The fourth printing ink in the process of common faults

Sticky

In the printing process, due to the slow drying of the ink, the ink is too soft, too thin, or the amount of ink to be given is too large, which can cause dirty or dirty images on newspapers. Most of this phenomenon occurs in the field or shaded part where the amount of printed ink is large.

1. cause

1) The image has a large amount of ink in the field and shadow

Newspaper printing is not like commercial rotary printing. Although the printing speed is very fast, it does not have a drying device. The ink on the solid and dark portions of the freshly printed newspaper is impermeable, passing through the folds of the folds and the clamping of the conveyor belt. Easy to contact with blank parts, resulting in sticky.

2) Large ink droplets cause ink emulsification

During the printing process, large ink droplets cause severe ink emulsification, which slows the drying of the ink and causes the newspaper to become dirty.

3) Slow fixing of ink

If the fixing speed of the ink is slow, the penetrative dryness and coagulability of the ink are poor, and the newspaper can easily become dirty.

4) Paper surface properties

The surface of the paper is smooth, dense, and poor in ink absorption. After the printing, the ink floats on the paper, and cannot be infiltrated and dried in a short time, which may also cause stickiness.

2. Solution

In the printing process, if the above problems occur, it is generally necessary to solve from the following aspects.

1) Viscous dirt caused by the machine structure can usually be solved by reducing the force of the carious teeth in the transmission system.

2) Adjust the machine's water transfer mechanism and ink transfer mechanism to ensure that the printing water has good quality, smooth water transfer, uniform ink supply, and moderate ink volume. In the printing process to control the ink balance, reduce the possibility of ink emulsification.

3) Adjust the internal structure of the ink, improve the cohesion of the ink, control the viscosity, use the ink with fast fixing speed and small residual viscosity, and at the same time improve the ink's penetration, drying and fixing properties.