What are the factors that affect the effect of water-based ink flexo printing?

There are many factors that affect the quality of water-based ink flexo printing, especially the drying of water-based ink. In the production process, we often encounter rapid drying slow drying of ink, which requires us to adjust. Flexographic water-based inks should be dried at a moderate speed during the printing process. For example, the drying process is fast, which leads to conflicting printing processes. Therefore, the performance of the ink the ability of the drying equipment on the printing press determine the speed of the printing press. Conversely, a higher printing speed can shorten the exposure time of the ink in the air slowly dry after printing.

1. Properly increase the pH of the ink to reduce the drying speed of the printing process without affecting the drying speed. The pH is usually controlled at 8.5 to 9.5. Dry too fast, add a stabilizer to control the pH value above 9, but more than 9.5, otherwise the properties of the ink will change. The surface tension of the ink is low, the screen version is more prone to clogging, drying is slower.

2. Without affecting the printing speed, try to let the ink dry slowly during the printing process. This can be adjusted by slowing down the desiccant. Different ink manufacturers need to add different amounts of slow drying agent, usually more than 5%. When the slow drying agent is added, the ink thickens the pH decreases. Therefore, water stabilizers are added to control the viscosity pH of the ink, while slow drying agents are added.

3. When printing tissue paper products, reducing the drying speed of the ink can reduce the warpage of the paper. This usually needs to be adjusted by adding a slow drying agent retarder. The reason is that since the water-based ink evaporates the water alcohol in the ink after printing, the paper is loosened warped on both sides. The effect of slowing down the desiccant is to prevent the ink drying out instantly reduce warpage.

4. Increasing the convection speed of the oven air can significantly accelerate the drying speed of the printed matter. Since the water-based ink contains a large amount of water alcohol, the enhanced convection can reduce the relative humidity in the oven accelerate the evaporation of the solvent.

5. The addition of slow drying agent can solve the scratches on the printed matter the dirty surface of the varnish. If the ink dries too quickly, the ink will dry on the surface of the printed material without entering the penetration stage, resulting in insufficient adhesion easy peeling the ink layer. When overprinting glazing, the latter color printing plate will paste the ink of the previous color. This can also be adjusted by changing the color sequence reducing the ink viscosity.

6. The addition of slow drying agent acceleration can reduce clogging. If the printing speed is too slow, ink will spread on the printing plate, causing ink dots to stick. However, if the ink dries too quickly, the ink will transfer completely, causing the ink to gather around the ink dots, causing sticking.

7. The paper guide roller generates heat, which can also accelerate the drying speed of the printed matter. When we print products, the amount of ink used is large. If the drying capacity of the printer is limited, the speed will turn on quickly every time it is turned on. After a period of time, the speed will have some room for improvement. This is why the paper guide roller is heated. After the paper guide roller is heated, the ink is easy to stick to the surface. Before starting the machine, open the independent drying device in advance. When the machine has just been turned on, you can turn off the suction device first, so that the device can accumulate the maximum heat in the shortest time. The speed can be increased quickly.