On the performance and color rendering effect of p

On the performance and color rendering effect of printing paper

paper and paperboard are one of the main raw materials for printing. After China's entry into the WTO, the quality standards of books and periodicals are in line with international standards, and the number of color packaging and printing products is increasing, which requires higher and higher quality of paper and paperboard. With the rapid development of offset printing, the quality standardization of China's paper industry is also gradually improving. However, so far, many printing plants have not done a good job in the storage and storage of printing paper and paperboard, which can no longer meet the requirements of the rapidly developing printing situation in the future. Therefore, it is imperative to implement standardized and scientific management for the storage and storage of printing paper and paperboard

I. current situation of storage and storage of offset paper and paperboard

in the past 10 years, the printing industry in various regions has developed rapidly, but as far as I know, there are many printing plants, especially small and medium-sized printing plants, and the storage and storage of paper and paperboard has not been greatly improved. Specific performance is:

1. Some factory leaders only realize that increasing the amount of paper feeding and storing more paper is beneficial to reducing printing failures, but they do not pay attention to the storage and storage of paper and paperboard according to scientific principles, and do not pay attention to it as an important part of the production process

2. Some factories have poor economic benefits, lack of working capital, and there is no storage period for paper and paperboard, let alone improve storage conditions

3. The work of "four prevention", moisture-proof, sun proof, folding proof and heat proof, was not done completely. Some factories only protect against moisture, but do not protect against sun and heat; Some factories only protect against sun and heat, but not moisture; Some factories do not do a good job of folding prevention

4. Many factory leaders and storekeepers only know the weight and name of commonly used paper, but little about other performance indicators and storage and storage common sense of paper

5. Some factories don't even have simple loading and unloading equipment. It's completely manual loading and unloading from paper entering the factory to stacking, which is easy to cause damage to the outer packaging and even the internal paper

6. Some factories store the whole piece of flat paper vertically for a long time, and the iron bar or steel wire is directly pulled into the paper edge. Even if the four sides are cut smooth before printing, the paper edge is deformed, resulting in poor paper feeding and misprinting during printing

II. How to implement the standardization of storage and storage. By 2020, the goal of promoting the utilization of new energy vehicles in the transportation industry will reach 600000 vehicles, with a total range of scientific management

high speed economic development must maintain the working environment and social environment in a good state, which is a necessary prerequisite for all future production activities. The paper warehouse is an important workshop or department in the printing factory. The leaders of the factory should not only pay attention to it ideologically, but also constantly learn from it. They require all localities to take epidemic prevention and control as a major political task at present. There are many scientific principles and advanced experience in the storage and storage of Zhang He cardboard, so that the storage and storage work can meet the requirements of the printing situation with rapid development after China's entry into the WTO

1. The influence of environmental temperature and humidity on the printability of printing paper and paperboard. The moisture content of paper and paperboard often does not meet the printing requirements when leaving the factory. It should be 6% - 7%. In addition, the packaging is not perfect. After long-term transportation or storage in a paper warehouse without good conditions for a long time, such paper will have serious faults such as poor paper feeding, uneven paper receiving, wrinkle, inaccurate overprinting, dirty back sticking and so on, Cause a lot of waste products. Therefore, all offset printing workshops not only need to install air-conditioning equipment to keep the temperature and humidity of the workshop within a certain range, but also must adjust the humidity of the paper and paperboard sent for printing, which is commonly known as paper drying, so that its water content can be balanced with the relative humidity of the workshop. The purpose is to make the paper and sheet adapt to the working environment of the printing workshop, correct the deformation of the paper, improve its dimensional stability, and improve its folding resistance and other mechanical strength. There are four methods to adjust the humidity: natural hanging and drying, paper drying machine adjusting the humidity, using the rising and falling temperature to achieve the uniformity of the water content of the paper stack, and using infrared radiation to eliminate the phenomenon of the lotus leaf edge of the paper stack. If the temperature and humidity of the storage place after paper drying and cutting are abnormal or there is no air conditioning equipment in the workshop, even after humidity adjustment, the paper will still be affected by the environment, resulting in changes in water content and deformation, and the above serious faults will also occur during machine printing. Therefore, in the absence of air conditioning equipment, since the relative humidity depends on the temperature, the paper must be stored under conditions similar to the temperature and humidity of the printing workshop. In addition, try to put the paper in the printing workshop a few days before the start of printing, so that it is in balance with the temperature and humidity of the workshop

2. conditions and storage methods of paper warehouse

① it can be seen from the above that both the paper warehouse and the workshop must maintain a certain temperature and humidity. The leaders of the factory should understand rationally, pay attention to it ideologically, and strive to improve the conditions of the paper warehouse. No matter in winter or summer, they should try to keep it within a certain range. Never use waste sheds or basements as paper warehouses, except basements with air conditioning equipment

② generally, the paper warehouse should be built in the plant area close to the car entrance, and there is a good road to each printing workshop on the other side. The first floor of the warehouse should be about 1.5m higher than the ground, so that it can be unloaded directly from the car, and it can also prevent ponding from flowing into the paper warehouse in the rainy season and damaging the paper. The warehouse should be bright and dry. There need not be too many windows. It is best to have ventilation ducts to avoid cold air blowing directly onto the paper stack in winter and rainy weather. The design of doors and windows should avoid ventilation and direct sunlight on the paper stack

③ when building a paper warehouse, measures should be designed to prevent rodents and pests. The paper, cardboard and other materials stored in the warehouse should be carefully checked, and the warehouse should be sprayed and rodentized regularly

④ all kinds of paper and paperboard should be stacked by classification. The storage area and forklift channel should be drawn on the ground in the warehouse. The width of the main channel is 1.5 ~ 2.0m, and the side channel is 1.0 ~ 1.5m. Paper should not be stacked 0.25 ~ 0.5m away from the wall

⑤ paper and paperboard are not allowed to be stacked on the cement floor, but should be placed flat on the wooden paper platform for forklift transportation. Pay attention to their neat and vertical stacking to prevent people from being injured by stacking. The temperature in the warehouse should be controlled at 18 ~ 20 ℃, and the relative humidity should be 40 ~ 65%. The temperature must be above 15 ℃ in winter, and excessive humidity should be prevented in summer. Dust and oil are also taboo for paper. Therefore, grease should not be stored in the paper warehouse, and dust prevention should be paid attention to when the wind blows

⑥ when stacking web paper, the end face should be placed on the board, and the height of the code should be limited. If the circular web is placed horizontally for too long, it will deform, affecting the normal operation of the rotary printing machine. When transporting and stacking paper and paperboard, it is not allowed to use it in 5g wireless communication equipment. Rough loading and unloading is allowed. It is not allowed to throw the paper wrapped in web paper or wood plywood from high places, and it is not allowed to use tools such as iron hooks that will damage the paper. When pushing the web paper, it should follow the direction indicated by the arrow about the future development direction of medical materials to prevent loosening

⑦ the acceptance, registration, inspection, disassembly and selection of paper and paperboard are essential work, and the warehouse keeper should be careful and meticulous

⑧ under the circumstances of necessity, some papers may be temporarily stored in the open air. They must be covered on the paper or paper table with watertight plastic covers. Special personnel should be assigned to patrol and protect them to prevent fires caused by cigarette butts or other sparks. Smoking and carrying matches, lighters and inflammables are absolutely prohibited in the paper warehouse