Sökning: "chemical pulps"

Visar resultat 1 - 5 av 91 avhandlingar innehållade orden chemical pulps.

1. 1. The initial phase of the sodium bisulfite pulping of softwood dissolving pulp

   Författare :Raghu Deshpande; Ulf Germgård; Martin Ragnar; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; bisulfite pulping; cellulose; delignification; extractives; glucomannan; hemicelluloses; lignin; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

   Sammanfattning : The sulfite pulping process is today practised in only a small number of pulp mills around the globe and the number of sulfite mills that use sodium as the base (cation) is less than five. However, due to the increasing interest in the wood based biorefinery concept, the benefits of sulfite pulping and especially the sodium based variety, has recently gained a lot of interest. LÄS MER

3. 2. Activation of dissolving pulps prior to viscose preparation

   Författare :Niklas Kvarnlöf; Ulf Germgård; Leif J. Jönsson; Carl-Axel Söderlund; Herbert Sixta; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dissolving pulp; enzyme; reactivity; viscose; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

   Sammanfattning : The conventional viscose manufacturing process is a mature process that needs to be improved with respect to its environmental impact and its production cost structure. Therefore a research study has been done with the aim to improve the reactivity of the dissolving pulp used, in order to reduce the chemical demand in the viscose process and thus reduce the cost and indirectly the environmental impact. LÄS MER

4. 3. Some aspects on strength properties in paper composed of different pulps

   Författare :Hanna Karlsson; Luciano Beghello; Lars Nilsson; Lennart Stolpe; Øyvind Gregersen; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; paper strength; reinforcement; multilayer; stratified; handsheet former; abaca; southern pine; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

   Sammanfattning : For papermakers, an understanding of the development of strength properties in the paper is of uttermost importance. Strong papers are desirable both in the traditional paper industry as well as in new fields of application, such as fibre-based packaging and light-weight building material. LÄS MER

5. 4. Preparation and Characterization of Chemical Pulps from Wood and Reed Canary Grass

   Författare :Helena Håkansson; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; pulping; wood; reed canary grass; acid hydrolysis; microcrystalline cellulose; Chemical Engineering; Kemiteknik;

   Sammanfattning : This thesis presents laboratory results from ethanol pulping of reed canary grass for the production of paper pulp. The focus was on the influence of cooking pa-rameters on the delignification. The strength of the grass pulps was found to be low and the use of such pulps will therefore be limited to a few products. LÄS MER

7. 5. Chemical Modification of Electrospun Cellulose Nanofibers

   Författare :Johannes Thunberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose Dissolution; Ionic liquid; Polypyrrole; Zeolitic Imidazolate Framework; Nanocellulose; Electrospinning; Cellulose; Metal-organic Framework;

   Sammanfattning : The forest industry is a large part of the Swedish economy and the export of pulp, paper and wood products constitutes 11% of the total Swedish export of goods. The main product of a pulp mill is purified cellulose, which has many great properties like biodegradability and non-toxicity. LÄS MER