Laser plates on Ryobi 3302

[robbg439]

I've worked with laser plates on a one-color hamada for a while. They work great for my purposes on 95% of the jobs I run. Recently I've added a Ryobi 3302 to my shop, and have been getting it up and running. One problem I'm having that I can't seem to figure out is that the image on the laser plates degrades very rapidly on the Ryobi, after only a couple hundred prints. This is especially true when working with halftones. I've kept most variables the same, I use plates from the very same box, I image them on the same HP5100 using the same settings, and the same fountain solution, and inks. Both presses have Crestline dampening as well.

My initial thought is that some roller or the blanket cylinder is exerting too much pressure on the plate and the excess pressure is making the toner flake off the plate surface. But I've checked every nip and everything is set to Ryobi's specs.

Does anyone run laser plates on a 3302? Is there a 3302-specific thing I should be doing to make the plates last as long on this press as they do on the Hamada? Maybe its the plate pressure? I have it set to .12mm right now. I use "Buckingham Laser plates" from stuff4print. The website says they are 5mil thick, which I believe would be around .127mm. But I just look at the box and it says the plates are 100 microns, which would be .1mm.

 

[old guy]

pull the number 3 ink form roller.

 

[robbg439]

pull the number 3 ink form roller.

Thanks. That would make sense, as my Hamada only has 2 ink form rollers. Its also a bummer, because I was hoping to be able to take advantage of the better inking you get with 3 form rollers. I was already getting much better prints, in the short time before my plates degraded. Maybe its asking too much, but is there any other way?

 

[old guy]

try setting the roller pressures on the light side. make sure plate to blanket isnt too heavy also

 

[old guy]

also if oscillator to form is too heavy it can make the form rollers drag on the plate.

 

[Green Printer]

If any of your rollers are skidding on the plate it will wear out in less than 500 impressions.
Make sure that the stripes to the oscillator for both ink and water forms are 2 mm larger than to the plate. The Hp laser plates are sensitive to any scrubbing action.
Also some ink ingredients will remove toner from the laser plates. This will be extremely accelerated with just a little scrubbing action or call it roller slip.

 

[robbg439]

If any of your rollers are skidding on the plate it will wear out in less than 500 impressions.
Make sure that the stripes to the oscillator for both ink and water forms are 2 mm larger than to the plate. The Hp laser plates are sensitive to any scrubbing action.
Also some ink ingredients will remove toner from the laser plates. This will be extremely accelerated with just a little scrubbing action or call it roller slip.

Interesting. The specified stripe setting for oscillator to form rollers is 3mm, and form to plate is 3.5mm. So I should switch it so that there is a wider stripe between oscillator and form?

Thanks for the help!

 

[Green Printer]

Interesting. The specified stripe setting for oscillator to form rollers is 3mm, and form to plate is 3.5mm. So I should switch it so that there is a wider stripe between oscillator and form?

Thanks for the help!

This is a common error. Some manuals have it the same width or have the stripe to the plate 1 to 2mm tighter than to the oscillator. I would make it 3.5 to the oscillator and 2 to 2.5 to the plate.

 

[robbg439]

I would make it 3.5 to the oscillator and 2 to 2.5 to the plate.

These settings did the trick! Thanks so much for the help.