Hi all,
Having many machines, we preferred the urethane rubber rollers, After pulling several of the machines from differing manufactures out of storage there were a few that had melted pinch rollers, yuck. So it was not unexpected that one of the old rollers started to go. It got sticky and you could put dents into it with your fingernail.
I believe it is crucial to know that Urethane is a water cured polymer. So when a 1/2" Studer roller started to get gummy, I took off the roller bearings and immersed the roller in water for about two weeks. In fact, I forgot about it because it was just an old spare and the rollers on the decks were OK.
When I pulled it. out, it was whitish and opaque. apparently the water had soaked into the middle of the rubber and saturated it. I though it was gone, but kept it on the bench. In a couple of weeks it had returned to it's golden semi clear and the rubber had recured to it's normal state and is no longer sticky and melty.
Everything about urethane rollers seems to be counter intuitive. They get harder in wet environments, but get softer in dry ones if they have not been fully cured. Using solvent cleaners usually pull water out of them making them get sticky, including the fluid that Athan supplies. If a roller is showing any sign of softening never use the Athan solvent on it, it will only make it more gooey. Use the Athan conditioner if the rubber shows signs of getting too hard. Also, a normal roller will often need to sit for a day to reharden after cleaning with the fluid.
