Low melt point fiber

Bonding with binder fibers n. Specially engineered low-melting point fibers are blended with other fibers in a web, so that a uniformly bonded structure can be generated at low temperature by fusion of the binder fiber with adjacent fibers. Skeist I (ed) (1990) Handbook of adhesives. Van Nostrand Reinhold, New York. 

Thermoplastic Fibers. The thermoplastic fibers, eg, polyester and nylon, are considered less flammable than natural fibers. They possess a relatively low melting point furthermore, the melt drips rather than remaining to propagate the flame when the source of ignition is removed. Most common synthetic fibers have low melting points. Reported values for polyester and nylon are 255—290°C and 210—260°C, respectively. 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

Polyesters are the most important class of synthetic fibers. In general, polyesters are produced by an esterification reaction of a diol and a diacid. Carothers (1930) was the first to try to synthesize a polyester fiber by reacting an aliphatic diacid with a diol. The polymers were not suitable because of their low melting points. However, he was successful in preparing the first synthetic fiber (nylon 66). In 1946, Whinfield and Dickson prepared the first polyester polymer by using terephthalic acid (an aromatic diacid) and ethylene glycol. 

Evaporation is used extensively for the deposition of aluminum and other low melting-point metals as well as hard coatings such as TiN for cutting tools, decorative coatings (jewelry), and for the metallization of paper and fibers. It is also a major coating... 

These polyesters were investigated by W. H. Carothers in the 1930 s, but they were not commercialized at that time because of their high flexibility and low melting point (54 ) which made then unsuitable for use as fibers that could withstand the heat of a flat iron. They are used as flexibilizers for other polymers and as reactants for polyurethanes. (PUs). 

Although polyethylene was considered a source of useful fibers at an early date, its low melting point (110-120°C) as well as other limitations precluded active development during the period when production of other fibers based upon the petrochemical industry expanded enormously. The higher melting point of high-density polyethylene gave some promise, but it was overshadowed by the introduction of polypropylene (PP) around... 

Two categories of pitch-based fiber exist isotropic carbon fiber produced from an isotropic pitch precursor, and an oriented, anisotropic fiber produced from a mesophase pitch precursor. Isotropic fibers were developed from low melting point isotropic pitches The precursor was melt-spun into fibers, which were oxidized to render them infusible, and then carbonized. Their low strengths and moduli make these fibers unsuitable for use in advanced composites. Orientation was accomplished by a hot-stretching process (>2200°C), but it is accompanied by the same processing difficulties encountered in the rayon precursor process. A different approach was suggested by the discovery of carbonaceous mesophase. ... 

It requires finishing temperatures of up to 300°C to complete the polymerization. Yields are almost quantitative so the finished polymer may be used directly. Nylon 12, too, has a relatively low-melting point and lower tensile strength in fiber or engineering applications than nylon 6,6 or nylon 6, like the other aliphatic polyamides described in this section (Table 21.4). It is interesting to note that nylon 6,6, the first of the aliphatic polyamides to be commercialized, also has the best properties for many purposes. 

Fibers are responsible for strength, thermal stability, and frictional properties. 1,200 fibers have been tested to-date for this application. The major groups include aramid, glass, carbon, steel, and cellulose fibers. Each fiber has its own set of problems in the application. This may be price, low melting point, low friction characteristics, corrosion, abrasion of metal elements, low strength, etc. Studies in this field affect the automotive, land transportation, military, and aerospace industries and are being maintained at a high level to further improve the properties of brake materials. 

An attractive property of ABS as a plastic for WPC is its relatively low melt point of 100-110°C (212-230°F). This keeps wood fiber from burning during processing. However, a recommended processing temperature for neat ABS is typically in the range of 177-260°C (351-500°F), which makes WPC manufacturing rather difficult. 

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