Cai Lun improved papermaking in the first year of Yuanxing of the Eastern Han Dynasty (105).

Cai Lun

The paper he made from bark, hemp heads, rags, fish nets and other raw materials, and went through processes such as beating, pounding, copying and baking, is the origin of modern paper. This kind of paper, the raw materials are easy to find, very cheap, the quality has also improved, and it is gradually used widely. In order to commemorate Cai Lun's achievements, later generations called this paper "Cai Hou Paper".

Paper is the crystallization of the long-term experience and wisdom of the Chinese working people. Paper is a sheet fiber product used for writing, printing, painting or packaging. It is generally made of aqueous suspension of plant fibers that have been pulped, staggered on the web, initially dehydrated, and then compressed and dried. China is the first country in the world to invent paper. According to archaeological discoveries, hemp fiber paper already existed in China during the Western Han Dynasty (206 BC to 8 BC). The texture is rough, the quantity is small, the cost is high, and it is not popular.

Since ancient times, Chinese working people have known how to raise silkworms and reel silk. During the Qin and Han Dynasties, the handicraft industry of making silk floss from cocoons was very popular. This method of treating secondary cocoons is called the flocculation method, and the basic points of the operation include repeated beating to break up the silkworm clothes. This technique later developed into pulping in papermaking. In addition, in ancient China, lime water or plant ash water was commonly used to degumm silk and linen. This technology also inspired the degumming of plant fibers in papermaking. Paper was developed with the help of these technologies.

There are very few historical documents about the papermaking technology of the Han Dynasty, so it is difficult to understand its complete and detailed process. Although there are speculations by future generations, they can only be used as reference. Overall, papermaking technology has many links, so there must be a process of development and evolution, and it is definitely not the work of one person. It is the crystallization of the long-term experience and wisdom of the Chinese working people.

In the early days of papermaking, the main raw materials for papermaking were bark and rags. The rags at that time were mainly hemp fiber, and the main varieties were ramie and hemp. It is said that cotton in my country was introduced from India at the same time as Buddhism in the early Eastern Han Dynasty, and was later used for textiles. The bark used at that time was mainly sandalwood and gourd bark. At the latest in the early Western Han Dynasty in the 2nd century BC, paper had been introduced in China. The original paper was made of hemp fiber or hemp fabric. Since papermaking was still in its infancy and the technology was crude, the paper produced was rough in texture, with many fiber bundles that had not been loosened, and the surface was not smooth. It is not suitable for writing and is generally only used for packaging.

Until the period of Emperor He of the Eastern Han Dynasty, after improvements by Cai Lun, a relatively stereotyped papermaking process was formed. The process can be roughly summarized into four steps:

The first is The separation of raw materials is to use soaking or cooking methods to degumm the raw materials in alkali solution and disperse them into fibers;

The second is beating, which is to cut the fibers by cutting and pounding, and The fiber is broomed and turned into pulp;

The third is paper making, that is, the paper pulp is infiltrated into water to form a slurry, and then a paper scoop (strip mat) is used to scoop out the pulp, so that the paper pulp is interwoven on the paper scoop to form a slurry. Thin sheet of wet paper;

The fourth is drying, that is, drying the wet paper in the sun or air, then peeling it off to become paper.

After the Han Dynasty, although the technology has been continuously improved and matured, these four steps have basically remained unchanged. Even in modern times, in wet paper production, the production technology is still not fundamentally different from the ancient Chinese papermaking method. . The development of papermaking technology mainly reflects two aspects: In terms of raw materials, mulberry bark and rattan bark were used to make paper during the Wei, Jin, Southern and Northern Dynasties. By the Sui Dynasty and the Five Dynasties, bamboo, sandalwood, wheat straw, rice straw, etc. had also been used as raw materials for papermaking and had been utilized successively, thus providing a rich and sufficient source of raw materials for the development of papermaking sheets.

Among them, the Tang Dynasty used bamboo as raw material for

papermaking

and made bamboo paper, marking a major breakthrough in papermaking technology. Bamboo fibers are hard, brittle, and easy to break, making technical processing difficult. The success of papermaking from bamboo shows that ancient Chinese papermaking technology has reached a fairly mature level. During the Tang Dynasty, processing technologies such as alum, glue, powder coating, gold sprinkling, and dyeing were successively introduced during the papermaking process, laying a technical foundation for the production of various craft papers.

The quality of paper produced is getting higher and higher, and there are more and more varieties. From the Tang Dynasty to the Qing Dynasty, the paper produced in China, in addition to ordinary paper, also has various colored wax paper, cold gold, gold, etc. Ribbed, gold and silver painted, calendered and other precious papers, as well as various rice papers, wallpapers, floral papers, etc. Make paper a necessity in people's cultural life and daily life. The invention and development of paper also went through a tortuous process.

After papermaking was improved in 105 AD, papermaking technology spread from Henan to other economically and culturally developed areas. Cai Lun was granted the title of Marquis Longting in Yangxian County, Shaanxi Province

Papermaking Related Sculptures

Papermaking technology spread to the Hanzhong area and gradually spread to Sichuan. According to folklore in Cai Lun's hometown of Leiyang, Hunan, Cai Lun also taught papermaking to his hometown during his lifetime. At the end of the Eastern Han Dynasty, papermaking in Shandong was also relatively developed, and Zuo Bo, an expert in papermaking, came out of Donglai County (today's Ye County). After papermaking was promoted throughout our country in the second century AD, paper became a strong competitor for silk and bamboo slips.

In the third to fourth centuries AD, paper had basically replaced silk and bamboo slips and became the only writing material in my country, effectively promoting the spread and development of science and culture in our country. During the Wei, Jin, Southern and Northern Dynasties from the third to the sixth centuries AD, my country's papermaking technology continued to innovate. In terms of raw materials, in addition to the original hemp and mulberry, it has also been expanded to use mulberry bark and rattan bark to make paper. In terms of equipment, the papermaking technology of the Western Han Dynasty was inherited, and more movable curtain bed paper molds appeared. A movable bamboo curtain was placed on the frame, and thousands of wet papers could be fished out repeatedly, which improved work efficiency. In terms of processing and manufacturing technology, alkali cooking and pounding have been strengthened, the quality of paper has been improved, and processed papers such as colored paper, coated paper, and filler paper have emerged.

Judging from the ancient paper unearthed from the Dunhuang Stone Chamber and Xinjiang Shaqi during this period, the paper fibers are evenly intertwined, the appearance is white, and the surface is smooth, which can be described as "beautiful glow". In the sixth century AD, Jia Sixie also recorded two articles in "Qi Min Yao Shu" about the processing and dyeing of papermaking raw materials

Flow chart of papermaking in the Han Dynasty

Huang Paper technology. At the same time, papermaking technology spread to my country's neighboring Korea and Vietnam. This was the beginning of the spread of papermaking technology.

Papermaking

During the Sui, Tang and Five Dynasties periods from the 6th to the 10th centuries AD, in addition to hemp paper, mulberry paper, rattan paper, sandalwood paper and daphne paper also appeared in our country Parchment paper, rice straw paper and new bamboo paper. In the bamboo-producing areas of the south, bamboo resources are abundant, so bamboo paper has developed rapidly. Regarding the origin of bamboo paper, some people previously believed that it began in the Jin Dynasty, but there was a lack of sufficient documentary and physical evidence. From a technical point of view, bamboo paper should only appear after the vellum paper technology has developed considerably. Because bamboo material is stem fiber, which is relatively hard and difficult to handle, it is unlikely that bamboo paper appeared in the Jin Dynasty. Bamboo paper should have originated after the Tang Dynasty, and developed significantly during the Tang and Song Dynasties. Bamboo paper was not available in Europe until the 18th century.

The paper-producing areas during this period were all over the north and south. Block printing was invented in the Tang Dynasty and became widely used in the middle and late Tang Dynasty [2]? As a result, the book printing industry emerged, which promoted the development of the paper industry. The output and quality of paper have increased, and the price has continued to decline. Various paper products are popular in people's daily life. Among the valuable papers are "hard yellow" from the Tang Dynasty, "Chengxintang paper" from the Five Dynasties, etc., as well as water-grained paper and various art-processed papers. There are many paintings and art works of the Tang Dynasty on paper, which reflects the improvement of papermaking technology.

During the Song, Yuan, Ming and Qing dynasties from the 10th to the 18th century AD, mulberry paper and bamboo paper were particularly popular and consumed in large quantities. Bamboo curtains used in papermaking mostly use fine bamboo strips, which requires the paper to be beaten to a very high degree, and the paper produced must be very fine and well-proportioned. Previously, in the Tang Dynasty, starch

Papermaking

paste was used as a sizing agent, which had the functions of filler and reducing fiber sinking to the bottom of the tank. After the Song Dynasty, plant mucilage was often used as "paper medicine" to make the pulp uniform. Commonly used "paper medicine" is the leaching solution of carambola vine, yellow hollyhock, etc. This technology had been used as early as the Tang Dynasty, but became so popular after the Song Dynasty that starch paste was no longer used.

Papermaking

At this time, there were many varieties of processed paper, and paper was used for an increasingly wide range of purposes. In addition to calligraphy, painting, printing and daily use, our country was also the first in the world to issue banknotes. . This kind of paper money was called "Jiaozi" in the Song Dynasty and continued to be issued after the Yuan and Ming Dynasties. Later, countries around the world also followed suit. Wallpapers, paper flowers, paper-cuts, etc. used for interior decoration during the Ming and Qing Dynasties were also very beautiful and sold at home and abroad. Various colored wax paper, cold gold, lacquered gold, ribbed, lacquered gold and silver painted paper, calendered paper, etc. are mostly enjoyed by the feudal ruling class. The cost is very high, and the quality is higher than ordinary paper.

During this period, works on papermaking also continued to appear. For example, Su Yijian's "Paper Book" of the Song Dynasty, Fei Zhu's "Paper Note Book" of the Yuan Dynasty, Wang Zongmu's "Chu Book" of the Ming Dynasty, and especially Song Yingxing's "Tiangong Kaiwu" of the Ming Dynasty, all have many records of ancient my country's papermaking technology. . The records about bamboo paper and leather paper in Volume 13 of "Tiangong Kaiwu" "Zhaqing" can be said to be a concluding narrative. The book also includes papermaking operation diagrams, which was the most detailed record of papermaking in the world at that time. After hundreds of years in the Yuan, Ming and Qing Dynasties, by the middle of the Qing Dynasty, my country's handmade papermaking had become quite developed, with advanced quality and a wide variety of varieties, which became the material conditions for the development and spread of the Chinese nation's culture over thousands of years.

The spread of papermaking

Papermaking was first introduced to Korea and Vietnam, which are adjacent to our country, and then to Japan. Shortly after Cai Lun improved papermaking, paper became available in Korea and Vietnam. Countries on the Korean Peninsula have successively learned the technology of papermaking. Pulp is mainly extracted from fibers in hemp, rattan, bamboo, and wheat straw. Around the end of the fourth century AD, Baekje learned to make paper with the help of the Chinese, and soon Goryeo and Silla also mastered papermaking technology. Since then, Goryeo's papermaking technology has continued to improve. By the Tang and Song Dynasties, Goryeo's vellum paper was exported to China. During the Western Jin Dynasty, the Vietnamese also mastered papermaking technology. In 610 AD, the Korean monk Tanzheng crossed the sea to Japan and dedicated his papermaking technology to the Japanese regent, Prince Shotoku. Prince Shotoku ordered it to be promoted nationwide. Later, the Japanese people called him the paper god.

Papermaking technology spread

China's papermaking technology also spread to some countries in Central Asia, and then reached India through trade.

Papermaking was misrepresented as having spread westward through the Battle of Talas. In fact, according to the records in Du You's "Jingxing Ji", there were no papermakers among the captured craftsmen. In recent years, Uzbek scholars have pointed out in their research that before the Talos War, papermaking technology was passed to Samarkand in a peaceful way through Kokand, the capital of Bahna. [3] In the 10th century, papermaking technology spread to Damascus in Syria, Cairo in Egypt, and Morocco. In the spread of papermaking, the contribution of the Arabs cannot be ignored.

Europeans learned about papermaking technology through the Arabs. The first European country to come into contact with paper and papermaking technology was Spain, which was once ruled by Arabs and Moors. In 1150 AD, the Arabs established Europe's first papermaking field in Sadiva, Spain. In 1276 AD, Italy's first papermaking factory was built in Montefaro to produce hemp paper. In 1348 AD, France established a papermaking field near Troyes, southeast of Paris. Since then, several paper mills have been established, so that France not only has a sufficient supply of domestic paper, but also exports to Germany. Germany did not have its own papermaking factory until the 14th century. Because Britain is separated from the European continent by a sea, papermaking technology was introduced relatively late, and it did not have its own paper mill until the 15th century. Sweden established the earliest paper mill in 1573, Denmark began papermaking in 1635, and the paper mill built in Oslo in 1690 was the earliest paper mill in Norway. By the 17th century, every major European country had its own papermaking industry.

After the Spanish immigrated to Mexico, they were the first to establish paper mills on the American continent. Papermaking in Mexico began in 1575. Before the United States became independent, the first paper mill was built near Philadelphia in 1690. By the 19th century, China's papermaking technology had spread to all countries on the five continents.

In order to solve the problem of poor paper quality in Europe, French Finance Minister Turgot once hoped to use Jesuit priests in Beijing to spy on China's papermaking technology.

During the Qianlong period, Chiang Youren, a French painter and Jesuit priest who worked for the Qing court, drew pictures of China's papermaking technology and sent them back to Paris. Only then did China's advanced papermaking technology spread widely in Europe. In 1797, Frenchman Nicolas-Louis Robert successfully invented a method of making paper using machines. Since the time of Cai Lun, the Chinese had been leading the papermaking technology for nearly 2,000 years and were finally surpassed by Europeans.

The invention and promotion of papermaking has had a profound impact on the spread of science and culture around the world, and plays a major role in the progress and development of society.

In response to the unhealthy trend that attempts to deny that Cai Lun is the inventor of papermaking and that China is the country that invented papermaking, the 20th International Papermaking History Association was held in Malmedy, Belgium, from August 18th to 22nd, 1990. The Congress unanimously recognized that Cai Lun was the great inventor of papermaking and that China was the country that invented papermaking. According to research by Comrade Shi Jianhou of the Luoyang Local History Chronicles Editorial Committee. Goushi is located in the outskirts of the ancient city of Han and Wei Dynasties in Luoyang (note in today's Book of Wei: "Zhishi" is "Fengshi"). The section of the Majian River that flows through Goushi was called the "Papermaking River" in ancient times, and the original "Papermaking River" along the bank "Stele Inscription" has been lost.)

In short, papermaking spread along the Tang Dynasty-Arab-Europe route.

Archaeological discoveries

Judging from the archaeological discoveries so far, papermaking was invented no later than the early Western Han Dynasty. The earliest ancient paper of the Western Han Dynasty unearthed was found in the ancient beacon pavilion in Luobu Nuoer, Xinjiang in 1933, and the date was no later than 49 BC.

The ancient paper unearthed in Baqiao, Xi'an City, Shaanxi Province in May 1957 was scientifically analyzed and identified as Western Han Dynasty hemp paper, dated to no later than 118 BC. In 1973, two pieces of hemp paper dating to no later than 52 BC were discovered in Shuijinguan, Juyanjian, Gansu Province. They were dark yellow and had a rough texture.

In 1978, three pieces of hemp paper from the period of Emperor Xuan of the Western Han Dynasty (73-49 BC) were unearthed in Zhongyan Village, Fufeng, Shaanxi; in 1979, five pieces of eight-piece beacons from the Western Han Dynasty were unearthed from the Maquanwan beacon site in Dunhuang County, Gansu. Katasai hemp paper. Fragments of paper maps from the period of Emperor Wen of the Western Han Dynasty (179 BC to 141 BC) were unearthed in Fangmatan, Tianshui, Gansu Province in 1986, indicating that the paper at that time could be used for writing and drawing. Judging from the quality of the above-mentioned paper unearthed in the Western Han Dynasty, the papermaking technology in the early Western Han Dynasty was basically mature.

Significance and Value

Papermaking - especially the papermaking technology improved by Cai Lun of the Eastern Han Dynasty (also known as "Caihou Paper"), is a revolution in writing materials. It is easy to carry and The materials are widely used and not rigid, which promotes the cultural development of China, Arabia, Europe and even the entire world.

After having text, the most important thing is to have a good carrier. The ancient Egyptians used papyrus from the Nile River to record history; in ancient Europe, people also used animal skins such as sheepskin to write text for a long time; and in China, before the invention of papermaking, oracle bones, bamboo slips and silk were used in ancient times. Materials for writing and recording. But oracle bones and bamboo slips were relatively heavy, and Qin Shihuang would need a whole cart just to read memorials. Although silk was light, it was very expensive and not suitable for writing. By the Han Dynasty, due to the rapid economic and cultural development of the Western Han Dynasty, oracle bones and bamboo slips could no longer meet the needs of development, which prompted the improvement of writing tools - paper was invented. Papermaking is an important chemical process. The invention of paper is a very valuable contribution made by China in the spread and development of human culture. It is a major achievement in Chinese history and has also had a profound impact on Chinese history. important impact.

The impact of papermaking

Chinese silk was also introduced to India. The earliest records are found in ancient Indian books. In the Indian politician and philosopher Kautilya's Arthashastra [4], there is a word cinapatta, which means "Chinese bundles of silk". ". Kautilya is said to have been born in the fourth century BC. He was a courtier of King Yue of the Mauryan Dynasty (the dynasty of Magadha in ancient India, founded in 321 BC and replaced by the Sunga Dynasty in about 187 BC). This shows that Chinese silk had been imported into India as late as the fourth century BC.

In addition, it can also be seen from many words in Sanskrit that the ancient Indian people had a much more accurate understanding of silk than the Greeks and Romans, because they knew that silk was spun by worms and that silk was drawn from cocoons (old n). .

Before silk was introduced to India, the ancient Indian people’s clothing materials were only cotton, wool, deerskin, etc. There may have been wild silk in ancient India, but until the Tang Dynasty, silk was rarely used. The introduction of Chinese silk added new clothing materials to the ancient Indian people. By the Song Dynasty, Indians near the trading ports between the two countries could already wear silk clothes. Of course, ancient China imported not only silk fabrics to India, but also raw silk. The Indians then dyed and woven the raw silk into damask and silk fabrics. Brocade, silk. Indian silk is as thin as cicada wings and extremely exquisite.

In addition to silk, paper and papermaking were also introduced to India from ancient China and had an important impact on Indian culture. In ancient India, writing materials sometimes used wooden boards and bamboo slices, and more often used bark and bay leaves. The word "birch bark" is often seen in Sanskrit classical works. It originally meant writing material. After the import of Chinese paper, people used this word to refer to paper, which shows the wide application of birch bark; Bay leaf is a kind of Palm leaves are large and long. Ancient Indians wrote and copied scriptures on the leaves[5]?. In the past, it was generally believed that paper was brought to India in South Asia by Muslims in the 12th century, but the actual situation is not necessarily the same. Since paper was introduced to the Western Regions and Central Asia in large quantities soon after Cai Lun's papermaking reform, and the people who used paper to write were not limited to the Han people, then from the Eastern Han Dynasty to the Northern and Southern Dynasties, the Indians who frequently moved here because of the spread of Buddhism may have something to do with India. The peoples of Central Asia must be exposed to and use paper, because paper is far superior to the bark and leaves of local traditional writing tools.

Papermaking Method

Ancient

Papermaking

Referring to the picture on the right, there were five main steps in papermaking in the Ming Dynasty. It can be seen from the picture that China's papermaking industry was already quite mature at that time. Experts in each process performed their duties and had developed some special tools for papermaking.

Cut bamboo and float it in the pond: Cut the bamboo and soak it in the pond to make the fiber fully absorb water. You can add bark, hemp heads, old fish nets and other plant materials and mash them. Cook over high heat: Boil the scraps until the fibers become pulp. In the picture, you can see that the broken materials in the large pot are pressed down with large stones to help them cook completely. Putting the material into the curtain: After the pulp has cooled, a flat bamboo curtain is used to pick up the pulp and filter the water to become a paper film. This step requires skillful skills in order to remove the paper film with moderate thickness and even distribution. Curtain-covering and pressing paper: Fold the scooped paper films one by one, press them tightly with wooden boards, and place heavy stones on them to press out the water. Fire drying: stick the semi-dry paper film next to the fire to dry, then peel it off to get the finished product.

Modern

Today's technology is advancing rapidly, and the modern papermaking process has been mechanized.

Groundwood Pulp uses mechanical grinding power to obtain wood fibers, also known as mechanical pulp. It can be further divided into general mechanical pulp, refined mechanical pulp, and thermal grinding machinery. Pulp etc.

Chemical Pulp uses chemical methods to separate fibers and lignin to obtain wood fiber. It can be further divided into soda pulp, sulfite pulp, sulfate pulp, etc.

Semichemical Pulp is a pulping method that combines mechanical and chemical methods, and can be further divided into neutral semi-chemical pulp, cold soda pulp, chemical mechanical pulp, etc.

Progress in methods

In the early years of the Western Han Dynasty, politics

Western Han Dynasty

was stable, ideological and cultural were very active, and the development of communication tools was Demand was strong, and paper emerged as a new writing material. Xu Shen wrote "Shuowen Jiezi", which was written in 100 AD. Talking about the origin of "paper". He said: "'Paper' is next to the tie, which is next to 'silk'." This sentence means that the paper at that time was mainly made of silk items, which was completely different from paper in the general sense. Xu Shen believed that paper was a thin piece of silk wadding left on the bed mat after being struck in water. This thin sheet may be the most primitive "paper", and some people call this "paper" "He Hoo".

This may be a prelude to the invention of paper. Records of this "paper" can be traced back to the first year of Yuanyan (12 BC) of Emperor Cheng of the Western Han Dynasty. "Hanshu: The Biography of Empress Zhao" records that the imperial concubine Cao Weineng gave birth to a prince and was persecuted by the empress Zhao Feiyan and her sisters. The poison they gave to Cao Weineng was wrapped in "He Ho" paper, and the "paper" said: "Grieve Weineng" , try to drink this medicine! You can't get it back, you know it!" It is speculated that paper may have a certain relationship with silk.

Cai Lun carefully summarized the experience of his predecessors. He believed that by expanding the sources of papermaking raw materials, improving papermaking technology, and improving paper quality, paper can be accepted by everyone. Cai Lun first used bark to make paper. Bark is a much richer raw material than hemp, which can greatly increase paper production. The lignin, pectin and protein contained in the bark are much higher than those of hemp, so degumming and pulping of the bark is more difficult than that of hemp. This prompted Cai Lun to improve papermaking technology. In the Western Han Dynasty, lime water was used to make pulp, and in the Eastern Han Dynasty, plant ash water was used to make pulp. Plant ash water is highly alkaline, which is beneficial to improving the quality of pulp. In the first year of Yuanxing (AD 105), Cai Lun presented a batch of high-quality paper he produced in Shangfang to Emperor Liu Zhao of the Han Dynasty. Emperor He of the Han Dynasty praised his talent and immediately ordered the world to adopt it. In this way, Cai Lun's papermaking method quickly spread throughout the country.

The "Han Dynasty Papermaking Process Flow Chart" vividly reproduces the papermaking technology of the Han Dynasty. Raw materials such as hemp and rags are soaked in water, chopped, washed, steamed, rinsed, pounded, and mixed with water. It forms a suspended slurry, scoops out the pulp, and becomes paper after drying.

Historical records: Emperor He of the Han Dynasty once visited Goushi, possibly to visit the papermaking workshop and paper village here (now divided into the former paper village and the back paper village, located about 2000 meters east of the ancient city of Han and Wei in Luoyang). meters, facing the Luo River) was probably the location of the papermaking workshop of the Han Dynasty. These two places have superior geographical environment for papermaking and relatively abundant papermaking resources (such as hemp, Chulin, etc.).

After Cai Lun donated paper, papermaking technology and paper became widely spread. At the end of the Eastern Han Dynasty, Zuo Bo from Donglai was also an expert in papermaking. The paper he made was whiter and more delicate than Cai Hou's paper. In "Sanfu Juelu" written by Zhao Qi, Zuo Bo's paper, Zhang Yi's pen, and Wei Dan's ink are mentioned as precious writing tools. The juxtaposition of pen, ink and paper shows that paper was a commonly used writing material at that time. Paper became a strong competitor to bamboo slips, wooden slips, and silk. By the third and fourth centuries, it basically replaced slips and silk as the only writing material, which effectively promoted the development of science and culture.

Ancient papermaking

Take bamboo paper as an example. "Tiangong Kaiwu" points out: before and after Mangzhong, climb the mountain to cut bamboo, cut it into five or seven feet long, and soak it in the pond for a while. After a hundred days of processing and beating, the rough shell and green skin are removed. Then use the best lime juice to slurry, put it in a barrel and cook it for eight days and nights, stop the fire for one day, take out the bamboo material, rinse it with clean water, and slurry it with firewood ash (plant ash water), then put it into the cauldron and cook it with ash. After being exposed to water for more than ten days, it will naturally become rotten. Take it out and put it into a mortar, pound it into a paste shape, and then pulp it to make paper. These records are roughly the same as the later folk methods of making bamboo paper.

Modern papermaking

Modern mechanical papermaking

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

1. Pulping

Pulping is the first step in papermaking. Generally, there are three methods to convert wood into pulp: mechanical pulping, chemical pulping and semi-chemical pulping. .

2. Preparation

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

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

3. Papermaking

The main work of the papermaking department is to uniformly interweave and dehydrate thin paper materials, and then dry, calender, roll, cut, sort, and package. Therefore, the common process is as follows:

a. Screening of paper stock

The prepared paper stock is then diluted to a lower concentration, and the debris and undissociated fiber bundles are screened out again through the screening equipment, so as to Maintain quality and protect equipment.

b. Mesh section

Let 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. Pressing section

The wet paper removed from the screen is introduced between two rollers with felt cloth, and the pressure of the rollers and the water absorption of the felt cloth are used. , further dehydrate the wet paper and make the paper tighter to improve the paper surface and increase its strength.

d. Drying section

Since the moisture content of the wet paper after pressing is still as high as 52-70, it is no longer possible to use mechanical force to remove moisture, so it is changed to The wet paper is dried by passing it over the surface of many cylinders that pass heated steam through them.

e. Calendering

f. Roll paper

g. Cutting, sorting, packaging

Take the front and roll it into There are many cylindrical paper rolls, which are cut into pieces of paper with a paper cutter. They are then manually or mechanically sorted to remove damaged or stained papers. Finally, every five hundred sheets are packed into a package (usually called a ream). ).

Modern Factory

After the wood for papermaking is sawn into appropriate sizes, the peeling process is carried out. The logs are put into a large drum. When the drum rotates, the logs rub against each other to remove the bark. The peeled bark will be used as fuel for the boiler. The peeled logs will be cut into square wood chips of 1.5 to 2 inches and 0.25 inches thick. Softwood chips and hardwood chips are different due to different physical properties. Need to be handled separately.

Wood is composed of small cell membrane fibers (cellulose fibers) bonded with a gelatinous substance called lignin. When making pulp, chemicals are used to cook the wood chips to decompose the lignin and separate the fibers. The chips are placed into huge containers called digesters, which function like kitchen pressure cookers. The chips and chemicals are cooked under pressure for 1.5 to 4 hours until they become a squishy mixture like oatmeal. , the separated fibers can be suspended in water. The mixture is washed to remove remaining chemicals and decomposed lignin and bleached to the appropriate whiteness. From here, the pulp passes through a series of refiners (refiners), which loosen the linear elements on the fiber walls in the pulp, making the surface rough and the fibers entangled with each other to form a sheet. Dyes and other additives are then added to give the finished paper the desired properties.

The pulp is added with water at a ratio of 20 parts water to 1 part fiber. It is passed through the forming fabric or wire of the paper machine. The fibers of the pulp are interlaced with each other to form paper and most of the water is removed. . Advancing at a high speed of 3,000 feet per minute, the paper passes through a series of absorbent cloths and steam-heated rollers called dryers to remove any moisture retained in the paper. The paper then goes through a coating process to add starch solution to both sides of the paper. The starch smoothes the surface of the paper and prevents the ink from melting when it is used for printing in the future. Since the coating process brings moisture, the paper needs to repeat the previous drying process. The dried paper is then polished by heavy and smooth rollers to make the surface smoother. The paper is collected at the rear and rolled into large paper rolls, and then divided into small paper rolls of suitable width. Some of the original rolls are packaged and shipped. Some are then processed and cut into flat sheets of appropriate sizes before being packaged and shipped.

Basic process of papermaking Process introduction:

Hydraulic pulper: The pulp plates are torn and rubbed against each other in the hydraulic pulper, thereby achieving the purpose of pulp disintegration.

Pulping: Beating causes the fibers to deform, swell, crush, cut, and become finely fibrillated. Through beating, the shape of the fibers can be changed, so that the pulp can obtain certain properties (such as mechanical strength and physical properties) to ensure that the paper and cardboard produced can achieve the expected quality requirements. Purification: The purpose of purification is to remove relatively large impurities in paper materials, such as metal shavings, cinders, etc. The principle of purification equipment is to use density differences to sort impurities. Commonly used equipment: conical slag remover.

Screening: The purpose is to remove impurities with low relative density and large volume in paper materials, such as pulp clumps, fiber bundles, grass clippings, etc.

Commonly used equipment: pressure screen.

Headbox: The headbox is a key part of modern paper machines. Its structure and properties have a decisive influence on the formation of the paper sheet and the quality of the paper.

Its main task:

It can effectively disperse fibers. The high-turbulence headbox can produce high-intensity micro-turbulence, which can effectively disperse fibers, prevent fiber sedimentation and flocculation, and effectively improve the strength of the paper sheet.

Distribute paper stock evenly along the transverse direction of the paper machine. (Determines the horizontal quantitative distribution of the paper web)

The spraying is stable and ensures that the pulp speed is coordinated with the web speed. (Determines the longitudinal quantitative distribution of the paper web)

Wire section: The pulp is dehydrated and formed in the wire section. The pulp concentration on the web is 0.1~1.2, the dryness of the paper sheet is 15~25 when exiting the roll, and the dryness of the formed paper is 90~95. It can be seen that the dehydration amount in the mesh accounts for more than 90% of the total dehydration amount.

Press section: Use mechanical pressing to further dehydrate and improve the dryness of the paper web. At the same time, the tightness and strength of the paper are increased, and the surface properties of the paper (such as smoothness) are improved. Mechanical pressing and dehydration is economically more cost-effective. The dryness of the press section of the paper machine is increased by 1 more. The steam consumption in the dryer cylinder department is reduced by 5. In this sense, the press section should remove as little moisture as possible. Using a new type of composite press, the dryness of the wet paper sheet coming out of the press section can reach 48~50.

The functions of the drying section:

1. Following the pressing section, it removes moisture from the wet paper and increases the dryness of the finished paper to 92~95.

2. Improve the strength of paper.

3. Increase the smoothness of the paper.

4. Complete the sizing of the paper.

Calendering: Calendering machine is used to improve the smoothness, gloss and thickness uniformity of paper.

Unwinding: Roll the paper out of the calender into a roll online.

Rewinding: The two sides of the roll rolled on the paper reel are not aligned, and the paper width is too wide. It must be cut and rerolled into roll paper or cut into flat paper crosswise.

Packaging: Roll the packaging paper with a basis weight of not less than 120g/square meter onto a roll paper to form an outer package.