Search for dissertations about: "Softwood"

Showing result 16 - 20 of 149 swedish dissertations containing the word Softwood.

  2. 16. Characterization of cellulose pulps and the influence of their properties on the process and production of viscose and cellulose ethers

    Author : Peter Strunk; Bertil Eliasson; Roland Adden; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose ether; dissolving pulp; ethyl hydroxyethyl cellulose; hardwood; multivariate data analysis; reactivity; softwood; sulfate; sulfite; viscose;

    Abstract : Today’s market offers an ever-increasing range of cellulose pulps (derivative pulps) made fromvarious wood types through different delignification processes. Each pulp segment has its uniquecharacteristics, which makes it difficult for the producer of cellulose derivatives to choose the mostsuitable pulp for optimum processability and product quality. READ MORE

  4. 17. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

    Author : Urban Öjteg; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

    Abstract : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). READ MORE

  5. 18. The effects of fines content and hydrogen sulphide gas pre-treatment on kraft pulping and the strength of polysulphide pulps

    Author : Elisabet Brännvall; KTH; []
    Keywords : Bleachhability; Delignification; Fines; Hydrogen sulphide pre-treatment; Kraft pulping; Mechanical properties; Polysulphide; Softwood; Yield; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : .... READ MORE

  6. 19. Sulfur-free pulping with anthraquinone

    Author : Lina Håkansdotter; KTH; []
    Keywords : Anthraquinone; Blechavility; Carbohydrate; Degradation; Delignification; Softwood; Strength; Sulfur-free;

    Abstract : .... READ MORE

  7. 20. Carbohydrate degradation and dissolution during Kraft cooking : Modelling of kinetic results

    Author : Dan Johansson; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kraft cooking; softwood; hardwood; cellulose; xylan; glucomannan; degradation; dissolution; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

    Abstract : Chemical pulp fibres from wood are commonly used in products associated with packaging as well as with printing and writing. The prevalent way of liberating fibres is by subjecting wood chips to Kraft cooking. This process has a history of almost 130 years and should be both well described and well established. READ MORE