TY - JOUR
T1 - Exploring the dew retting feasibility of hemp in very contrasting European environments: Influence on the tensile mechanical properties of fibres and composites
AU - Réquilé, Samuel
AU - Mazian, Brahim
AU - Grégoire, Marie
AU - Musio, Salvatore
AU - Gautreau, Maxime
AU - Nuez, Lucile
AU - Day, Arnaud
AU - Thiébeau, Pascal
AU - Philippe, Florian
AU - Chabbert, Brigitte
AU - Chamussy, Anne
AU - Shah, Darshil U.
AU - Beaugrand, Johnny
AU - Placet, Vincent
AU - Benezet, Jean-Charles
AU - Le Duigou, Antoine
AU - Bar, Mahadev
AU - Malhautier, Luc
AU - De Luycker, Emmanuel
AU - Amaducci, Stefano
AU - Baley, Christophe
AU - Bergeret, Anne
AU - Bourmaud, Alain
AU - Ouagne, Pierre
PY - 2021
Y1 - 2021
N2 - Retting of fibrous plants such as flax is an essential step in the extraction of fibre bundles and their transformation into textiles and reinforcement fabrics for use in garments and composites. Dew-retting is traditionally performed from Northwest France to the Netherlands, as the climate is highly favourable for this process. Hemp is a plant that can be grown almost all over Europe with a low environmental impact. A retting step is also required to facilitate the separation of the hemp fibres before their transformation into textiles for garments or for 1D to 3D reinforcement composites, which requires thoroughly separated fibres. Dew-retting is currently used in flax production zones. The present work demonstrates that dew retting can be conducted under different climates on different soils, from dry Mediterranean environments up to the cooler regions of eastern France. If the ternary combination of moisture, temperature and solar radiation is appropriate, field retting (dew-retting) can be as short as about three weeks. In less favourable conditions, such as in dryer areas or when retting is performed late in the season after seed maturity (cooler temperatures), it lasts longer, but it can reach suitable levels. When conducted with care and with proper monitoring of the retting level, the dew-retting process does impact neither the tensile properties of elementary hemp fibres (by degrading crystalline cellulose I) nor the tensile properties of unidirectional and injected composite materials. Consequently, if extracted with a suitable process such as scutching and hackling, fibres suitable for load-bearing composites can be produced from dew-retted hemp stems produced in a wide range of climates and locations, therefore not limited to the conventional “dew retting zone” of flax production areas.
AB - Retting of fibrous plants such as flax is an essential step in the extraction of fibre bundles and their transformation into textiles and reinforcement fabrics for use in garments and composites. Dew-retting is traditionally performed from Northwest France to the Netherlands, as the climate is highly favourable for this process. Hemp is a plant that can be grown almost all over Europe with a low environmental impact. A retting step is also required to facilitate the separation of the hemp fibres before their transformation into textiles for garments or for 1D to 3D reinforcement composites, which requires thoroughly separated fibres. Dew-retting is currently used in flax production zones. The present work demonstrates that dew retting can be conducted under different climates on different soils, from dry Mediterranean environments up to the cooler regions of eastern France. If the ternary combination of moisture, temperature and solar radiation is appropriate, field retting (dew-retting) can be as short as about three weeks. In less favourable conditions, such as in dryer areas or when retting is performed late in the season after seed maturity (cooler temperatures), it lasts longer, but it can reach suitable levels. When conducted with care and with proper monitoring of the retting level, the dew-retting process does impact neither the tensile properties of elementary hemp fibres (by degrading crystalline cellulose I) nor the tensile properties of unidirectional and injected composite materials. Consequently, if extracted with a suitable process such as scutching and hackling, fibres suitable for load-bearing composites can be produced from dew-retted hemp stems produced in a wide range of climates and locations, therefore not limited to the conventional “dew retting zone” of flax production areas.
KW - Composite materials
KW - Elementary fibres
KW - Field-retting
KW - Hemp
KW - Mechanical properties
KW - Composite materials
KW - Elementary fibres
KW - Field-retting
KW - Hemp
KW - Mechanical properties
UR - http://hdl.handle.net/10807/189457
U2 - 10.1016/j.indcrop.2021.113337
DO - 10.1016/j.indcrop.2021.113337
M3 - Article
SN - 0926-6690
VL - 164
SP - 113337--
JO - Industrial Crops and Products
JF - Industrial Crops and Products
ER -