Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties
The complete flax stem, which contains shives and technical fibres, has the potential to reduce the cost, energy consumption and environmental impacts of the composite production process if used directly as reinforcement in a polymer matrix. Earlier studies have utilised flax stem as reinforcement i...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-05-01
|
| Series: | Polymers |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4360/15/10/2239 |
| _version_ | 1797598563884072960 |
|---|---|
| author | Sofie Verstraete Bart Buffel Dharmjeet Madhav Stijn Debruyne Frederik Desplentere |
| author_facet | Sofie Verstraete Bart Buffel Dharmjeet Madhav Stijn Debruyne Frederik Desplentere |
| author_sort | Sofie Verstraete |
| collection | DOAJ |
| description | The complete flax stem, which contains shives and technical fibres, has the potential to reduce the cost, energy consumption and environmental impacts of the composite production process if used directly as reinforcement in a polymer matrix. Earlier studies have utilised flax stem as reinforcement in non-bio-based and non-biodegradable matrices not completely exploiting the bio-sourced and biodegradable nature of flax. We investigated the potential of using flax stem as reinforcement in a polylactic acid (PLA) matrix to produce a lightweight, fully bio-based composite with improved mechanical properties. Furthermore, we developed a mathematical approach to predict the material stiffness of the full composite part produced by the injection moulding process, considering a three-phase micromechanical model, where the effects of local orientations are accounted. Injection moulded plates with a flax content of up to 20 V% were fabricated to study the effect of flax shives and full straw flax on the mechanical properties of the material. A 62% increase in longitudinal stiffness was obtained, resulting in a 10% higher specific stiffness, compared to a short glass fibre-reinforced reference composite. Moreover, the anisotropy ratio of the flax-reinforced composite was 21% lower, compared to the short glass fibre material. This lower anisotropy ratio is attributed to the presence of the flax shives. Considering the fibre orientation in the injection moulded plates predicted with Moldflow simulations, a high agreement between experimental and predicted stiffness data was obtained. The use of flax stems as polymer reinforcement provides an alternative to the use of short technical fibres that require intensive extraction and purification steps and are known to be cumbersome to feed to the compounder. |
| first_indexed | 2024-03-11T03:23:56Z |
| format | Article |
| id | doaj.art-f2abe3b0fe684763b6144c1c2e86cbb8 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-11T03:23:56Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-f2abe3b0fe684763b6144c1c2e86cbb82023-11-18T02:57:16ZengMDPI AGPolymers2073-43602023-05-011510223910.3390/polym15102239Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical PropertiesSofie Verstraete0Bart Buffel1Dharmjeet Madhav2Stijn Debruyne3Frederik Desplentere4Research Group ProPoliS, Department of Materials Engineering, KU Leuven Campus Bruges, Spoorwegstraat 12, 8200 Bruges, BelgiumResearch Group ProPoliS, Department of Materials Engineering, KU Leuven Campus Bruges, Spoorwegstraat 12, 8200 Bruges, BelgiumSurface and Interface Engineered Materials, Department of Materials Engineering, KU Leuven Campus Bruges, Spoorwegstraat 12, 8200 Bruges, BelgiumResearch Group M-Group, Department of Mechanical Engineering, KU Leuven Campus Bruges, Spoorwegstraat 12, 8200 Bruges, BelgiumResearch Group ProPoliS, Department of Materials Engineering, KU Leuven Campus Bruges, Spoorwegstraat 12, 8200 Bruges, BelgiumThe complete flax stem, which contains shives and technical fibres, has the potential to reduce the cost, energy consumption and environmental impacts of the composite production process if used directly as reinforcement in a polymer matrix. Earlier studies have utilised flax stem as reinforcement in non-bio-based and non-biodegradable matrices not completely exploiting the bio-sourced and biodegradable nature of flax. We investigated the potential of using flax stem as reinforcement in a polylactic acid (PLA) matrix to produce a lightweight, fully bio-based composite with improved mechanical properties. Furthermore, we developed a mathematical approach to predict the material stiffness of the full composite part produced by the injection moulding process, considering a three-phase micromechanical model, where the effects of local orientations are accounted. Injection moulded plates with a flax content of up to 20 V% were fabricated to study the effect of flax shives and full straw flax on the mechanical properties of the material. A 62% increase in longitudinal stiffness was obtained, resulting in a 10% higher specific stiffness, compared to a short glass fibre-reinforced reference composite. Moreover, the anisotropy ratio of the flax-reinforced composite was 21% lower, compared to the short glass fibre material. This lower anisotropy ratio is attributed to the presence of the flax shives. Considering the fibre orientation in the injection moulded plates predicted with Moldflow simulations, a high agreement between experimental and predicted stiffness data was obtained. The use of flax stems as polymer reinforcement provides an alternative to the use of short technical fibres that require intensive extraction and purification steps and are known to be cumbersome to feed to the compounder.https://www.mdpi.com/2073-4360/15/10/2239flax fibresinjection mouldingmechanical propertiesshort fibre reinforced thermoplastics (SFRT)bio composites |
| spellingShingle | Sofie Verstraete Bart Buffel Dharmjeet Madhav Stijn Debruyne Frederik Desplentere Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties Polymers flax fibres injection moulding mechanical properties short fibre reinforced thermoplastics (SFRT) bio composites |
| title | Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties |
| title_full | Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties |
| title_fullStr | Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties |
| title_full_unstemmed | Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties |
| title_short | Short Flax Fibres and Shives as Reinforcements in Bio Composites: A Numerical and Experimental Study on the Mechanical Properties |
| title_sort | short flax fibres and shives as reinforcements in bio composites a numerical and experimental study on the mechanical properties |
| topic | flax fibres injection moulding mechanical properties short fibre reinforced thermoplastics (SFRT) bio composites |
| url | https://www.mdpi.com/2073-4360/15/10/2239 |
| work_keys_str_mv | AT sofieverstraete shortflaxfibresandshivesasreinforcementsinbiocompositesanumericalandexperimentalstudyonthemechanicalproperties AT bartbuffel shortflaxfibresandshivesasreinforcementsinbiocompositesanumericalandexperimentalstudyonthemechanicalproperties AT dharmjeetmadhav shortflaxfibresandshivesasreinforcementsinbiocompositesanumericalandexperimentalstudyonthemechanicalproperties AT stijndebruyne shortflaxfibresandshivesasreinforcementsinbiocompositesanumericalandexperimentalstudyonthemechanicalproperties AT frederikdesplentere shortflaxfibresandshivesasreinforcementsinbiocompositesanumericalandexperimentalstudyonthemechanicalproperties |