.

 

[CarolM]

I placed a strip of duct tape on the sample before putting out in the sun. This reaction was after 6 hours of bright sunlight.