Fibres To Fabrics

BIOTECHNOLOGY IN THE TEXTILE INDUSTRY Genetic Engineering. With improved understanding of how genes are responsible for the various characteristics and properties of a living organism, techniques have been developed to isolate the active components (DNA) and manipulating them outside the cell. Fragments of DNA obtained from one organism are transferred to another so the properties and capabilities of the first are given to the second. E.g. Lipolase, an enzyme used in washing powders and liquids, dissolves fats. The lipase gene is removed from one type of fungus and transferred into another where they can grow more easily in a fermenter and harvested as the enzyme Lipolase in quantity Cotton Genetic engineering is aimed towards improving insect, disease and herbicide resistance, fibre properties and performance. Bio-pesticides are being used to control beetle and caterpillar activity in fruit and vegetable crops. This has been extended for the use of bio-pesticides for the cotton boll weevil which destroys the cotton fibres but the pesticide is not harmful to other beneficial insects; a toxin gene which has been inserted into the cotton plants to produce a caterpillar resistant plant. When the caterpillar goes to eat the cotton the toxins produced by the plant paralyse the gut of the caterpillar. There is undergoing development to encourage natural polyester (poly hydroxyl butyrate PHB), to grow within the central hollow of the cotton fibre so creating a natural polyester-cotton. Achievements so far are coloured cotton growth e.g. blue cotton for denim, development of cotton producing an enzyme within the fibre which can then be used for filtration system of waterways which uses the enzyme to digest dirt and residues within the water for clean water waste. Cotton fibres are also being customized to produce a fibre with greater strength, reduction in shrinkage and a change to the absorbency rate. Sheep and goats Developments in genetics to produce more efficient feeding methods, greater insect and pest resistance, softer and finer fibres and even a technique for biological wool and hair harvesting. An injection of special protein will temporarily stop growth of hair and after 4-6 weeks a natural break will appear at the base of the fibre. The hair or fleece can then be peeled off; with sheep this allows an increase in daily shearing output from120 – 300 fleeces per team. However, there is concern within the research over the levels of abortion in ewes so further research is required. Cloning – Dolly the sheep born in 1996 was the first domestic animal to be cloned from an adult cell taken from the mammary gland. Cloning of animals could lead to specific characteristics being targeted such as quality of wool for specific end purposes. Dolly died at the age of 6 years in 2003 from advanced arthritis and lung cancer. Dolly and her lamb, Bonnie Photo courtesy of, The Roslin Institute, The University of Edinburgh Silk Research is being conducted in China to overcome the dependence of silk worms on the mulberry leaf, improvement to the strength and fineness of silk, increase of viral resistance and the production of coloured fibres. Micro-Organisms Dragline spider silk, , the silk which spiders use to catch themselves with when they fall, is a proteinacious fibre which cannot be produced in sufficient quantities to make it viable plus spiders themselves are very cannibalistic. Therefore research has gone into ways of producing the quality strong fibre, also known as Biosteel; originally spider silk DNA was transferred into bacteria such as E Coli to manufacture proteins or produced in tobacco and potato plants through their leaves and also tubers in potatoes with the strength and resilience of spider silk for the use in bullet proof vests as it has high tensile strength similar to kevlar but with good elasticity which kevlar does not. By 2010 further developments produced the spider silk protein in the milk of transgenic goats; the gene of dragline silk was taken from the orb-weaver spider and placed it in the DNA that prompts milk production in the udders of goats, one litre of milk produced 1 – 2 grams of the silk protein. Using wet spinning process the silk protein solution was extruded to produce the fibre. Currently spider silk is used for medical applications such as ligament repair as it is elastic and the body does not reject it and industrial applications such as parachute cords. Monoclonal Antibodies These are protein molecules made from identical immune cells which are clones of a unique parent cells. They have an amazing ability to ‘recognize’ specific substances, even if in limited concentration, and so bind themselves to the epitope which is part of an antigen. These have been developed as a marking tool, Biocode, for the prevention of counterfeiting and used within a variety of industries – food, drink and textiles. The codes (protein molecules) embodied on the markers can be detected by customs and trading standards officers by using simple equipment in the field. Carefully selected monoclonal antibodies will bind themselves to the marker molecules and produce an easy to see colour change. This has been evaluated for use with branded denims and is used in polyamide and acrylic resins, placed in dyes or applied to the surface of ink-jet printers. DNA Probe Probes are another technology which has evolved from genetic engineering. Short pieces of DNA can be designed to stick to other pieces of DNA and therefore help to identify species e.g. tell cashmere from wool and other goat hair. This came about because of the increase in specialty animal hair and fraud in labelling. These probes also identify various cellulosic origins e.g. cotton ramie etc. Finishing  Bio-stoning is currently the most used enzyme process which uses Cellulase that attacks the cellulose. Traditionally pumice stones were used in a tumble machine to abrade and remove particles of indigo dye from the surface of denim. Cellulase amylase enzymes can also cut through the cotton fibres to achieve the same effect without the damaging effect to the fibres and machines that stones have. It is also less time consuming as a higher wash load can be achieved, the stones do not have to be removed from the fabrics and there is a reduction in the sludge deposit which has to be disposed of (better environmentally). However there are disadvantages in that there could be fabric degradation and loss of strength and colour staining of the white weft yarn so loss in colour contrast. The enzyme can also react with the indigo dye and can cause a reddening effect. To counteract these neutral or alkaline cellulases within the pH range 6-8 can control the problems but these are costly.  Bio-polishing uses a Cellulase action similar to bio-stoning removes the fine surface fibrils of cellulosic fibres such as cotton, ramie, viscose and lyocell fabrics so eliminating pilling to give better print definition, brighter colours and a softer fabric without loosing any absorbency. Removing the fine fibres causes a weight loss of approx. 3-5% and strength loss of 2-7%. With tubular cotton fabrics however the removed fibrils tend to get trapped inside the cloth rather than wash away. This method if often used on Ramie, as a cotton and linen substitute, and to upgrade poor quality cottons.