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Graphics Printing



If you have read our columns over the years, you may have thought some of the printing problems and mistakes we’ve described were fanciful. Actually, they are all taken from real-life experiences. We committed many of the mistakes ourselves, but most were taken from our experiences as consultants. This month, we’d like you to join us as we recall a visit to a facility where confusion reigned, a situation that is not nearly as unusual as you might expect. You may consider the conditions at this facility extreme, but they occur to some extent in virtually every printing operation, regardless of the types of products being printed.

Production control gone wild

We were called into a large manufacturing plant (part of a multinational company) to assess and improve its printing operation. Screen printing and pad printing were just two of the many production processes employed by the company. We were told the company’s "printing guru" had retired and left the production department with limited printing expertise. The company’s managers wanted employees to be well versed in the technical aspects of the screen- and pad-printing processes and standard operating procedures in the printing department to be up to the mark. We expected the job to be a simple and routine check up.

The production department not only employed printing processes, but also injection-molding, metal-forming, assembly, testing, ultra-sonic welding, and spray-painting processes. The print processes were part of this broader production line and located in a specific area of their own. The company operated several shifts and said they followed ISO 9000 standards. On the surface, the company appeared to be a typical manufacturing unit.

However, after we arrived, one look at the equipment quickly gave us an indication of what was to follow. The printing equipment was covered in ink. The company attempted to improve the look of the machines by repainting them. The combination of dried ink under the paint and newly dried ink over the paint gave the equipment a slightly surreal look, rather like frequently used candlesticks that have seen many a holiday. But these conditions left nothing to celebrate.

The company had been operating for 20 years, printing not only decorative graphics, but also critical safety information. Our assessment of the facility identified 61 points in their printing processes where action needed to be taken to ensure safe, accurate, efficient production of a quality product. As these points had not yet been addressed, it was clear that their product quality was inferior. To what degree? Well, put simply, the inks they printed just didn’t stick to their substrates.

Now, you would have thought that 20 years of printing experience would have taught the company’s employees how to select ink that adheres to their product. Apparently, they had successfully chosen and printed the appropriate inks in the past. But as it turned out, they had trouble years before their print guru left. Maybe their guru was like so many in that he was an expert at resolving problems he had created himself. Over the years he and the rest of the team became conditioned by bad practice, which resulted in the situation described here.

The screen inks the company used were well matched to the materials for which they were intended and included single-component and two-component UV-curing inks. But by their natures, the substrates were difficult to get ink to adhere to, which made the applications arduous. These challenges made it imperative to mix the inks according to the manufacturers’ technical-data sheets. Unfortunately, the inkroom personnel did not know where the data sheets were, and each mixed the inks to his or her own liking. There were electronic scales available, but they were inaccurate and rarely used.

The ink technicians were convinced they could determine correct mixtures based on how the ink flowed from their wooden spatulas. Sometimes the inks just needed a couple of squirts of solvent to perfect the mix. An onlooking ink technologist would have broken down in tears at the sight of the mixing practices.

With two-component inks, the amount of catalyst used has to be mixed in a precise ratio to the base ink. This is particularly the case when adhesion is difficult. Inks also must be cured as specified by the ink manufacturers. Otherwise, the full characteristics of the cured ink will not develop. This results in poor mechanical and chemical resistance, in addition to inadequate adhesion.

The ink mixing (using the term loosely) was carried out in an enclosed room where machine parts also were cleaned. Pad-printing plates and printing screens also were produced in this room. The cleaning tank was an open plastic bowl regularly filled with cleaning solvent. The combination of cleaning solvent, ink solvent, and screen wash produced a heady mixture. One operator commented, "Sometime ago, Mary passed out while she was mixing inks, but she recovered after having a cup of coffee. They installed an exhaust system, but it’s too noisy, so we only switch it on if we feel dizzy."

The exposure unit was used to expose both stencils and photopolymer plates for pad printing. The unit was filthy, and there was no record of when the exposure lamp had last been replaced. On average, each screen or plate had to be remade three or four times before it was suitable for use. And when a screen or plate could finally be put on the machine, it often would break down within a few prints. Alterations were made to the exposure time until the image was okay and the screen/plate appeared hard enough. Some of the operators dried the pad plates in an oven after developing, while others didn’t think it was even necessary.

The film positives used for stencil and plate exposure were a disgrace. They were covered with scraps of dirt and scratches. The films were made for producing pad-printing plates and appeared right-reading when the emulsion side was on the back. These films were also used for producing screens, but nobody in the company knew that the emulsion had to be on the other side for stencil exposure. They never could understand why the fine detail on their stencils was often degraded. Hence, the impression they had was that screen printing only was suitable for printing large areas. A few years ago, when they changed from white to orange mesh, the problems improved slightly but the fine detail was still poor.

"What do your standard operating procedures say?" we asked. "Oh, we don’t bother with those. They were written by the quality department," one employee replied. When we reminded them that they operate under ISO 9000 standards, they responded with "What’s that?!"

Can it get worse? Oh yes it can! The company purchased a multicolor inline screen-printing system three years ago. It was designed to print three colors, but it didn’t. Two colors? Yes. Three colors? No.

We asked, "Why don’t you print three colors?" The reply was, "We do–we just pass substrates through twice because the second print station is faulty and it’s not been fixed."

"For how long?" we asked.

"Two years."

"Bet you get plenty of overtime?"

"Oh yes," the press operator replied with a broad smile. He also had major problems with ink adhesion and tried to fix it by cleaning the components with solvent before printing. It helped, but it didn’t solve the problem. The ink sometimes stayed soft and just scratched off. Recovering printed parts that had to be reprinted would sometimes take an entire shift, plus overtime.

Nobody else could use the automatic press. In fact, all the operators had their own machines. They said that the presses each had special characteristics and that \"you had to know your machine.\" The management accepted this, and everyone got lots of overtime.

It would be easy to jump on the operators and blame them, but the problem rests fairly and squarely on the shoulders of management. Over the years, the printing processes had deteriorated. The print guru had not retired after all. Instead, he left in a hurry and took whatever knowledge he had committed to memory or written down. Nobody wanted to take responsibility because no one understood printing.

Injection molding, assembly, ultra-sonic welding, etc. were all covered by some degree of expertise within management, but printing was a dirty, smelly process that consumed overtime faster than a Hummer uses gas. In truth, some portion of the blame also has to be laid at the door of the equipment and consumable suppliers who never commented on the state of the operation. But why should they walk into a hornet’s nest?

Making repairs

The strategy we developed for the company was to implement key safety issues immediately, bring ink mixing under control, and repair and service the machines. Management would have gained more credibility with the work force had they done so sooner.

Next, standard operating procedures were written with the cooperation and assent of the printers. A training course was created and delivered to the operators, quality-control personnel, and members of the management team. One of the project engineers was given responsibility for printing, and his main function was to ensure that any technical issues were addressed and incorporated into standard operating procedures.

The operator who was in charge of the now fully operable three-color press spent his newly acquired free time training others on "his" machine, carrying out print and production trials, and working to reduce the level of print rejects throughout production to zero. Two press operators retired, but increased efficiency more than picked up their workload. The company went from near disaster to cost reductions in excess of $75,000 in 12 months!

None of the solutions we introduced was particularly clever. It was about standardization and control, following procedures, and most of all, understanding the processes.


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