Enzymatic treatments retting

Bodros and Baley [37] studied the tensile properties of water retted nettle fibers. Bacci et al. [39] investigated fiber yield of nettle cultivation and quality of fibers extracted by alkalization. Bacci et al. [38] compared the effects of different fiber extraction method combinations including water retting, mechanical decortication and enzymatic treatments on resultant fibers chemical composition and tensile properties. Bajpai et al. [40,41] prepared nettle fiber-reinforced poly lactic acid (PLA) and PP composites by compression molding. Bajpai et al. [42] studied the effects of various environments on the tensile strength of nettle fiber-reinforced PP composites. 

Bacci et al. [39] treated nettle stalks with boiling soda solution xmtil the bark, the source of fiber, was easily removed from the core of the stalk than performed alkalization treatment on the bark. Enzymatical fiber retting maybe faster and more reproducible than the traditional biological fiber retting methods and is extensively studied for flax and hemp extraction enhancement [39]. 

There have been limited amount of research devoted to enzymatic treatment of agro-residual fibers [12,13,58]. When comparing different extraction procedures including water retting, alkalization and enzyme treatment, Yilmaz [13] foimd the strongest and finest corn husk fibers to be produced by a fiber production route of water retting followed by enzyme treatment. 

Although ramie fibre is usually degummed chemically, there have been promising developments in microbial degumming (retting). Additionally some researchers reports that the use of ultrasonic vibrations speeds up the degumming process. The enzymatic treatment seems to be promising. 

Retting. The removal of the bast fibers from bark and woody stem parts is promoted by a biological treatment called retting (rotting). This is an enzymatic or bacterial action on the pectinous matter of the stem. After retting, the bundles are dried iu fields. Retting may be carried out iu several ways. 

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