Answers to frequently-asked questions
Is there one item that symbolizes our industry? One totem that is recognized by both apprentice and master? Of course, it's the squeegee. Yet I have a question: How come this low-tech, inexpensive tool of the trade is so often mistreated and last in line for problem-solving in our industry? After all, by filling the mesh with ink and keeping the mesh in contact with the substrate, the squeegee plays a leading role in screen printing.
The answer to this question, I suspect, lies in our lack of knowledge about the characteristics and use of the squeegee. Hopefully, by the end of this article, you will have enough Information to choose the right squeegees for your work and enough expertise to troubleshoot squeegee-related production problems.
What's a Squeegee Made Of?
It's been almost a decade since black neoprene and brown buna-N squeegees were supplanted by color-coded, high-density polyurethane squeegees. High-density blades resist the corrosive effects of inks and solvents, while the color coding (indicating the blade hardness) is especially useful in shops that print with a variety of inks and substrates. For example, a blue bullnose for dark-garment printing is easy to distinguish from an orange square edge used for halftone printing.
Some squeegees are composed of more than one material. To prevent roll-over from excessive squeegee pressure, printers used to shim soft blades with strips of aluminum. Today, some squeegees are available with a stiff material (a fiberglass sheet or hard polyurethane) between two layers of softer polyurethane. This provides the more flexible printing edge of a softer blade, while reducing the blade deflection. Some composite squeegees also come with a rigid material in the top two-thirds of the blade, while the softer polyurethane is on the bottom to serve as the printing blade.
What is Squeegee Durometer?
The durometer of a squeegee is the measure of its hardness, and a guide to the blade's ability to resist bending during printing. Squeegee durometers are measured on the Shore A scale, an industrial standard of 1-100 used to indicate the hardness of rubbery materials. The higher the durometer, the greater the blade rigidity. The lower the durometer, the more the blade will flex during printing.
Did you enjoy this article? Click here to subscribe to the magazine.