Coated linerboard In recent years, flexography has been the main printing method of corrugated board, but it is usually monochrome printing on corrugated board. However, with the reform of retail industry, especially the rise of "large carton storage", while the quality of corrugated board itself has been improved, its printing quality has been paid more and more attention. In this case, multi-color direct flexography is on the rise. Direct flexographic printing technology, that is, direct printing on the surface of corrugated board, has cost advantages, but it is easy to appear "washboard" phenomenon. The "washboard" surface of corrugated board will inevitably affect its appearance printing effect. In recent years, direct flexographic printing technology and equipment have made significant progress, such as using photopolymer printing plates and new elastic padding. In addition, the new corrugated molding technology has greatly reduced the "washing board" phenomenon and warping phenomenon of corrugated board, and improved the external surface performance of corrugated board. The demand of coated linerboard. Because there is no drying process in the direct flexographic printing equipment of corrugated board, it is required that the surface coating of coated linerboard is of open structure in order to absorb ink quickly. It is very important to coat the surface strength of linerboard and increase the proportion of bleached chemical pulp on the linerboard. The hiding power of white pigment on corrugated medium is more effective than that of bleached pulp, and adding proper proportion of pigment will not reduce the strength of paperboard. When it has the same strength as unbleached kraft paper board, the new coated linerboard can obtain better printability at reasonable cost. The market of N-type corrugated board micro corrugated board is growing rapidly. Among them, compared with multi-layer composite recycled corrugated board, N-type corrugated board not only has high stacking strength, but also has a lighter weight of 35%-40% at the same thickness, which reduces the transportation cost. Micro corrugated board has a small basis weight, so its production speed is lower than most other products produced on the linerboard machine. At present, it is necessary to develop special equipment for producing micro corrugated board with light basis weight linerboard and core paper. The American International Paper Company's paper mill in Pensacola, Florida, aimed at this market, and began to switch production to research and develop this kind of equipment. The linerboard suitable for digital printing will grow rapidly in the year. When flexo printing corrugated board, it takes a long time to make plate, change plate and start up, which wastes a lot of costs, while digital printing can avoid or minimize the above costs. The most promising digital printing technology of corrugated board is high-speed and wide-width inkjet printing technology. However, the fiber surface layer of linerboard can not adapt to this printing technology, so it is necessary to develop a new variety of coated linerboard with cationic surface properties to meet this requirement.