Improvement of surface on rubber roller

[Oksitocin]

Dears,

We are developing a soft rubber compound for covering rubber rollers used in printing industry.
The rubber compound we got is 25-30 shA hardness but we have some problem with the surface we got after grinding the roller-it is not smooth enough.
I will be grateful if someone has any proposal for improving the grinding surface.

 

[Nletoile]

You need to slow down the traverse speed of the grinder very slow. I am not sure of the exact numbers, but for example on my Cincinnati grinder an 8" long face roller it takes about 3-4 minutes for the grinder to go across the whole face. You will need to look through a magnifying glass to see the finish then adjust the speed accordingly. That should solve your problem.

 

[Oksitocin]

We tried all different speeds and that did not solve the problem. It must have some problem in the compounding...

 

[Nletoile]

it definitely could be the compounding then, also i use a 65A EPDM to cover my rollers so there could be a huge difference there. what material are you using?

 

[Compositepro]

The softer the rubber, the more difficult it will be to grind because the rubber deforms from the forces applied during grinding. To get a good surface the final pass must remove only very little, and very slowly, in order to not deform the rubber substrate as the surface is removed. Chilled water or a cold air gun may be required to harden the rubber and to remove the heat of grinding. The abrasive must also be the correct type, with the abrasive grains having sharp knife edges on them (I believe silicon carbide is good). Abrasives for metals have blunt edges because sharp edges would break-off. Fillers in the rubber will make grinding easier but it also makes the rubber harder.

http://www.exair.com/en-US/Primary ...ystems/Pages/Cold Gun Aircoolant Systems.aspx

 

[JDLSHF]

Grettings!

Have you tried manually sandpaper the roll? Not with any machine, but human hands and a fine, water sandpaper, sheet? Sometimes the human hand can have that dampening effect on rough things, and can regulate the applied force. But depending on the rubber, you might really have to cool down to harden it, thus making it easier to finish.

The human usage has 2 problems: might not have an even surface with very fine accurancy, and it's more exausting for a worker than the machine.

Hope it helped.