Reduce blocking effect of TPU's

Hi all,

I'm looking for some additives to reduce blocking. I added alreadey silica (matting agent) to my TPU without obtaining the desired result. The additive were mixed in a solvent based TPU system, after evaporation of the solvent the final TPU-film must be without blocking properties.

Is there a relation between shore A and the blocking properties of a TPU.

kind regards

Reply to
Dummy
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Particulate anitblocking agents reduce blocking by creating a rough surface. The rough surface will then have less contact area with the neighboring surface, which is also rough. A softer, more compliant material will overcome this separation due to the deformation and flow of the polymer.

You could try a slip agent, such a migrating silicone or erucamide. These will diffuse to the surface and create a weak boundary layer. Do you need a silicone free surface?

If you are really hooked on the silica, consider either more silica or larger silica. Or maybe a combination of small and large. You might end up losing your Shore number however.

John Aspen Research, -

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Reply to
john.spevacek

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