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The Kappa number is determined by ISO 302:2004. [1] ISO 302 is applicable to all kinds of chemical and semi-chemical pulps and gives a Kappa number in the range of 1–100. . The Kappa number is a measurement of standard potassium permanganate solution that the pulp will consu
the Kappa number, indicating lignin content in pulp; represents: the Von Kármán constant, describing the velocity profile of turbulent flow; the kappa curve, a two-dimensional algebraic curve; the condition number of a matrix in numerical analysis; the connectivity of a graph in graph theory; curvature
In set theory, kappa is often used to denote an ordinal that is also a cardinal. Chemistry. In chemistry, kappa is used to denote the denticity of the compound. In pulping, the kappa number represents the amount of an oxidizing agent required for bleaching a pulp.
Hexenuronic acid decreases a wood's kappa number, which is a measure of bleachability of wood pulp, by 3-7. [3] It readily reacts with common wood pulp bleaching agents like ozone, peracetic acid, and chlorine dioxide.
The lignin is degraded and becomes more watersoluble and thereby more easy to wash away from the pulp, while the anthraquinone is regenerated. This process gives an increase in yield of pulp, typically 1–3% and a reduction in kappa number. [8]
As potassium permanganate is titrated, the solution becomes a light shade of purple, which darkens as excess of the titrant is added to the solution. In a related way, it is used as a reagent to determine the Kappa number of wood pulp. For the standardization of KMnO 4 solutions, reduction by oxalic acid is often used. [47]
Kraft pulp is darker than other wood pulps, but it can be bleached to make very white pulp. Fully bleached kraft pulp is used to make high-quality paper where strength, whiteness, and resistance to yellowing are important. The kraft process can use a wider range of fiber sources than most other pulping processes.
Dissolving pulp is mainly produced chemically from pulpwood in a process that has a low yield (30 - 35% of the wood). This makes up of about 85 - 88% of the production. [2] Dissolving pulp is made from the sulfite process or the kraft process with an acid prehydrolysis step to remove hemicelluloses. For the highest quality, it should be derived ...