Press Maintenance - A Pressman's Guide

If any press is to run successfully, it needs a good preventative maintenance program. Some pressmen rely on outside companies or other departments to do their maintenance, but most take it upon themselves. Each press is different, but if the pressman needs somewhere to start, here is a good place. I itemize each point according to it’s order on an offset heatset web press, but the principle of it can apply to nearly any offset printing maintenance program. Here goes:


Rollstand and Infeed Maintenance
There are of course different types such as zero-speed and flying pasters, but the principles are the same.
1. Clean all idler and festoon rollers. These tend to build up with tape from the splices. Spend the time to get these very clean.
2. Lubricate well. A good pressman will consult the operators manual and isolate all the grease point. In addition, especially on a zero speed splicer, there are various chains to lubricate.
3. Clean all photo electric eyes for web guides. This should be an almost daily assignment. A little dust can cause you a lot of headache.
4. Regularly inspect the web severing knife and soft rubber rollers. Don’t wait until you start missing splices. Inspect also the tail edge of the cut to look for anything irregular.
5. Clean and vacuum underneath and around the paster. In addition, vacuum all the electrical components inside.
6. Check the infeed nip pressure. This will ensure good tension which can be hard to troubleshoot when having web breaks.


Printing Units
1. Check all roller settings according to the manufacturer’s specifications. If these are kept in tolerance, you will get less plate wear and more life from your rollers.
2. Wash up the unit at regular intervals. This could be weekly or even monthly, but make sure it is done. Recondition the rollers.
3. Clean any washup trays, roller ends, side frames, ink fountain, anywhere that you can find dust or ink.
4. Check bearer pressures and replace blankets as necessary.


Water System Maintenance
1. Flush out the water system and replace with new water. If you have an unstable water source, reestablish your pH and conductivity. It will eliminate troubleshooting ink and water balance issues later.
2. Clean the water trays and the reserve tank.
3. Replace the filters.
4. Clean all sensors.


Dryer
1. Clean all the nozzles in the heatset dryer. Scrape any residue off of them. A fluttering web – more related to tension issues – can cause a buildup.
2. Clean out any air filters of debris.
3. Lubrication. Although this is done rarely, there are various motors, drives and pulley systems that should be given attention.


Chill Rolls
1. Clean each roller thoroughly, especially the nip.
2. Flush the system out. This is done much more rarely if you have a good water supply. If you have minerals in your water, you may want to consider using an acid solution to clean them.


Press Folder
1. Do a thorough lubrication. There should be a well regimented program for the folder.
2. Replace or inspect all components. This would include tucker blades, jaws, and delivery belts. Also inspect pins and cross perforator for wear.
3. Inspect chopper table. This would include the chopper blade, brushes and delivery rollers.
4. Clean. This become especially necessary if you run glue lines. A clean folder just runs better, period. I know of a pressroom consultant who makes over 1,000 per day. After he cleans the area around the problem, it usually goes away. Save a few dollars and do it yourself. For more tips on troubleshooting a folder problem, search this website.


Of course, these are some of the basics. The owners manual should provide the pressman with all the details necessary to do it properly. A more solid approach would be to make a maintenance program based on the TPM system. Make a maintenance program and stick with it. It will pay dividends.



Related posts:
Web Press Troubleshooting Guide