The PS version is prone to problems in the printing process

The task of the PS version is to transmit the graphic part as accurately as possible to the blanket. Graphic part of the hydrophilic, non-graphic part of the ink. But in reality there is no such ideal, there will be various issues related to the PS version.

1. The non-graphic part of the layout is dirty, that is, the non-graphic part is pro-inking. There are the following reasons.

A. The chemical composition of the fountain solution is improperly configured and erodes the hydrophilic layer of the blank portion. This is done by replacing the dampening fluid with a dampening fluid that is properly configured according to the manufacturer's instructions.

B. The roller sleeve of the plate roller is dirty or worn, damaging the blank surface. Treatment method: clean or replace the version of the water roller sleeve, wet wash can protect the printing plate.

C. Inking too much during halftone printing causes the ink to spread, which eventually sensitizes the non-graphic area. Treatment method: Use thinner ink film for printing.

D. Sand with sandpaper on the rubber blanket is retained, and the printing plate is worn. Filling ball measures: Clean the rubber cloth, change the paper; Add anti-accumulation agent to the fountain solution; Adjust the amount of water to the minimum, add more concentrate, gum arabic and/or alcohol or alcohol as needed The product keeps the non-image area of ​​the printing plate clean while reducing the amount of water; in the BB printing, the pressure between the printing plate and the rubber fabric is reduced. If an impression cylinder is present, the pressure between the impression cylinder and the paper should be checked; if the build-up occurs mainly in the first printing unit, the amount of water should be increased to help clarify the squash on the paper.

E, aluminum base oxidation. Oxidizes dirty and looks like a lot of clear dots or doughnut-shaped spots on the canal. It often appears in areas that have long been in contact with wet reel water rollers. Plates tend to oxidize if they are too slow to dry, or stored in moist places before development or during two printing runs. If the printing press breaks while the plate is not yet dry, the plate will also oxidize. Action: Follow the recommended plate handling procedure. Store plates in a dry place. During the plate making process, a cheesecloth is used to quickly dry the plate. In the printing process, such as parking, should rely on the printing roller to leave, open the empty car until the plate is dry.

F. Incorrect working of the water roller and/or ink roller in the ink system, may cause the print to appear dirty in the circumferential or axial direction. Measures: Check the pressure of each roller in the ink system, cleanliness, geometric accuracy, and overall condition.

G. Pre-exposure (grayed) occurs in the pre-printing stage of the plate. Measure: Store the plate in a light-proof box; install appropriate safety lighting equipment at the plate making site.

H. The ink is too soft or too oily. At this time, contact the ink manufacturer.

I. Excessive dampening solution causes the imprinting to be snow flakes; the ink color appears solid in gray, and the color is dark on the ground; in the zoomed-in state, the unevenness in the field is found, filled with tiny white spots. Excessive fountain solution emulsifies in the ink. When the ink film is split, the water droplets are exposed, and these water droplets hinder the transfer of the ink to the paper. At this point to reduce the amount of water supply.

Source: China Printing Information Network