Fully bleached sulfite chemical pulp, a process for the production thereof and products derived therefrom
AssigneeSCA Hygiene Products AB
InventorsArmin Reinhard, Andreas Geisenheiner, Othar Kordsachia, Rudolf Patt
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Abstract
A process for preparing a bleached sulfite chemical pulp includes delignification of chips of a lignocellulosic material in a sulfite pulping process until the defibration point of the material is reached, and bleaching of the fibrous material thus obtained by a chlorine-free bleaching sequence which includes at least one first bleaching step with a chlorine-free oxidant in the presence of a base. The chemical pulp prepared according to this process and paper or nonwoven made from such pulp have a high degree of brightness (at least 83% ISO) and high strength.
Claims22
A process for preparing bleached sulfite chemical pulp, comprising the following steps:
- delignifying chips of a lignocellulosic material in a sulfite pulping process until a defibration point of said lignocellulosic material is reached, and a fibrous material is obtained;
- and
- bleaching the fibrous material with a bleaching sequence which is performed exclusively with chlorine-free reagents and comprises at least a first bleaching step with a chlorine-free oxidant in the presence of a base.
A chemical pulp, obtainable by a sulfite pulping process and subsequent chlorine-free bleaching, wherein said chemical pulp has a degree of brightness of at least 83% ISO and a test sheet produced from said chemical pulp without beating has a strength, expressed as breaking length (measured according to Zellcheming V/12/57), of at least 6 km.
Dependencies are inferred from the claim text.