Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Development of thermoplastic biocomposites based on aligned hybrid yarns for fast composite manufacturing
University of Borås, Faculty of Textiles, Engineering and Business.
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Sustainable development
The content falls within the scope of Sustainable Development
Abstract [en]

The interest in natural fibres as reinforcement for composite materials has been steadily increasing due to their attractive mechanical properties and the possibility of making more eco-friendly materials. Currently, various alternatives are being introduced for commercial applications, as fibres such as hemp, jute and flax exhibit properties, which make them appropriate for structural composite components. Biocomposites offer reductions in weight and cost and have less reliance on foreign oil resources, making them attractive. Several investigations have revealed that the full utilisation of fibre mechanical properties in the final composites can be exploited, provided an aligned fibre orientation is chosen. In fact, a major challenge for natural fibre reinforced composites is to achieve high mechanical performance at competitive prices. The use of commingled/hybrid yarns is one of the more promising methods for manufacturing structural thermoplastic composites.

Commingled yarns of thermoplastic and reinforcing fibres offer a potential for cost-effective production of composite parts, thanks to reduced applied pressures and impregnation times during processing. Besides economic advantages, there is also direct control over fibre placements and ease of handling of fibres in yarn process. The yarn technologies provide homogenous distribution of reinforcing fibre and matrix. Variation in natural fibre properties has been a major problem facing composite manufacturers, compared to carbon and glass fibres that have well-defined production processes. This issue can be addressed by regenerated cellulose fibres. These fibres can be reproduced easily with high surface evenness and even quality, making it possible to get consistent results, which is not possible with natural fibres. Combination of natural and regenerated cellulose fibre brings together the best of both materials. The end result is a product with superior properties, which could not be obtained by the individual components.

This thesis describes the development of aligned hybrid yarns with low fibre twist, for high performance natural (hemp) and man-made (Lyocell) cellulose fibre-reinforced biocomposites, suitable for use in structural or semi-structural applications. The properties of composites in terms of fibre orientation, off-axis angle and alkali treatment were investigated, focusing on determining void%, water absorption, mechanical and thermo-mechanical properties. The results show that combining hemp and Lyocell in PLA composite leads to the reduction of moisture absorption and can improve the mechanical properties. The mechanical properties of the composites were highly affected by the fibre direction. The alkali treatment on hemp fibre improved the mechanical properties of the composites.

Place, publisher, year, edition, pages
Borås: Högskolan i Borås, 2015. , p. 52
Series
Skrifter från Högskolan i Borås, ISSN 0280-381X ; 74
Keywords [en]
Hybrid yarns, Mechanical properties, Porosity, Weaving, Alkali treatment, Compression moulding
National Category
Textile, Rubber and Polymeric Materials
Research subject
Resource Recovery
Identifiers
URN: urn:nbn:se:hb:diva-764ISBN: 978-91-87525-79-7 (print)ISBN: 978-91-87525-80-3 (print)OAI: oai:DiVA.org:hb-764DiVA, id: diva2:854028
Public defence
2015-11-27, D207, Allegatan 1, Borås, 10:00 (English)
Available from: 2015-10-26 Created: 2015-09-15 Last updated: 2015-12-18Bibliographically approved
List of papers
1. Characterization of thermoplastic natural fibre composites made from woven hybrid yarn prepregs with different weave pattern
Open this publication in new window or tab >>Characterization of thermoplastic natural fibre composites made from woven hybrid yarn prepregs with different weave pattern
2015 (English)In: Composites Part A: Applied Science and Manufacturing, Vol. 81, no February 2016, p. 139-144Article in journal (Other academic) Published
Keywords
A. Fabrics/textiles B. Mechanical properties E. Weaving E. Compression moulding
National Category
Engineering and Technology
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-3991 (URN)10.1016/j.compositesa.2015.10.042 (DOI)
Available from: 2015-12-10 Created: 2015-12-10 Last updated: 2018-06-01Bibliographically approved
2. Manufacture and characterisation of thermoplastic composites made from PLA/hemp co-wrapped hybrid yarn prepregs
Open this publication in new window or tab >>Manufacture and characterisation of thermoplastic composites made from PLA/hemp co-wrapped hybrid yarn prepregs
2013 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 50, p. 93-101Article in journal (Refereed) Published
Abstract [en]

PLA/hemp co-wrapped hybrid yarns were produced by wrapping PLA filaments around a core composed of a 400 twists/m and 25 tex hemp yarn (Cannabis Sativa L) and 18 tex PLA filaments. The hemp content varied between 10 and 45 mass%, and the PLA wrapping density around the core was 150 and 250 turns/metre. Composites were fabricated by compression moulding of 0/90 bidirectional prepregs, and characterised regarding porosity, mechanical strength and thermal properties by dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC). Mechanical tests showed that the tensile and flexural strengths of the composites markedly increased with the fibre content, reaching 59.3 and 124.2 MPa when reinforced with 45 mass% fibre, which is approximately 2 and 3.3 times higher compared to neat PLA. Impact strength of the composites decreased initially up to 10 mass% fibre; while higher fibre loading (up to 45 mass%) caused an increase in impact strength up to 26.3 KJ/m2, an improvement of about 2 times higher compared to neat PLA. The composites made from the hybrid yarn with a wrapping density of 250 turns/metre showed improvements in mechanical properties, due to the lower porosity. The fractured surfaces were investigated by scanning electron microscopy to study the fibre/matrix interface.

Place, publisher, year, edition, pages
Elsevier Ltd, 2013
Keywords
Natural fibre composite, Hybrid yarns, Mechanical testing, Compression moulding, Biocomposites, Resursåtervinning
National Category
Chemical Sciences Polymer Chemistry
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1560 (URN)10.1016/j.compositesa.2013.03.012 (DOI)000320149000011 ()2320/12281 (Local ID)2320/12281 (Archive number)2320/12281 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-11-02Bibliographically approved
3. Novel aligned hemp fibre reinforcement for structural biocomposites: Porosity, water absorption, mechanical performances and viscoelastic behaviour
Open this publication in new window or tab >>Novel aligned hemp fibre reinforcement for structural biocomposites: Porosity, water absorption, mechanical performances and viscoelastic behaviour
Show others...
2014 (English)In: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 61, p. 1-12Article in journal (Refereed) Published
Abstract [en]

This paper examines the thermal and mechanical behaviour as well as moisture absorption of aligned hemp composites using hemp/PLA wrap spun yarns. Uniaxial composites were fabricated with 30 mass% hemp using compression moulding. The properties of composites in terms of hemp fibre orientation (aligned and random), off-axis angle and alkali treatment were investigated. It was found that the testing direction influenced the mechanical properties of the composites. Compared with all the fabricated composites, the aligned alkali hemp/PLA yarn composite possessed the best mechanical properties, including tensile, flexural and impact strengths, lower porosity and water absorption. The water absorption for all composites was higher than for neat PLA, both at room temperature and 80 C. The PLA in its treated composites had higher crystallinity, which was attributed to effective heterogeneous nucleation induced by hemp. Based on SEM observation and theoretical analysis of DMTA data, there was a favourable interfacial adhesion in all composites.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Fabrics/textiles, Mechanical properties, Porosity, Compression moulding, Resource recovery
National Category
Chemical Sciences
Research subject
Resource Recovery
Identifiers
urn:nbn:se:hb:diva-1835 (URN)10.1016/j.compositesa.2014.01.017 (DOI)000335104100001 ()2320/13548 (Local ID)2320/13548 (Archive number)2320/13548 (OAI)
Available from: 2015-11-13 Created: 2015-11-13 Last updated: 2017-11-02Bibliographically approved

Open Access in DiVA

cover(2308 kB)180 downloads
File information
File name COVER01.pdfFile size 2308 kBChecksum SHA-512
727ab7a3c4a46c82fe272caf3a9ecf65aa8becb205ee96f24552428a0b693ac2f946c19bd10c95c99825756373264be79b3cabf680e56473d49624927167f3d7
Type coverMimetype application/pdf
inside(9892 kB)1149 downloads
File information
File name INSIDE01.pdfFile size 9892 kBChecksum SHA-512
2ce4181395a42891e1fb783784d12746088b568927e82989afeb7f7cc7982371fe0f304a88446ec6801d61959ad772278365e5bcedd8bf490432c8450a185168
Type insideMimetype application/pdf
spikblad(312 kB)177 downloads
File information
File name SPIKBLAD01.pdfFile size 312 kBChecksum SHA-512
17d3ff2a676df468fc9f1a027447a6e43dfde89a0be049b76947aa12a5b800f0a1a94b77af55c7652ad2d17f1d35a05665de76e3050fd7e4dd83060b7353d292
Type spikbladMimetype application/pdf

Authority records BETA

Baghaei, Behnaz

Search in DiVA

By author/editor
Baghaei, Behnaz
By organisation
Faculty of Textiles, Engineering and Business
Textile, Rubber and Polymeric Materials

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

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 3042 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf