Fibre properties

Cross-linking agents have been proposed for the improvement of chitin fibres in the wet state. Epichlorohydrin is a convenient base-catalysed crosslinker to be used in 0.067 M NaOH (pH 10) at 40 °C. The wet strength of the fibres was considerably improved, whereas cross-hnking had neghgible effect on the dry fibre properties. Of course, the more extended the chemical modification, the more unpredictable the biochemical characteristics and effects in vivo. Every modified chitin or modified chitosan fibre should be studied in terms of biocompatibiUty, biodegradabiUty and overall effects on the wounded tissues. 

Oxidative bleaching of wool is invariably carried out with hydrogen peroxide. The active species involved is likely to be the same as on cellulosic substrates but specific reactions with wool amino acid residues must be considered. The primary reaction is oxidation of cystine disulphide bonds leading to the formation of cysteic acid residues (Scheme 10.41). The rupture of disulphide crosslinks, with attendant increase in urea-bisulphite and alkali solubility values, adversely affects fibre properties. As the severity of bleaching conditions increases, the urea-bisulphite solubility remains little changed but the relationships between alkali solubility and cysteic acid (Figure 10.36) and between cystine and cysteic acid (Figure... 

Important parameters, characterizing fibre properties, are the attenuation a and numerical aperture NA. The attenuation (Equation 1) represents optical losses caused by absorption or scattering of the light guided through the unit fibre length. It is given by ... 

Weibull plots of various fibre properties, such as the filament count, modulus, elongation at break and the strength, can provide important information on the quality and performance of the manufacturing process. The results can be used to formulate a strategy for the improvement of the yarn properties. 

Source Adapted from (i) Cell Wall Mechanics of Trecheids , M.R.E. London, Yale University, 1967, p. 169-170 (ii) A Microscopic Study of Coniferous Wood in Relation to its Strength Properties , H. Garland. Ann. Missouri Botan. Gard., 1939, 26, 1-95 (iii) Morphological Foundations of Fibre Properties , L.J. Rebenfeld, J. Polymer Sci., 1965, C9, p. 91-112). 

Gerking, L., Modification of fibre properties by polymer and within spinning line, presentation (Lecture 52b) given at the 32nd International Man-Made Fibres Congress, Dombim, Austria, 22-24 September, 1993. 

The properties of fibre-reinforced composites are for example determined by a) length, diameter, orientation, volume fraction and properties of the fibres, b) the properties of the matrix and c) the nature of the bond between fibre and matrix. The ratio between length and diameter is an important fibre property. A small diameter means that the area is also small and consequently there is less chance of defects occurring in that area and so less chance of the fibre breaking. 

A.R. Horrocks, B.K. Kandola, G. Smart, S. Zhang, and R. Hull, Polypropylene fibers containing dispersed clays having improved fire performance. Part 1 Effect on nanoclays on processing parameters and fibres properties, J. Appl. Polym. Sci., 2007, 106 1707-1717. 

PLA is the most commonly used biodegradable polymer found in fibre form. PLA fibre properties compare favourably with both PET and rayon fibres. Potential PLA fibre applications include apparel, bedding, carpet, furnishings, personal care, nonwovens and industrial textiles. 

The most successful approach for flame-retarding acrylic fibres is to copolymerise halogen-containing monomers into the fibre. These modacrylic fibres have excellent permanent flame retardancy and acceptable fibre properties. Some problems including reproducibility of dyeing gave rise to their substitution by flame-retardant modified polyester, for example for curtain fabrics and other decorative textiles. 

Polypropylene fibres can be flame retarded with bromine- and phosphorous-containing additives to the polymer melt. However, very high add-ons are necessary and fibre properties are adversely affected. When polypropylene is used in carpets, flame retardancy can be achieved by incorporating halogen-containing compounds and antimony trioxide into the latex backing. ... 

The key fibre property that determines pill loss is the flex life of the anchor fibres. The higher the flex life, the longer the pill remains on the fabric surface. The specific details of these curves depend on fabric and yam characteristics as well as on the particular mechanical forces acting on the fabric. The pill curves for a knit and a woven fabric made from the same polyester yams are shown in Fig. 11.3. 

Occurrence, formation, structure and reactions. Wiley-Interscience, New York,. 597-637 Gummerus M (1985) Sulphite treatment of TMP rejects. Part 1. Properties of fibre fractions at various freeness levels and their influence on the reject pulp. Pap Puu 11 635-647 Heitner C, Hattula T (1988) Ultra-high-yield pulping. Part VI The effect of sulphonation on the development of fibre properties. J Pulp Pap Sci 14 J6-J11 James AN, Tice PA (1965) The presence of carboxyl groups in lignosulfonate preparations. Tappi 48 239-244... 

Cartie DDR, Irving PE. Effect of resin and fibre properties on impact and compression after impact performance of cfrp. Composites Part A 2002 33 483-93. 

Akin D.E. McAlister D.D. Ill Foulk J.A. Evans J.D., Cotton fibres Properties and interaction with flax fibres in blends.. International Cottontest Conference. Bremen 26, 189, 8p, Mar. 13-16, (2002). 

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