What processes are involved in making paper?

There are two forms: mechanism and handmade. Mechanism is continuous in the paper machine, will be suitable for the quality of paper pulp, diluted with water to a certain concentration, in the paper machine's net part of the initial dewatering, the formation of wet paper, and then by the press dewatering, and then drying into paper. Handmade with bamboo curtains, polyester mesh or copper mesh frame, will be dispersed in the water suspended in the fiber copied into wet paper, by the press dewatering, and then drying or drying into paper. Mechanism and handmade two kinds of paper made by the biggest difference is that the handmade paper in the toughness of the tension is much better than the mechanism of the paper. Also than the mechanism of cotton soft, especially in painting and calligraphy paper.

Modern papermaking program can be divided into pulping, modulation, copying, processing and other major steps

1. Pulping process Pulping is the first step in papermaking, the general wood into pulp method of mechanical pulping, chemical pulping and semi-chemical pulping method and so on three.

2. Modulation process The modulation of paper for the other focus of papermaking, paper after the completion of the strength, color, printability of the advantages and disadvantages of paper preservation period is directly related to it.

Generally common modulation process can be roughly divided into the following three steps: a. scattered pulp b. pulping c. adding glue and filling

3. Copying process The main work of the copying department is to dilute the paper, so that it is uniformly intertwined and dewatering, and then drying, calendering, paper rolls, cutting, selecting and packaging, so the general common processes are as follows:

a. Screening of paper will be modulated to dilute the paper into the paper, and then the paper will be diluted into the paper, and then the paper will be cut into the paper. The modulated paper is then diluted to a lower concentration, and through the screening equipment, sieve out the debris and undissociated fiber bundles again to maintain quality and protect the equipment.

b. Mesh section The paper stock flows out of the headbox onto a circulating copper or plastic mesh that is evenly distributed and interwoven.

c. Press section The wet paper removed from the mesh surface is led to a two rolls with a burlap, and the wet paper is further dewatered by the squeezing of the rolls and the absorbing effect of the burlap and the paper is made tighter to improve the surface of the paper and to increase its strength.

d. Drying cylinder As the wet paper after pressing, its moisture content is still as high as 52 - 70%, at this time has been unable to use mechanical force to press the water, so instead of letting the wet paper through a number of internal hot steam cylinder surface to make the paper dry.

e. Roll paper As a result of wet paper after pressing, its moisture content is still as high as 52 - 70%, at this time can no longer be used to press the mechanical force to remove water, so instead of letting the wet paper through a number of endothermic steam cylinder surface to make the paper dry.

f. Cutting, selection Packaging: Take the front has been rolled into a cylinder of paper rolls, with a paper cutter cut into a sheet of paper, and then manually or mechanically selected, remove the broken or stained paper, and finally every five hundred packages into a package (usually called a order).

[edit]Paper silk flow shallow understanding

Fiber is the composition of the most basic substances of general paper, at the same time this fiber must be plant-based fibers. Some of the use of wool, silk and other animal fibers made of sheet material, although all kinds of paper functions and characteristics, can not be called "paper"; the use of chemical polymer fibers produced by the completion of the paper, can only be called synthetic paper.

Another important element of papermaking is fiber pulping knockdown, the use of churns and high-powered machinery, so that the plant fibers fork broken, and then copied into the paper have a greater bond, unlike the polished silk fibers are easy to slip; in addition, the debris produced after pulping and paste, in the copying of the paper has to fill the holes and adhesion to the paper function. In ancient times or modern hand-copied paper, the use of bamboo frames in the pulp to sieve the floating fibers in the pulp, due to the sieving action of the front and back of the short side and the left and right sides of the long side of the sieving action, so the hand-copied paper fibers can be very uniform in various directions to freely arrange the paper, there is no production of this paper, the problem of silk flow. In addition, the modern anhydrous dry papermaking method, the use of air dispersal and gluing method of manufacturing paper, the fibers are also presented in a free arrangement, there is no direction of the flow of silk.

Wet mechanical paper, regardless of the old circular mesh machine, single mesh machine, double mesh machine, you can use a very thin pulp about 1% or so, from the head box flow cloth in the paper mesh surface, the mesh presents horizontal or oblique rise type movement, the fibers will be presented in the direction of the movement of the paper mesh in straight columns, the principle of the river as the rapid flow of water, if there is no other disturbing factors, the driftwood naturally along the direction of the water flow arrangement of the majority of less oblique or lateral flow, to reduce the resistance, so that the water flow, the water flow, the water flow and the fiber. Flow to reduce resistance, so the thin pulp fibers on the paper net, before the loss of water due to the unidirectional effect of the flow caused by the net forward, most of the fibers form a parallel flow direction arrangement, so the formation of the future of mechanical papermaking, "Silk flow" arrangement of reasons.

The paper flow of the paper all kinds of "sex", "shape" has a great impact, such as tear resistance, curling, extension length, shrinkage and processing of paper folding, book stiffness and turnover suitability and so on, there is an absolute impact, such as the trademark of the paper flow to parallel Out of the body height, in order to make the automatic packaging machine smooth operation. But the importance of the paper stream is rarely emphasized, not a good thing on the printing project.