The Solution Process and Cause Analysis of Color Header Color Problem
Most newspapers use color headers, the most common of which are red headers in magenta and yellow solid overlays. The newspapers printed by our company, such as "Qingdao Daily", "Qingdao Morning Post" and "Qingdao Evening News", all use red headers. During the printing process, a small amount of black, that is, cross-color, often appears on the red header, because the black is added, making the header look dirty. In this paper, the author introduces the solution process and cause analysis of this problem to the big characters for your reference.
Solution process
First of all, we communicated with the captain. According to the description of the captain and the observation of the scene, we found that after printing 30,000 to 40,000 newspapers, the red header will start to appear black, and the situation is lighter at first. As the printing continues, the cross-color will be aggravated, and the red header will appear more and more heavy black, which looks dirty. At this time, the captain's processing method is to replace the black version, so that it can be adhered to the printing.
At that time, the printing color sequence was green, yellow, black. At the end of the black, the head color magenta and yellow are in the second and third colors, respectively. The presses are all vertical, from bottom to top are cyan, magenta, yellow, and black. This color sequence, together with the vertical placement of the printing press, reminds us of whether the black ink has entered the ink fountain or rubber roller of magenta ink or yellow ink in various ways, so we carefully checked it. Printing press. As a result, it was found that all the ink fountains did not have a lid, and the ink in the yellow ink fountain was obviously not pure yellow, and the main pollution included the washing water in which the blanket of the black and yellow unit was dripped. So, it's no wonder that the color of the header will be black. After finding the cause of the problem, the shop immediately cleaned the yellow ink fountain and re-applied the magenta ink fountain and the yellow ink fountain.
I thought that this cross-color problem would be solved. But the actual situation is not as we think, the header still appears cross-color.
We also think that there is a problem with the plate? But we have been using the big brand plate, the quality is very stable, so we decided not to consider the issue of the plate, continue to check around the press. In further communication with the captain, it was found that a new fountain solution was being tested on the machine recently, so we took the acidity meter to the equipment for on-site measurement and found that the pH of the fountain solution in the tank was too high. We have also taken samples from the unsealed vats of fountain solution. After various concentrations, the buffering ability of the fountain solution is poor. The slight change of the ratio will cause the fountain solution to change greatly. The results of the buffering experiments of two different brands of dampening solution are shown in Fig. 1. This is also the reason why the pH of the dampening solution in the water tank is too high.
To this end, we immediately cleaned the water tank and replaced the latest used fountain solution with the stable quality fountain solution that we have been using. In this way, the problem is solved and the header no longer appears to be cross-colored.
Living Room Arm Chairs,Purple Accent Chair,Living Room Couch Sets,Livingroom Sets
Foshan City Misirui Furniture Factory Co.,Ltd , https://www.misiruifurniture.com