Despite its important role in the screen-printing process, the squeegee often doesn
When it comes to squeegee sharpening, you have two general types of sharpeners from which to choose: grinding-wheel systems and knife-cutting systems. Grinding wheel sharpeners are the most used variety in the screen-printing industry. They operate on the principle of running a grinding wheel spinning at a high speed down the length of the squeegee blades printing edge. This type of machine is widely available in a range of sizes in both manual and automatic models (Figure 5). In contrast, knife-cutting systems use a razor or knife-like blade to cut away a thin strip of the squeegee edge, thus creating a new sharp edge (Figure 6).
There are pros and cons to both methods. Although the grinding-wheel method works quite well, I have found that it requires more operator skill than the razor-cutting method. Finding a compatible grind wheel/squeegee material combination is essential for best results.
I find the razor-cutting method to be simple, quick, and accurate, requiring very little operator skill. In my opinion, it also produces a sharper edge. Additionally, it does not produce the poly urethane dust left behind by the grinding-wheel method. However, knife-cutting systems remove more material during the sharpening process, which may lead to more frequent squeegee replacement. I encourage you to research both methods before making an equipment purchase.
Replacement Inevitably, after your squeegees have gone through enough cycles of cleaning and re-sharpening, the material will have to be replaced due to material degradation and/or material loss. Although squeegee replacement can be expensive, the expense is marginalized when considering the ROI achieved through increased print speeds and image quality.
Squeegee on press
Your squeegee settings on press are crucial and a key part in optimizing press performance. This is where the rubber hits the road (no pun intended) and, ultimately, where your press operators need to be most skilled. Because of the variables from shop to shop, press to press, and the general variables associated with ink, mesh, and substrate, there are no exact answers about what your squeegee settings should be. Rather, there are simple principles that, when followed, will result in better print quality, consistency, and efficiency. These principles include squeegee angle, squeegee pressure, and squeegee stroke.
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