Search for dissertations about: "cellulose fibres"

Showing result 1 - 5 of 123 swedish dissertations containing the words cellulose fibres.

  2. 1. Microfibrillated cellulose : Energy-efficient preparation techniques and key properties

    Author : Mikael Ankerfors; Lars Wågberg; Minna Hakkarainen; Paul Gatenholm; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microfibrillated cellulose; microfibrillar cellulose; nanofibrillated cellulose nanofibrillar cellulose; nanocellulose; MFC; NFC; production techniques; energy efficient; gel properties; films; enzymes; carboxymethylation; carboxymethyl cellulose; CMC; mechanical properties; oxygen barrier; homogenization;

    Abstract : This work describes three alternative processes for producing microfibrillated cellulose (MFC) in which pulp fibres are first pre-treated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated with a combined enzymatic and mechanical pre-treatment. READ MORE

  4. 2. Microfibrillated cellulose: Energy-efficient preparation techniques and applications in paper

    Author : Mikael Ankerfors; Lars Wågberg; Akira Isogai; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Microfibrillated cellulose; microfibrillar cellulose; nanofibrillated cellulose; nanofibrillar cellulose; cellulose nanofibrils; nanocellulose; MFC; NFC; CNF; production techniques; energy efficient; gel properties; films; enzymes; carboxymethylation; carboxymethyl cellulose; CMC; mechanical properties; oxygen barrier; homogenization; linting; papermaking; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Abstract : This work describes three alternative processes for producing microfibrillated cellulose (MFC; also referred to as cellulose nanofibrils, CNF) in which bleached pulp fibres are first pretreated and then homogenized using a high-pressure homogenizer. In one process, fibre cell wall delamination was facilitated by a combined enzymatic and mechanical pretreatment. READ MORE

  5. 3. Processing and properties of thermoplastic composites containing cellulose nanocrystals or wood-based cellulose fibres

    Author : Lilian Forsgren; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Extrusion; Cellulose nanocrystals; Cellulose; Thermal stability; Tensile properties; Wood-based fibres; Injection moulding; Composite;

    Abstract : Cellulose nanocrystals (CNC) were surface modified with dialkylamines to increase the compatibility between the CNC and the polymeric matrix, and promising results were obtained, with a 300 % stiffness increase when the mixed dispersion was compression moulded on a laboratory scale. The manufacturing process was up-scaled using water-assisted mixing in a twin-screw extruder (TSE) followed by a second compounding step and injection moulding (IM). READ MORE

  6. 4. Carbon fibres from lignin-cellulose precursors

    Author : Andreas Bengtsson; Monica Ek; Jim Parkås; Daniel Söderberg; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Carbon fibre; Kraft lignin; Cellulose; Dry-jet wet spinning; Kolfiber; Sulfatlignin; Cellulosa; Våtspinning; Luftgapsspinning; Fiber- och polymervetenskap; Fibre and Polymer Science;

    Abstract : It is in the nature of the human species to find solutions of complex technical problems and always strive for improvements. The development of new materials is not an exception. One of the many man-made materials is carbon fibre (CF). READ MORE

  7. 5. Experimental study of alkalinisation of cellulose in industrial relevant conditions

    Author : Diana Carolina Reyes Forsberg; Ola Sundman; Bertil Eliasson; Ulf Germgård; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Mercerisation; Alkalinisation; Cellulose I; Cellulose II; Alkali cellulose; Viscose; Cellulose ether; Carboxymethylcellulose; Sodium glycolate; Sodium diglycolate; Raman spectroscopy;

    Abstract : Mercerisation of cellulose pulp with a solution of NaOH is the first step of manufacturing cellulose-based value-added products, e.g. viscose fibres and cellulose ethers. During this process, cellulose transforms into a swollen crystalline structure, alkali cellulose (Na-Cell). READ MORE