Evaluating squeegee materials for quality and performance on press is one of the keys to successful screen printing. This article describes material formulations, essential vocabulary, and criteria for making effective comparisons.
By James Elliot
Abrasion resistance Evaluating abrasion resistance is the most subjective of all comparisons. It’s critical that you run each sample for an equal number of impressions on the same mesh counts and similar setups before making a visual or tactile comparison of the edge. At the same time, examine for chipping and make notes of any such problems during printing. Also note when you sharpen the blade. And when you sharpen, make sure that the two materials are sharpened to the same depth of cut. If you use an abrasive (wheel or belt) sharpener, be sure to use the same grit for the same number of passes and advance the same amount with each pass. If you see a difference in action on an abrasive sharpener, you should repeat that action and vary the grit and depth of cut. Some squeegees seem more difficult to sharpen than others, particularly when you take off a lot of material in one pass or use a finer grit. You’ll usually find that those squeegees are actually formulated to be more abrasion resistant than the other sample you’re testing—and your sharpener is doing exactly that, abrading the material. If you consult the manufacturer, you’ll probably find tha the company can indeed make a squeegee that sharpens easier, but it will wear faster on press. Sometimes on-press durability makes it worth adjusting your sharpening technique.
Cosmetics, packaging, and flatness Cosmetics in this case are dimples, surface irregularities, edge quality as supplied, bubbles, etc. These are all qualities that can waste material. If a roll has a flaw, point it out to the supplier and ask for another roll. Every company makes a bad roll now and then and will happily exchange it. You don’t want to see serious flaws on a regular basis. Packaging should protect the material from damage, but not coil the material so tightly that remains dramatically curled when you unroll it. Note that the thicker the material and the higher the durometer, the greater the natural tendency to curl.
Some printers may feel that these points for comparison are cumbersome and that the tests are a lot of work; for others, comparing and testing squeegee properties is cursory. But those who take the time to educate themselves about their tools and consumables, scrutinize their squeegees, and consider material qualities and performance are typically among the best in the business. Even if you feel that the exercises described here are more than your shop can handle, just keep in mind that carefully observing even the most basic aspects of squeegee evaluation will help you find better value and pave a path to an improvement in your printing.
James Elliott is the manager of screen-product sales for Pleiger Plastics Co. He spent the bulk of his career in the screen-printing industry, starting as an artist and printer, and has since worked with several international manufacturers.
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