A squeegee is used in screen printing for pushing ink through a mesh screen. There are few different types of inks such as plastisol ink, water-based ink and discharge ink that need different squeegees to push ink through the mesh.Squeegees are used for automatic screen printing machines (M&R Auto) and manual machines . We decide what type of squeegee to use by its colour and it’s hardness which is measured with a durometer.
There two common types of squeegee; the standard resistance squeegee and the eco squeegee. A standard resistance rubber squeegee has a high quality blade which helps avoid bubbles and craters in the print. There are single layer rubbers and triple layer rubbers. A triple layer rubber is mostly used for fine detail and high speed machines which is useful for companies that do a lot of high speed bulk print orders.
A hardness gauge is a measurement of the hardness of the squeegee/scraper; the hardness of the absorbent pick allows you to determine how much ink is needed to drive the mesh. The hardness gauge plays an important role in creating crisp designs and durable prints depending on the type of design to be printed. The optimum hardness gauge for a screen printer depends on the amount of ink deposition required for the design; if the design has fine detail, your hardness gauge as a printer will need to be between 80-90, which pushes less ink through the mesh and does not foul the print head. The details. A softer hardness squeegee between 50 and 60 hardness will deposit more ink through the mesh. It is usually used on a white background.
Red - soft single layer (durometer 65)
Green - single layer (durometer 75)
Blue - single layer (hardness gauge 85)
Yellow - triple layer (durometer 70/90/75)
Red - soft triple layer (hardness 65/90/65)
Screen printing squeegee bending results in two changes: the angle between the squeegee and the screen changes and the printing pressure transmitted to the substrate is reduced. For example, a squeegee is compared to a set of springs. As the springs are stressed at a certain angle, they begin to bend and transmit less and less force. The printing angle of the squeegee decreases, the printing pressure is insufficient and the printing result is not satisfactory. With a small printing angle, the printing pressure is reduced, the ink volume is high and the ink layer becomes thicker. (In this case the printing operator will increase the printing pressure, the curvature of the squeegee increases and the final ink layer remains unsatisfactory. The solution is to increase the stiffness of the squeegee and increase the angle of the squeegee.) This is the effectiveness of the squeegee. The effect of width on the four functions of the squeegee.
The effective width of an absorbent squeegee is usually between 20 mm and 30 mm. The choice of the optimum effective width depends on the flatness of the substrate, the screen image resolution and other printing parameters such as squeegee angle, speed and ink type. When printing high resolution images on flat/smooth substrates, the effective width is small (less than 20 mm), hard and can be printed quickly with the right ink. On rough and coarse substrates the effective width should be increased (sometimes more than 30mm), the hardness should be reduced and low hardness absorbent steaks should be less adaptable and not overly curved. You can also use an intermediate hard and soft triple squeegee or a double squeegee. Flexing. As a rule, the effective width increases, the print speed decreases and the print angle increases.