Tenacity polypropylene fibers

Pinoca, L. Africano, F. High tenacity polypropylene fiber and process for making it, U.S. Patent... 

Kavesh S and Prevorsek D.C, High Tenacity, High Modnlns Polyethylene and Polypropylene Fibers and Intermediates therefore US patent 4,413,110, 1 November 1983. 

S. Kavesh, D.C. Prevorsek, High tenacity, high modulus polyethylene and polypropylene fibers intermediates therefore, U.S. Patents 4,413,110 assigned to Allied Corp., Nov. 1,1983. 

Polypropylene and polyethylene are strong fibers with good elongation and recovery properties. The tenacity of fibers varies from 3.5 to 8 g/d (31-81 g/tex), with an elongation at break of 0%-30%. The fibers recover well from stress, with 95% recovery at 10% elongation. The fibers are moderately stiff and have moderate resil iency on bending. Moisture does... 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

FIGURE 3.37 Tenacity and elongation versus take-up velocity for two CR polypropylenes. (From Jack, H.P. McKinley, J.R. Symposium on Polypropylene—Growth Fiber of the Eighties, New York, September 1981. With permission.)... 

Polyolefins such as polyethylene (PE) and polypropylene (PP) are known for their lightweight, ease of processing, excellent chemical resistance, water repellency, and reasonable strength and tenacity. This makes them the material of choice for many textile fibers and nonwoven applications. 

Polypropylene (PP) fiber was supplied from Kolon Glotech Co., Ltd., Korea. The specific gravity and the melting point of PP fiber were 0.91 and 160-165°C, respectively. And the tenacity and elongation of the PP fiber were 1.5-4.5 g/denier and 50-350%,... 

The production machines can be normal spin-draw winders, as for the other melt-spun fibers. But here also, compact machines have been developed, for example for bulked continuous filament yarn (BCF, for carpet) with all the process steps on one machine, at an end speed of <1000 m min h Polypropylene is small in textile applications (in sportswear) but it has a reasonable position in high-tenacity yarns, in low-temperature applications such as ropes, cables, and geotextiles. It should be added that polypropylene can be drawn to high ratios (see Section 17.7.2). This results in very good tenacities, but the helix configuration of the isotactic chain in the crystals severely limits the modulus. 

Figure 14.21 Comparison of the tenacity and specific modulus of various fiber-forming materials with SPS [22]. PAN polyacrylonitrile PP polypropylene PE polyethylene PET polyethylene terephthalate PBO polybenzoxazole PVA polyvinylacetate.

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