1. Types:

There are many types of paper. The Ministry of Light Industry of my country divides various types of paper into 17 categories according to their different uses (11 categories of paper and 6 categories of cardboard)? 11 categories of paper For - printing paper, writing paper, drawing and drawing paper, electrical insulating paper, cigarette paper, absorbent paper, instrument paper, photosensitive paper, transfer paper (base paper), industrial technical paper, packaging paper. ?The six categories of cardboard are - binding cardboard, box-making cardboard, insulating cardboard, industrial technology cardboard, construction cardboard, and shoe-making cardboard.

2. Usage:

1. Printing paper - Among printing papers, there are papers with different properties and characteristics, such as newsprint, letterpress printing paper, Offset printing paper, offset printing coated paper, dictionary paper, map paper, nautical chart paper, gravure printing paper, weekly newspaper, illustrated newspaper, white board paper, writing paper, etc.

2. Newsprint - mainly used for printing newspapers and letterpress books and periodicals. Its paper is soft, has good elastic plasticity, and has strong ink absorption performance. The ink can be fixed on the paper surface quickly. The surfaces are calendered successively. Both sides are smooth and not easy to fluff. The printing on both sides is relatively clear and solid. It has a certain mechanical strength and can be suitable for high-speed web printing. The opacity is very good. Since the raw materials used are mainly mechanical wood pulp, which contains essential elements and impurities, the paper should not be stored for a long time. The paper will easily turn yellow and become brittle. The paper is highly absorbent and has poor water resistance, and the paper is easily damaged.

3. Letterpress printing paper - mainly used for letterpress printing machines to print anthologies, classics, general books, textbooks, magazines, etc. Its characteristics are similar to newsprint, and its quality is worse than newsprint. The paper's smoothness, water resistance, and whiteness are worse than newsprint. Its ink absorption capacity is not as good as newsprint, but it absorbs ink evenly.

4. Offset printing paper - mainly used for offset printing of color pictorials, albums, posters, color trademarks and some high-end publications.

5. Offset paper can be divided into single-sided offset paper and double-sided offset paper. Single-sided offset paper is often used in color posters, cigarette boxes, trademarks, etc. Double-sided offset paper is used for printing pictures, illustrations, maps, etc. ?

6. Offset paper should have small stretchability and strong water resistance to prevent paper deformation and inaccurate overprinting during multi-color overprinting. It should also have no lint, no dusting, and a tight texture to prevent multi-color overprinting. During the first printing, under the action of the adhesive pulling force of the ink, it will cause fuzzing and powder removal, causing white spots on the imprint, which affects the quality of the printed product; the ink absorbency should not be too high, as it can hinder the penetration of the connecting material in the ink, making the ink The surface of the paper dries to form a film layer to ensure the gloss of the printed product; the surface is smooth to ensure that the imprint is solid, and the paper should be free of sand and other debris to prevent damage to the blanket and printing plate. ?

7. Offset printing coated paper - also known as coated paper. It is made by applying a layer of inorganic coating on the surface of the coating base paper and then super-calendering. The paper surface is smooth and the whiteness is high. It is specially used for offset printing of single-color or multi-color art pictures, illustrations, and pictorials. , albums, product trademarks, product samples, calendars, etc.

The earliest paper existed 2,200 years ago in the early Western Han Dynasty, but it was still very rough and not widely used. In 105 AD, Cai Lun of the Eastern Han Dynasty improved it and was considered the originator of modern papermaking. ("Pyrus" is not the current concept of "paper". It is a writing medium made by treating the plant papyrus to a certain extent. The papermaking technology invented in China broke the original arrangement of plant fibers. The finished product can be called "paper" by rearranging it randomly and crosswise. )

Chinese people invented writing during the Yin and Shang Dynasties, and began to use oracle bones as writing materials. In the Spring and Autumn Period, bamboo pieces were discovered and used. and wood chips and silk as writing materials. But because silk was too expensive and bamboo pieces were too bulky, paper was invented. One of the four great inventions of ancient China?[1]?, papermaking, together with the compass, gunpowder, and printing, provided the material and technological foundation for the prosperity of ancient Chinese culture. The invention of paper ended the complicated history of ancient bamboo slips and greatly promoted the spread and development of culture.

The Western Han Dynasty map paper unearthed from Fangmatan, Tianshui, Gansu Province is the earliest pulp paper discovered in the world.

Sheets made of plant fiber are used for painting, printing books and newspapers, packaging, etc. It is different from Zan Di, which is animal fiber "silk". Paper: The general name for paper. Paper is measured in sheets, so paper is generally divided into: letterpress printing paper, newsprint, offset printing paper, coated paper, book cover paper, dictionary paper, copy paper, cardboard, etc.