In the previous article we spoke about the advantages of having an Anilox Roll Inspection program. This is a continuation of that article.
Act before it Happens
Sonia Across from Cheshire Anilox technology mentions that “A preventive maintenance program is fundamental to ensuring maximum performance from anilox rolls. This means not only ensuring rolls are thoroughly cleaned after each use but also tracking their essential data points.’
converters need to be aware prior to the start of job, if their anilox rolls meet the criteria they logged the last time that job was successfully produced. This includes measuring the volume of the anilox roll using equipment like a Capatch strips, ink drawdown tests, high power microscopes or interferometric cameras.
It is crucial that when an anilox roller is returned to storage that any chips or scoring lines have been documented. The volume should be measured, and the data should be captured so the pre-press department knows that roll is fully ready to run the next job.
Ms Arcos continued, ‘Our technical sales engineers can conduct an anilox roll audit in relatively short period of time and with minimal press disruption. Using a high-powered digital microscope, the rollers are inspected for screen parameters, cleanliness, wear, damage and any other aspect that can affect their performance. However, since suppliers are not typically in a printer’s facility on a daily basis, the printer should invest in measurement tools and gain knowledge in order to diagnose and address print issues themselves.
To inspect the engraved surface visually you just need a well-lit area where the anilox roll is supported by precision bearing blocks. After visual evaluation, the next logical step is that with the help of a magnifying device you inspect the engraved surface closely. You need to be able to inspect the engraved surface close enough to determine if the surface is plugged, worn, or damaged.
The primary controlling factor in flexographic printing is cell volume. To ensure print consistency, the printer’s process needs to be optimised through scientific testing and the anilox rolls need to be standardised for each print application.
When optimised for various elements required of the printer, including solid coverage, line work, screens, process work, and combinations, the anilox roller’s performance is standardised to reproduce line colours, solid ink density targets, and acceptable dot gain values.
Part of the inspection process should be the comparison of solid ink density and/or line colour transferred by the new roll to established standards. This comparison of roll performance to established standards also can be used throughout the life of the anilox roller by utilising running targets on live jobs. Again, after each test is being performed this data should be logged properly on the pre-press department to avoid using anilox rollers that are substandard.
Ms Arcos concludes this by saying ’Implementing a maintenance and inspection process will save the converter lots of money and time in anilox roll purchases, long set up, water press, ink wastage, waters stock and lost business.
This is a Three part series article.