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Retted fibres

It is a much simpler and more cost-effective alternative to separate the bast fibre from the plant straw [26]. The raw material for this procedure is either field dried or slightly retted plant straw. The bast fibres are separated from the woody part by mechanical means. Weather-dependent variations of fibre quality are eliminated. However, the produced green fibres are much coarser and less fine as compared to dew or water retted fibres. [Pg.10]

The normal test for dynamic evaluation of materials or components is the Wohler fatigue test, to characterize fatigue behaviour. Hysteresis measurements are carried out on flax and glass mat-reinforced polypropylene, with a needle-punched flax mat using green and retted fibres to make plates with a quasi-isotropic composite structure, and with treatment by a coupling agent. [Pg.50]

The crop should be cut in August and left in the field to ret (fibres are separated fi om the stem by the action of wetting and drying). Then it is rowed up and baled. Dual-hemp crops can be grown for fibre and oilseed, in which case they are combined and the straw left to ret and then baled normally. [Pg.394]

Hemp is retted in water tanks in a manner similar to flax, after which the stalks are laid out to dry. The fibres are then separated either manually or mechanically by passing through fluted rollers which crush the woody tissues. At this state the hemp is softened by beating with a softwood mallet on a flat stone or a hard floor. The same effect can also be achieved when a heavy millstone, usually operated by water power, rolls over the fibres for 3 or 4 hours. Finally the fibres, which tend to stick together, are separated by combing. [Pg.71]

Y. Li, K.L. Pickering, R.L. Farrell, Analysis of green hemp fibre reinfraced composites using bag retting and white rot fungal treatments. Ind. Crops Prod. 29(2), 420-426 (2009)... [Pg.282]

For areas with special application requirements, specifically modified polyester fabrics, as well as fabrics from aramid fibres, fluorine polymers and arylamides like Kevlar (ref. DuPont), have proved to be satisfactory. The membranes show different characteristics depending on the coatings used. Fluorine polymers such as PVDF (polyvinylidene fluoride) are used on PES fabrics (refs Mehler and Ferrari) a PTFE (polytetrafluoroethylene) coating is very suitable for fibreglass fabrics (ref Verseidag) and there is a newly developed composite membrane with THV (ret Dyneon), a polymeric blend of tetrafluoroethylene, hexafluoropropylene and vinylidenefluorine, used as a coating on PES fabrics, of which VALMEX vivax (ret Mehler) is one example. [Pg.59]

Artificial retting [25] involves warm-water or canal retting and produces homogeneous and clean fibres of high quality in 3-5 days. Plant bundles are soaked in warm water tanks. After sufficient retting, the bast fibres are separated from the woody parts. The sheaves or hurds are loosened and extracted from the raw fibres in a breaking or scotching process. [Pg.10]

Yu H, Yu C (2007) Study on microbe retting of kenaf fibre. Enzyme Microb Technol 40 1806-1809... [Pg.38]

Van Sumere CF (1992) Retting of flax with special reference to enzyme retting. In Sharma H, Van Sumere C (Eds) Biology and processing of flax. M Publications, Belfast, UK, pp 157-198 Van Sumere C, Sharma H (1991) Analyses of fine flax fibre produced by enzymatic retting. Aspects Appl Biol 28 15-20... [Pg.94]

Retting is a process of the separation or loosening of bast fibres from its non-fibrous components [80]. Water-retting is performed by immersing the stalks of the fibre crops in water for a certain period of time. Water penetrates the central... [Pg.163]

Fig. 6.5 A comparison between not-treated flax fibre, dew-retted flax fibre and enzyme-retted fiax fibre reinforced HOPE composites. Adapted from [88]. Low indicates 0.05% enzyme and 5 mM chelator, medium indicates 0.1% enzyme and 10 mM chelator and high indicates 0.3% enzyme and 25 mM chelator... Fig. 6.5 A comparison between not-treated flax fibre, dew-retted flax fibre and enzyme-retted fiax fibre reinforced HOPE composites. Adapted from [88]. Low indicates 0.05% enzyme and 5 mM chelator, medium indicates 0.1% enzyme and 10 mM chelator and high indicates 0.3% enzyme and 25 mM chelator...
Enzyme-retting and treatments have been shown to be an effective method of treating natural fibres to improve the interface between the fibres and the matrix, leading to improved mechanical properties of the composites. However, it is... [Pg.166]

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See also in sourсe #XX -- [ Pg.50 ]



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