Prepress and humidity control of dry carbon paper

Dry-type paper must be wet-processed before printing to ensure that the paper is fed, fed, and delivered smoothly during the printing process. In the process of servicing dry carbon paper printing companies, I discovered that problems such as stretched, curled, and tight edges of dry carbon paper affected printed work. The reasons for these problems were as follows:

1. Dry carbon paper is coated, dried, cut, and recoiled from the base paper through a non-toxic fatty acid salt solution and a colored coating. The finished product actually becomes a single adhesive tape, and the moisture absorption performance of the positive and negative paper is reversed. There are obvious differences, that is, the moisture absorption performance of the colored coating surface is extremely poor, and the white surface of the base paper is extremely sensitive to moisture absorption, which is one of the main reasons causing the paper curl and tight edges.

2. Dry carbon paper must be transported long-distance or long-term storage after being shipped from the factory. Due to China's vast territory, large and vertical climate variations and frequent changes, such as spring, the room temperature in Heilongjiang is between 18-20%, and the indoor humidity is 20%. Between 30%. In Yinchuan, the indoor temperature and humidity are basically the same, at 18-20% and 18%-20% respectively. The coastal areas and Chongqing, Chengdu, the temperature at 15-20 degrees Celsius, humidity is as high as 60% to 75%. Since the moisture absorption characteristics of dry carbon paper are not compatible with the printing environment of the company, problems such as static electricity and double-sheet wrinkles occur during printing, which brings difficulties to the printing work.

For the above reasons, in order to balance the moisture content of dry carbon paper with the temperature and humidity of the printing shop environment, and ensure the high quality of the printed matter, the national tax paper printing company has a wealth of experience. For example, at the ticket center of the National Taxation Bureau of Hebei Province, they pay great attention to the balance between the base paper and the printing environment. Generally, two or three days before the printing, they bring the 1000-carbon paper to the workshop and enter natural balance. Another example is the Shanghai Commercial Plant. In addition to the natural balance of the base paper, the printed products are put into plastic bags after they are put into the machine, and then placed in the packing box and then transferred to the next road to fight the code. This effectively ensures that the dry copy paper is high. Quality printing was successfully completed.

Since 2000, I have visited 85 key tax invoice printing companies and related universities and research institutes in various provinces and municipalities across the country. I have collected and summarized their advanced experience in the prepress technology handling of Haitian brand dry carbon paper. : "When the relative humidity of the printing environment changes by 10%, the moisture content of the dry writing paper also changes by about 1%. Generally, the moisture content of the dry copy paper changes every time the temperature changes by 5 degrees Celsius. 0.15% to 0.2%.”