Paper is consumed by people in huge quantities. One hundred and fifty kilograms per person per year. From what and how to make paper, read the article.
Historical information
Long ago, in 105 BC, Cai Lun, an imperial subject from China, made paper from mulberry wood. He made a mixture of his wood, hemp, rags, added wood ash and put it all on a sieve to dry. Then he polished the dried mass with a stone.
It turned out paper from wood, and the Chinese eunuch Cai Lun became the first author of its technology. So consider the Chinese. But scientists have a different opinion. This is due to the fact that archaeologists often find scraps of paper in China that date from an earlier period.
Raw materials
Paper is made from wood pulp, other fibers of plant origin: reed, rice, straw, hemp, as well as rag waste, waste paper and other materials. To obtain pulp, wood of different tree species is used. Wood pulp can be obtained in several ways.
The most economical is the mechanical method. At a wood processing enterprise, the wood is crushed, it turns out crumbs. It is mixed with water. Pulp paper obtained in this way is fragile; newspapers are made from it. High quality paper is made from cellulose, which is obtained using a chemical method. For this, small chips are cut from a wooden beam. It is sorted by size. Then immersed in a solution with chemicals and boiled in a special machine. After that, they are filtered and washed, as a result of which excess impurities are removed. This produces paper raw materials called wood pulp. It makes paper for magazines, books, brochures, wrapping materials of great strength.
DIY sawdust paper
Sawdust from pine or spruce is poured with water and boiled exactly one day. Caustic soda is added to the water. For lack of such, you can use baking soda. After cooking, the mixture is washed with water and squeezed. Then again the sawdust is poured into a pot of water and put on fire. As soon as it boils, the pan is removed from the fire, its contents are crushed using a mixer. It turns out a porridge-like mass of a homogeneous consistency.
While the sawdust is boiled, a frame is made, put on a pallet, gauze is stretched on it. The mass is poured onto the prepared frame and evenly distributed over the entire surface. Excess water will drain into the drip tray. But to quickly remove moisture, it should be blotted with absorbent wipes. Then the frame is turned over and the sheet obtained from the mass is easily separated from it.
The sheet must be covered on both sides with paper or newspaper and put between the boards, pressed on top with something heavy. Under such a press, he should lie for about five minutes. After that, the sheet is carefully placed on the foil and dried in the sun, in the oven, near the battery.
Composition
Paper from wood is made on the basis of wood pulp obtained using a mechanical production method. Sometimes other materials are taken as a basis. Such paper can be made even at home. But it will be of poor quality.
Nowadays, cellulose is obtained chemically using technological processes. To obtain high quality paper, it must contain the following ingredients:
- Hydrophobic sizing, which prevents the spreading of ink on paper. They do not appear on the back of the sheet. As sizing, gum rosin is used.
- Resin, glue or starch. Thanks to these substances, paper made of wood becomes more durable and resistant to various influences on it.
- Kaolin, talc or chalk make the paper less transparent, increase its density.
Types of wood
It can be hard and soft. The first type of wood is obtained from coniferous trees: pine, fir, spruce, sequoia and tsuga. Softwood is obtained from broad-leaved species: beech, maple, poplar, birch, oak. In regions with a tropical climate - made of teak, black and mahogany.
Paper made from wood of these species is highly regarded. But they, unfortunately, are slowly growing. They are cut down more than reproduced. Therefore, in tropical forests, trees of valuable species are becoming smaller.
Paper production today
This paper is considered to be one that is made from pulp, the individual fibers of which are obtained by soaking the cellulosic raw materials. The mass is first mixed with water, and then scooped out by the form on which the grid is stretched. Excess water drains, the mass dries, a sheet of paper is obtained. That is how the Chinese citizen Cai Lun got his first piece of paper. During this time, although about two thousand years have passed, no significant changes have occurred.
Today, paper is manufactured in modern factories with huge workshops, the equipment of which performs various operations. After the production of wood pulp, the fibers are shaped and structured, for which paper raw materials are mixed with adhesives and resins. The glue repels water from the paper, and the resin prevents ink from spreading. Paper made of wood, the photo of which is presented for review, does not need such processing for printing needs, since printing ink does not spread.
The next step is staining. To do this, the paper is placed in a mixer with pigments or dyes. Then the porridge mass enters the machine, which is called paper-making. After all the processing steps in this machine, the mass becomes a paper roll tape that passes many rollers: one squeezes the water, the other dries the tape, the third polishes it.
At the next stage, the paper is sent to the workshop for wet pressing. Here the fibers are degreased and compacted even more. The result is a dry paper made of white wood, wound in huge rolls that go into the printing house. There they are cut in accordance with the required dimensions.