Tissue Paper - Soft Technology

The toilet paper and tissue industry is a unique category of the paper industry. Many tissue paper manufacturers do not include themselves in the paper industry and consider themselves as consumer goods production companies. It is true that the success of tissue paper makers depends on their ability to combine the immediate benefits with the performance of the product, such as the softness, strength, appearance, and absorbability of paper, as well as its low cost.

However, because this industry is an industry popular with consumers, they cannot deny the fact that the papermaking process promotes the improvement of product quality. In recent years, the development of several technologies has helped manufacturers to improve product quality and meet consumer demand.

Through air drying process (ATD)

In recent years, the remarkable improvement in the production process of tissue paper has been the 40-year-old ATD process that continues to rejuvenate. In the past five years, the production capacity of penetrating gas drying equipment has increased by more than 49%. In mid-2000, more than 27% of domestic tissue paper machines installed in North America used penetrating gas drying technology. This is based on Valmet's paper machine manufacturer in Helsinki reported.

The traditional hygienic paper Yankee drying section is composed of a Yankee dryer and a hot air hood. The paper web spreads to the surface of the web and is drawn by the suction fan. With through-air drying technology, hot air is not drawn from the surface of the web, but passes through the web and passes through the cylinder blanket into the penetrating air drying cylinder. Some penetrating air-drying toilet paper machines use common Yankee-type dryers in combination with penetrating air dryers, and some use only penetrating air dryers.

The increasing use of penetration gas drying technology has resulted in improved product characteristics, reduced product quality differences, and reduced costs. According to Valmet's introduction, products produced using through-air drying have better absorbency than products that are generally dry-dried, with reduced quantitation. However, penetrating gas drying consumes a lot of energy, and because the quantitative reduction, the fiber is saved, and the energy consumption is also compensated.

VALMET: According to Valmet, in all of North America, all through-air dry toilet paper machines are supplied by Valmet, and more than 90% of the through-air dryers used in toilet paper machines are supplied by Valmet. Valmet's drying cylinder is a ductile iron three-layer shell structure and has 25 years of experience. Later technical developments were supported by Val-met's pilot plant for tissue paper in Karlstad, Sweden.

FLEISSNER: TAD technology gives living paper a soft, high bulk thickness advantage. This technology has been used in the United States for some time and has been developed in Europe and is expected to be transferred to Asia. This was introduced by Fleissner Gmbh & Cq, a mechanical manufacturing company in EgeIs-bach, Germany. Fleissner has completed a cooperation agreement with major paper machine manufacturers to provide a complete set of soft tissue paper equipment. Fleissner said it has provided more than 40,000 sets of TAD dryers to the world.

According to the company, high-tech Through-Air Dryers (HighTechThroughAirDryers) have the following benefits for tissue paper:

· Cylinder open area of ​​95%

·Cylinder air flow and temperature uniformity adjustment across the cylinder surface

· High water evaporation rate

·Production speed can be as high as 2200mpm, copy width up to 1000mm

. The diameter of the cylinder can reach 5400mm

TOSCHI: Another machine manufacturer is Of-flclne Meccaniche Toschi, who has formed a manufacturing partner and sells TAD toilet paper machines using the technology “plagiarism” transferred from Procter & Gamble, a global toilet paper machine manufacturer. . The agreement allows the sale of these paper machines worldwide. The design of a prototype workshop was just completed and a large paper machine was designed at the same time. This paper machine will have a variety of scales, and the width of the paper machine can reach 4 meters. Pto Corporation organized a group that transferred technology to the world to lead and manage this work in 1996. This is a new source of revenue and growth for the company.

Use different methods

Since TAD can produce very soft, bulky, high paper, its investment costs and high energy consumption should be taken into account, which was reminded by Voith Paper of Heidenheim, Germany. The company has developed a method that can replace TAD called "TissueFlex," which is said to increase the softness and bulk of the paper and is more economical. This process uses a shoe press on a Yankee dryer.

In January 2000, the first toilet paper machine using Industrial TissueFlex was successfully operated in the Americas. This is V. i Mountain Company reported. The equipment was installed in ComPanhia Melhora, Sao Paulo, Brazil. entosdeSacPaulo within MogidaoCruzes factory. Prior to installing the machine, two presses were installed on the machine's Yankee dryer and the speed was opened to 1600 mpm. With this new process, the same effect can be achieved with only one press on the Yankee dryer at the same speed. After TissueFlex was driven, the thickness of the paper was increased by 20% and the flexibility was greatly improved. The fiber savings are estimated at more than 5%.

New paper machine

In recent years, advanced tissue paper technology has emerged and several new paper machines have been created. For example, RecardSPA, a European tissue paper manufacturer, is installing a new paper machine at the Cartiera Partenope plant in Na Ples, Italy, which is estimated to have been installed by the end of 2000.

The plant will likely produce 140 tons of household paper per day. The plant has two pulp preparation lines, one for producing raw pulp and the other for producing waste pulp and mixing them together. The new paper machine is a CrescentFormer with a maximum speed of 1800mvm and a width of 3250mm. The paper machine has a high-efficiency hood with a 1040mm diameter vacuum press roll, a 750mm diameter blind hole press roll, and a Yankee dryer with a diameter of 5.4m. The paper machine is also equipped with 4 sets of 2500mm unwinding machines and one slitting and rewinding machine.

Secondary fiber market

As the tissue paper has been produced using recycled fibers, the recent development of technology has promoted them to use a higher proportion of waste paper production. This makes the waste paper recovery and stock preparation system more burdensome.

The secondary fiber system of a tissue mill must be able to work at higher concentrations and higher efficiencies. For example, ComerSpa, which supplies a complete secondary fiber processing system for paper mills, has developed a Cyberscreens line for screening recycled pulp and raw pulp under high concentration. These screening devices can remove plastics, stickies, and polyesters from secondary fibers as much as possible. This Corner screen, through its patented internal rotor, can provide higher throughput and screening efficiency. This type of screen uses a narrow slit width of 0.15mm and a 1.4mm diameter round aperture sieve, which can operate at a concentration of 3% to 4%.