Chemical pulp produced by cooking woodchips in a solution of calcium-, sodium- or magnesium-sulphite.
Paper pulp from wood chips and pressure-cooked in a solution of caustic soda and sodium sulphide. Also known as kraft. Sulphite pulp is produced from the wood of coniferous trees. Wood chips are cooked in calcium bisulphate or sodium sulphite, and bleached, producing fairly long strong fibres. Since the end of the 1860's until recent years, it has been the most widely used pulp in America. In fact, the term 'sulphite' has become generic and is still accurately used to describe any paper made from wood in distinction from papers made from cotton or other fibres. Sulphite pulp is available in a range of grades up to pure alpha cellulose.
Paper pulp made from wood chips and pressure-cooked in a solution of bisulphite of lime.
Paper pulp made from wood chips cooked under pressure in a solution of bi-sulphite of lime.
an acid pulp produced from chips reduced to their component parts by cooking a pressurized vessel using an acidic liquor. Sulphite pulp can be produced using various techniques to increase yield of pulp per tonne of raw fibre, to produce high-yield sulfite pulp (HYS) and high-yield sulphite pulp;
Chemical pulp where various sulphites or bisulphites are used as main cooking chemical
A chemical pulping process which involves cooking wood chips in a liquor containing sulphur dioxide, and calcium, magnesium, sodium or ammonium sulphite. It was the predominant chemical pulping process until overtaken by the kraft process in the 1930s. It now accounts for under 5% of the market. Although it produces a brighter pulp, with a higher yield, than kraft pulp, it is not as versatile as the kraft process, and the recovery of chemicals used in the sulphite process is more difficult.
Chemical pulp produced by cooking wood in a liquor containing sodium, magnesium, ammonium or calcium bisulphite; not produced in Finland (SAP is an exception)
Paper pulp made from wood chips cooked under pressure in a solution of sulfurous acid and one of its salts, (bisulphite of lime). The process has been modified to eliminate its previos high polluting effluent. Unbleached sulphite pulps are light brown and are easily bleached to a high white pulp by Oxygen bleaching.
Cooking by using calcium bisulphite and sulphurous acid for the dilignification of wood.
Chemical pulp produced with the sulphite process.
Paper made from wood pulps cooked in a bisulphite solution.