Looking forward to the future it is clear that today's narrow concept of fibre as a basic element for textiles, ropes and nets will become an outmoded notion. The emphasis will instead shift to new and exciting developments in fibre technology and their applications, exploring such fields as biomimetics, nanotechnology and biodegradability.
New millennium fibres describe and identify the scope of high-tech fibres. The present status and prospects of the fibre/textile technology are discussed and the high performance fibres are reviewed from origin to future applications, including carbon fiber.The themes of the book are summarised with a discussion on health care and the environment.
As the 21st century progresses fibres will enter into more novel and unexpected applications. We are approaching the age of the wearable computer and organic electroluminescence wearable displays. New potential is open in the fields of car and aerospace industry, civil engineering, separation membranes using hollow fibres for artificial organs, biodegradable fibre for ecological conservation and fibres with biological functions.
Introduction
Bio-technology can simply be defined as the application of living organisms and their components to industrial products and processes. It encompasses a range of scientific and engineering techniques for applying biological systems to the manufacture or transformation of materials in order to develop novel products and processes.
The fibre related industries are using bio technology for:
Making changes to production processes.
Utilizing fibres as biotechnology materials.
For producing new useful materials.
Let us discuss the present applications and signs of future developments in bio-fibre manufacturing.
FIBRES PRODUCED BY BACTERIA:
Bacteria multiplies very fast and is capable of growing on a variety of raw materials ranging from carbohydrates such as starch and sugars to gaseous and liquid hydrocarbons such as methane, ethanol etc. For culturing, the nutrients are supplied to fermenter and cells are harvested when they have consumed and stop growing. The spectrum of biotechnology includes production of fibres using bacteria such as bacterial cellulose, bacterial polyester, sorona etc.
1)BACTERIAL CELLULOSE:
Cellulose is the main component of plant cell wall. Some bacteria produce cellulose called bio cellulose or bacterial cellulose. Plant cellulose and bacterial cellulose have the same chemical structure, but different chemical and physical properties. The manufacturing of biocellulose involves the cultivation of acetic acid bacterium i.e., aceto bector acetic (1 x 2 to 1 x 3 mm in size) for 7 to 10 days in a medium containing 5% sucrose, nitrogen and salt at 30oC.This bacterial strain produces a gel like material containing fine cellulose fibre, which is too thin (about 20 50 mm in diameter) to classify in term of conventional denier unit. Cellulose produced by Aceto bector is chemically pure and free of lignin and hemi cellulose. It is produced as an extra cellulose polysaccharide in the form of ribbon like gel sheets. It has high crystallinity high degree of polymerisation, high tensile strength and tear strength and high hydrophilicity.
It is used as artificial blood vessels for microsurgery. The extremely fine filament is used to produce a new type of artificial leather with a mild touch. Due to its hydrophilicity, it is used temporarily as a skin substitute and in wound healing bandages. The bacterial cellulose sheets are being used for loudspeaker diaphragms. Because of its outstanding sound reproducibility, Sony has now commercialised high quality headphones using these bacterial cellulose sheets. It is also being used for producing activated carbon fibre sheets for absorption of toxic gas.
2)BACTERIAL POLYESTER
More than 100 bacterial species are known to be polyester producing, which includes alcaligenes species, bacillus species, photosynthetic bacteria and blue green algae. These micro organisms produce and store polyester, which can be used as an energy source in case of starvation in the same way as animal and plant store energy in the form of glycogen and amylopectin. Polyester so produced is stored in the bacterial body as particles of 0.5 to 1.0 micrometer in diameter, which can be extracted using organic solvent. Recently a new method was developed to produce bacterial co-polymeric polyester efficiently by fermenting a suitable combination of bacteria and food. ICI, U.K has applied this fermentation technology to produce random co-polyester of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) by feeding two ester carbon sources to the bacteria. The co-polyester can have its 3HV component varying in concentration from 0 to 30% and is now commercially available under the trade name of BIOPOL.
Applications of Bacterial Polyester:
A slow releasing system for agriculture chemicals is now been developed using biodegradable polyester microcapsules containing chemicals. These microcapsules are decomposed in the soil gradually and thus release chemicals over a long period. Since the bio polyester is bio compatible, they also find application in medicine. The surgical suture, gauze, bandage or the material used to repair bone fracture or deficiencies, made from bacterial polyester cause no inflammation in the organs or tissues where they are applied. Beside this, bio polyester is optically active and piezo-electric with application in the field of optics and electronics.
Developments in wool
Maximum work is being carried out on animal hair fibres, the most prominent among them being wool. Biotechnological methods are adopted to enhance the quality and yield of wool fibres. By identifying useful genes, breeders are able to select the breeds for improved production and quality. Genetic engineering helps to modify the genetic makeup of animals and provide them with specific properties. Genetic modification of sheep has been done to resist attack from blow fly larvae by engineering sheep that secretes an insect repellent from its hair follicles. Modern reproductive technologies like artificial insemination, semen freezing, embryo transfer and embryo micromanipulation have been applied to produce animals with new genes. Merino sheep that grow about 13% faster and larger than normal have been produced.
Biological Wool Shearing:
Bioclip is a biological process for removing the fleece that has been available to wool producers since 1998. The science behind Bioclip was developed by the CSIRO Livestock Industries unit over the last 20 years. Biological wool shearing (bio clip) is a technique that relies on an artificial epidermal growth factor which when injected into sheep, interrupts hair growth. A month later, breaks appear in the wool fibre and the fleece can be pulled off as a whole, without the use of mechanical hand piece, in half the time it takes to shear a sheep. Also it will be free of second cuts and skin pieces contaminating the fleece.
DEVELOPMENTS IN SILK:
Now silk worms can produce finer and longer silk than nylon using biotechnology. The National Institute of Seri cultural and Entomological science, Japan has succeeded in breeding a new type of silkworm that can produce a fine homogeneous silk filament of about 1500 metres in length.
1) Ready coloured yarns from silkworm:
The need to dye silk to specific fashion colours could soon be outdated according to the scientists working for the Silkworm Research Institute at Suzhou University, China. The team has been trying to create ready coloured yarns by manipulating the diet of the worms during the all-important pre-cocoon spinning stages of their life cycles. Now recent trials conducted in Siangsu Province suggests that the colours in which the yarn is produced are limited to simple red, green and yellow, and the team is confident that it will soon be able to offer the fashion industry a choice of up to a dozen shades which require no further dyeing. Moreover it is suggested that the coloured silk from cocoons has remedial and cosmetically advantageous properties when worn next to the skin.
2) Shape-memory silk yarn:
A silk yarn lacks elasticity in comparison with wool because of the difference in its internal structure. To produce a highly elastic silk yarn, the yarn is chemically treated by dipping in a solution of hydrolysed fibroid keratin and collagen, dried, crimpled, dipped again in water and thermo-set in wet state under high pressure at 110oc for 10 minutes, yielding shape memory silk. When this product is wet-heated at 60oc, the silk yarn becomes crimpled and bulky. Since its twisted structure fixed in the memory, even when the silk is untwisted again into uncurled yarn, the silk yarn reversibly recovers its curled shape by steaming. This elastic silk can be applied in various textile products including outer garments, tights and knitted yarns.
3) Biocosmetics from silk protein:
Biotechnology has now provided a way to produce new products from silk having specific functions. Kanebo developed the facial treatment cosmetics(Fresh-Up powder and Bio-powder foam) from silk inorder to capture the elegant image of silk in the market. Fatty dirts on the skin surface can be removed by washing with soaps. Protein dirts from dead skin, however cannot readily be removed unless they are first hydrolysed with the enzyme proteinase. Certain conventional cosmetics contain proteinase, but its hydrolysis activity deteriorates rapidly with time, particularly when left with surfactant in the wet state. Many attempts have been made to maintain the proteinase activity in cosmetics. Kanebo applies an enzyme immobilization technique for this purpose by encapsulating proteinase in water-insoluble fibroin. The encapsulated proteinase is stable to heat and its hydrolysis activity lasts for a considerable period, since fibroin protects proteinase against heat and moisture. The enzymatic activity deteriorates only 10% after 300 day storage at 45C in the fibroin. Fresh-up powder is made up of granules of of mixed proteinase-encapsulated fibroin powder and detergent.
DEODORANT FIBERS
Various artificial enzymes have now been developed and used in every day life. For example hematin (Ferri [Fe3 ] protoporphyin IX) is used to develop deodorant fibre that has 100 times better efficiency than the active carbon. For this, amorphous rayon was chosen as the supporting material because this rayon is porous. The deodorant fibre consists of amorphous rayon supporting 3% wt fe-pthalocyanine type artificial enzyme. The deodorant fibre is capable of destroying an offensive odour by decomposing the foul smelling molecules such as indole (faeces), hydrogen sulphide (rotten eggs) and mercaptans. The deodorant fibre is used at present in commercial products such as nappies, inner sole of a shoe, in refrigerators and the mat for a toilet seat.
CHITIN:
Chitin, a polysaccharide is the major component of crab and shrimp shells. Its structure is similar to that of cellulose being composed of poly 2-acetamido 2-dioxy-D-glucose.. It has excellent anti-thrombogenic characteristics and can be absorbed by the body and promote healing. Unitika Ltd. developed an artificial dressing, Beschitin-W from crab shells. Fibres, fabrics, sutures and non-woven fabrics from chitin are now available. For example, chitin non-woven fabric has excellent characteristics as an artificial skin because of its good adhesion to the human body surface and its value in stimulating new skin formation. It accelerates healing and reduces pain. A standard type artificial skin (10 x 12 cm) costs more than $200 at present. Chitin can also be used as a food material to control cholesterol levels in blood. It has promising application in the field of fabric finishing, dyeing and shrink-proofing of wool. It is also useful in filtering and recovering heavy and precious metals and dyestuffs from the waste streams.
CHITOSAN:
Alkali treatment of chitin yields chitosan, which is now used as a food additive. Since chitosan dissolves easily in acetic acid (vinegar), it can be applied in the food and bio medical industries. Fuji Spinning Company Ltd., have developed chitosan porous beads, consisting of numerous pores running radially from the surface to the center. Because of their good compatibility with living cells, the beads are used for cell culture. It can be processed into fine beads of 10m in diameter that can be used for high pressure liquid chromatography. Other applications are: as a slow drug release membrane; colour adsorbent; anti-friction agent for paper; in cosmetics such as the conditioner for hair; and as an enzyme immobiliser.
ALGINATE FIBRES:
Research work shows that wounds under moist condition would infact heal better and faster, which would also remove the problem of fibres being trapped in the healing wound. The concept of moist healing has since been responsible for the development of many fibres, which have improved wound management techniques and patient care. Alginate fibres are one such example where naturally occurring high molecular weight polysaccharides obtained from seaweeds have found use in medical textiles. Upon contact with wound fluid, these fibres are partially converted to a water soluble sodium alginate that swells to form a gel around the wound thus keeping the wound moist during the healing period. They can be easily removed once the treatment is completed.
COLLAGEN:
Collagen which is obtained from bovine skin, is a protein available in fibre or hydrogel (gelatin) form. Collagen fibres used as sutures are as strong as silk and biodegradable. It is traditionally used in the food and cosmetic industries. Collagen has uses as bio-materials. When collagen is crosslinked in 5-10% aqueous solution, it forms a transparent hydrogel with high oxygen permeability. This hydrogel can be processed into a soft contact lens. Collagen can also be utilized fro Drug Delivery Sysytems (DDS). Sumitomo Pharmaceutical Co. and Koken Co. jointly developed a slow drug release system using atelocollagen as the drug carrier. Atelocollagen is a three stranded protein produced from bovine skin by removing the telopeptide regions present at both terminals using the enzyme proteinase. The drug is immobilised within a collagen cylinder, which swells in the body to release the drug gradually, so maintaining a constant concentration in blood over a long period.
CONCLUSION:
Bio-technology is an emerging interdisciplinary technology that is booming in the field of textiles during the recent decade. Biotechnology today is no longer a baby in the laboratory; this technique has matured enough to sooth the sore throat of those raising doubts over its feasibility in mass production. It gives value addition to our textile products and thereby helping us to gain prominent positions in the global market.
Reference:
1.Biotechnology in fibre manufacturing- Dr.Wasif A.I., Garg Mayank.A., Lodha Abhishek.S. and Mehta Shankhesh.G., New Cloth Market, June 2005, Page No.25-31.
2.New Fibres- Dr.Tatsuya Hongu, Prof.Glyn O Philips, Woodhead publishing Limited, England.
3.The impact of bio-technology on the textile industry Paul F Hamlyn, Textile Magazine,1995,Page No.6-10
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5.http://www.wiley-vch.de/books/biopoly/pdf_v05/bpol5003_37_46.pdf
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9.http://woolinnovation.com.au/page__2159.aspx
10.https://www.fibre2fashion.com/product_launch/rossera/biotech.htm
About the author:
Mr. M. Parthiban, Faculty of textile chemistry, SSM college of engineering, Komarapalyam
Pin - 638 183 Email: parthi_mtech@yahoo.com
Mrs. S.Manjula, lecturer, dept of apparel and fashion technology, Kongu Arts and Science College , Erode. Email: sri_manjula@yahoo.com
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