Lightweight coated paper has good printability and is suitable for rotogravure or offset printing, even for lithographic offset printing. At present, in more developed countries and regions, the demand for light coated paper is increasing rapidly. In recent years, the papermaking industry in China has been steadily moving forward. The production and consumption of paper and paperboard have maintained a rapid growth momentum, and the annual growth rate has exceeded 10% (see Figure 1). This has laid a solid foundation for the rapid development of the domestic printing and packaging industry. Foundation. In 2004, the total output of paper and board in China reached 46.66 million tons, with a total consumption of 53.35 million tons. It increased by 13.2% and l1.4% respectively over the previous year. Both output and consumption rank second in the world. From the end of the 20th century to the beginning of the 21st century, the growth rate of coated paper was even more striking. From 1991 to 2000, the output of coated printing paper and paperboard increased from 182-20,000 tons and 11,500 tons to 1.02 million. Tons and 2 million tons, respectively, increased by 4.6 times and 16-4 times in 10 years: consumption increased by 4.29 times and 23.84 times respectively. After entering the 21st century, the ordinary coated paper market at home and abroad continues to maintain optimism, but the growth rate is slowing down. At the same time, the demand for and consumption of a new member of the coated paper family, low-weight coated paper (light coated paper), is increasing year by year. Interpretation In 2002, China's low-quantity coated paper production increased significantly, resulting in a coated paper output of 1.8 million tons, an increase of 38.46% over the previous year, which is second only to the growth rate of white paperboard. In order to meet the needs of consumption growth, light coated paper accounted for about 1 million tons of 13 coated paper projects with a total capacity of 2.03 million tons converted and newly built in 2005. According to statistics, the demand for low-quantity coated paper is increasing at a rate of 3 to 5% globally, especially in industrially developed countries. It is the upstart in printing paper products now and in the future, and its market prospects. Very optimistic. The so-called light coated paper. It refers to a paper with a relatively low coating amount and is a type of coated paper with a relatively low basis weight, and the English name is Light Weight Coated Paper. At present, the specific concept of light-coated paper is somewhat vague. In Europe, it generally refers to paper containing wood pulp (about 30%), and the coating amount on one side is generally 6 to 10 g/m2 and the basis weight is 50 to 70 g/m2; while in Japan, paper made in Japan The Federation called coated paper with a double-sided coating weight of 12 g/m2 or less as "microcoated paper." In China, there is no clear definition for light-coated paper. Customs generally refer to it as “lightweight coated paperâ€, which stipulates that the mechanical fiber contained in the base paper is not less than 50% of the total fiber weight. . In 2002, the tariff code of the customs was adjusted to include the low-quantity coated paper with a mechanical pulp content of 10% to 50% in the base paper, which increased the statistical coverage of lightweight coated paper. Broadly speaking, according to the current situation of low-quantitative coated paper at home and abroad, the quantitative range of light-coated paper can be determined between 50 and 120 g/m2. The higher ration paper is mainly used as a low-grade bond paper. The light-coated paper belongs to the coated paper sequence, and its fibrous structure is uniform and its thickness is uniform. In terms of paper physical properties and printability, it has similarities with common coated papers. Generally speaking, various properties lie between coated paper and offset paper, and the color printing effect is comparable to that of coated paper. Whiteness, smoothness, gloss and printability. In general, the opacity is also higher. As we all know, the production of ordinary coated paper is based on the principle of multi-layer pressing. The raw materials are mostly 100% chemical wood pulp, and the cost is high. The principle of low-quantity coated paper is that it is coated one by one, and the production involves the use of cheaper mechanical pulp, thus reducing the cost, compared to the use of bleached chemical pulp, the cost of The investment will be reduced by about 30%. In addition, the weight of light coated paper is generally much lower than coated paper. With the same number of pages as the low-quantitative offset printing coated paper, the weight and thickness of the publication can be reduced by 10 to 15%, which facilitates packaging, shipping, carrying and mailing, and can greatly reduce the postage of the mailing product. Global or large-scale magazines, newspapers and print magazines welcome. Lightweight paper is processed paper, which is more expensive than general offset printing paper, but much cheaper than coated paper that uses all chemical wood pulp and is coated. Therefore, light coated paper also has the characteristics of low cost and high added value. The light-coated paper contains more mechanical wood pulp, and the remaining lignin and other compounds in the mechanical pulp cause the paper sheet to be discolored, brittle, or even damaged. Therefore, the light-coated paper on the market still has the disadvantage of poor durability. Therefore, it is more suitable for printing prints (such as newspapers, magazines, etc.) that do not require long-term preservation. manufacture We know that the production of ordinary coated paper is based on the surface coating of the offset printing base paper and then super-calendered. The coated amount of coated paper is relatively large. After the paper mill produces the base paper, the base paper has to be coated by a special coating machine so that the paper has high surface properties such as smoothness and whiteness. Light-coated paper is easier to make than coated paper. It is more complicated than producing ordinary printing paper. The simplest method is to add a coating device directly on the paper machine, which is somewhat similar to the online coating in the printing process. Usually the coating device is a roller coating device, and the coating amount is also low. After coating, it can achieve the effect of filling the surface gap of the paper and improving the whiteness and smoothness of the paper. In the production of base paper, compared with coated paper, the light-coated paper uses different pulps to be beaten separately. The selected paper machine adopts a wire mesh former and the headbox is closed to ensure that the vehicle speed is 1200 to 1500 meters. minute. The base paper produced on this type of paper machine can be coated in a paper machine, and then sent to the outside of the machine and processed into a light coated paper by a super calender. The on-line coating device in the machine is usually a light applicator formed by combining a feeding roller, a back roller and a blade metering portion between the press section and the drying section. Heated by drying oven to facilitate coating drying and prevent sticking of paper. Light coating paper coatings are generally made of calcium carbonate, china clay, accompanied by carboxymethyl cellulose, cationic starch, and latex, etc. This coating has excellent rheological properties and water retention properties, as well as the function of lubricating scraper. Ensure the quality of coating after light coating. In recent years, the demand for lightweight coated paper in China has been rising. At the same time, it is also one of the products that the paper mills are currently focusing on and focusing on development. Domestic companies producing light coated paper mainly include Chenming Paper Group, Jindong Paper, and Shandong Huatai Group. UPM Group. Ningxia Meili Paper Industry. Shandong Quanlin Paper and other paper companies. In October 2002, APP (Asian Pulp Company) Jiangsu Zhenjiang Jindong Paper Co., Ltd. established the second 500,000 ton coated paper production line to be put into production. Together with the first coated paper production line originally built, Jindong Paper Co., Ltd. has become the largest company in the world in terms of coated paper production. This company has two widening coated base paper production lines with a speed of 9700mm and a speed of 1,500 meters per minute. The annual production capacity is over 700,000 tons. The qualities of base paper and coated paper are quality products. Chenming Paper Group has successfully developed 51g/m2 low-quantity coated paper, and it has a production capacity of 51~120g/m2 low-weight coated paper with various specifications. The product structure is complete. New favorite Lightweight coated paper has good printability and is suitable for rotogravure or rotary offset printing, even for lithographic offset printing (higher weight light weight coated paper). At present, light-coated paper is widely used in printing magazines, catalogues, advertisements, trademarks, newspapers and periodicals (insert pages) and other fields. In the United States, light-coated paper has been listed as the most promising type of paper by the “Guidelines for the development of new products for light industryâ€. According to statistics. In the United States, 52% of light coated paper is used to print magazines. For example, the monthly "Reader Digest" printed and distributed tens of millions of copies in 19 languages. The text of this magazine is printed on light coated paper. In addition. There are 25% light coated paper used for catalogs. 20% of print ads. In Europe, 42% of coated paper is used to print magazines. 30% for advertising and 22% for catalogs. Japan's mid- to low-grade lightweight coated paper is also the fastest growing paper in recent years, and it continues to increase. In more developed countries and regions, the increasing demand for light-coated paper is mainly due to the huge impetus for the development of advertising and color printing. China's low-quantity coated paper started late. In commercial advertisements, many coated papers are used. This is rare in the international market. Foreign coated pulp papers produced in China are rarely used. In the past, domestic light-coated paper was used for magazine printing. In the area of ​​newspaper inserts and other areas, the trend of using light-coated paper has gradually emerged in the commodity catalogs and advertising industries in recent years. This has made the domestic market for light-coated papers more active since the 21st century, with consumption and demand increasing year by year. rise. In 2002, domestic self-produced light-coated paper was about 25 million tons. The national consumption amounted to 900,000 tons, and the shortage was imported from abroad. It can be seen that the domestic market for low-quantitative coated paper has broad development space. At present, domestic and foreign printing paper. Lightweight paper has become a hot topic. Although in recent years, more than 10 light coated paper production lines have been newly built in China. Although the annual production capacity has more than 1 million tons. However, the output has been below 500,000 tons for many years and the pace of development has been slow. In foreign countries, lightweight coated paper is the fastest growing paper product in recent years. Foreign light-coated papers have the same or slightly reduced product printing performance, but the cost is greatly reduced, and the market is growing. The current domestic cultural paper wants to market the main product of the book paper. The offset paper is changed to light coated paper. However, it is a process in which the printing performance of a product has been improved but the cost has been greatly increased, resulting in the slow development of the domestic market for light coated paper. Research and development techniques for light coated papers are still moving forward, from coating pigments. Coating technology. The coating equipment was further updated to further reduce the basis weight of light-coated paper. The focus of in-depth research should still be on improving or ensuring its print performance while minimizing or controlling costs. Domestic can be used to copy cheap non-wood fiber such as bamboo pulp, bagasse pulp, reed pulp, etc. to replace the mechanical pulp components in foreign light-coated paper. Use chemical wood pulp rationally. Can produce a lightweight coating and other cultural paper that can meet market demand. In order to achieve the upgrading of cultural paper. Only lightweight coated paper with quality that meets market demand and is not costly. It is the real darling of domestic and future printing paper products. Source: China Printing Author: Zhang Xiaolin
Lightweight paper - the new darling of printing