Three On-Press methods to Determine if Anilox Rolls are Plugged
When an anilox roll is plugged with dried coating deposits, it will not deliver consistent volumes of coating to the sheet. There are several ways to find out if the roll is plugged without removing it from the press:
Use disposable volume testing strips or an anilox roll analysis service: Disposable testing strips use a calibrated amount of indicator fluid to measure cell capacity. This method will quantify the volume loss but will not reveal the reason for the loss. An anilox roll analysis service offers more precise results and will indicate if volume loss is due to cell plugging or wear. A strip is used to make an impression of the anilox engraving and sent to an anilox manufacturer or supplier where it is read on a high-powered measuring instrument. The customer then receives a detailed report with volume readings, cell images and a recommendation for restoring cell capacity through cleaning or re-engraving.
Look to the finished product for signs that the roll needs cleaning:
Inconsistent or poor coating quality
Reduced coat weights and gloss readings
Low coating consumption
Gaps in coverage and coating density
Horizontal lines running across the sheet
Inspect the roll using a handheld roll scope: While it can sometimes be difficult to see coating build-up due to its clear nature, a visual inspection with a roll scope can be helpful in assessing the condition of the roll to rule out surface wear.