Pulp and paper industry Pulp and Paper Manufacturing Process in the paper industry Conclusion. References

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Pulp and paper production

Pulp and paper production.


  1. Pulp and paper industry

  2. Pulp and Paper Manufacturing Process in the paper industry

  3. Conclusion.

  4. References.

Pulp and paper industry.
The pulp is fed to a paper machine where it is formed as a paper web and the water is removed from it by pressing and drying.
Pressing the sheet removes the water by force. Once the water is forced from the sheet, a special kind of felt, which is not to be confused with the traditional one, is used to collect the water. Whereas, when making paper by hand, a blotter sheet is used instead.
Drying involves using air or heat to remove water from the paper sheets. In the earliest days of paper making, this was done by hanging the sheets like laundry. In more modern times, various forms of heated drying mechanisms are used. On the paper machine, the most common is the steam heated can dryer.[citation needed]
History of the paper industries

Papermaking as a craft is ancient, and for centuries it used various fibers, mainly grasses (cereal straws and others), or rags from old clothing made from them, in various preindustrial times and places. The commercial planting of domesticated mulberry trees to make pulp for papermaking is attested as early as the 6th century.[1] Due to advances in printing technology, the Chinese paper industry continued to grow under the Song dynasty to meet the rising demand for printed books. Demand for paper was also stimulated by the Song government, which needed a large supply of paper for printing paper money and exchange certificates.[2]

An example of an enterprising paper mill during the late phase of the preindustrial era is the mill by William Rittenhouse and sons at what is now preserved as Historic RittenhouseTown in Pennsylvania.
The first mechanised paper machine was installed at Frogmore Paper Mill, Apsley, Hertfordshire in 1803, followed by another in 1804.[3] The site operates currently as a museum.[4]
During the 19th and 20th centuries, the paper chemical technologies for making the pulp from wood rather than grasses underwent some major industrial-era upgrades, as first the soda pulping process and then the Kraft process helped reduce the unit cost of paper manufacture. This made paper newly abundant, and along with continual advancements in printing press technologies, as well as in transport technologies (for distribution), during these same centuries, led to greatly increased sales and circulation of newspapers, other periodicals, and books of every kind.
The pulp and paper industry has been criticized by environmental groups like the Natural Resources Defense Council for unsustainable deforestation and clearcutting of old-growth forest.[5] The industry trend is to expand globally to countries like Russia, China and Indonesia with low wages and low environmental oversight.[6] According to Greenpeace, farmers in Central America illegally rip up vast tracts of native forest for cattle and soybean production without any consequences,[7] and companies who buy timber from private land owners contribute to massive deforestation of the Amazon Rainforest.[8] On the other hand, the situation is quite different where forest growth has been on the increase for a number of years. It is estimated for instance that since 1990 forests have grown in Europe by 17 million hectares,[9] which has been supported through the practice of sustainable forest management by the industry. In Sweden, for every tree that is felled, two are planted.[10]
The pulp and paper industry consumes a significant amount of water and energy and produces wastewater with a high concentration of chemical oxygen demand (COD), among other contaminants.[11] Recent studies underline coagulation as an appropriate pre-treatment of pulp and paper industrial wastewater and as a cost-effective solution for the removal of COD and the reduction of pressures on the aquatic environment.[12]

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