1 current development trend of super-calendered paper at home and abroad 1.1 super calendar paper supercalendered paper (Supercal ender Paper) referred to as SC paper, also known as magazine paper (MagazinePaper) in Europe is a kind of mechanical pulp-based non-coated Fabric printing paper, quantified 40-65g/m2, quality between newsprint and traditional lightweight coated paper (LWC). SC paper is characterized by a high filler content, typically 20% to 30%. The paper sheet is supercalendered and has a high degree of smoothness and gloss. The difference between SC paper and LWC paper is mainly that the filler of SC paper is distributed in the whole slurry, while the pigment of LWC paper is mostly concentrated on the surface of the paper sheet, and under the same ash content, the glossiness of LWC paper is higher. SC paper and LWC paper are high value-added printing papers containing machine pulp, which can be used for gravure printing and offset printing. They are widely used in magazines, advertisements, catalogues, samples, pocket booklets, and newspaper color inserts. SC paper is further divided into SC-A, SC-B, and SCC grades. In addition, depending on the slurry ratio and the different configurations of the supercalendering equipment, there are SC-A+ and SC-B+.
In the past decade or so, SC papers have developed rapidly worldwide (mainly in Europe and North America). The average annual increase rate of production for the 10 years was 11.5%. It was the fastest growing type of printing paper including coated paper and lightweight coated paper, while the growth rate of newsprint over the same period was only 1.5%. The development of SC paper in the past two years has shown strong momentum in Western Europe. It is reported that in 2000, the consumption of SC paper in Western Europe increased by nearly 7%, and the price showed a rising trend. In France, due to the shortage of LWC paper and its high price, the SC paper was brought to the market. Users of LWC paper turned to purchase SC paper and even SC-B paper. The demand for French SC paper in 2 years increased by more than 10%. The rate is above 6%, while the United Kingdom is up to 15%. The most noteworthy development is the use of SC offset paper as an alternative to LWC offset printing paper. The goal of SC paper development is to achieve high quality to achieve or completely catch up with LWC paper.
In recent years, great progress has been made in the development of high-speed wire-folding paper machine technology, dilution water headboxes, new vertical wire mesh formers, fully enclosed straight-pass presses with shoe presses, single-row dryers, and central drives. The use of reel machines, soft-roller supercalenders, and corresponding quality control systems and various chemical auxiliaries increase the speed of the paper machine, increase the amount of paper filler, improve the smoothness of the paper sheet, reduce the difference between the two sides, and produce Consistent high-quality, high-quality SC paper with good printability has created good conditions, and in particular, soft roll overpressure technology has made revolutionary progress, which is particularly important for the production of SC paper. The traditional super calender speed limit is within 800m/min, while the new generation of soft roller overpressure speed can be more than 1500m/min. At present, the use of overpressure in high speed paper machine has become a reality. The production cost of SC paper is lower than that of LWC paper. It has been reported that SC-A paper produced by a paper mill in North America has whiteness, opacity, printability, etc., comparable to LWC paper, and its production cost is 15% lower than that of LWC paper. 20%. High-quality, low-cost SC papers have attracted great interest from paper suppliers. In Europe and North America, high-speed large-scale SC paper machines have been launched, and some uncompetitive news paper machines have been converted to produce SC paper. According to incomplete statistics, from 1998 to 2002, the new SC paper production capacity in North America and Europe was close to 2 million tons, an average annual increase of 4%. The Fujian Longyan Supercalendered Paper Mill, which was established in China during the 8th Five-Year Plan, was completed and put into operation in the “Ninth Five-Year Plan” period. However, due to lack of funds, the plant does not yet have the conditions to produce SC paper. So far, no such products have been available in China. .
1.2 SC Paper Quality Requirements According to the printing requirements, SC paper is divided into gravure printing paper and offset printing paper. Gravure printing requires the paper sheet to have high smoothness, dense surface, low ink absorption and good opacity. Offset printing requires high surface strength in addition to good printability. SC-A can be used for gravure and offset printing, and SC-B is suitable for offset printing. In recent years, there have been higher-grade SC-A+ papers, with a whiteness of 75% and glossiness of >55%, and its quality is comparable to LWC paper.
1.3 Main Technical Features of SC Paper Fiber ratio of SC paper. Traditional SC paper is made from 70%-80% bleached groundwood pulp (SGW) or bleached thermomechanical pulp (TMP) with 20%-30% softwood bleached kraft pulp (NBKP). The more manufacturers are equipped with bleached deinked pulp (DIP) to produce SC paper, with the amount exceeding 30%, and there is a tendency of increasing year by year. Germany in 1999 Lang PaPier production machine # 5 75% DIP, 25% SGW, 5% BKP papermaking SC paper, which is the vehicle speed is 1400-1600m / min, divided into 28% ashes, the printing surface roughness (SIO) <1.2 Pm, gloss (45°) > 45%, quality close to SC-A (SC-B+) standard. Schongau Paper Mill #9, which was put into operation in 2000, produces 100% DIP paper at a speed of over 1500m/min. DIP generally uses old newspapers and old magazine papers, both mechanical and chemical pulps, but also retains high-quality fillers and fine fibers in magazine papers. This is exactly the pulp ingredients required to make high quality SC paper.
The filler content of SC paper is about 25% in the 1980s, and it is currently up to 35%. The filler is generally made of clay or talc. In recent years, some paper mills use precipitated calcium carbonate (PCC) to improve the whiteness of paper and not Transparency, it is reported that the Finnish Myllykoski paper mill uses PCC to produce a new SC paper, named M-PluS, which promotes standard SC paper very close to LWC paper (Table 6 is abbreviated). The standard LWC web price is about 20% higher than conventional SC paper. In comparison, LWC paper has higher production cost and lower production efficiency. Now Myllykoski can produce SC with higher whiteness and opacity than LWC. Paper, and the price is 10% lower than LWC. In addition, the bulk of the paper is about 10% higher than LWC. It is believed that low cost, high brightness, high bulk SC paper will be more attractive. SC paper is a high-tech paper grade, and it is necessary to add effective chemical additives in the slurry. In this regard, the China Pulp and Paper Research Institute has conducted some research work and achieved certain results. SC paper filler content is high, can save a lot of fiber raw materials, China's rich talcum powder resources, low prices, combined with the use of waste paper as fiber raw materials to produce high value SC paper, the economic benefits are obvious. At present, vast areas of China are returning farmland to forests, planting poplar, and using APMP to copy SC paper is also a good choice.
1.4 Equipment Features for SC Paper Production SC paper requires good sheet formation and a small difference between the two sides. The paper sheets, fillers, and fine fibers copied from ordinary Fourdrinier paper machines have a large gap between the two sides of the paper web in the Z direction. Therefore, it is not suitable for high-quality SC paper with high papermaking filler content. Interfolding formers have been updated for several generations and have now been developed into a new generation of vertical insert forming machines using a combination of vacuum forming rolls and dewatering boards, including Valmet's OptiFomer and Voith's TQV formers. The common feature is that the pulp stream discharged from the headbox is first depressurized by a forming roll and then dehydrated by entering the wiper area, which integrates the Gapblade formers and roll clamps. The advantages of the Gaproll formers are both improved retention and improved sheet formation. When producing SC paper with higher filler content (above SC-B grade), only pulse dewatering and shearing need to be moderated in the area of ​​the wiper board. Generally no reverse pressurization dewatering plate is provided to avoid damaging the slurry forming on the forming roll. The surface layer. The difference between the two sides of the paper sheet made by the inserting net shaper is very small, and the Z direction of the filler is distributed on both sides of the sheet, which is exactly what SC paper needs.
Pressing forms have a great influence on the two sides of the paper sheet. SC paper, especially SC-A paper, not only requires the same smoothness on both sides, but also requires the same ink-absorbing performance. From the current trend, two straight-through full-closed presses (a Boot pressure or two shoe pressures are the best choices. They not only solve the problem of both sides of the sheet, but also solve the problem of the open-type press threading caused by the decrease of wet strength due to the increase of the amount of filler. It is particularly important when the speed of the vehicle exceeds 1500m/min. SC paper pressure finishing, in the past with the main external pressure, in recent years due to the advent of a new generation of soft roller super calender, the development trend is to use the internal pressure. Voith's Janus MKZ and Vabet's Optiload have already invested in actual production and operations around the world. The speed has exceeded 1500m/mn. If overpressure is used outside the machine, not only does the investment increase exponentially, but also the operating costs are high. It is reported that the annual operating cost of the overpressure in the machine is only 72% of the overpressure of the machine. However, if an SC paper with a particularly high degree of smoothness is produced, for example, the #11 paper machine produced by the Laakirchen paper mill in Austria produces SC-A+ grade paper, External overpressure.
2 Selection of Process Equipment for Ishigaki Newsprint Project The main equipment for the Ishigaki newsprint project was introduced from September to October 2000. Finally, Valmet and other companies in Finland won the bid. Before this, Shiqi Paper Company had organized a delegation to study abroad and conducted a survey on the domestic paper market, and had a clear understanding of the selection and configuration of the paper machine production line equipment for this project.
2.l Project Background In recent years, the production and consumption of newsprint in China have grown rapidly. In 1995, the production volume was 790,000 tons, and the consumption was 850,000 tons. In 1999, the production volume was 1.13 million tons, and the consumption was 1.46 million tons, with an average annual growth. The rates were 9.4% and 14.4% respectively, and the increase in consumption greatly exceeded the increase in production. Consumption in 2005 may exceed the forecast of 2.4 million tons. The current domestic newsprint production capacity plus several major newsprint projects newly launched in the past two years, it is expected that by 2005, the domestic newsprint production capacity will also exceed 2.4 million tons, that is, the basic balance between supply and demand in the newsprint market. According to customs statistics, 249,600 tons of newsprint was imported in 1999 (in 1998, 236,000 tons). As China's entry into WTO (WTO) accelerates the global economic integration process, newsprint will still maintain a certain amount of imports, and manufacturers will face fierce competition. Market competition. China's production of newsprint requires a shortage of wood resources. Many paper mills, including the newly launched papermaking projects, have turned to waste paper, which uses waste paper as a secondary raw material to produce newsprint. The raw materials mainly depend on imports. The Shijie project is no exception. The original plan and newsprint project support The APMP project was also changed to a deinking pulp project.
In recent years, China’s waste paper imports have increased rapidly. In 1998, it was 1.92 million tons, an increase of 18.3% over the previous year; in 1999, it reached 2.52 million tons, an increase of 31.4%, mainly from the United States. In 1999, the United States exported 7.72 million tons of various waste paper. China’s imports account for about one-third of its exports. As the import volume of production waste paper under construction projects during the “10th Five-Year Plan” will increase by a large margin, the price of waste paper may increase. Compared with the developed coastal areas, the freight rate of waste paper raw materials in Shiji Paper mill is relatively high, which is a disadvantage of this project in cost competition. In this situation, the introduction of equipment for the Shiqi project will have to consider the production of high-quality newsprint, as well as the production of high-value-added papers, in order to strengthen the market's resilience.
2.2 Determination of Production Varieties There are two trains of thought in the selection of production varieties for this project. First, the soft roll calender in the paper machine is replaced with a soft roll super calender, and the path to develop SC paper is followed. The other is on paper. The addition of metered size presses to produce surface sizing newsprints has led to the development of film coated offset (FCO) papers. SC paper and FCO paper are promising types of paper. Due to the limited funds, it is impossible for the Ishigaki project to introduce both equipment. After going abroad for inspection and analysis of the market, a clearer understanding was obtained. In recent years, the production of light coated paper in China is in the ascendant and has developed rapidly. According to incomplete statistics, the national production capacity including all-chemical pulp light-coated paper is about 350,000 t/a. With the light-coated paper projects currently in operation, the total production capacity will exceed 800,000 t/year by 2005. a. It does not include the capacity of foreign-funded plant Changshu Asia Pacific with a total capacity of 350,000 t/a. Due to the high costs and problems, the consumption of light coated paper in China was less than 200,000 tons in 1999. The optimistic forecast is that the demand in 2005 will be only about 700,000 tons (accounting for 2.8 million tons/year of total coated paper demand). 25%), the production capacity exceeds the consumption demand. If the stone paper machine uses the size press device, it is estimated that it can only be used as the surface treatment of the modified newsprint for several years. On the other hand, the demand for printing paper in China's books and periodicals is rapidly growing. In 2000, the output was 2.9 million tons, and the demand was 3.3 million tons. The forecasted production volume in 2005 was 3.6 million tons, the demand was 4.8 million tons, and the gap was 1.2 million tons.
However, most existing book printing and printing papers mainly consist of straw pulp, including letterpress paper, offset book paper, offset paper, and so on. More than 50% of them do not meet the needs of low-quantitative, colorful, and high-speed offset printing in the printing industry. Therefore, both the quantity and the quality of books and publications cannot meet the requirements of development.

Dermal Filler

Dermal Filler,Voluma Derm Filler,Hyaluronate Acid Dermal Filler,Injectable Dermal Filler

Shijiazhuang Asa Technology Co., Ltd. , https://www.hskinlift.com