How to Choose the Right Squeegee in Screen Printing？
After years of working in screen printing, I often hear new friends complain: obviously, the screen and ink are selected correctly, but the printed products always have problems such as uneven ink layer, rough lines, and missing prints. In fact, the problem is likely to lie in the "unremarkable" squeegee.
As the "core executive component" of screen printing, the squeegee may seem like a simple rubber strip, but it directly determines the ink transfer volume, pattern clarity and printing efficiency. Choosing the right squeegee can double the printing quality and reduce consumable loss. Today, combining practical experience, I will teach you to quickly choose the right squeegee and avoid common mistakes.
To choose a squeegee, first grasp the three core elements: material, hardness, and cross-sectional shape. Combining these three with the substrate and printing needs, you can achieve precise matching.
I. First of all, the material is the basic premise
At present, the mainstream squeegee material on the market is mainly polyurethane (PU), which is wear-resistant, solvent-resistant, and has good resilience. It is suitable for most inks and substrates and is the industry standard. In addition, natural rubber has good elasticity but poor solvent resistance, and is only suitable for short-term printing with water-based inks; silicone rubber is high-temperature resistant and corrosion-resistant, suitable for printing on special materials such as ceramics and glass. For beginners, PU material is preferred because of its strongest versatility and less chance of stepping on pitfalls.
II. Secondly, hardness is the key to determining printing precision
Measured by a Shore hardness tester, the common range is 55°-90°, divided into low, medium and high grades. Low hardness (55°-65°) is relatively soft, can fit uneven surfaces, and has a thick ink deposit, suitable for printing on textiles, rough plastics, etc.; medium hardness (65°-80°) has the best comprehensive performance, balancing clarity and adaptability, and is the "universal choice" for flat printing and conventional patterns; high hardness (80°-90°) has a sharp edge, wear-resistant and solvent-resistant, suitable for fine line and four-color dot printing, such as printed circuit boards and high-precision labels.
Then look at the cross-sectional shape, which directly affects pressure distribution and ink release. The flat-mouth squeegee is the most commonly used type, which can bear large pressure, has strong versatility, and is suitable for large-area color block printing; the sharp-mouth squeegee has good flexibility and adhesion, suitable for printing on curved and uneven surfaces; the blunt-mouth squeegee is between the two, not easy to chip, and suitable for scenes requiring high durability of the edge.
In addition to the three core elements, pay attention to two practical details: first, the size. The width of the squeegee should be more than 5cm wider than the pattern, and the height exposed from the handle should be controlled at 20-30mm to balance flexibility and controllability; second, match the ink. For solvent-based inks, choose solvent-resistant PU squeegees; for UV inks, choose UV aging-resistant ones to avoid swelling and deformation of the squeegee.
III. Finally, a practical suggestion for beginners
Start with medium hardness (70°-75°) and flat-mouth PU squeegees for initial selection. After small-batch testing, adjust the hardness or shape according to the printing effect. At the same time, regularly check the squeegee edge, and replace it in time if there is wear or chipping to avoid affecting the printing quality.
Although the squeegee is small, it is the "invisible key" of screen printing. Mastering the above methods, you can accurately choose the right squeegee according to your own needs, take fewer detours and improve efficiency. If you have any confusion about selection in specific scenarios, welcome to leave a message in the comment area to communicate~
