Fabric thickness

Tank Roof. The roof of a vertical cylindrical tank is treated like a building stmcture and uses the same basic rules as the building codes. For example, the API codes require a roof to be designed for the dead load plus a 122-kg/m (25-lb /ft ) Hve load. The minimum fabrication thickness of roof plates is 3/16 in. (4.8 mm). 

Thickness. Because two fabrics that have identical weight per unit area values may have widely varying bulks, the specification of thickness is essential for properly characterizing a fabric. Fabric thickness has been shown to be direcdy proportional to thermal insulation, or warmth (121). Fabric warmth is the result of the entrapment of air between fibers and yams. A thicker fabric in general allows an increased amount of entrapped air and thus is warmer. 

The proper methods for measuring fabric thickness are described in ASTM D1777. Because fabric thickness is dependent on the appHed pressure, any measurement of thickness should also report the pressure at which the measurement was made. Thus, an apparatus capable of applying variable pressure to the sample while determining thickness would be desirable. Many instmments, however, allow only incremental increases in pressure, depending on the weight used. Regardless of the instmment used, it is always necessary to state the pressure under which the thickness was deterrnined. 

Resilience of textile fabrics when compressed in the bent state is related to wrinkle resistance and retention of shape, drape, and hand. Resilience is an important parameter for evaluating blankets, wearing apparel in which warmth is a factor, pUe fabrics including carpets, and bulk fiber utilization in mattresses, cushions, etc. The general method for determining compressional resilience is to compress and unload the material cycHcahy, creating a plot of compressive force versus fabric thickness. 

Surface resistivity (W/o) Expressed in ohms/square. It is numerically equal to the resistance between two electrodes forming opposite sides of a square on the surface of a material. The size of the square is irrelevant. For conductive materials, surface resistivity is the ratio of the volume resistivity to the fabric thickness (r/t). 

Thermal Conductivity. The most frequently investigated thermophysical property of textiles is thermal conductance, or U, the heat flux without convection transfer (usually expressed as calories/meters2 x seconds x °C), or its reciprocal, thermal resistance. Thermal conductivity, or k, is thermal conductance normalized with respect to the heat flux per unit degree temperature across unit thickness of the material (expressed in calories/ meters x seconds x °C). Many studies have demonstrated that thermal conductance primarily depends on fabric thickness and air present in the material however, the conductivity of air accounts for the greater part of the conductivity values observed (1 2,... 

Instead of the system silica/silicate also other systems such as titania/titanate, zirconia/zirconate can be used as a reference system [xiv]. The response time of freshly fabricated thick-film sensors based on thin-film /3-alumina is very short (about 15 ms at 650 °C). After several weeks of operating this time increases 10 times (150 ms) [xv]. Solid electrolyte C02 sensors using Ni/carbonate composite as measuring electrode are suited for measuring of C02 in equilibrated water gases [xiv]. Using semiconducting oxides and carbonates like ITO (indium tin oxide) Nasicon-based C02 sensors are able to measure at room temperature [xvi]. 

Although the thickness of spun-coated films may be controlled by the concentration of the polymer in the solution, the spinning rate, and the spin-coating temperature, it is difficult to fabricate thick films and the thickness obviously cannot be monitored during deposition. In addition, no combinatorial fabrication methods have been developed for spun- coated PLEDs (see above). 

Figure 8.8 is the common method, which is clear for expression of the formulation of the curvature radius and undulation of the fibre in the textile structure, but it is not detailed enough compared to the observed properties of textile structures. Fibre sections are not perfectly circular as supposed in the schematic. They contain many irregularities. For a sample made from POFs, the fabric thickness h is smaller than the period of the POF crossing p, because the POF is a monofilament and harder than normal synthetic fibres. Therefore, the following equation is more adapted to woven OFs (Masuda et al., 2006) ... 

After neglecting fabric thickness decrement due to uncrimping, the problem could be considered as an in plane situation and that the extensions are small in opposed directions. As it is seen in the experimental part of the study, some of the mechanical specittations and the geometrical details of the fabric ate computed using the properties of the fabric constituents. 

Table 10.4 shows the effect of two heat sources on various types of fabric. Woven and nonwoven fabrics of different area densities made from aramid and FBI fibre have been compared in terms of their respective thermal protective performance (TPP) indices and the results are shown in Table 10.5. TPP values are the times for a temperature gradient of 25 °C to be generated across the fabric thickness when exposed to a heat source as defined in ASTM D4108. The higher the TPP value, the better the thermal protective property. The original fabric constructional data were published in imperial units and they have been converted to SI units for consistency. Woven fabrics were designed as the outer shell material in firefighters turnout coats, and the needlefelt, nonwoven fabrics could be considered for use as a backing or thermal liner in thermally protective apparel. This work shows that nonwoven fabrics provide...

There are conflicting requirements of protection and comfort in protective clothing. Fabric thickness is a major factor in determining the protection afforded against radiant and convective heat, but at the same time it impedes removal of metabolic heat... 

PVC plastisol based coating compositions are desirable coating vehicles from the standpoint of fabrication, thick film capability, and have the ability to be formulated with high solids, but generally exhibit poor durability, color retention, chalk resistance and dirt resistance ... 

X-ray exposure of samples to fabricate thick-film resist structures has developed into an important technique for microfahrication of a wide variety of devices. The use of X-rays to expose thick-film resist samples is advantageous for a variety of reasons including ... 

Filtration properties are effected by the nonwoven fabric production properties. For the filtration purposes depending on the size of the particulate to be filtered, fabric thickness plays quite important role moret titan other properties. 

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