Physical Properties of Fibers

The mere fact that a substance may be classed as a fiber does not automatically mean that it is useful. Most known fibers have no known use or very limited uses. Physical properties usually considered in choosing a fiber are strength, durability, and temperature range of usefulness, and also safety if it can be considered a physical property. Under some circumstances hardness will also play a role. In automotive brake systems hardness can become a key factor, because hard fibers can erode metal disks and drums very rapidly. A very large book could be devoted to this subject. Serpentine minerals, Asbestos, alone had more than 3000 known uses. 

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Noncrystalline domains in fibers are not stmctureless, but the stmctural organization of the polymer chains or chain segments is difficult to evaluate, just as it is difficult to evaluate the stmcture of Hquids. No direct methods are available, but various combinations of physicochemical methods such as x-ray diffraction, birefringence, density, mechanical response, and thermal behavior, have been used to deduce physical quantities that can be used to describe the stmcture of the noncrystalline domains. Among these quantities are the amorphous orientation function and the amorphous density, which can be related to some of the important physical properties of fibers. 

Modification of Textile Fibers. The reaction of hydrophobic chemicals with textile fibers offers the possibUity of permanent repeUency without alteration of the other physical properties of fibers. However, the disadvantages caused by complex processing, and resultant higher costs of carrying out chemical reactions on fiber in commercial textile plant operations, have limited the commercial appHcations. The etherification and esterification of ceUulose have been most effective in terms of achieving durable water repeUency (32,33). Radiation grafting of reactive repeUents onto fibers has been studied as a potential commercial process (34,35), as has modification by plasma polymerization of gas monomers or plasma initiated polymerization of Hquid monomers (36). 

These properties will differ in chemically different resins but even chemically similar resins by different supplier can show different performance characteristics. However, in many cases the lowering of the physical properties can be tolerated depending on the end use of the injection molded part. It should be noted based on customer reports that the physical properties of fiber reinforced polyamide parts are not effected by such high aluminum pigment loading. 

With two exceptions, all fibers shown in Table VII had strong hydroxyl bands in their infrared transmission spectra. The exceptions are two recent hydroxyl-free compositions made by the Davy process [39]. One is a low silica composition and the other is a non-silica composition (46.2% AI2O3 - 36.0% CaO - 4.0% MgO -13.8% BaO). An in-depth analysis of the physical properties of fibers shown in Table VII is available [36-37]. 

Compared to recycled HOPE without fiber, physical properties of fiber composites demonstrated significant increases in tensile strength and modulus of elasticity. Additional research is needed to improve composite binding characteristics to allow the stronger flax flbers in the fabric to carry the composites load (Foulk et al. 2006). 

D. K. Needham, D. R. Buchanan, B. S. Gupta and H. R. Horton, Enzymatic removal of formalin-flxed tissues from polyester arteries, and its effect on physical properties of fibers . Journal of Biomedical Materials Research, vol. 16, no. 5, pp. 659-668, Sep. 1982. 

Physical Properties of Fibers Used in Materials for Filtering Media... 

The physical properties of fibers produced from precursor liquid crystalline solutions are generally superior to those obtained from the corresponding isotropic solutions. Probably the most well-known commercial fiber derived from a lyotropic system is Kevlar , produced by Du Pont. Cellulose fibers have not yet been produced commercially from mesophase solutions using the direct solvent route [15]. Tencel , the commercialized cellulose fibers by... 

Table 8,1 Comparison of Physical Properties of Fiber Reinforced MDF Cement and Aluminum. ( 1991, Materials Research Society, reprinted with permission.)... 

Fibers of all types have played an important role in the development of civilization. In this chapter a definition of a fiber will be discussed and why this particular form of matter is unique. Many physical properties of fibers are related to less obvious variables such as asymmetry, surface tension, diameter, length, surface-to-volume ratios, and internal structure. The changes of properties that occur as assemblies of fibers are combined and connected in various configurations as related to phosphate fibers will also be explored. 

Many fiber materials are hygroscopic, that Is, they take up humidity from the ambient air. This can change their physical properties (for example, tenacity). The humidity in turn depends on the temperature of the air. Hence, the physical properties of fibers and textiles depend considerably on the testing chamber climate. 

Shimiyu, J., Okui, N., Kikutani, T. Fine structure and physical properties of fibers melt spun at high speeds from various polymers. In High-Speed Fiber Spinning. Science and Engineering Aspects, Ziabicki, A., Kawai, H., eds. John Wiley Sons, New York, 1985, pp. 173-201. 

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