Commonly used printing paper and classification-Jinling paper machinery equipment

　　Commonly used printing paper and classification

　　The printing methods are different, and the corresponding paper must be selected according to the requirements and characteristics of the use and printing process. The following is an introduction to some commonly used paper specifications in publishing, for your reference:

　　1. Letterpress paper

　　Letterpress paper is the main paper used when printing books and magazines. It is suitable for the main text of important works, scientific and technological books, academic journals and textbooks of colleges and universities. Letterpress paper can be divided into four grades: No. 1, No. 2, No. 3 and No. 4 according to the different distribution ratios of paper materials. The number of paper represents the quality of the paper. The larger the number, the worse the paper quality.

　　Letterpress printing paper is mainly used for letterpress printing. The properties of this paper are similar to newsprint, but not exactly the same. The fibrous structure of relief paper is relatively uniform, and the gaps between the fibers are filled with a certain amount of fillers and sizing materials, and have been bleached, which forms the paper has a better adaptability to printing. Although its ink absorption is not as good as newsprint, it has the characteristics of uniform ink absorption; water resistance and paper whiteness are better than newsprint.

　　Letterpress paper has the characteristics of uniform texture, lint-free, slightly elastic, opaque, slightly water-resistant, and certain mechanical strength.

　　Weight: (49-60)±2g/m2

　　Flat paper specifications: 787×1092, 850×1168, 880×1230; there are also some special sizes of paper

　　Web specifications: width 787, 1092, 1575

　　The length is about 6000m-8000m

　　2. Newsprint

　　Newsprint is also called white newspaper, which is the main paper used in newspapers and books. It is suitable for the main text of newspapers, periodicals, textbooks, comic strips, etc. The characteristics of newsprint are as follows: the paper is loose and light, and has good elasticity; good ink absorption performance, which ensures that the ink can be better fixed on the paper. After the paper is calendered, both sides are smooth and lint-free, so that the print on both sides is clear and full; it has certain mechanical strength; it has good opacity performance; it is suitable for high-speed rotary printing.

　　This paper is produced with mechanical wood pulp (or other chemical pulp) as raw materials, and contains a large amount of lignin and other impurities, so it is not suitable for long-term storage. If the storage time is too long, the paper will turn yellow and become brittle, have poor water resistance, and is not suitable for writing. The printing ink or book ink must be used, and the viscosity of the ink should not be too high. The moisture content of the plate must be strictly controlled during lithographic printing.

　　Weight: (49－52)±2g/m2

　　Flat paper specifications: 787×1092, 850×1168, 880×1230

　　Roll paper specifications: width 787, 1092, 1575; length about 6000m-8000m

　　3. Offset paper

　　Offset paper is mainly used when printing higher-level color prints on offset (offset) printing machines or other printing machines, such as color pictorials, picture albums, posters, color printing trademarks, and some advanced book covers, illustrations, etc.

　　Offset paper is divided into special grade, No. 1, No. 2 and No. 3 according to the proportion of pulp. There are single-sided and double-sided, and two grades of super calender and ordinary calender.

　　Offset paper has small elasticity, uniform ink absorption, good smoothness, tight and opaque texture, good whiteness, and strong water resistance. Conjunctival type offset printing ink and better quality lead printing ink should be used. The viscosity of the ink should not be too high, otherwise the phenomenon of powder removal and napping will occur. To prevent the backside from sticking and dirty, generally use anti-dirty agent, powder spraying or interleaving paper.

　　Weight: 50, 60, 70, 80, 90, 100, 120, 150, 180 (g/m2)

　　Flat paper specifications: 787×1092, 850×1168, 880×1230

　　Web specifications: width 787, 1092, 850

　　4. Coated paper

　　Coated paper, also known as coated paper, is made by coating a layer of white slurry on base paper and calendering it. The paper surface is smooth, the whiteness is high, the paper fiber distribution is uniform, the thickness is uniform, the flexibility is small, there is good elasticity and the surface is smooth, the whiteness is high, the paper fiber distribution is uniform, the thickness is uniform, and the flexibility is It is small, has good elasticity and strong water resistance and tensile properties, and has very good ink absorption and receiving state. Coated paper is mainly used for printing picture albums, covers, postcards, exquisite product samples and color trademarks. The pressure should not be too high when printing on coated paper, and offset printing resin ink and bright ink should be used. To prevent dirt on the back side, add anti-dirty agent, spray powder and other methods. There are two types of coated paper, single and double-sided.

　　Weight: 70, 80, 100, 105, 115, 120, 128, 150, 157, 180, 200, 210, 240, 250 (g/m2)

　　Among them: 105, 115, 128, 157 (g/m2) imported paper specifications are more

　　Flat paper specifications: 648×853, 787×970, 787×1092 (currently there is no roll paper in the country). 889×1194 is imported coated paper specification

　　5. Draw a newspaper

　　The texture of the painted newspaper is white and smooth, and it is used to print pictorial newspapers, atlases and posters.

　　Weight: 65, 90, 120 (g/m2)

　　Flat paper specifications: 690×960, 787×1092

　　6. Written paper

　　Written paper, also called book cover paper, is the paper used for printing book covers. Written paper is made of paper with pigments, with colors such as gray, blue, and beige.

　　Weight: 80, 100, 120 (g/m2)

　　Flat paper specifications: 690×690, 787×1092

　　7. Embossed paper

　　Embossed paper is specially produced and a kind of cover decoration paper. The surface of the paper has a pattern that is not very obvious. The colors are divided into gray, green, beige and pink, and are generally used to print monochrome covers. The embossed paper is kneeling, and the spine is easy to break when binding. When printing, the paper has a large curvature and it is difficult to feed the paper, which affects the printing efficiency.

　　Weight: 120-40g/m2

　　Flat paper specifications: 787×1092