Inaccurate printing position

Even if there are no problems with the screen size and printing machine, the inconsistency of the shape of the printing material will cause inaccurate printing position. For example, in paper color printing, after one color is printed and dried, the temperature changes, causing the size to change. As a result, when printing the second and third times, there will be inaccurate registration problems.

When printing plastic, changes in temperature and humidity can cause changes in its size, affecting printing accuracy. In addition, the shape of plastic products and the conditions during molding (such as temperature and time) are not completely consistent.

Deformed pattern

The printing pressure applied by the scraper to the screen should be enough to make the screen and the printed object in line contact. Do not exceed.

If the pressure is too high, the screen will contact the inside of the substrate, which will cause the screen to expand and contract. The pattern will deform.

Silkscreen printing is with the smallest printing pressure among various methods.

If the pressure must be increased, the gap between screen surface and substrate should be reduced so that the pressure of the scraper can be reduced.

Screen marks

Sometimes, you may find screen marks on ink film. Poor fluidity of the ink is the main reason. During the silkscreen printing, when the screen is lifted, the ink transferred to the substrate fills the marks by its own flow, making the ink film smooth and flat.

If the ink has poor fluidity, when screen is lifted, the ink flow is small, and the screen marks cannot be filled.

To prevent screen marks from appearing on printed products, there are something we can do.

1. Use ink with high fluidity for silkscreen printing.

2. Use slow-drying ink for printing, increasing the flow time so that the ink can gradually spread and solidify.

3. When making screen, try to use single-filament screen with finer threads.

Smudges on screen prints

Sometimes, there may be smudges on screen prints. What's the reason? The ink is not fully dried.

Usually, when printing with oxidation drying ink, smudges are common. This is because the ink layer is thick. The ink dries quickly on the surface but slowly inside. When printed products come into contact with each other or with other objects, smudges will occur.

Generally, adding cobalt desiccant or lead desiccant to the ink can increase the drying speed of the ink, and prevent smudges.

In addition, when stacking printed products, they should not be too much. Overstocking is also easy to cause smudges. The products must be fully dried before stacking.

Evaporative drying ink can reduce smudges. There is more to improve it. You should strictly comply with the process requirements during printing, and strictly follow the operation procedures.

Ink cracking

Solvents and large changes in temperature can cause ink cracking. Generally, styrene products that use weak solvents such as alcohol and petroleum-based solvents can have cracking. Some substrate materials can also cause cracking due to their own factors.

To prevent ink cracking, materials with strong solvent and oil resistance can be chosen as substrate. Keep constant temperature in the workshop.

When printing multiple colors, every color should be fully dried after printing, and the drying temperature should be strictly controlled.

Generally speaking, pay attention to these things, you can prevent ink cracking.