These five key process areas present opportunities to reduce the price of raw materials and more.
By Mike Ruff
The labor and production aspects of making press-ready, high-quality screens bring additional CSFs and equipment needs into play. Considerations include the environment, coating procedures, exposure, development, and drying of screens. It’s beyond the scope of this article to cover specific processes such as mesh tensioning and the use of automatic coating machines to get correct and repeatable emulsion thicknesses, but once again, this is not the place to look for money-saving shortcuts. Think about the initial purchase of a coating machine, for example, against the cost of having press downtime and inconsistent print quality that will result from manually coated screens.
Screen inspection, verification, and record keeping
When I do consulting work for screen printers, after assessing and evaluating their screenrooms, I ask them about their screen inspection and verification procedures. Answers range from “We don’t have any” to “Let me show you my records,” and of course the latter is better. An often overlooked but critically important component to a profitable screen-printing operation is not allowing questionable screens to reach the press. Inspecting the screens to verify they are accurate and documenting these steps are CSFs regardless of what type of printing you do.
I asked Bron Wolff, a very experienced production manager who is also an ASDPT member, about the importance of screen inspection, verification, and record keeping in the screen room. He said, “I don't know how you can run or manage a company without them. I read an article years ago by Tamas Frecska (former editor of Screen Printing) and he stated that 75-80% of the problems on press are created before the jobs even get to press. I believe his numbers are low; it's higher. We document damn near everything—the number of turns to a screen, the tension, and the mesh count. We check the mesh count coming in the door to make sure what the manufacturer shipped us is right and within specifications. We check the emulsion thickness and have charts to show spectral output of the direct-to-screen unit to check longevity of the bulbs. We follow preventative maintenance schedules; we face coat screens; we have temperature and humidity gauges in the screenroom.
“I know screenmakers are going to tell me it is a pain and takes too much time to do things this way. But numbers are what it’s about. My overtime in the shop is a third of what it was in 2010 when I took over. Manpower expenditure is down, scrap and rework is down over 80%, press proofs are a half hour compared to half a day or more, and my sales and throughput are up 40%. So you tell me how important processes, procedures, and documentation are.”
You can see by Bron’s statistics that it takes a time to identify and control your CSFs in the screenroom, but the return on investment can be huge. You have to make good decisions about the right frames, mesh, coatings, exposure, and calibration, and then maintain, inspect, measure, and document everything you do. If you are passionate and diligent about quality in your screenroom control, you can have a world-class production facility. It will pay off in more prints hour, week, month, and year.
Mike Ruff has 41 years of experience in the graphic-arts industry and is currently the chief technology officer for Nazdar Consulting Services. He is a former business owner and is certified by G7 as an expert trainer and a process control and conformance expert. He is a regular speaker and has conducted training classes and webinars for prepress, production personnel, management, and sales staffs. He is a member of the Academy of Screen and Digital Print Technology and numerous other graphic-arts and color industry groups. He can be reached at email@example.com.
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