Not long ago, three of our offset printing presses were sold to a buyer in India, a booming printing economy that is buying up a lot of North American used printing equipment. Since they had already purchased offset presses from our printing plant, they knew that we maintained our equipment well. Not surprisingly though, the very first order of business was to check the condition of the cylinder bearers.
Thankfully, 20 years of changing the bearer felts paid off and the cylinder bearers were in good condition. That was enough to convince them that they had a good used piece of equipment. They bought all three presses, which I might add was during a soft market.
Setting the bearer cylinders should only be undertaken by either the press manufacturer or the most experienced pressman. This bearer to bearer setting is critical and may even be worth inviting a professional into your plant to do it for you.
Here are three tips to keeping your bearers in good condition on your offset press:
- 1. Change the felts regularly. As a rule, the pressman should do it every week. If you want to do it more often though, it can only help.
- 2. Ensure they are lubricated. Most presses have oil lines running to them. Ensure these are not plugged.
- 3. Check the cylinder bearer settings. These settings should come properly set by the manufacturer. But in time you may have to adjust them. Different methods are used, but probably the most popular is to use a light shinging behind the two bearers that are touching and turn the impression on. Others will use tinfoil or a blue paste to check the actual stripe setting. Whichever way you choose, if you put excessive pressure or not enough, it will greatly determine the quality of the printed product.
For a detailed explanation on how to set the bearers, see this link.
All parts of a press are of course critical, but the cylinder bearers rate high on the list. Not having them set right or in bad condition will make your life miserable. Gear streaks (vibration from the gears) will cause inconsistencies in your halftones. Improper settings can even cause plate wear. So when it comes to the cylinder bearers, do it right and make the pressman happy.