What are the precautions for using woven bag water-based ink?

What are the precautions for using woven bag water-based ink?

1. The water-based ink manufacturers of woven bags have learned to properly increase the pH of the ink to reduce the drying speed of the screen printing process without affecting the drying speed. The pH value is generally controlled at 8.5 to 9.5. If the drying is too fast, the pH value is controlled above 9 by adding a stabilizer, but it cannot exceed 9.5, otherwise the ink properties will change. The surface tension of the ink is lower, the screen version is more likely to block the plate, the drying will become slow.

2. Without affecting the screen printing speed, try to make the ink dry faster during the screen printing process. This can be adjusted by slowing down the desiccant. The amount of slow-drying agent required for inks of different manufacturers is different, generally more than 5%. After adding the slow drying agent, the ink will thicken the pH will decrease. Therefore, when adding the slow-drying agent, water stabilizer should be added to control the ink viscosity pH value.

3. The addition of slow-drying agent can solve the scratches of screen printing sticky surface of varnish. Ink drying too fast will cause the ink to dry on the surface of the printing material before entering the penetration stage, resulting in insufficient adhesion, the ink layer is easy to fall off. When overprinting glazing, the latter color printing plate will stick the ink of the previous color. This can also be adjusted by changing the color sequence reducing the ink viscosity.

4. Adding slow-drying agent speeding up can reduce the blocking phenomenon. If the screen printing speed is too slow, the ink will spread on the printing plate, causing dot adhesion. However, if the ink dries too fast, the ink cannot be transferred, causing ink to accumulate around the dots blocking the plate.

5. The heat of the paper guide roller can also accelerate the drying speed of screen printing. When we use a large amount of ink in screen printing products, if the drying capacity of the screen printing machine is limited, the speed will be fast every time the machine is turned on, there will be room for speed increase after a period of time. This is the heat of the paper guide roller. Sake. The ink is easy to stick to the surface of the paper guide roller after it heats up. Before starting the machine, the drying device is turned on in advance. The machine can be turned off immediately after the machine is turned on, so that the equipment can accumulate large heat in a short time.

6. If the amount of ink used in screen printing products is large, try to use high color density ink anilox roller with higher line number, which is conducive to the drying of screen printing products can also reduce the water mark phenomenon.