How is the pulp of household paper made?

How is the pulp of household paper made? process flow

Traditional pulping refers to the production process of decomposing plant fiber raw materials into colored or bleached pulp by chemical method, mechanical method or a combination of the two. Usually, the process is crushing, cooking, washing, screening, bleaching, purifying and drying the pulp. A new biological pulping method has been developed in modern times. Firstly, special strains (white rot fungi, brown rot fungi and soft rot fungi) are used to decompose lignin structure, then the remaining cellulose is dissociated by mechanical or chemical methods, and then bleaching is carried out. In this process, most lignin has been opened by biological decomposition, and chemical methods only play an auxiliary role. Compared with the traditional method, it uses less chemical products, so it can discharge less or no waste liquid, which is an environmentally friendly and clean pulping method.

classify

① According to the manufacturing method, it is divided into chemical pulp (including caustic soda pulp, sulfate pulp, sulfite pulp, etc. ) and mechanical pulp.

(Including grinding stone and wood pulp, disc grinding mechanical pulp, thermal grinding mechanical pulp, etc.). ) and chemical mechanical pulp; Pulp products are divided into wood pulp, straw pulp, bamboo pulp, cotton pulp and waste paper pulp. According to the variety of raw materials;

③ According to the processing depth, it can be divided into natural pulp, semi-bleached pulp, bleached pulp and refined pulp.

④ According to the yield of wood pulp, it can be divided into chemical pulp (40-50%), high yield chemical pulp (50-65%), semi-chemical pulp (65-84%), chemical mechanical pulp (85-94%) and mechanical pulp (94-98%).

(5) According to the purpose, the pulp used by enterprises is called self-use pulp, and the pulp sold as a commodity is called market pulp. For a specific variety, it is often named by several different classification methods, such as bleached kraft softwood pulp, natural sulfite reed pulp, poplar ground wood pulp and so on. , so that users can roughly understand the properties and uses of pulp according to its name.

Among all kinds of pulp, chemical pulp still occupies the largest proportion. 1987, the global chemical pulp output reached11350,000 tons, accounting for 7 1% of the total pulp output (155.86 million tons), and mechanical pulp accounted for 2 1%. Due to the late development, the relative output of chemical mechanical pulp is relatively small. Due to the continuous improvement of the recycling rate of waste paper and the relative increase of the amount of fillers and coatings in paper, the amount of pulp is relatively reduced, so the growth rate of pulp is generally lower than that of paper and paperboard.

How to make waxed paper? 1. Draw a black oil pastel on the colored paper board.

2. First draw a piece of paper with an oil pastel, any color will do, as long as the painting is complete, then cover all colors with a black oil pastel on this paper until all colors are covered with a black oil pastel, and then it's finished. Just scratch it with a toothpick or something sharp.

How is salt made? Salt making method: salt is dried in seawater or boiled in well water or salt lake to precipitate salt crystals. The salt made in this way has many impurities and is called raw salt. Crude salt can be dissolved, precipitated, filtered and evaporated to produce refined salt.

There is a formula for how people are made: 1+ 1 = 3, which is the process of making people. Ask your parents if you don't understand!

Hope to adopt

How is the real leather made? Simply put, leather is made from animal skin through very complicated physical (mechanical) processing and chemical treatment. Different animal skins and changes in processing methods have created a variety of leathers. Traditionally, the tanning process is generally divided into three stages: preparation stage, tanning stage and finishing stage.

(1) In the preparation stage, its main purpose is to remove all useless things from animal skin, such as hair, fat, various glands in the skin and soluble protein, and to treat the collagen fibers of animal skin (that is, the main body of leather) to facilitate post-processing and improve the quality of leather.

The main processes at this stage are: soaking, removing meat, unhairing, liming, degreasing, softening and curing.

(2) Tanning stage, the main purpose is to change the collagen fiber structure of animal skin into leather by chemical methods. At the same time, it also determines the quality and properties of the obtained leather.

The main processes in this stage are: pre-tanning, main tanning and retanning.

(3) In the finishing stage, its main purpose is to enrich some special sensory properties of leather, such as thickness, softness, color, surface state, water resistance and so on.

The main processes at this stage include peeling, smoothing, neutralization, dyeing, fatliquoring, drying, softening, flattening, leather grinding, painting and embossing.

How are stamps made? To make stamps, you must first choose a topic-project approval-design-approval-plate making-printing-announcement-distribution and other steps, and finally go to the postal counter.

How is tea made? Different teas are made in different ways. So we should treat it dialectically:

Green tea: fixing-kneading (shaping)-drying.

White tea: withering-drying

Yellow tea: fixation-rolling-yellowing-drying.

Black tea: withering-rolling or cutting-fermentation-drying.

Oolong tea: drying-drying-drying-deactivating enzyme-kneading-frying-(kneading)-drying.

Black tea: fixation-rolling-stacking fermentation-drying.

Gynostemma pentaphyllum: fixation-rolling-baking-tea processing-packaging, etc.

How is black tea made? Black tea can be divided into two categories, one is strip black tea and the other is broken black tea. Striped black tea is made through seven main stages: picking, collecting, rolling, withering, fermentation, drying and classification. Broken black tea is made through seven main stages: picking, collecting, withering, CTC (cutting, tearing and kneading), fermentation, drying and grading. 1. Black tea Black tea is made by withering and rolling (cutting) tea suitable for making this product. Fermentation. It is extracted by typical processes such as drying. Because of its dry brown color, the brewed tea soup is mainly red, hence the name. Black tea was called black tea when it was first created. During the processing of black tea, a chemical reaction centered on enzymatic oxidation of tea polyphenols occurred, and the chemical composition of fresh leaves changed greatly, and tea polyphenols decreased by 90%.

How is glass made? Usually, glass is made of ore.

Special glass is formed by adding other chemicals to the glass solution.

Composition of glass

(1) ordinary glass (Na2SiO3, CaSiO3, SiO2 or Na2O CaO 6SiO2)

(2) Timely glass (glass made of pure timely as the main raw material, and its composition is only silicon dioxide).

(3) Tempered glass (same composition as ordinary glass)

(4) Potassium glass (K2O, calcium oxide, silicon dioxide)

(5) Borate glass (silica, B2O3)

(6) Some metal oxides are added in the manufacturing process of colored glass (ordinary glass). Cu2O- red; CuO- blue-green; CDO-light yellow; CO2 O3- blue; Ni2o 3- dark green; MnO 2- purple; Colloidal gold red; Colloidal silver yellow)

(7) Color-changing glass (advanced colored glass with rare earth oxide as colorant)

(8) Optical glass (a small amount of photosensitive substances, such as AgCl and AgBr, and a very small amount of sensitizer, such as CuO, are added to ordinary borosilicate glass raw materials to make the glass more sensitive to light).

(9) Rainbow glass (made by adding a large amount of fluoride, a small amount of sensitizer and bromide into ordinary glass raw materials)

(10) Protective glass (Appropriate auxiliary materials are added in the manufacturing process of ordinary glass to make it have the function of preventing strong light, high heat or radiation from penetrating and protect personal safety. Such as gray dichromate, iron oxide absorbs ultraviolet light and part of visible light; Blue-green-nickel oxide and ferrous oxide absorb infrared and some visible light; Lead glass-lead oxide absorbs x-rays and r-rays; Dark blue-dichromate, ferrous oxide and iron oxide absorb ultraviolet, infrared and most visible light; Cadmium oxide and boron oxide are added to absorb neutron current.

(1 1) Glass-ceramics (also called crystalline glass or glass-ceramics, it is made by adding gold, silver, copper and other crystal nuclei to ordinary glass, instead of stainless steel and precious stones, used as radomes and missile heads).

(12) glass fiber (fiber drawn or blown from molten glass, with a diameter of several microns to several thousand microns and the same composition as glass)

(13) glass fiber (long glass fiber)

(14) glass fiber reinforced plastic (reinforced plastic with strength similar to that of steel, composed of epoxy resin and glass fiber). )

(15) cellophane (transparent cellulose film made of viscose solution)

(16) sodium silicate (Na2SiO3) aqueous solution, named because its composition is the same as that of ordinary glass)

(17) metallic glass (glassy metal, usually made by rapid cooling of molten metal)

(18) fluorite (colorless and transparent CaF2 _ 2, used as prism and transparent mirror in optical instruments)

(19) plexiglass (plexiglass)

How are tea cakes made? Pu 'er raw tea is made from low-temperature green dried raw tea, which is softened by steam steaming and then pressed by mold. The technology of cooked tea is to use sun-cured green tea as raw material, which is screened after fermentation and then autoclaved.

1, the color of raw tea cakes is mainly turquoise and dark green, and some of them turn yellow-green and yellow-red after aging. The color of soup is mainly yellow-green, yellow-red and golden. The bottom of new tea leaves is mainly green and yellow-green, and the old tea leaves are red, yellow or jujube red. Raw tea has a bitter, astringent, sweet and sweet taste, and the aroma is obvious. Raw tea mainly has the functions of clearing intestine, reducing blood fat, refreshing, lowering blood pressure and losing weight.

2. The color of cooked tea is mainly reddish brown. The aroma has obvious accumulation and fermentation smell. Cooked tea tastes mild and mellow. Fully fermented cooked tea, the soup is thick, sweet, smooth and almost not bitter. Mild fermentation, sweet taste and obvious aroma. Light fermented soup is mostly dark red, while heavy fermented soup is mainly red and black. The leaves are mostly reddish brown and dark brown. Cooked tea can lower blood fat and blood pressure, prevent arteriosclerosis, prevent constipation and induce diuresis.

I have been drinking Pu 'er tea from Suyue Tea House, and I feel very good. Now I still chat with their tea artist Zhang Ci from time to time, which has benefited a lot. Gdgd800 is her (wēi) micro (XIN) number. She's very nice. Ask her if you don't understand anything.

Pu 'er tea, for example, is not a temporary * * *, nor an echo, but a time, which has become a part of life.