CASE STUDY

Anilox Scoring Investigation

The investigation started with an inspection of decks 1, 2, 3 & 4 for blade pressure, wear, contact angle and filters & magnets for metal in the system.

Results:

All of the printing decks were clean of ink, colored water, etc…

All of the anilox rolls had streaks and water spots from the rolls being aloud to drip dry.

Set up a two color job (Pacifica Pizza), red and blue:

pH @ 8:00 am
Red 10.5 | Blue 9.9

pH @ 8:45 am
Red 10.5 | Blue 8.6

During the run we found rocks, dirt and starch on the board prior to printing. Samples sent to our Green Bay facility .

After two hours of running we found blade material on the magnets that is indicative of excessive blade wear. Samples sent to our Green Bay facility for evaluation by our lab technician.

Removed the blades and send them to Green Bay for blade angle evaluation.

The metal blade was replaced the blade on the first down with a graphite blade.

The inspection of the roll on all the presses and found that all the rolls with doctor blade chambers have scoring.

I took Echocheks from the 2nd print deck on the four color Ward press and the 1 st down on the two color Ward press and sent them to Green Bay for evaluation.

Two Color Ward Press:

Press operator said the lines/scoring is because of the metal blades. This was not a problem when they ran plastic blades.

Conversation with Press Manager:

We reviewed all of the information and findings from the day’s observations and investigating.

• Scoring on all rolls with doctor blades.
• High chamber Pressures.
• Sever blade contact angle.
• Metal in magnets.
• Rocks, dirt and starch on board.
• pH levels

The maintenance manager was given the responsibility of internal investigator to the scoring problem. Customer reported that no other rolls were scored other than Harper rolls and the operators are doing everything correctly. Based on the findings they were doing what they believed to be correct. The possibility is the chambers they are using may not be designed for using metal blades. Customer would contact Ward for their input.

After showing plant manager what was determined. I explained it would not be worth while to remanufacture another roll if they continue to stay with the status quo. Customer agreed to trial the graphite blade and is open to our recommendations.

Recommendations:

• ProFilter and magnets
• Graphite blades
• Monitor and document
• Blade wear angle
• Pressure
• Contaminants in system

Follow up: 6/11/04

Customer stated the graphite blade is working well on the 1st down with only 13 psi and the print quality meets their expectation. He also said there isn’t any metal in the ProFilter magnet, and they will be ordering ProFilters & magnets for the rest of their downs with blades.

Follow up: 6/15/04

Customer again stated the graphite blade continues to perform well at 13 psi.

• Metering well.
• Not leaking.

Based on the investigation the customer has switched to a graphite blade material and the scoring has been greatly reduced to an acceptable level.

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