Processing of Natural Fibres

The numerous chemical and mechanical processes through which the fibres are turned into end-product can be grouped into  

These operations are similar for both natural and chemical fibres. The details of the operations difier with the fibre chemistry and origin, and with the way the fabric was obtained by weaving or by knitting, respectively. In all cases chemical products are used for assisting, or for producing the required effect, and in all cases pollutants are produced, either in effluents, or in the atmosphere. 

The aetual trend of natural surfactants based on renewable raw materials combine a high emulsifying power with good electrolyte stability and extremely good skin compatibility. 

The biodegradability of chemical substances depends on their chemical structure. Branched hydrocarbon chains such as tetrapropylene alkylbenzene sulphonates, alkylphenol polyglycol ethers on the one side and quaternary ammonium compounds on the other show poor biodegradability, more particularly under anaerobic conditions.  

The nature of renewable raw materials matches the requirement for biodegradability under aerobic and anaerobic conditions (Table 9.6.6). The linear hydrocarbon chains facilitate biodegradability without the formation of eco-toxic metabolites as is the case with alkylphenol polyglycol ethers. 

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Wielage, B., Lampke, T., Utschick, H., and Soergel, F. (2003) Processing of natural fibre reinforced polymers and the resulting dynamic-mechanical properties. J. Mater. Process Technol, 139, 140-146. 

F. G. Torres, M. Aguirre, Rotational moulding and powder processing of natural fibre reinforced thermoplastics. International Polymer Processing. 18 (2), 204-10(2003). 

As ToF-SIMS is a surface analytical technique, it is well suited to the study of surface interaction between a material and its environment or between a material and products applied to it. The surface modifications can then be studied, making it possible to establish links with degradation processes. Published papers on the study of natural fibres related to cultural heritage typically illustrate this aspect of ToF-SIMS analysis. 

Sulfonated azo dyes (reactive dyes) are widely used in the textile industry. Due to the simultaneous hydrolysis in the dyeing process, 15-60 % of the reactive dyes reach the waste water system. In addition, their use strongly increases with the colouring of natural fibres, and so a total of 60 % of all dyes emitted to the waste water are reactive materials. 

In recent years starch, the polysaccharide of cereals, legumes and tubers, has acquired relevance as a biodegradable polymer and is becoming increasingly important as an industrial material (Fritz Aichholzer, 1995). Starch is a thermoplastic polymer and it can therefore be extruded or injection moulded (Balta Calleja et al, 1999). It can also be processed by application of pressure and heat. Starch has been used successfully as a matrix in composites of natural fibres (flax, jute, etc.). The use of starch in these composites could be of value in applications such as automobile interiors. An advantage of this biopolymer is that its preparation as well as its destruction do not act negatively upon the environment. A further advantage of starch is its low price as compared with conventional synthetic thermoplastics (PE, PP). 

The properties and swelling processes of cotton fibres after treatment with liquid ammonia are compared with conventional and hot mercerized cotton in Table 9.3. The nature of the improvement in properties resulting from the treatment of cotton with liquid ammonia depends on the conditions of its removal from the fibre. Dry removal of ammonia after treatment converts Cellulose I to Cellulose III,... 

These oils are used in the fibre and textile industries either to lubricate the textile machinery or as components of process oils used for the working of natural fibres, the production and processing of synthetic fibres or the finishing of intermediate or final products. Textile oils are often made from technical white oils and oxidation inhibitors plus agents ensuring removal of the oils by washing, even after a long... 

Handbook of natural fibres. Volnme 2 Processing and applications... 

Textiles for apparel are commonly woven or knitted from natural or manufactured hbres. Natural hbres include ceUulosic fibres such as cotton, hnen and hemp, or protein hbres such as silk and wool. Growing of natural fibres frequently involves significant water, land and chemical use. Natural fibres are biodegradable, however, because of the chemicals used in the finishing and dyeing processes, these fibres can still negatively impact soil and groundwater upon disposal. 

Torres, F.G., Diaz, R.M. Morphological characterisation of natural fibre reinforced thermoplastics (NFRTP) processed by extmsion, compression and rotational moulding. 

Properties such as density, electrical resistance, ultimate tensile strength and initial modulus are related to the internal structure and chemical composition of the fibres. Properties may also vary according to variations in diameter along with the length of individual filaments, size and maturity, as well as the processing methods used for the extraction of fibres. These fibres are biodegradable and non-abrasive. However, incompatibility of the fibres and poor resistance to moisture often reduces the potential of natural fibres and these drawbacks have become a critical issue in their development." ... 

Handbook of natural fibres. Volume 2 Processing and appUcations... 

Lea o AL, Rowell R, Tavares N et al (1998) Applications of natural fibres in automotive industry in Brazil - thermoforming process. In Prasad PN (ed) Science and technology of polymers and advanced materials. Plenum, New York... 

Savastano H Jr, Santos SF, Radonjic M, Soboyejo WO et al (2009) Fracture and fatigue of natural fibre-reinforced cementitious composites. Cement Concr Compos 31 232-243 79. Rahman WA, Tin SL, Razak RA et al (2008) Injection moulding simulation analysis of natural fibre composite window frame. J Mater Process Technol 197 22-30 Toledo FRD, Andrade SF, Fairbaim EMR, Melo FA et al (2009) Durability of compression molded sisal fibre reinforced mortar laminates. Construct Build Mater 23 2409-2420 Pillai MS (2006) Applications of natural coir fibre, proceedings, natural fibres vision 2020, New Delhi 8-9th December... 

International Year of Natural Fibres 2009 - http //www.natiu alfibres2009.org lorio I, Leone C, Nele L, Tagliaferri V (1997) Plasma treatments of polymeric materials and Al alloy for adhesive bonding. J Mater Process Technol 68 179-183 Jahn A, Schroder MW, Ffiting M, Schenzel K, Diepenbrock W (2002) Spectrochim Acta A Mol Biomol Spectrosc 58 2271... 

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