I've written about how to reducing blanket piling and what causes it. But this time I wanted to share how we have recently greatly reduced piling on our blankets. It is something that I rarely see published in other research, so I want to share with fellow pressmen out there who might benefit from this tip.
What We Print
Our factory produces most of it's work on a light weight coated 40 pound stock. We find that we have to wash blankets every 80,000 revolutions. I'm not sure what other printers out there get, but with a good ink and water balance, we can sometimes push this to 120,000 impressions. Above is a picture of what we get after that amount. It is in our black unit, so it shows some paper dust too. We've also found that blanket piling is greatly influenced by the paper we use and the ink and water balance.
What We Tried
However we tried something different recently that involves our water system. We have a system that uses what we call a "spin clean". It cleans the water by means of a device that uses centrifugal force to clean contaminants. That gets the water moderately clean. However we added several filters with high particle retention rates. This gets our water really clean.
Immediately after the change, we are now washing our blankets every 250 to 300 thousand impressions. Even after this amount, the blankets are not badly piling. Very handy on long runs. I have never appreciated the value of having extra clean water until now. I have recently come to realize why it makes sense.
Why It Works
Reverse piling is caused by minute particles in the water emulsion that are on the plate. When this thin film of water on the plate transfers to the surface of the blanket, it deposits these minute particles on the blanket. Over time they build up. But what if you minimize the number of particles that are in your water system. It will not completely eliminate the buildup, but it will minimize the piling that happens on the blanket if you have a clean and filtered water source.
Why You Should Try It
We use an automatic blanket washing system which wastes about 500 impressions per wash. Other printers may shut down for washes, but it doesn't matter how you wash blankets, what matters is the waste and lost time that are saved by reducing your blanket washes. It's doesn't take long for the few extra dollars in filters to pay for themselves.
I don't claim this will work for everyone, but hey, if you have long runs, it's worth investigating. Also, I would be interested to know how long your press can go without washes. I would be interested to know. Maybe you have some tips too. Please feel free to share in the comments below. And don't forget to subscribe or like me on facebook if you think this tips like this are useful.