Printing Roll Nitrile Based (Oil Resistant Printing Roll)

[Oksitocin]

Hi there,

We are working with rollers and recently we came at a problem. The rollers that we cover with oil resistant rubber with hardness from 35-45 shA came out from the autoclave with holes and the rubber was porous. We vulcanized them at the temperature 125*C and pressure around 2atm for 1h30min. How can we avoid these holes to have a perfect printing roll for offset machine? Plese help and thank you in advance.

 

[tom1953]

I see that there have been no responses to your posting from 5 months ago, so I'm wondering if you're still having this problem.
Porosity in rollers can have many causes: moisture in the compound, low pressure in autoclave (I assume you're curing in an autoclave), insufficient pressure of wrap, air in the rubber as applied, undercure.

More details would be needed to try to figure out what is (or was?) causing the porosity you describe. My first thought is insufficient pressure in the autoclave . . .

Tom Jablonowski, TSE Industries, Inc.

http://www.tse-industries.com

 

[Oksitocin]

Hi Tom,

Thanks for your answer. We`ve made a research and now we cure the rollers under bigger pressure in autoclave, and with bigger wrap pressure and they don`t have porosity, but from time to time holes are appearing as a trapped air and the wrapping tape is cutting the rubber during vulcanisation.