Screen decontamination in screen printing production

Successful screen production requires handling some simple questions. Screen decontamination is a problem that is easy to handle. However, many operators and sales personnel have done a very bad job. As a result, it has caused waste, affected the printing quality, and shortened the life of the template.

When there is dirt or dry ink on the printed part of the picture, the screen should be decontaminated. After the printer is stopped, the frame will be lifted. At this time, some operators will rub the abrasive cloth with solvent. The lower side of the template, the sound of the entire printing plant can hear, and often the template is damaged.

A truly knowledgeable operator rarely scratches the stencil-printing surface because he knows that the sharpness of the printed image requires that all graphic edges maintain a clear emulsion layer graphic interface. Forced rubbing can damage the graphic interface of the emulsion layer, and even wipe off the emulsion layer, leaving only a bare mesh.

When printing high-line color images, the emulsifier film under the wire is only 5-6um thick, and the mesh diameter of the mesh itself may be only 30um, and cannot withstand friction. Therefore, the key to avoid rough decontamination is to first prevent the stencil from being contaminated.

The main cause of the template pollution is the improper control of the ink, leaving dry ink in the mesh. When using solvent-based inks or water-based inks, the reason is that the ink is too thin or too thick. There should be no change in the state of ink transfer. When using UV-curable inks, efforts should be made to avoid exposure of the screen to UV light and to avoid sunlight.

Another ink control problem and improper control of the printing speed can lead to uneven supply, which can quickly dry the ink-receiving cells.

The final cause of the ink drying is the improper setting or wear of the squeegee. When printing high-level images with a high number of screen lines, it is required to use the squeegee rim. The ink plate will deform or be worn during normal use. The sharpness of the image will then drop, indicating that the ink may not be able to pass through the mesh properly. If this problem is not resolved in time, the ink will dry up in the mesh. To avoid this problem, the squeegee should be turned over regularly to extend the life of its squeegee, or it can be replaced with a new squeegee before the print quality has dropped.

In order for the mesh to function properly, care should also be taken to remove dirt from the ink or the substrate. Due to electrostatic adsorption of airborne contaminants and poor storage conditions, the surface of the substrate will become contaminated with dirt. The above problems can be solved by improving the storage conditions and process control. In addition, static elimination devices and substrate decontamination devices can also be used. Prevent dirt and dirt from transferring from the printing surface to the mesh.

What should I do if the template is contaminated? When using a flatbed screen printer, stop the printer after printing a set of prints, and then input a blotter paper so that the screen contacts the blotter.

Let the screen be in the printing position, and then use a non-abrasive soft cloth moistened with a screen cleaner to wipe away the dirt on the surface of the squeegee. Do not use too much force so that the dirt will fall through the mesh. The following absorbent paper, if necessary, can be repeated with a piece of absorbent paper to clean the mesh. Some of the dirt particles that fall on the top may be large and cannot pass through the mesh, but they can stick together with a soft cloth. After the cleaning is completed, the stencil can be blown with a blower ("Cold Air").

When cleaning circular press screen printing machines, you will encounter different situations. Due to the design of the structure, it is not possible to wash the dirt on the absorbent paper like a conventional screen printer. Fortunately, because the printing speed is faster, the ink is less likely to dry on the mesh. If this happens, first stop the printer when the group job is printed, and then use a non-abrasive cloth to apply the screen cleaner or thinner to the top of the template at the printed graphic site. The solvent scrubs dirt in the mesh.

Sometimes the dirt under the template is also removed. In this case, the dirt should be wiped gently with a soft cloth, and do not use too much force. The above cleaning and decontamination methods should be used frequently in the production process to extend the service life of the template and reduce the scrap rate.

Reprinted from: Advertising Business Network