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Northern bleached softwood kraft (NBSK) is the paper industry's benchmark grade of pulp. Market NBSK is produced mainly in Canada and the Nordic countries. Some NBSK is also produced in north-western United States and in Russia. NBSK futures are traded on the Chicago Mercantile Exchange.
This pulp grade is very diverse. All NBSK pulps have long fibers and is often used as reinforcement pulp. [1]
NBSK from British Columbia is mainly from Lodgepole Pine, with a significant amount of White Spruce. Redcedar, douglas fir, hemlock, and larch make up a smaller portion of the chip furnish. NBSK is known for having longer fiber lengths and larger fiber diameter than anywhere else in the world due to very long growing season and mild climate.
NBSK from Siberia is made from pine, spruce and european larch and tend to be shorter and thinner than other NBSK pulps due to the short growing season. The larch makes up about 15% of the wood furnish and gives a rather coarse fiber that makes Siberian NBSK less desirable as reinforcement pulp.
The only single species NBSK is of plantation Radiata pine from New Zealand, Brazil and Chile. It has good brightness and cleanliness that is appreciated in printing and writing papers.
NBSK from Scandinavia is only from scots pine and norway spruce in the normal mix 7:3. The mix might vary much with the season as norway spruce grows on wetter lands that is easier accessed in the winter when the ground is frozen.
The most common use of NBSK is as reinforcement fibres when making paper or as raw material for kraft paper. It is also used in tissue paper.
Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material – a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or more broadly to include the same type of tissue elsewhere, such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, woodchips, or fiber.
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. It is designed for use in printing presses that employ a long web of paper, rather than individual sheets of paper.
Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine solid particles from liquids or gases.
Pulp is a fibrous lignocellulosic material prepared by chemically, semi-chemically or mechanically producing cellulosic fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemicals or plant-based additives, pulp is the major raw material used in papermaking and the industrial production of other paper products.
Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the structure of hardwoods lack resin canals, whereas softwoods lack pores.
Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper and has certain superior attributes such as foldability and rigidity. According to ISO standards, paperboard is a paper with a grammage above 250 g/m2, but there are exceptions. Paperboard can be single- or multi-ply.
Pulpwood can be defined as timber that is ground and processed into a fibrous pulp. It is a versatile natural resource commonly used for paper-making but also made into low-grade wood and used for chips, energy, pellets, and engineered products.
Kenaf [etymology: Persian], Hibiscus cannabinus, is a plant in the family Malvaceae also called Deccan hemp and Java jute. Hibiscus cannabinus is in the genus Hibiscus and is native to Africa, though its exact origin is unknown. The name also applies to the fibre obtained from this plant. Kenaf is one of the allied fibres of jute and shows similar characteristics.
A paper machine is an industrial machine which is used in the pulp and paper industry to create paper in large quantities at high speed. Modern paper-making machines are based on the principles of the Fourdrinier Machine, which uses a moving woven mesh to create a continuous paper web by filtering out the fibres held in a paper stock and producing a continuously moving wet mat of fibre. This is dried in the machine to produce a strong paper web.
The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na2S), 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. In some situations, the process has been controversial because kraft plants can release odorous products and in some situations produce substantial liquid wastes.
Abies grandis is a fir native to northwestern North America, occurring at altitudes of sea level to 1,700 metres (5,600 ft). It is a major constituent of the Grand Fir/Douglas Fir Ecoregion of the Cascade Range.
A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or fully chemical methods. The finished product may be either bleached or non-bleached, depending on the customer requirements.
Kraft paper or kraft is paper or paperboard (cardboard) produced from chemical pulp produced in the kraft process.
Cotton paper, also known as rag paper or rag stock paper, is made using cotton linters or cotton from used cloth (rags) as the primary material. Prior to the mid-19th century, cotton paper was the main form of paper produced, with pulp paper replacing cotton paper as the main paper material during the 19th century. Although pulp paper was cheaper to produce, its quality and durability is significantly lower. Although pulp-paper quality improved significantly over the 20th century, cotton paper continues to be more durable, and consequently important documents are often printed on cotton paper. Different grades of cotton paper can be produced.
The sulfite process produces wood pulp that is almost pure cellulose fibers by treating wood chips with solutions of sulfite and bisulfite ions. These chemicals cleave the bonds between the cellulose and lignin components of the lignocellulose. A variety of sulfite/bisulfite salts are used, including sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg2+), and ammonium (NH4+). The lignin is converted to lignosulfonates, which are soluble and can be separated from the cellulose fibers. For the production of cellulose, the sulfite process competes with the Kraft process which produces stronger fibers and is less environmentally costly.
Deinking is the industrial process of removing printing ink from paperfibers of recycled paper to make deinked pulp.
Fluff pulp is a type of chemical pulp made from long fibre softwoods. Important parameters for fluff pulp are bulk and water absorbency.
Southern bleached softwood kraft (SBSK) is a wood pulp mainly produced in the southern USA. The main raw materials are slash pine, longleaf pine, shortleaf pine, loblolly pine and virginia pine.
Bleached Chemi-ThermoMechanical Pulp (BCTMP) is a pulp product used by the paper industry as a less-expensive alternative for Northern Bleached Softwood Kraft (NBSK).
Mechanical pulping is the process in which wood is separated or defibrated mechanically into pulp for the paper industry.
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