The latest papermaking technology and its trend 0

New paper-making technology and its trends

I. background of developing new paper-making technology and packaging materials

the total output of paper and paperboard in Asia reached more than 100 million tons in 2002. However, due to the large population (about 2.4 billion), the average paper consumption per person is only 41.8 kg, including 242 kg in Japan, 33 kg in China and 5.6 kg in India

the annual growth rate of paper and paperboard consumption has reached 3.1%, especially in Asia and South America. On the one hand, the demand for pulp is in a downturn, on the other hand, recycled paper is widely used all over the world. In terms of varieties, printing paper, packaging paper and paperboard account for a high proportion in paper consumption. Nationwide, the provinces that produced more than 1million tons of paper and board in 2003 include Shandong, Zhejiang, Guangdong, Henan, Jiangsu, Hebei, Fujian, Hunan and Sichuan; The total output of paper and board has reached 34.02 million tons, accounting for 83% of the total output of paper and board in China

in 2003, the output of paper and paperboard in 12 provinces (autonomous regions) and cities in eastern China accounted for 72.5% of the national paperboard output, an increase of 0.5% over the previous year,; The proportion of 9 provinces (districts) in the central region is 21.8%; 0.2% lower than the previous year; The proportion of nine provinces (autonomous regions) and cities in the western region is 5.7%, a decrease of 0.3% over the previous year. Judging from the completion of the output of paper and paperboard across the country and the changes in the layout of papermaking areas, the production concentration has become higher and higher. As the three major paper industry clusters in China, the eastern region has become the main production base of China's paper industry

the paper industry has become a pillar industry in Guangdong, Zhejiang, Jiangsu, Shandong and other provinces, which are located in the three major paper industry clusters in China - the Pearl River Delta cluster, the Yangtze River Delta cluster and the Bohai Rim cluster. The paper industry has developed rapidly and its production capacity has expanded sharply. Some provinces are not satisfied with this. For example, Guangdong plans to build a papermaking base, with a production capacity of 10million tons, and Guangdong will control one third of the national industry. In this regard, some experts are worried that the continuous increase of production capacity will inevitably lead to strong competition for limited water, raw materials and other resources in the cluster. This should be paid enough attention by the industry. Because all kinds of signs show that the shortage of resources has blocked the industrial clusters, and the resource crisis is approaching the paper industry cluster

while industrial clusters play an important role in the large-scale and modern development of China's paper industry, a phenomenon that cannot be ignored also surfaced, that is, the formation of an adverse situation of resource shortage. The resource crisis is urgent, and the paper industry cluster. In the past two years, due to the rapid growth of the paper industry and the limited raw material resources of wheat straw, the price of wheat straw in Shandong Province almost doubled in 2003, reaching more than 600 yuan per ton. What makes enterprises complain is that wheat straw is of poor quality, high moisture content and many impurities. Many enterprises in Shandong have to buy wheat straw in large quantities in neighboring provinces of Jiangsu, Anhui, Henan and Hebei, and even reed in the northeast, which increases costs and affects the economic benefits of the industry

China's forest area only accounts for 3.9% of the world, the forest volume is less than 3% of the world's total volume, and the forest coverage rate is 13.92%. The per capita forest area and per capita volume are lower than the world average level, ranking 120th and 121st in the world respectively, and the forest coverage rate is 142. China imports a large amount of wood and its products every year to meet the needs of the market. However, it is not a long-term strategy to solve the shortage of China's total demand by importing forest products. First, the national economic strength is not strong enough to spend tens of billions of foreign exchange every year to import forest products; Second, the international timber market is unpredictable, and relying on imports will put China in a very passive situation

secondly, because some tree species are vulnerable to diseases and pests, as packaging materials, they are subject to processing conditions and processes, and the cost is too high in import trade. Thirdly, a large number of logging undoubtedly caused adverse effects on the environment, and we also visited several neighbors of our experimental machine factory. At the same time, afforestation and the rate of forest formation are far from meeting the market demand for wood. Therefore, it is necessary to develop and utilize other green materials as soon as possible to replace papermaking raw materials and wood packaging materials. It is worth noting that for the development of Chinese Mainland, its forest paper integration policy is being implemented and promoted, which will increase the forest coverage, which is currently only 16% (36% in Europe), and is used as pulping raw materials. Its non wood (bamboo, grass) output in 2002 was 11million tons, which is the highest in the world. The papermaking technology in this area is also leading the world

II. New papermaking technology

(I) banana tree papermaking method

Japan's national chemical laboratory has invented a method of making pulp with bagasse and banana, which can replace the method of making paper with wood pulp. It is a technology of making high strength paper. Paper making method is to boil trees and other paper making materials in sodium sulfide and sodium hydroxide, and then bleach them in bleach, producing a strong smell and a large amount of bleaching waste. The new paper making method does not need to go through bleaching, and the waste can be treated by the recycling process to prevent pollution. This paper-making method has low production cost and is most suitable for small-scale paper mills

the key of this technology is to treat banana fiber as smooth as cotton. The specific method is as follows: peel the banana peel, dehydrate it with the press used to make sucrose, and then ferment it. The opener used in the production of cotton, hemp and other fibers can be used for the textile of banana fibers after some modification. The banana cloth made in this way feels like hemp and can be used to make food packaging bags

(II) Acetobacter fiber papermaking method

Acetobacter fiber is used as papermaking raw material, which avoids the pulping process of general plant fiber due to its high cellulose purity. In Japan's paper industry, the addition of Acetobacter cellulose to pulp can improve the strength and durability of paper, and solve the problem of the decline in the strength of paper fiber after the recycling of waste paper. Adding Acetobacter fiber to ordinary pulp can produce high-quality special paper. For example, ajjnomoto company and Mitsubishi company jointly develop super grade paper for currency manufacturing, which has good printing quality, water resistance and high strength. Advanced writing paper with bacterial fiber has good ink absorption uniformity and adhesion. After mechanical homogenization, the gel fiber is mixed with various incompatible organic and inorganic powders and fiber materials to produce diaphragms, non-woven fabrics and papers with different shapes and uses. It is very solid, and makes full use of the extremely strong winding and bonding ability and tensile strength of nano microfiber to objects. When making carbon fiber board for filtering and adsorbing toxic gases, adding Acetobacter cellulose can improve the adsorption capacity of carbon fiber and reduce the leakage of filler in paper

(III) new materials to replace wood

1. Straw is the main material, combined with polymer chemical raw materials such as PP, PVC and other auxiliary materials, processed into various products with modern industrial equipment. Compared with traditional raw materials, the products are highly waterproof, fireproof, mothproof, acid proof, surface abrasion resistant, non chemical reaction, non radioactive, easy to clean, anti-aging, non fragile, light weight, high strength, excellent environmental adaptability, etc. The process adopts low foaming, cross-linking or nano technology. In addition to the product pattern color can be formed from the finished product in one time with its own unique characteristics, post-processing surface type and built-in coating can also be used. Because the physical properties of the raw materials themselves are not easy to oxidize, the colors of the coating are colorfast, aging resistant, uniform, non falling off, rich in color, fresh in beauty, and can meet the psychological needs of consumers of different grades

2. Grass + plastic = wood

a factory in Kansas, USA, made a new kind of wood from wheat stalks, plastic fragments, old newspapers and a little wood. At present, it has replaced wood and has been used to make electric poles. In the future, it will also be used to make railway sleepers, decks, railings, doors and windows. With this kind of biosynthetic wood, the number of trees felled can be reduced, and the cost can also be reduced. This kind of wood has another advantage, it will not bend or crack like common wood, and because of the addition of different colors of plastic, it is different in paint. This kind of wood can also be cut like ordinary wood and made into different shapes

different proportions of plant fiber and plastic can be made into different kinds of wood. If more fiber and less plastic are used, they can be made into lighter varieties with greater softness, 50% to 90% greater bearing capacity than some wood, longer service life, and will not deteriorate due to ultraviolet light; If you want to make strong wood for waterproof or outdoor use, you should use more plastic and less fiber

(IV) nanostructured surface paper

the Institute of nanoscience and technology of central China Normal University (Wuhan) has developed a new type of superhydrophobic, self-cleaning nanostructured surface paper, which uses nano dispersion technology to divide the organic mother liquor into micron sized "islands", and inorganic nanoparticles are evenly dispersed in the "islands", forming a superhydrophobic lotus like structure. According to relevant parties, this kind of nano paper has prepared a layer of nanostructured film on the surface of ordinary paper. In addition to the functions of ordinary paper, it also has excellent properties such as super hydrophobic, self-cleaning, moisture-proof, aging resistance, soft optical fiber, low water absorption, low elasticity, high printing surface strength, and simple process, low cost, and easy industrialization. This product is the first in China, and its increased cost is only about 10% of the cost of ordinary paper. Therefore, it has a broad market prospect

(V) paper cans (bottles) inject vitality into the packaging industry

1. Paper cans

Japanese relief printing company developed and invented a new type of paper can packaging that can maintain a high degree of sealing and sterilization, and its food preservation ability is no less than that of metal cans. Practice has proved that at room temperature, the food in the can will not deteriorate for at least one year

the main characteristics of this paper can are: lighter than iron cans and glass bottles; It can be filled at high temperature. Due to the edge protection of aluminum foil packaging, the penetration of oxygen is reduced, so the shelf life of circulation at room temperature can reach more than one year; The tank body material is made of paper, aluminum, polyethylene, polyester (PET) and other composite materials, which ensures the strength of the tank body and can be directly circulated in the original shape of the tank. Therefore, like the traditional round tank, it can be used by the automatic sales machine, which is convenient for recycling and processing, can be burned and pollution-free. At present, this kind of packaging paper can is used for the packaging of beer, fruit juice and other beverages, and has been well received. The paper can is designed into a concave shape on the side of the can, which increases the strength of the can and will not produce a deflated can

at present, the annual consumption of aluminum cans in China is 6 ~ 7billion. Raw materials need to be imported in large quantities, and the price is expensive. Coupled with environmental pollution and other factors, the state no longer approves the construction of new aluminum cans production lines. Whether to find a new packaging container to replace aluminum cans has become a concern of the industry. The birth of paper cans has overcome the disadvantages of aluminum cans and has broad prospects for development. According to experts, it takes at least 17million yuan to build an aluminum cans production line, while only 2million yuan to build a paper cans production line; The minimum batch of aluminum cans is 20million, and the economic batch of paper cans is more than 20000

2. Making paper bottles from waste paper

Kao Corporation of Japan recently developed a new paper bottle that can be sealed with a metal bottle cap, which the current cartons cannot do today. The company said that with this new technology, paper bottles of various shapes can be made. This brand-new paper bottle is made of three layers of materials, the middle layer is pulp, and the bottom and surface are covered by paper shoes of another texture

"the hardness of waste paper bottle is not the same as that of plastic bottle