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Issue 05/2016

  • Text
  • Bioplastics
  • Biobased
  • Products
  • Materials
  • Fibres
  • Plastics
  • Packaging
  • Renewable
  • Properties
  • Applications

Fibres & Textiles

Fibres & Textiles Biobased textile world The textile world is biobased; since the stone ages. By mankind natural fibres (hairs, wool, silk, cotton, flax, Jute …) were spun to yarns, twisted to ropes and woven to textiles since more than 7,500 years. Only end of the 19 th century the history of manmade fibres started – in the beginning these were also biobased (based on cellulose) [1]. Today these cellulose based fibres have a share of 9 % worldwide, in Germany even 28 % of all manmade fibres [2] with increasing trend. The 20 th century profiled to the age of manmade fibres. 1935 Carothers discovered the PA 6.6 fibres [1]; only 3 years later Paul Schlack developed PA 6. After 1945 the biobased PA 11 was created based upon castor oil. Yet late as 2009 Arkema launched a type for monofilaments and fibres. [3] Polylactides (PLA), used since the 1990 s in textile applications, was at that time too expensive for wide use due to prices of about 50 €/kg. In 2002 Cargill, USA dared the big jump to install a synthesis plant of 140.000 tonnes per annum. Due to the large scale the polymer price dropped to 2.50 €/kg and PLA became an important fibre material. Today industrial production plants are run in the Netherlands, in Japan, China and Thailand. 2011 in Guben, Germany a pilot plant with 500 tonnes/annum has been installed. [4] In the background of the discussion on bio-fuel, corn starch based PLA provoked the question if a relevant intrusion in the food farming can be justified. Alternatively, rain forests in Brazil are burnt to plant cultivation for different kind of industrial use. In marine breeding stations genetic modified algae are grown as a raw material for polymers. Still there is no solution how the uncontrolled distribution of the algae to the sea may be prevented. These questions need a holistic balance of the sustainability, its importance exceeding significantly the reduction of CO 2 . The Castor plant grows on arid soil which is not fertile for food stock and such does not impair the food chain. Sebacic acid produced from Castor oil is used commercially for PA 11 and PA10.10 and as well for the partly bio based polyamides PA 4.10, PA 6.10. Cathay Biotech launched an alternative way using biobased Pentamethylenediamine. Synthetized with adipic acid a biobased PA 5.6 is created as alternative to PA6 and PA6.6 [5]. Most promising are the so-called drop-in approaches, which replace fossil based raw materials partly or fully by biobased substances. Fibres spun from these biobased polymers do not differentiate from the respective mineral oil based polymers. A 30 % biobased PET can be synthesized using ethylene glycol from bioethanol. Research is going on to produce biobased terephthalic acid. In 2011 Toray Industries reported on the synthesis of paraxylene from bioethanol by Gevo, USA [6]. This would enable to synthesize of 100 % biobased PET. Braskem developed 100 % biobased polyethylene. Two types of fibre polymers are available. The feedstock sugar cane is claimed not being genetic modified; the cultivated land was not rain forest. The fibres of partially biobased poly-trimethyleneterephthalate (PTT) have a long story already in use for carpets in home and automotive applications. Invista is offering a 70 % biobased elastomeric fibre from dextrose of corn for the use in garments. Polyethylenefuranoate (PEF) could become a 100 % biobased alternative to PET which should be close to PET in terms of processing and performance. 2,5-Furandicarbonic acid (FDCA) is polymerized with ethylene glycol to PEF. Higher glass transition temperature at lower processing temperatures could be the advantages for textile applications e.g. in automotive applications. FDCA may be produced from biomass from plant waste. This would not only mean no intrusion in the food production but waste of the vegetable food production could be used when the logistic demands can be fulfilled. 14 bioplastics MAGAZINE [05/16] Vol. 11

Fibers & Textiles (picture: courtesy Groz-Beckert) Already in the beginning of the 20 th century a fibre had been developed on base of the milk protein casein, yet was non-competitive to the cheap synthetic fibres. Today Cyarn Textile Trade Co. Ltd, China is offering a wet spun casein fibre with fair strength (25-35 cN/tex) which is claimed to have an excellent skin contact due to humidity absorption. Process originated zinc ions should lead to bacteriostatic effects, which was proven in biological tests [7]. The casein based fibre Qmilk of the Qmilch Deutschland GmbH distinguishes itself by extraordinary marketing expenditure. The fibre is gel/melt spun thus not requiring an ecological and economical costly solution process. [8] Silk produced from silkworm Bombyx Mori is one of the oldest and for clothing most precious fibres. Rarely spider silk was used for wound dressing in pre-Christian times. Only in the last 20 years a break-through is visible for biotechnological generated spider silk. From data of Thomas Scheibel, Bayreuth, Germany and Spiber Inc., Japan one may anticipate readiness to market of spider silk fibres in about 10 years. Big chemical enterprises are following this development which speaks for feasibility and large market potential. This short view shows, that a wide spectrum on partially or fully biobased fibres was established already besides the natural fibres and the cellulosic man-made fibres. Besides the PLA fibres drop-in solutions have found or will find in short term their way to application. Yet if very big volumes cannot be realized, the fibres will remain in niches. There is no doubt, that we need biobased fibres. The fossil raw materials are limited and will run short, not because, but as well for the fibre materials. The important and still open question is, what might be the biobased sources which do neither interfere with the food production, nor destroy the rain forest, nor pollute uncontrolled the world seas with algae. The use of waste from food production may be a solution; the logistic challenges and the fulfillment of a high quality standard are not solved yet. Still the cellulose-based manmade fibres based on sustainable forestry seem to be the real green way. [1] [2] [3] [4] biobasierte-polyester/pla/ [5] [6] [7] [8] By: Martin Dauner Head of Nonwovens Technology Institute of Textile Technology and Process Engineering Denkendorf, Germany bioplastics MAGAZINE [05/16] Vol. 11 15

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