Change search
ReferencesLink to record
Permanent link

Direct link
Extrusion processing of wood raw materials for use in wood-polymer composites
Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
2011 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The interest in wood-polymer composites and their use in different applications has been growing over the last 10-15 years. Environmental issues and demands on lower material costs are the driving forces behind the increasing use of renewable materials such as wood and other natural fibres as reinforcement in polymer composites. Wood flour consisting of small wood particles is currently used as the main wood raw material in commercial wood-polymer composites. However, the reinforcing potential of wood flour is limited. A better reinforcement could be achieved by using wood fibres with a higher aspect ratio as raw material, but individual fibres are seldom used in composite manufacturing due to processing problems and high cost. Therefore, the objective of the work was to study the possibility to use wood chips as raw material and separate individual fibres with higher aspect ratios from the wood chips during the composite manufacturing process. First, the effect of the extrusion process only on wood raw material was studied without a matrix polymer, and then composites using polypropylene as matrix were made. The main goal was to produce wood particles/fibres with high aspect ratio during the manufacturing of wood polymer composites. The effects of extrusion parameters, different screw configurations, raw materials and raw material pre-treatments were evaluated. The size of the separated wood particles and fibres was measured using optical fibre analysis methods. Microstructure of wood particles as well as the fractured surfaces of prepared composites were examined using electron microscopy. The mechanical properties of the composites were measured using flexural and impact testing. The results showed that wood chips can be used as raw material in a one-step manufacturing process of wood-polymer composites. Also, individual fibres with a higher aspect ratio than wood flour were separated from the wood chips with suitable processing conditions

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2011.
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
Research subject
Wood and Bionanocomposites
URN: urn:nbn:se:ltu:diva-26720Local ID: fbceb5a6-c7fb-4ded-baa0-c87feac9b6c0ISBN: 978-91-7439-229-6OAI: diva2:999890
Godkänd; 2011; 20110302 (ysko); LICENTIATSEMINARIUM Examinator: Professor Kristiina Oksman, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Diskutant: Associate Professor Roberts Joffe, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet Tid: Torsdag den 7 april 2011 kl 13.00 Plats: E246, Luleå tekniska universitetAvailable from: 2016-09-30 Created: 2016-09-30Bibliographically approved

Open Access in DiVA

fulltext(6353 kB)0 downloads
File information
File name FULLTEXT01.pdfFile size 6353 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Hietala, Maiju
By organisation
Material Science

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

ReferencesLink to record
Permanent link

Direct link