Textile selection

Table IV. Seip Textiles Selected for Further Analysis...

It was presumed that there lay tremendous distance to reach our targets by simply studying primary structure of polymer chains in order to imitate hand and appearances of natural fibers and textiles selected through our lengthy history. 

Starch can be split into amylose and amylopectin by a commercial process based on selective solubilities. Amylose is used for making edible films, and amylopectin for textile sizing and finishing, and as a thickener in foods. 

Continuous recuperative furnaces employing metallic recuperators (heat exchangers) have been in use since the 1940s. Operation of these furnaces is simplified and the combustion process is more precisely controlled no reversal of air flow causes temperature variations. The recuperator metal must be caretiiUy selected because of chemical attack at high temperature. Recuperative furnaces are often used in the production of textile fiber glass because they maintain a constant temperature. 

Properties. As prepared, the polymer is not soluble in any known solvents below 200°C and has limited solubiUty in selected aromatics, halogenated aromatics, and heterocycHc Hquids above this temperature. The properties of Ryton staple fibers are in the range of most textile fibers and not in the range of the high tenacity or high modulus fibers such as the aramids. The density of the fiber is 1.37 g/cm which is about the same as polyester. However, its melting temperature of 285°C is intermediate between most common melt spun fibers (230—260°C) and Vectran thermotropic fiber (330°C). PPS fibers have a 7 of 83°C and a crystallinity of about 60%. 

Nonwoven technologies that employ machinery and processing principles traditionally used to manufacture textile, paper, or extmded materials, when viewed collectively, form what may be termed the primary or basic nonwoven fabric manufacturing systems. These systems are or can be continuous processes. Common to each of these systems are four sequential phases fiber selection and preparation, web formation, bonding, and finishing. 

Many large chemical companies produce amino resins and the raw materials needed, ie, formaldehyde, urea, and melamine. Some companies may buy raw materials to produce amino resins for use in their own products, such as plywood, chipboard, paper, textiles, or paints, and may also find it profitable to market these resins to smaller companies. The technology is highly developed and sales must be supported by adequate technical service to select the correct resin and see that it is appHed under the best conditions. 

Modified starches may be acid-modified, oxidized, or heat-treated. Acid-modified (thin-boiling) starches are used mainly in textiles as warp sizes and fabric finishes. Here they increase yam strength and abrasion resistance and improve weaving efficiency. Tbin-boiHng starches also have selected appHcations in paper and laundry starch preparations. 

Miscellaneous. In ore flotation, sodium sulfite functions as a selective depressant. In textile processing, sodium sulfite is used as a bleach for wood (qv) and polyamide fibers and as an antichlor after the use of chlorine bleach. Synthetic appHcations of sodium sulfite include production of sodium thiosulfite by addition of sulfur and the introduction of sulfonate groups into dyestuffs and other organic products. Sodium sulfite is useful as a scavenger for formaldehyde in aminoplast—wood compositions, and as a buffer in chrome tanning of leather. 

Stress—Strain Curve. Other than the necessity for adequate tensile strength to allow processibiUty and adequate finished fabric strength, the performance characteristics of many textile items are governed by properties of fibers measured at relatively low strains (up to 5% extension) and by the change ia these properties as a function of varyiag environmental conditions (48). Thus, the whole stress—strain behavior of fibers from 2ero to ultimate extension should be studied, and various parameters should be selected to identify characteristics that can be related to performance. 

Disperse—Vat Combinations. These require a two-step fixation. The disperse dye is fixed first, usually by dry heat, followed by impregnating of the textile with an alkaU and reducing agent solution and short steam fixation for the vat dye. The selected disperse dyes fixed in the polyester fiber are not destroyed by the reducing agent, but disperse dye remaining on the cellulose is destroyed. 

Textile motors Crane motors Determining the size of motor Sugar centrifuge motors Motors for deep-well pumps Motors for agricultural application Surface-cooled motors Torque motors or actuator motors Vibration and noise level Service factors Motors for hazardous locations Specification of motors for Zone 0 locations Specification of motors for Zone I locations Motors for Zone 2 locations Motors for mines, collieries and quarries Intrinsically safe circuits, type Ex. f Testing and certifying authorities Additional requirements for ciritical installations Motors for thermal power station auxiliaries Selection of a special-purpose motor... 

Frazier test Measures the amount of air transmitted through a filter under selected differential pressures. Historically used for textile products. 

With some processes, the prevention of the contamination of a process stream, or a product, by certain metals, or the products of corrosion, overrides any other considerations when selecting suitable materials. For instance, in textile processes, stainless steel or aluminium is often used in preference to carbon steel, which would be quite suitable except that any slight rusting will mark the textiles (iron staining). 

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