What are those foam looking rollers on a processing machine?

[Andrew Wise]

I've made a little jig for helping wipe off remjet after hand processing film in a lomo. 

The rollers I'm using are 3D printed, contacting the film by just the edge. But I'm curious about the foam rollers used in processing machines. 

They look like a shrunk down version of one of those foam rollers people use under their back, with all the little bumps. Or a paint roller designed to give texture. 

does anyone know of an off the shelf product I could cut down?

[Richard Tuohy]

Hi Andrew,

I think you might be referring to the rubber 'tyres' that make contact with the film.  Actually, they aren't rubber but rather silicone (at least mine are).  They are called 'soft touch rollers'  They are soft, but not like foam.

Sounds like what you have 3D printer are more like the rollers called 'emulsion rollers'.  These only touch the film on the edges and are what is required when you need to have the film run emulsion side down on a roller.

cheers

richard

 

[Andrew Wise]

19 hours ago, Richard Tuohy said:

Hi Andrew,

I think you might be referring to the rubber 'tyres' that make contact with the film.  Actually, they aren't rubber but rather silicone (at least mine are).  They are called 'soft touch rollers'  They are soft, but not like foam.

Sounds like what you have 3D printer are more like the rollers called 'emulsion rollers'.  These only touch the film on the edges and are what is required when you need to have the film run emulsion side down on a roller.

cheers

richard

 

Thanks Richard.

 

I did a google search using soft touch rollers and came across this site JJ Short

but they appear to be rubber, and a pretty dated site. 
Silicone would be much nicer ? 

the 3D printing doesn’t really leave the nicest surface even after sanding. I find on the loop where the edge of the emulsion is contacting the roller, if it tracks sideways slightly it will rub a slither of emulsion off. It’s far from the image area so not an issue, but just gets stuck on the mohair paint roller. I was hoping that I could use the soft touch rollers, but maybe they were not intended for touching the emulsion. 
 

Maybe I’d be best to find someone to make some up on a lathe with a very smooth surface. 

[Richard Tuohy]

Those little bits of emulsion slithers are called 'skivings'.  Yep, they are a problem.  Indeed, with normal 'soft touch' rollers the roller underneath the rubber or silicone tyre are actually a little bit shaped, rising to a gentle point in the middle.  This causes the film to ever so slightly move towards the centre of the roller away from the edges so as to avoid this rubbing that causes skivings.  

[Robert Houllahan]

If you are talking about the buffers in the Rem-Jet removal stack then they are often a sponge material on a plastic core.

The ECN2 process goes from the prebath which softens the backing then into the buffer stack that has rotary buffers and water jets that remove the backing and wash it away.

Then on to the developer tank.