Crimp ratio

The warp and weft yams are usually specified in mass per unit length, termed the count of the yarn. In the SI system of units, the tex of a yam is used and is defined as the number of grams per 1000 m. Thus, knowing the tex of the yarns in a given fabric and the crimp ratios, the fabric areal density, Wp, can be calculated ... 

In addition, the crimp ratio (i.e., the difference between the length of the yarn and the length of the fabric) can be determined for woven fabrics that feature yam undulations. The combination of the yam crimp ratio and the yarn modulus is needed to describe the tensile mechanical behavior of a composite fabric (Fig. 6.17). 

Determination of the fabric tensile behavior from the yarn modulus and the crimp ratio for a typical yarn. 

The factors influencing the area of material inside the braided preform are the total cross-sectional area (Agy. A -y) of the yarn filaments, the number of yarns in each layer (Ngy. b MEY cy)> the braid angle 9), and the crimp ratio Rq), for the n layers. The yarn filament total cross-sectional area is calculated using the fineness (G, in tex or grams per kilometer) divided by the density (p) of each of the constituents of the yarns. 

Crawford bomb 66 cresylite = mixture of trinitrocresol and picric acid (french) crimping 66 critical diameter 66 CR-propellants = RDX containing rifle powders (USA) cross section ratio -> propellant area ratio 269 crusher 149 362 C.TD. = coefficient of detonation transmission (coefficient de self exitation) (french) 87 CTPB = carboxyl-terminated polybutadiene (USA) 61 329 cumulative priming 66 c.u.p. = coefficient d utilisation pratique (french) 198 cuprene 52 cupric salicylate 163 curing 67... 

The authors also studied the behavior of the calcium salt (26). Again, this material showed distinct characteristics in that a pentahydrate and 8/3 (2.66 stoichi-ometic ratio) hydrate were formed. Whereas TGA in crimped and open pans were performed as before, the emphasis of this paper was on the spectroscopic characterization of the hydrates, particularly given the fractional stoichiometry outlined previously. TGA studies indicated three water loss stages, whereas single-crystal XRD indicated three binding states for the water. This series of papers has therefore... 

Note Crimp stability is normally expressed as the ratio of values of crimp retraction measured before and after a specified mechanical and/or thermal treatment of the yarn. 

Geometrical shear stress (in-plane stress condition) Multiaxial fatigue ratio ffbAyt/ffbult Non-crimp fabric... 

Each fiber producer has developed its own method for modifying the fiber-making process to prepare colored fibers from polymer and concentrate. The color concentrates may be ground to powder and fed in a proper ratio with polymer powder. Alternately, the producer can dilute the colored concentrate pellets in a proper ratio with natural pellets to produce a letdown prior to extrusion. Some systems have been designed to inject melted color concentrates directly into the melt stream during fiber preparation. Such a method proves difficult because for some colors four or more pigments must be added accurately with a concentration ratio difference of 1000 1 or more. The rest of the fiber process is quite conventional, as described elsewhere in this chapter. The extruded colored melt must be quenched, drawn, crimped, and cut to make ST or processed to make filaments with or without texturing. 

Stretch ratio is exceeded. The other layer, however, will still be at a much lower stress level. Hence, if a stretching ratio is applied of, for instance, 1 7 and the stress is relieved, the highly oriented layer will show more elastic recovery (Rl) than the lower-oriented layer (R2). This difference in length will lead to an internal stress and as soon as the film is hbrillated and the fibres are free from external stresses, they will show a spiral crimp, with the high-molecular weight layer on the inside and the low-molecular weight layer on the outside. This structure is shown in Fig. 18. 

This type of pavement is often used for toll plazas, roundabouts and bus stops. Steel fibres are typically between 15 and 50 mm in length with enlarged ends that act as anchorages or crimps to improve bond. However, limits apply to the ratio of fibre length to the minimum dimension of test specimens (such as test cylinders and beams). Typically, fibres are added to the concrete at a rate of approximately 45 to 75 kg/m (Austroads 2012). 

Extrusion takes place through several spinnerets at the same time. The filaments are quenched with air, and the group from each spinneret is then taken up to produce yarn, the draw ratio and degree of orientation depending on the take-up equipment, on whether the process is single or two stage, and on the end use. Continuous filament fibers are not crimped or texturized as produced. Such bulk-... 

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