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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 (Na 2 S), known as white ...
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.
A pulp mill in Rauma, Finland Woodchips for paper production. 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 (kraft and sulfite ...
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 ...
In 2005, elemental chlorine was used in 19–20% of kraft pulp production globally, down from over 90% in 1990. 75% of kraft pulp used ECF, with the remaining 5–6% using TCF. [31] Most TCF pulp is produced in Sweden and Finland for sale in Germany, [31] all markets with a high level of environmental awareness. In 1999, TCF pulp represented 25 ...
The TMP pulp discharged from the tertiary refiner is treated for latency removal, series screened, cleaned, thickened, and stored in two medium density storage tanks. Screened rejects are further refined, screened, and cleaned before storage. The unbleached TMP is recovered from storage and bleached to brightness levels in the bleach plant.
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.
More than 90% of the fluff pulps are fully bleached chemical softwood pulps, of which more than 90% are kraft pulps. The most common raw material source for fluff pulps are southern bleached softwood kraft from loblolly pine. SBSK from other species and NBSK are also used to make fluff pulp. [4] Thicker fibres are preferred to improve the bulk.