into the Mudanjiang Hengfeng Paper Co., LTD. (hereinafter referred to as "Hengfeng Paper") production workshop, the machine roaring, blue and white. Blue is the automatic paper making machine, white is the rapid rotation of white paper. There is not a drop of pulp in the entire production process.
Hengfeng paper production workshop. Photo by Su Jinggang/People's Daily Online
Hengfeng Paper, an old state-owned enterprise with a history of 71 years, is the first key high-tech enterprise in the paper industry recognized by the Ministry of Science and Technology and the Chinese Academy of Sciences. At present, there are 21 machine-made paper production lines, with an annual production capacity of 230,000 tons, mainly producing all kinds of cigarette paper, thin printing paper, household paper, food wrapping paper and other ten series of products. This year, Hengfeng Paper developed a 19g thin printing paper, the world's thinnest printing paper, and achieved mass production. The quantity of ordinary thin printing paper is between 28 grams and 45 grams per square meter, and this ultra-thin paper is only 19 grams per square meter.
19 grams of thin printing paper. Hengfeng paper supply picture
Just how thin is it? The thickness of cicada wings ranges from 0.2 mm to 0.35 mm. The thickness of a single page of 19 gram thin printing paper is only 0.025 mm. For example, a 2000-page book, with ordinary paper, the thickness of the whole book should be more than 7 centimeters, if you use this paper, the thickness is about 2 centimeters. Paper is thinner, pulp is used less, wood is lost less, and it is greener and more environmentally friendly. At present, the product is used in the printing of dictionary books of the Palace Museum and some foreign books.
In 2021, Hengfeng Paper successfully developed 22g thin printing paper, and now the research and development of new products has reduced the weight of paper from the original 22g to 19g, and the difficulty has been upgraded again. So how is the printing paper as thin as cicada wings made? Think back to cicada wings, thinness is accompanied by fragility and transparency. 19 g thin printing paper is only 0.025 mm thick, to be applied to double-sided multi-color printing, must have toughness and non-printing characteristics. Paper can have these characteristics, the key lies in the papermaking process. Papermaking is mainly divided into beating and papermaking links. Beating is to disperse wood raw materials evenly into water; Paper making is to dehydrate and dry the processed slurry to make paper. The R & D team experimented repeatedly in the process of beating and papermaking, analyzed the chemistry, elements and form of the paper through modern instruments, and formulated the scheme many times to determine the process.
"The product is thin and the opacity is difficult, so we tried to add a dye to make the paper a slightly blue color to give it a better opacity." Mudanjiang Hengfeng paper Co., Ltd. director engineer Liang Jie said.
Then the product entered the fully automated production line and encountered unexpected problems. Due to the faster production speed of machine-made paper, thinner paper passes through a fully automatic wheel, often the paper breaks and cannot enter the production process.
"We repeatedly made some process adjustments, and the workshop equipment was adjusted accordingly. After three trials, the final product was successfully produced." Liang Jie said. After a year of unremitting efforts, 19 grams of thin printing paper has been successfully developed, and now the product has crossed the ocean and gone to the world, representing the professional level of Chinese paper.
On the road of scientific and technological innovation, Hengfeng Paper continues to break through barriers and move forward all the way. Since 2003, Hengfeng Paper has undertaken more than 20 national and municipal science and technology projects in Heilongjiang Province, 13 kinds of new products such as "MHF cigarette paper" have passed the provincial appraisal, participated in the preparation and revision of 14 national or industry standards, won 9 provincial science and technology awards and new product awards, 10 provincial scientific and technological achievements, and 99 authorized patents. "In the past, customers made requirements, and enterprises passively researched and developed. Now it is gradually turning to lead customers through our research and development strength. only strong research and development ability can ensure that product quality is always ahead of the market." Liang Jie said.
Time has witnessed every step of papermaking technology exploration and leap. Hengfeng Paper industry uses science and technology to build up the high point of the business, constantly broaden the boundaries of its own exploration, and provide a powerful engine for development through intensive technology.
