Introduction to white board
The size of the white board is 787mm*1092mm, the size of the large paper is 889mm*1194mm, or other specifications or web rolls are produced according to the order contract.
The white paper due to fibrous tissue is relatively uniform, the surface layer has a filler and rubber composition, and coated with a coating, and after rolling light processing, so the cardboard texture more closely, more uniform thickness. The paper generally is white and smooth, with ink evenly, off the surface of powder and hair loss is less than the strength of paper folding is good, but the water content is high, generally around 10%, there are certain scalability, which brings the influence to printing will. The difference between white board and coated paper, offset paper and letterpress paper is that the paper is heavy, the paper is thick and the color of the front and back is different. The white board paper is one gray and one white, and also called "grey bottom coating white".
The white paper is a face of each layer of slurry and the bottom slurry in circular net paper machine dryer or combination machine is made of cardboard. Pulp is generally divided into surface (surface), two, three, four layers, the fiber content of each layer of pulp is different, and the fiber ratio of each layer of slurry is also different according to the quality of paper.
The first layer is the surface layer slurry, require high whiteness, has a certain strength, usually using bleached kraft pulp or bleached chemical pulp and adding some white edge pulp; the second layer is lining, to play the role of isolating surface layer and core layer, also has certain whiteness, usually with 100% mechanical pulp or light colored pulp; the third layer is the core layer, mainly for filling, in order to increase the thickness of the cardboard, increase the stiffness, generally uses the mixed waste paper pulp or pulp, the most commonly used several layer thick cardboard trough net quantitative high several times to hang pulp; the last layer is the bottom layer, can improve the board the appearance, increase strength, prevent curling function, usually with high yield pulp or pulp as raw materials made of cardboard better, the color of bottom than gray, also may require the production of other color of bottom.