40" Press roller maintenance

[tpeetros]

We are having a debate within our shop on how often rollers in our various 40" Komori's should be re-set and/or replaced. Presses are all set up for AQ, no UV. We only use Bottcher rollers. Any feedback would be appreciated.

thanks

 

[Servicetech]

Kind of depends what kind of print quality you wish to maintain.

For optimum print quality, the water rollers should be checked regularly, and likely replaced every 6-9 months, maybe a year if you're lucky. Ink rollers not as often but are just as important IMHO.

Get yourself a good durometer gauge with a 1KG weight for checking the hardness of your rollers. here is a couple pics of the one I used for years. I cant' give you a tolerance spec off hand but if you record the durometer, over time you'll develop an idea of durometer tolerance that you wish to maintain.

 

[cityhunter731]

How about Nip roller pressure gauge, does anybody have any data whats the correct pressure to set on the rollers

 

[Servicetech]

The Komori operation manual gives these roller settings in nip width, not pressure.

I am not aware of any accurate way to convert a pressure measurement into nip width, as even slight deviation from the given roller hardness would affect the final nip width.

If you want to use a digital gauge to set the rollers on a Komori, you should get one that is designed to measure nip width. I had one for a while, but I was unhappy with its accuracy. I sent it back to the manufacturer (who shall remain nameless) numerous times before I gave up on it.

 

[saso777]

With Bottcher water rollers usually 10-12 months ink rollers much longer but always do checks with durometer gauge.

 

[CD102]

Heidelberg rollers are supposed to be set based on roller stripes and nip widths. That method is described in all their operations manuals. And that's the way the trainer taught all the pressmen in my plant when our presses were installed. Many years down the road, that plant was closed. When I was applying for jobs all over the country, one potential employer asked if I knew how to set rollers using a type of digital scale. When I professed I had never set rollers that way, my phone interview was over. When I did finally get another operator job, my new employer didn't have a shore durometer tester and still doesn't have a standard for hardness. Life is interesting.