Tire cords

an aUphatic polyamide, was introduced as a commercial tire cord in 1947 and grew in usage to - 5.4 billion kg/yr (- 2 billion Ib/yr) in the 1990s (10,11). Nylon-reinforced tires use nylon-6 poljmier (polycaprolactam) fibers as well as nylon-6,6 (poly(hexamethylenediainine adipamide)) fibers. Nylon tire cords are characterized by extremely good fatigue resistance in compression and good adhesion to most mbber compounds with simple RFL adhesives. 

Introduced in 1972, the whoUy aromatic polyamide, poly i ra-phenylene teraphthalamide), termed aramid, was the subject of extensive evaluation as a tire cord in all types of tires (8,14). As of the late 1990s, however, only specialized appHcations have emerged for aramid tire cord that draw on their high strength-to-weight ratio to produce tires with lower weight (16). 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Introduced successfully for tires in 1967, glass fibers had properties that made them very attractive for use in tires (5,8). The britdeness of glass fibers, however, imposed some limitations on the final tine cord properties because of the requirement that each fiber be individually coated with a mbbery adhesive to avoid interfilament damage during fabrication and use. This additional treatment step is introduced at the fiber manufacturing stage. For several years fiber glass was used extensively in bias-belted and radial tires, but was ultimately replaced by steel belts in radial tires. 

A tire reinforcement s use is dependent on several physical properties (26). Some of the most important are tabulated in Table 1. These properties effectively screen candidates for use in tires. The secondary features define a fiber s potential for tire use. 

Whenever a new high strength fiber is developed, its potential for tire cord use is always explored because of the commercial attraction of large volumes available in the tire market. Few materials have emeiged to displace the current two major fibers, nylon and polyester (14). Nonetheless, many examples of fibers offering attractive properties for tire cords have been reported in the literature, eg, polyethylene ketone (17), poly(paraphenylene benzobisoxazole) (18), acrylics (19), and high strength poly (vinyl alcohol) (20) (see Vinyl polymers). 

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Tire cords Tire-derived fuel Tire-derived fuel (PDF)... 

Polyamides. In 1988, 77% of U.S. demand for adipic acid was for nylon-6,6 fiber, while 11% was used in nyon-6,6 resins (195). In Western Europe only about 66% was for polyamide, because of the stronger competition from nylon-6. The fiber appHcations include carpets (67%), apparel (13%), tire cord (7%), and miscellaneous (13%). Nylon-6,6 resins were distributed between injection mol ding (85%) for such appHcations as automotive and electrical parts and for extmsion resins (15%) for strapping, film, and wire and cable. 

Tire Ya.rns, A method to iacrease the strength of viscose yam from the 0.2 N /tex (2.2 gf/den) standard to levels needed ia tires was first patented by Courtaulds ia 1935 (18). By raising the ziac concentration ia the spia bath to 4% the thread could be stretched more by immersing it ia a hot dilute acid bath duting extension. Filament strengths iacreased to about 0.3 N/tex (3.3 gf/den), and the cross section became rounder, with a thicker skin than regular viscose. Pairs of these yams were capable of beiag twisted iato tire cords which outperformed traditional cotton cords. 

Catalysts. Iodine and its compounds ate very active catalysts for many reactions (133). The principal use is in the production of synthetic mbber via Ziegler-Natta catalysts systems. Also, iodine and certain iodides, eg, titanium tetraiodide [7720-83-4], are employed for producing stereospecific polymers, such as polybutadiene mbber (134) about 75% of the iodine consumed in catalysts is assumed to be used for polybutadiene and polyisoprene polymeri2a tion (66) (see RUBBER CHEMICALS). Hydrogen iodide is used as a catalyst in the manufacture of acetic acid from methanol (66). A 99% yield as acetic acid has been reported. In the heat stabiH2ation of nylon suitable for tire cordage, iodine is used in a system involving copper acetate or borate, and potassium iodide (66) (see Tire cords). 

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