Natural fibres preparation

Hinrichsen, E. (1994) Preparation and characterisation of natural fibre reinforced thermoplastics composites, MPhil thesis, Brunei University, UK... 

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 starting point in the textile supply chain is the raw material preparation. Textile fibres are obtained from two main sources natural (cellulose or animal) fibres or synthetic fibres. Natural cellulosic fibres include conventional and organic cottons, rayon, linen, hemp, jute, ramie and sisal. Cotton is used to produce 40% of world textile products (Saicheua et al., 2012). The major environmental concern in cellulosic fibre production, especially for cotton fibre, is the chemical fertilizers and pesticides used during cultivation. The second concern is the high level of water consumption (Dave and Aspegren, 2010 Muthu, 2014). Cotton is one of the most popular natural fibres used in the world. Three percent of the world s cultivated land is used for cotton production and 16% of the world s insecticides are used on this crop alone (Saicheua et al., 2012 Muthu, 2014). Moreover, the use of chemical fertilizers, pesticides, machinery and electricity causes some human health and environmental problems. Also cotton growing requires 7—29 tonnes of water per kg of raw cotton fibres (KaUiala and Nousiainen, 1999). Other types of cellulosic fibres are hemp and flax, which can be considered to be the most significant sustainable fibres in the non cotton natural fibre sector (Werf, 2004 Muthu, 2014). 

Murphy, Norton, 2008. Life Cycle Assessment of Natural Fibre Insulation Materials. Final report Imperial College London, Prepared for the NNFCC. http //eiha.org/media/attach/ 372/lca fibre. pdf. 

In terms of green composite or bio-composite, the sol-gel sihca can be applied to natural fibres. An earlier work reports the generation of sihca into the voids of kenaf fibre about 20% of nano-silica could be incorporated into the fibre. Figure 7.2 showed the incorporation of sol-gel silica in the void of kenaf fibres. The kenaf sol-gel silica mixture could be used to prepare bio-composites or green composites by choosing the right polymer matrices. 

A lot of research work has been performed all over the world on the use of natural fibres as a reinforcing material for the preparation of various types of composites. 

Natural fibre composites are prepared using various composites manufacturing methods such as compression moulding, injection moulding, Resin transfer moulding (RTM) and vacuum bagging. The preforms are mostly fibres, fabrics or non-... 

Prepregs are also used. It is often necessary to preheat the natural fibres to reduce the moisture before processing the composites. Equation (23.1) is commonly used in the preparation of composites. 

In addition to the garments prepared from woven fabrics, knits (especially single jersey and interlock) are also the major products suitable for garment finishing. The garments prepared from traditional natural fibres or their blends can be suitably processed in garment form. Some specialty fabric types such as blends of wool/nylon and wool/cotton have recently been processed in garment form in order to meet specific market demands of comfort and performance. 

Examples of filled polymer compositions are discussed, where the role of the preparation method has been clearly identified in relation to compound structure and end properties. Particular attention is also given to recent developments in the field of natural fibre-filled composites, supercritical fluid assisted processing of filled polymers, re-use of thermoset recyclate fillers and silicate layer polymer nanocomposites. 

Common to the preparation of natural fibre-reinforced thermoplastics made by melt processing, is the need to maximise fibre-matrix interfacial bonding, minimise the moisture content and heat history of the organic filler and reduce odour arising from exposure to processing temperatures of around 200 °C. 

Dvorikova, R. A., Nikitin, L. N., Korshak, Yu. V, Shanditsev, V. A., Rusanov, A. L., Abramchuk, S. S., and Khokhlov, A. R. New magnetic nanomaterials of hyperbranched ferrocenecontaining polyphenylenes prepared in liquid and supercritical carbon dioxide in Quantitative Foundation of Chemical Reactions. G. E. Zaikov (N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia), Tanislaw, Grze-gosz (Kaminski Institute of Natural Fibres, Poland), and Lev N. Nikitin (A.N.Nesmeyanov Institute of Organoelement Compounds, Russia). Nova Science Publishers, Inc. New York.,pp. 93-100 (2009). 

The natural protein fibres, such as sheep s wool and dlk, contrast with the fibres prepared firom animal or plant proteins. Exploratory tests have shown that the thermolysis of these natural fibres begins at about 250° and continues almost to 400 °C. 

Polymer composite materials which we investigated on failure occurrence are made on the basis of natural fibres, such as linen, cotton and jute. As the matrix material used epoxy resin R70 with hardener H71 often used for laminating contact while the texture is determined in advance. Jute fabric has a surface density in level 340 g- m , linen fabric 320 g-m and cotton fabric 130 g-m . For each reinforcement three components types have been prepared. Laminates structures with two, four and six layers have been prepared. 

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