Ancient papermaking methods

Take the bamboo paper manufacturing method recorded in the ancient Chinese book "Tiangong Kaiwu" as an example. The steps for making paper from bamboo in ancient times are as follows: 1. Cut bamboo and float it in the pond. Cut young bamboo, put it into the pond, and soak it for more than a hundred days. Natural microorganisms are used to decompose and wash away the green skin of the bamboo.

2. Boil the bamboo on a full fire. Put the bamboo obtained above into the "Wang" bucket and steam it with lime for eight days and eight nights.

3. Mortar: Take out the bamboo treated above, put it into a stone mortar, and beat it with a stone hammer until the bamboo is smashed and resembles clay.

4. Swing the material into the curtain. Pour the broken bamboo material into the water tank, and use the bamboo curtain to swish the material in the water. The bamboo material becomes a thin layer attached to the bamboo curtain, and the rest of the water is poured into the water. The four sides of the bamboo curtain flow down into the trough.

5. Cover the curtain and press the paper, and then pass the curtain over repeatedly so that the wet paper falls on the board to form a piece of paper. In this way, the steps of spreading materials and covering curtains are repeated until thousands of sheets of wet paper are stacked, and then a wooden board is placed on top to squeeze out most of the water.

6. Dry through fire. Raise the wet paper one by one and dry it. The equipment for baking paper is made of adobe bricks built into an alley. A fire is lit in the alley. After the temperature of the adobe bricks rises, the wet paper is pasted one by one for drying. After drying, peel it off to get paper.

Edit this paragraph about modern papermaking methods

The modern papermaking process can be divided into main steps such as pulping, modulation, papermaking, and processing

1. Pulpmaking Process pulping is the first step in papermaking. Generally, there are three methods for converting wood into pulp: mechanical pulping, chemical pulping and semi-chemical pulping.

2. Preparation process The preparation of paper stock is another key point in papermaking. The strength, tone, printability and shelf life of the paper after completion are directly related to it.

The common preparation process can be roughly divided into the following three steps: a. Slurrying b. Beating c. Gluing and filling

3. The main work of the papermaking department in the papermaking process In order to uniformly interweave and dehydrate thin paper materials, they are then dried, calendered, rolled, cut, sorted, and packaged. Therefore, the common process is as follows:

a. Paper The screening of materials dilutes the prepared paper stock to a lower concentration, and uses screening equipment to screen out debris and undissociated fiber bundles again to maintain quality and protect equipment.

b. Mesh Department: Make the paper material flow out from the head box on the circulating copper wire mesh or plastic mesh and evenly distribute and interweave it.

c. The pressing part leads the wet paper removed from the screen to a room between two rollers with felt cloth, and uses the squeezing of the rollers and the water-absorbing effect of the felt to further press the wet paper. Dehydrate and make the paper denser to improve the paper surface and increase strength.

d. Calendering: The moisture content of the pressed wet paper is still as high as 52-70%. At this time, it is no longer possible to use mechanical force to remove the moisture, so the wet paper is allowed to pass through many processes. The paper is dried on the surface of the cylinder through which heated steam is passed.

e. The moisture content of rolled paper after being pressed is still as high as 52-70%. At this time, mechanical force can no longer be used to press out the moisture, so the wet paper is made to pass through the surface of many cylinders with hot steam flowing inside. Paper is dry.

g. Cutting, sorting and packaging: Take multiple paper rolls that have been rolled into tubes, cut them into pieces of paper with a paper cutter, and then manually or mechanically sort and remove them. Paper that is torn or stained will end up in packages of five hundred sheets (often called a ream).

Edit this paragraph to explain the paper flow

Fiber is the most basic material that makes up ordinary paper, and this fiber must be plant fiber. Some thin sheets made from animal fibers such as wool and silk cannot be called "paper" even though they have various functions and characteristics of paper. Paper made from chemical polymer fibers can only be called synthetic paper. .

Another element of papermaking is fiber beating and tapping. Using stirrers and high-horsepower machinery, the plant fibers are bifurcated and broken, and then made into paper, which has a greater binding force, unlike smooth silk fibers. It is easy to slip off; in addition, the debris and paste produced after beating can fill the pores and bond the paper during papermaking.

In ancient or modern handmade papermaking, a frame of bamboo was used to sift out the floating fibers in the pulp. Since the sifting action has front and rear short sides and left and right long sides, the handmade paper fibers can be very uniform and free in various directions. Arrangement does not produce the silk flow problem mentioned in this article. Furthermore, the modern waterless dry papermaking method uses air dispersion and gluing to make paper. The fibers are also arranged in a free shape and have no direction of filament flow.

Wet mechanical papermaking, whether old-fashioned rotary screen machine, single screen machine or double screen machine, can use very thin pulp of about 1%, which is spread from the head box behind the papermaking screen surface, so that the papermaking screen appears level Or the inclined movement will cause the fibers to appear in line along the direction of papermaking net movement. The principle is the same as the rapid flow of river water. If there are no other disturbing factors, the driftwood will naturally be arranged in the direction of the water flow, with less diagonal or transverse flow. In order to reduce resistance, the fibers in the thin pulp on the papermaking wire have a unidirectional flow rate due to the advancement of the papermaking wire before the water is lost. Most of the fibers are arranged in parallel flow directions, thus forming a "filament flow" arrangement for mechanical papermaking in the future. reason.

The flow of paper has a great influence on various "properties" and "shapes" of paper, such as tear resistance, curling, elongation, shrinkage and origami processing, book stiffness and turning. Openability, etc., all have an absolute impact. For example, the flow of trademark paper must be parallel to the original height, so that the automatic packaging machine can operate smoothly. However, the importance of paper flow is rarely taken seriously, which is not a good thing in printing project planning