Fibre degummed

The effect of an electrolyte process on hemp fibre degumming was tested at the Institute of Natural Fibres, Poland. Experiments were conducted using an oxidation process and using a reduction process. In both cases 0.01 M and O.IM solutions of hydrochloric acid and sodium hydroxide were used as electrolytes. 

Silk degumming in aqueous solutions of acids and alkalies is greatly influenced by pH and temperature. An alkaline reaction at a pH > 9 and acid reaction at pH <2,5 ensure a rapid elimination of sericin completely after 30 min of treatment. The temperature should not exceed 95°C to avoid weakening of the fibre. The degree of hydrolysis of fibrion also depends on pH of the bath. 

Degumming of remie is a long and complex procedure. Different degumming technologies [67-72] use different auxiliaries. Besides boiling-off, other treatments such as scuthing, washing in acid solution and water etc. directly effect the sheen and gum content of the mass of cleaned fibre. 

Proteases Bacillius subtilis B. Licheniformis B. Oryzaeof Scouring of animal fibres, or degumming of silk, modification of wool properties. 

The fibre must be degummed before bleaching, and the addition of a small amount of hydrogen peroxide to the soap liquor assists in removal of the gum and brings about a slight preliminary improvement in colour. The silk is bleached in a 0-6 per cent w/w solution made as follows ... 

Ahmed, M. Chattopadhyay, S.K. Gaikwad, R.S. Dey, S.K. Characteristics of degummed ramie fibre and its cotton blended yarns., Indian Journal of Fibre Textile Research 29 (3) 362-365 (2004). 

Clarke AK et al (2004) Degumming of bast fibres. European Patent EP 1425440... 

The apphcation of a protease treatment to silk was introduced as an alternative to the degumming process using alkaline soap solutions (Freddi et al., 2003 Gulrajani et al., 2000). Alkaline soap has a deleterious effect on the silk, resulting in a harsh feel to the material. Enzyme degumming with protease removes the sericin without damaging the fibre. Results of enzyme treatment have shown that the fibre is stronger than that obtained by traditional alkaline soap treatments. 

Raw silk are untreated fibres peeled from the cocoon and have to be freed from sericin in a process called degumming to bring out the smooth and lustrous qualities of silk fabrics. 

Jiang, P., Liu, H., Wang, C., Wu, L., Huang, J., Guo, C., 2006. Tensile behavior and morphology of differently degummed silkworm Bombyx mori) cocoon silk fibres. Materials Letters 60 (7), 919-925. 

The process of loosening the bond between the fibre bundles and surrounding tissue (decomposing the natural adhesive pectin) is called degumming. There are several degumming methods (Fig. 2.2) however, only two are commonly used, water and dew retting. 

The degumming (retting) of hemp is discussed in Section 2.2.4. However, research has been conducted on hemp fibre into new retting techniques. 

The research showed that optimal processing conditions during the application of laccase preparations for enzymatic degumming of raw hemp fibres required the following conditions ... 

Degumming (retting) is the process of extraction of the fibre whereby jute stalks or crude ribbons are immersed in water for a certain period of time. Bundles are then submerged in water for 7 to 10 days. Retting takes place due to the joint action of water, aquatic and plant surface organisms, mostly bacteria in the begiiming the process is aerobic, later anaerobic. 

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. 

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