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Mechanical pulping is the process in which wood is separated or defibrated mechanically into pulp for the paper industry. The mechanical pulping processes use wood in the form of logs or chips that are mechanically processes, by grinding stones (from logs) or in refiners (from chips), to separate the fibers.
Usually, the news items are printed onto newsprint. The whole production process can be divided into four parts: Content gathering, Pre-press, Press and Post-press. The term production process should not be confused with manufacture as Production process is the stage at which many taxes are levied and collected in almost all countries.
Old newsprint (ONP) Paperboard; Corrugated fiberboard; Recycled paper can be used to make paper of the same or lower quality than it was originally. The sorted paper is baled and shipped to a papermill. The pulpmill uses waste paper grade according to the paper quality they want to make.
Recycling one ton of newsprint saves about 1 ton of wood while recycling 1 ton of printing or copier paper saves slightly more than 2 tons of wood. [9] This is because kraft pulping requires twice as much wood since it removes lignin to produce higher quality fibres than mechanical pulping processes.
The first step in all mills using wood (trees) as the fiber source is to remove the bark. Bark contains relatively few usable fibers and darkens the pulp. The removed bark is burned, along with other unusable plant material, to generate steam to run the mill. Almost all wood is then chipped before being processed further in order to free the ...
The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper.
Today, even with the presence of modern tools and machines for papermaking, most processes still involve the traditional steps that Cai Lun employed, namely the process of soaking felted fiber sheets in water, draining the water, and then drying the fiber into thin sheets. [7]
Newsprint is a low-cost, non-archival paper consisting mainly of wood pulp and most commonly used to print newspapers and other publications and advertising material. Invented in 1844 by Charles Fenerty of Nova Scotia , Canada, it usually has an off white cast and distinctive feel.