The nightmare of seeing a score line on your print run!
A score line on your print run is never good. This will instantly result in print downtime, wastage and re-running the print job. Not a process that any print business wants to deal with.
Scoring can be prevented or at least reduce the consequence of this, by instigating a cleaning and maintenance procedure for your flexographic print production.
Scoring occurs on an anilox roller when either dried ink, or a fragment of metal, from the doctor blade becomes trapped between the anilox surface and the blade. With the anilox roller rotating the trapped ink or metal scores around the anilox circumference. This in turns destroys the row of cells and transfers onto the finish of the printed product. It will appear as darker line of colour through the print.
The consequence of a score line is print rejects. This then results in production downtime, re-run of print, lost time, material wastage and additional costs for the business.
Core components of scoring:
Anilox Roller: Dried ink can build up above and around the print unit. Particles can break loose and become trapped between the roller surface and the blade, resulting in a circumferential damage to the cells.
Setting routine care and maintenance of the anilox roll, will in the long term save your business time and money.
Inspecting anilox rollers regularly is essential, a daily, weekly and monthly cleaning regime is a must.
The repair of an anilox roller comes at significant costs to your business, not only the cost of the refurbishment but also the cost and inconvenience of removing the rollers from the print unit. Repairing anilox roller can potentially impact your print capability for several weeks.
At the various stages, whether cleaning on press or off, there are cleaning solutions that are specifically formulated to effectively care and clean your anilox rollers.
Doctor Blade: Over time the doctor blade will wear. Eventually small particles of metal can enter the inking system. If they aren’t filtered out quickly, they will become lodged in between the blade and the anilox roller. The metal will then begin to score the outer surface of the anilox, damaging the cells.
In addition to this if the doctor blade is not positioned correctly, it can exert too much pressure on the anilox. This will result in wear and breakage of the blade and scoring to occur.
Magnets can be fitted to attract and filter metal fragments to help avoid scoring.
The incorrect set up of the doctor blade can cause premature and excessive wear and tear. It is critical that the doctor blade is set up correctly. Ideally the doctor blade should just kiss the anilox roll.
As with many products, there are less expensive doctor blades available, but generally these are of sub-standard quality and will wear quicker or break easier, producing metal fragments.
Score line on anilox roller
Cell of an anilox roller, damaged by scoring
To prevent and minimize scoring, remember to:
- Keep anilox rollers and surrounding areas clean: create strict cleaning schedules and use the appropriate cleaning solutions, to prevent damage and eliminate the build-up of dried ink.
- Regularly inspect anilox rollers: being pro-active to audit their condition, will enable action to be taken before damage or print deterioration starts.
- Repair or replace damaged anilox: damaged or worn anilox rollers will contribute to reduced print quality and increased print rejects.
- Use a good quality doctor blade: improved quality will provide stronger blade, providing longer life.
- Fit magnets: fragments of metal from doctor blades will be filtered before scoring the anilox cells.
- Ensure doctor blade set up is correct: too much pressure will wear the anilox roller and again cause damage with metal fragments entering the system.
- Set regular audits of your print process: this should involve checking the complete print system, including anilox rollers and its cell structure, doctor blades, end seals, ink pipes and chambers and the general print process.
The over-riding aspect is good house-keeping and maintenance procedures. Making this part of your process and equipping your operators with the correct equipment, training and knowledge will pay dividends to your operational bottom-line.
Maintaining good quality print will result in reduced print rejects, high productivity and control of your costs.
Print Tech Solutions will support your anilox rollers and print system maintenance programme to assist you in producing the best possible print quality.
To book your site assessment or on-site training contact us now.
