As you know, paper was invented in China in the II century BC, and it was made from plant fibers soaked in water. A thousand years later, she came to Europe, where they learned to make it from wood, first by hand, and several centuries later by mechanical means. Today, the technology of paper production has become much more sophisticated, and the production volumes are enormous.
Instructions
Step 1
The main raw material for modern paper production is wood pulp, which is mainly obtained from birch, pine or spruce. Poplar, eucalyptus, chestnut and other trees are sometimes also used. In production, it is sometimes mixed with waste paper.
Step 2
There are two ways to produce wood pulp - chemical and mechanical. The first method is considered more costly, but the resulting paper is of high quality and is usually used for the production of magazines, wrapping materials, books or brochures.
Step 3
To create it, wood boards are cleaned of bark and crushed into chips on special machines. Then the chips are sorted by size on large sieves and sent for cooking in a dedicated machine. As a rule, acid is added to the wood during the cooking process. The boiled wood is washed to remove impurities. At this stage, waste paper, purified from ink, is sometimes added to the raw paper.
Step 4
Then the shape and structure of the paper fibers changes. For this, additional substances are added to the raw materials, for example, glue or resin, which will make the paper more durable and resistant to moisture. Thereafter, the raw paper is bleached using various dyes or pigments.
Step 5
The finished paper pulp is poured onto the mesh of a special machine, consisting of two constantly moving rollers. It is on the mesh area that the formation of the paper web begins. As the pulp moves along the conveyor, some of the contained water flows out through the mesh, and the paper fibers begin to intertwine with each other.
Step 6
The damp paper is then passed through several rollers, which remove the remaining moisture, heat it with steam, dry it and polish it. At the end of this conveyor, the paper belt is compressed to further dehydrate and compact, and then wound into a huge roll.
Step 7
The mechanical method of making paper is in many ways similar to the chemical one. But during it, boiled wood is not cleaned, and paper raw materials are not bleached. As a result of this economical method, paper of lower quality is obtained, which is mainly used for the production of newspapers.
