Textile fabrics, characterization

The performance of a textile fabric is characterized by terms such as strength, hand, drape, flexibiUty, moisture transport, and wrinkle resistance. Although the interactions among fibers in a fabric array are complex, its properties reflect in part the inherent properties of the fiber as well as how the fibers are assembled. 

Composites. The history of phenoHc resin composites goes back to the early development of phenoHc materials, when wood flour, minerals, and colorants were combined with phenoHc resins to produce mol ding compounds. In later appHcations, resin varnishes were developed for kraft paper and textile fabrics to make decorative and industrial laminates. Although phenoHcs have been well characterized in glass-reinforced composites, new developments continue in this area, such as new systems for Hquid-injection molding (LIM) and sheet-molding compounds (SMC). More compHcated composite systems are based on aramid and graphite fibers. 

Braids are intertwined textile structures characterized by bias yam orientation. According to the German Industry Standard Din 60000, braids are defined as 2D or 3D fabrics with even thread density and closed fabric appearance, whose braiding threads cross each other in diagonal direction to their own edges (Wulfhorst and Gries, 2006). 

Textile test specimens vary widely in both physical and chemical characteristics however, most samples can be characterized without any special preparation. Usual samples include fibers, yarns, and fabrics that can be presented directly to most commercial spectrophotometers. It is important to realize that variability within the textile sample is fairly high. A statistical sampling scheme is necessary to achieve a fair representation of a production lot. In the case of fabric samples, several layers of fabric or an appropriate background, such as ceramic or Teflon tile, will be necessary to create diffuse reflectance or transreflectance signals. Textile yarns and fabrics have bidirectional orientations and, hence, either a rotational sample cup or at least three rotations of the stationary cup are necessary to compensate for the differences owing to the sample orientation. Another difficulty with the textile fabrics is that they are usually dyed with various dark or pastel colors. Black and gray samples are more difficult to measure however, using appropriate procedure dyed fabrics are analyzed quite frequently. It is not uncommon to use separate calibrations for (i) white or pastel, (ii) medium shade, and (iii) dark color samples. 

The thin-layer wicking technique has been used to characterize textile fabrics with respect to their surface tension ys (based on the acid-base approach [84]). The technique is based on the Washburn equation and was originally introduced by Giese et al. [115] and later modified by Chibowski and Holysz [116]. The method was found to be especially suitable for characterizing (strips of) textile fabrics [123,124] and the process of surfactant and dye adsorption by the fabrics [125-127]. 

Mandal, S., Song, G., Ackerman, M., Paskaluk, S., Gholamreza, F., 2013. Characterization of textile fabrics under various thermal exposures. Text. Res. J. 83 (10), 1005-1019. 

The computer display then shows the steady-state values for characteristics such as the thermal conductivity k [W/(mK)], thermal resistance R [m K/W] and thickness of the sample s [mm], but also the transient (non-stationary) parameters like thermal diffusivity and so called thermal absorptivity b [Ws1/2/(jti2K)], Thus it characterizes the warm-cool feeling of textile fabrics during the first short contact of human skin with a fabric. It is defined by the equation b = (Xpc)l, however, this parameter is depicted under some simplifying conditions of the level of heat flow q [ W/m2] which passes between the human skin of infinite thermal capacity and temperature T The textile fabric contact is idealized to a semi-infinite body of the finite thermal capacity and initial temperature, T, using the equation, = b (Tj - To)/(n, ... 

Detergent Applications. The primary function of FWAs in the laundry process is to whiten fabric load and maintain the original appearance of the white, laundered articles. Laundering is characterized by repeated appHcation to the same item. Fluorescent whiteners used in this repetitive process have to compensate for the reduction in whiteness and contribute toward prolongation of the usefiil life of the textile material. 

As these results show, naturally degraded cellulose has not yet been fully characterized or duplicated. However, a sharp drop in DP and an accompanying strength loss are common to all the artificially and naturally degraded samples. Since it is the weakened condition of the textile that is being addressed in the consolidation study, any one of the model systems should serve as a useful substrate, at least in the initial studies, even if not all the properties of naturally degraded fabrics are matched. 

Examination of archaeological textile evidence includes analysis of two classes of evidence to yield what is referred to as attribute data. These data are derived from (1) technical fabrication examinations of the fiber-yam-fabric evidence and (2) the physical and chemical analyses of the fiber. Both classes of information are necessary to characterize fully the fabric evidence, and both require photomicrography as an initial step in the analytical procedure. The nature of the information sought leads to different avenues of testing. Because both are essential to the complete understanding of the textile, the sets of results obtained in the testing complement each other. 

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