Textiles lyocell

Alceru [Alternative cellulose Rudolstadt] A process for making cellulosic filaments and staple fibers. The cellulose is first dissolved in an aqueous solution of N-methyl morpholine N-oxide (NMMNO) and then spun. Developed by the Thiiringische Institut fur Textil- and Kunstoff-Forschung e.V. Rudolstadt, Germany, and Zimmer (Frankfurt) from 1987. A pilot plant was built in April, 1998 and a commercial plant was planned for installation in Baoding, China in 2005. A superabsorbent version of the fiber has been developed by Stockhausen. The fiber is now made commercially by Sea Cell GmbH, a subsidiary of Zimmer. See also Lyocell. 

CHA 05] Chang Lang Y., Chung Hee P., Yun-kyung K., et al, BiodegradabiUty of viscose Rayon and Lyocell fibers , Journal of the Korean Society of Clothing and Textiles,... 

X 10" m years per functional unit and the biodiversity impact was 5.02 x 10 potentially lost nonendemic species per functional unit. For lyocell, the land occupation was 9.77 X 10 m years per functional unit and the total biodiversity impact was 3.02 X 10 potentially lost nonendemic species per functional unit. The ratio of each type of textile made out of cotton, lyocell and polyester to wool, the textile with the greatest biodiversity impact, was also calculated and it worked out to 1 21 for cotton, 1 157 for lyoceU and 1 9461 for polyester. 

Natural cellulose tibers such as cotton, ramie, etc. have been used as blends for textile applications. High modulus regenerated cellulose tibers are produced on a commercial scale. For instance, Lyocell , a high performance ceUulosic tiber, has been used in many nonwoven applications because of its high strength, durability, absorbency, purity and biodegradability. 

As for viscose fibres, these are mostly produced as staple fibres for textile and nonwoven applications. In 2011, world production was 3.246 million tons [49] while filament yam for textile and technical applications reached 332 000 tons in 2011 [49] with a share of technical yarns of 56 000 tons. Technical viscose fibres, also called rayon or viscose rayon, are used mainly as carcass reinforcing fibres in fast-running and run-flat tyres. Lyocell fibres are produced only as staple and virtually exclusively by Lenzing AG, Austria, with a production capacity of 140 000 tons in 2011 [50]. 

The production of lyocell is a new technology for producing cellulosic fibers by means of a direct solvent process. This means that a genuine solution of the cellulose in N-methylmorpholine-N-oxide (NMMO) monohydrate is produced and spun, and not a cellulose derivate as in the case of viscose. The cellulose can, however, be obtained from used textiles or by crushed wood pulp. After filtration of the honey-like spinning solution, it is spun through an air gap into diluted aqueous NMMO solution. 

Current lyocell, like the almost identical polsmosic viscose rayons developed half a century ago (33), has so far proved to have similarly hmited and variable potential in the fashion textile markets for which it, and the process for making it, was designed. Whether a cheaper, high-fibrillation version would improve lyocell s prospects in nonwovens is still open to debate. 

Most fibres made from regenerated cellulose such as viscose, lyocell, and Celsol are characterised by stiffness as well as a fuzzy and uneven surface that makes fabrics susceptible to pilling, even over a short period of use. In order to modify the surface properties of cellulosic fibres and fabrics and to improve their quality biotechnological approaches based on specialised enzymes are widely used. Finishing processes, employing cellulases and xylanases, can replace a number of mechanical and chemical operations, which have been applied until now to improve comfort and quality of fibres and textiles. The principle of enzyme action in the finishing process is controlled hydrolysis of cellulose, in which impurities and fuzz are removed from the surface of fibres, without decreasing their mechanical tenacity or the elasticity of the fabric. 

Lyocell is the first in a new generation of cellulosic fibres made by a solvent spinning process. A major driving force to its development was the demand for a process that was environmentally responsible and utilised renewable resources as their raw materials. The first samples were produced in 1984 and commercial production started in 1988. A wide range of attractive textile fabrics can be made from lyocell that are comfortable to wear and have good physical performance. This physical performance combined with its absorbency also make lyocell ideal for nonwoven fabrics and papers. 

Lyocell fibres are converted to a very wide range of textile and industrial products. In many areas, the particular properties of lyocell lead to environmental benefits for customers during product manufacture and use. 

The acceptance of lyocell by the garment processing industry was relatively straightforward as they were already used to enzyme systems for indigo denim. (It is also interesting to note that cellulase enzymes were only introduced for textiles in the mid-1980s so prior to that lyocell would have been impossible to process to a controlled fibrillated finish.)... 

The early stages of the commercialisation of lyocell were focused towards the fashion textile apparel sector. However, this has changed during the first years of the twenty-first century so that lyocell is now targeted equally into the industrial sector, with particular emphasis on the key nonwovens markets... 

Burrow, T.R., The textile applications of Courtaulds Lyocell fiber . World Text. Congr. 

Nat. Nat.-Polym. Fibres, 68-77, University of Huddersfield, Queensgate UK, 1997. Burrow, Tom, Recent results with lyocell fibers in textiles , Lenzinger Ber, 78, 37 0,... 

Gandhi, K., Burkinshaw, S.M., Taylor, J.M. and Collins G.W., A novel route for obtaining a peach skin effect on lyocell and its blends , AATCC Review 2/4, 48-52, 2002. Taylor, J.M., Alwis, P., Harrington, L. and Geubtner, M., Easy Care Tencel Textiles , Melliand Textilberichte/Intemational Textile Reports (German Edition), 83, No. 3 E37-F, 2 pages, March 2002. 

There is much to be still learnt about the dyeing of PLA but it would seem that processes are available to achieve commercial viability. In real terms, it is not that long ago that fibers such as lyocell and indeed PET were introduced to the textile world, with many technical difficulties in their processing. These are now well accepted fibers and it will be interesting to watch as PLA follows a similar course. 

The conversion of cellulosic wood pulp into a textile fiber dates to the earliest periods of synthetic fiber manufacture viscose rayon and lyocell processes are well known. However, it is stiU conceivable to improve upon... 

Rencheng T, Jianping Z, Shiying M. Lyocell textile dyeing and finishing technology. Beijing China Textile Press 2001. p. 28—29. 

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