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Not so pretty in pink

Posted: 4/4/2019

Have you seen it?  Your TPO membrane is pink when you open the box or a roll.  Pink may be alright for your new baby girl and it certainly can help you feel better after eating a dozen pickled eggs, but on your brand new TPO?  Not so much.

We hear it often, “Why are my new TPO flashings all pink?”  Generally, these comments occur shortly after a contractor opens a box of TPO accessories or unrolls some new TPO membrane.

Here are some examples:


The Cause

Well, we talked to a really smart scientist type guy to find out why this happens and here is what he said:

”The weathering package which includes powerful antioxidants and these antioxidants help protect the finished product from heat and photo induced oxidation and degradation.  The antioxidants are particularly effective free radical scavengers but they are susceptible to pinking.  

Basically pinking (also called “gas fading”) is a surface reaction of these antioxidants with air pollutants, mostly nitrous oxides and sulfur oxides, produced in combustion processes. . . . . . ”

And here was our initial reaction:

But then he said this:

“Gas heaters, forklifts and vehicle traffic, etc. can create nitrous and sulfur oxides in the atmosphere and usually we see the pinking happen when the material is stored inside for long periods of time with gas heaters or considerable forklift traffic.”

There you have it.  TPO turns pink when it has been stored inside for long periods of time.  You are buying Mule-Hide products from ABC Supply.  ABC Supply uses gas powered forklifts and gas powered heaters.  Pinking will not only happen in the ABC Supply warehouse, it will happen in your own warehouse too.

Can I Still Use It?

Absolutely!  Once pink TPO is exposed to UV radiation and/or heat, it will turn white again.  In the photo below, you can see where the pink molded sealant pocket is turning white again when heated with a hand gun. 

Here is another example. That piece of TPO Skirted Edge Metal shown earlier was set out in the sun at 8:30 am. Here are some progress photos as it is exposed to the sun:

So next time you find some pink TPO, don’t worry.  Just put it in the sun and watch your troubles disappear.


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