Pulp printing common problems and solutions

Paste printing is widely used in clothing. Its advantage is that it can produce a special texture effect. It has elasticity, good hand feeling, and can coat light color on deep background. But the glue printing is very easy in the screen printing process. Produce quality problems.

1, the pattern of the edge from the clear to the blurring process

Since the fluidity of the slurry is good at the beginning of the printing, the squeegee does not require a great deal of force to cut the slurry. As the moisture in the mortar continuously evaporates, the slurry gradually thickens and the viscosity increases. The force of the squeegee must be increased to cut the excess slurry. Due to the increase in the strength, the screen is elastically deformed to generate a pattern displacement. With the disappearance of the squeegee blade force, the pattern edge of the screen printing surface will stick to the slurry after the screen is rebounded. In the second printing, The paste will be printed on the edge of the pattern, creating a blurring pattern.

Solution: a. use a small elastic mesh, such as polyester mesh; b. increase the tension of the mesh; c. reduce the resilience of the mesh; d. adjust the viscosity of the slurry at any time.

2, the pattern of acute angle rounding, the reasons for the loss of small outlets

As the paste gradually thickens during the printing process, its fluidity becomes smaller, and the pressure of the squeegee must be increased to pass through the mesh when passing through the mesh, but due to the buckling effect of the photoresist at the edges of the screen pattern, The squeegee cannot squeeze the slurry out of the mesh at any time, so that the slurry stays in the mesh to form a film, resulting in clogging of the rim of the photographic film.

Solution: a. Use low mesh, monofilament, thin mesh; b. Photoresponsive layer can not be too thick; c. The slurry should always maintain a certain degree of mobility.

3, the cause of the skinning phenomenon in the printing process

Any printing paste has a common characteristic that the ink layer becomes thinner and dries faster. The same is true for the paste. Since the screen is larger than the pattern, the paste in the screen has enough space for stacking. It is impossible for the squeegee to clean the paste during each printing, especially when the pattern is often thin. The ink layer, these ink layers will form a semi-dry film in a short time, these films are brought into the leak hole by the squeegee to block the mesh, forming a partial blocking phenomenon.

Solution: In the screen area between the screen area and the frame with a wooden bar to do the isolation, the slurry is controlled within a certain range, the squeegee can each time the screen side of the pattern of the slurry is clean, that is to say pulp It is impossible to produce a thin layer of ink within this range, so that the phenomenon of skinning can be eliminated.

Source: Hot Flower Printing