What trend in defect counts means the anilox is failing
Look at several weeks, not one day. Coming back soon after a wash looks like the roll. A sudden blade line is counted apart.
When the anilox is failing, counts of the same missing ink or ink streak rise week after week, and a wash only holds for a few days. One sudden doctor blade line is not this trend. Three weeks rising in a row means schedule a roll change or a roll check. Do not start from the ink formula every week.
Why it is judged this way
Draw the weekly counts of this defect as a few bars. If the bars climb, and changing the ink and changing the paper both do nothing, the roll is the likely cause. With no weekly counts, only an old hand’s feeling, you are weeks late.
What to compare
| What you see | What to call it | What not to do |
|---|---|---|
| Three weeks rising and a wash does not hold | Schedule a roll check | Keep changing the formula |
| One sudden line on a single day | Check the blade or a scratch first | Scrap it as a dead roll |
| The count comes down after the roll is changed | The judgment holds | Leave that result unwritten |
At job change or when a roll is opened
- Once a week, write the count of this defect.
- If it keeps rising, stop and check the roll.
- After the roll is changed, see whether the count drops.
