Rubber Roller Alternatives

[KB P]

I am having issues with excessive wear on a drive roller on a labeling machine. Two pinch rollers (knurled aluminum) press lightly against it to pinch a label web between and drive it. Originally the drive roller was made of nitrile rubber. It was wearing too fast so I changed it to a higher durometr of nitirile rubber. It was better but eventually the roller would wear excessively again. My rubber vendor suggested switching to a carboxylated nitrile rubber which is supposed to have better wear properties. This did not help much.

Looking at material properties of different rubber, it looks like polyurethane might be a better option. Any thoughts?

 

[ornerynorsk]

For material feed rollers I would almost always defer to urethane over other types of elastomers. With urethane (and perhaps other materials, as well) your durometer is not necessarily going to be higher to get the optimum grip/feed and wear characteristics. There is a point of higher durometer requiring higher roll pressure, and thus diminishing returns in wear. I'm speaking mostly of experience in woodworking machinery feeders, but I believe the principal will be the same with other feedstock.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[tom1953]

FYI, with polyurethanes, most commonly used are castable (liquid) polyurethanes, but there are also millable (solid, rubber) polyurethanes. Millable PU's sweet spot (of best properties) are in intermediate hardnesses (50-75A); castables have better properties at 80+. MPU is very commonly used for small rollers in paper handling machines (e.g., ATMs).