Abrasion of Squeegees in Screen Printing and its Effect on Performance with Application in Printed Electronics

2021, February 26th @12:30 PM (GMT+1)

      Abstract:

The presentation discusses a novel method for accelerated wear testing of squeegees used in screen printing. In this study, squeegees were abraded on a conventional screen press and subsequently used to in print tests to evaluate the effect of wear on the printed product. Squeegees were also characterised in terms of their solvent absorption, surface hardness and ability to resist flexing to see how this correlated with ink transfer characteristics. There was a good correlation between resistance to flexing and ink film thickness for unworn squeegees, which was more effective than a comparison based on Shore A hardness.  Squeegee wear was found to vary between different squeegee types and caused increases in ink transfer and wider printed features. In production this will lead to greater ink consumption, cost per unit and an increased likelihood of product failure. While more wear generally gave greater increases in ink deposition, the effect of wear differed, depending on the squeegee. There was a correlation between the angle of the squeegee wear and ink film thickness from a worn squeegee. An ability to resist flexing gave a high wear angle and presented a sharper edge at the squeegee/screen interface thus mitigating the effect of wear.