Other synthetic fibres

Many other synthetic fibres are found in the literature, the trade names of some of them are Novoloid, PBI, Polycarbonate, Alginate, Flurocarbon (Teflon), min- 

Bicomponent fibres are sjmthetic fibres composed of two firmly but separately combined polymers of different chemical and physical structures. The structure of the bieomponent depends on the shape of the spinnerette orifice (side-by-side, sheath eore, matrix - fibril and multi-fibrillary) and the type of spinning method. Due to the structural differences, the two components shrink differently on heat treatment and form crimp and greater bulk in the fibre. The first fully synthetic bicomponent was an acrylic (Sayelle, Orion 21). The use of sheath-core fibres composed of nylon 6,6 and nylon 6 (Heterofil, ICI) for floor coverings is described. 

Biconstituent fibres eonsisting fibrils of a polymer aligned parallel to the fibre length interspersed in a continuous matrix of another polymer and their structure, resembles the bilateral strueture of wool. Clearly fibrillar-matrix ratio and the nature and relative dimension of the eomponents can be altered to vary the physico- 

Z Carroll Porezynski, Natural Polymer Man-made Fibres, National Trade Press Ltd., London, 1961. 

Dembeck, Guide Book of Man-made Textile Fibres and Textured Y ams of the World, 3rd ed.. United Piece Dye Works, New York, 1969. 

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These dyes have affinity for one or, usually, more types of hydrophobic fibre and they are normally applied by exhaustion from fine aqueous dispersion. Although pure disperse dyes have extremely low solubility in cold water, such dyes nevertheless do dissolve to a limited extent in aqueous surfactant solutions at typical dyeing temperatures. The fibre is believed to sorb dye from this dilute aqueous solution phase, which is continuously replenished by rapid dissolution of particles from suspension. Alternatively, hydrophobic fibres can absorb disperse dyes from the vapour phase. This mechanism is the basis of many continuous dyeing and printing methods of application of these dyes. The requirements and limitations of disperse dyes on cellulose acetate, triacetate, polyester, nylon and other synthetic fibres will be discussed more fully in Chapter 3. Similar products have been employed in the surface coloration of certain thermoplastics, including cellulose acetate, poly(methyl methacrylate) and polystyrene. 

Ca is a constant having the value of approximately 8 GPa for viscose-rayon yam. De Vries also investigated some other synthetic fibres his values for the constant Ca were found to be proportional to EjSO, so that the product CaS SO is a constant ... 

Excellent softener for synthetic fibres. If applied to acrylics at temperatures above 80C the very soft bulky handle is very resistant to repeated washing or dry cleaning. Applicable for boiling basic dyebaths. On other synthetic fibres it gives a semi-durable finish. Good non-yellowing properties. 

There are many other synthetic fibres have been developed over the years in... 

Figure 1-35. Formula ofrepeat unit of PTO fibre, showing possible chelated form. 1.8.6 Other synthetic fibres...

A very important factor in the manufacture of nylon, as well as most of the other synthetic fibres, is drawing. Freshly-spun yam, in which the molecules are unorientated, can be stretched to four times its original length with corresponding decrease in its diameter. The elongation is accompanied by progressive increase in orientation. In Fig. 7.3 a microscopic view of a... 

Pure polyvinyl chloride is the composition of PCU, produced in Germany, and of Rhovyl and Thermovyl, made in France. PCU loses its mechanical stability and shrinks considerably, due to the stretched molecules resuming their original configurations, at temperatures of 75 to 80 C. It compares unfavourably, therefore, with other synthetic fibres for textile uses. It has found certain specialized applications for making fishing lines, filter cloths, and sails. 

They are used for cellulose acetate and other synthetic fibres. 

Polypropylene (PP) fibre is one of the most widely used synthetic fibres in the textile industry. PP has some advantages it is cheaper and stronger than many other synthetic fibres and it has been applied widely in various fields, e.g., carpets, automotive interior trim, films, packaging, protective cover, and cables. In particular, it is used for healthcare applications such as surgical masks, babies nappies, and filters, which need to display antibacterial effects. 

The dyeability of polyester fabric is poor compared to that of other synthetic fibres, due to the lack of polar molecules and pendent groups. Lan et al. (1997) used an exdmer laser at 248 nm, 1 Hz and fluence range (20-150 mJ/cm ) to treat the surface of polyester fabric in order to improve both the hydrophobicity and dyeability. Rgure 2.13 shows that the contact angle for a water droplet on an untreated surface (Hg. 2.13a) is less than 90° while, after... 

Polymers added in the form of fibres are now replacing the asbestos reinforced Portland cement that appeared in the mid-1980s. The fibres commonly used today besides steel and glass are PP and PA. A variety of other synthetic fibres can be used including PE, PES, aramid and carbon [39]. 

Cellulose films and fibres 210 000 Usage directly related to production of cellulose acid is consumed during the extrusion process, which results in the regeneration of the cellulose and the formation of Na2S04. Market now stable it declined sharply when polyolefin films penetrated the packaging market and polyester and other synthetic fibres cut into the cellulose fibre market... 

The first form of regenerated cellulose was developed in 1884 by de Chardonnet. Cellulose was nitrated and dissolved in a mixture of ether and ethanol. The solution was extruded through a small orifice and the solvent evaporated to leave a fibre. The fibre (which was too inflammable for direct use) was then passed through aqueous ammonium hydrogen sulphide at about 40°C this treatment resulted in denitration. The product (often called Chardonnet s/ifc) was popular for many years but was gradually displaced by other synthetic fibres. Commercial production of the material ceased in 1949. 

Walton and Majumdar [122] studied the tensile creep of Kevlar fibres and the bending creep of cementitious composites made with these fibres (2.4% by volume of short random 2-dimensionally dispersed fibres). The creep coefficients of the aramid fibres themselves were found to be smaller than those of other synthetic fibres (polyethylene, polyvinylchloride and polycarbonate). The creep of the composite was of the same order of magnitude as that expected in a plain mortar matrix. 

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