Loss of tack

[tmoon42]

I have 2 ply epdm membrane that is calendered, wound up into a cart separated by a liner.
Coming out of the cart/liner, one ply is always less tackier than the other
It's as if one of the ply looses tack? Liner is the same on both sides.

The gum properties are exactly the same right out of the calender rolls, so something downstream is causing the 1 side to loose tack?
The tack seems to change after the lamination roller.
The tacky side contacts a heated (>140F) lamination roller while the side that looses tack is in contact with a cold ( <90f) hard rubber roller. The hard rubber roller seems to have some whiteish residue build up too.

I guess my question is, could a single roller with some build up of unknown material cause miles and miles of the membrane to loose tack day after day?

I know temperature can affect tack, but does temperature history also affect tack?

 

[TugboatEng]

With EPDM tapes, the more you stretch them the stronger the autoadhesive bond will be. Is the tacky side being bent around the roller at a larger diameter?

 

[tmoon42]

No tape, membrane. Both go through similar small/large rollers.

 

[Compositepro]

Tackifiers and other additives in rubber are relatively low molecular weight ingredients that can bloom to the surface or be drawn away from it into the rubber, depending on how compatible they are with the rubber. A liner can help to keep an ingredient from migrating away from the surface just due to surface tension effect. I've also seen where the catalyst used to cure the silicone release on the liner also catalyzed the polymer film products' surface, causing loss of tack.

 

[Luis.Tormento]

Many thinks can occur on tackiness, temperature, time for the tackifier to bloom, dilicone influence. My recommendation is to activate the surface of the rubber compound with UV to surpass this problem