1920.] 



THE INDIA RUBBER WORLD 



803 



TORON AND TORON-TREATED TIRES.' 



ANEW ARTKLt, •TiiRON." lias rccciitly been developed as a 

 means of decreasing the cost, improving the quality and pro- 

 longing the life of both pneumatic and solid automobile tires. 

 In the manufacture of tires, it is employed as a liquid to impreg- 

 nate the fabric, cord and other fibrous material used in their 



Fig 



CH;^ 



construction. Chemically described, it is a sulphur terpene com- 

 poinid produced from reaction between turpentine and sulphur 

 dissolved in a solvent such as xylol. 



A marked characteristic of toron is its capacity to thoroughly 

 penetrate fibrous material so that the fabric or cord is completely 

 impregnated after the solvent is evaporated. This material 

 possesses the additional characteristic of acting as a dye, thus 

 colorijig gray goods a pleasant yellow or khaki color. Moreover, 

 the impregnated material gains in strength so that after treat- 

 ment in association with rubber in a tire structure, American 

 peeler acquires a strength comparable to Egyptian or Sea Island 

 til;cr as used m the manufacture of tires under the prevailing 

 practice. 



FRICTION INCREASED BY USE OF TORON. 



More important still is the fact that rubber may lie calendered 

 to toron-treated fabric with ease and with a complete absence of 

 >kips or blisters, as the surface of the fabric is uniformly prone 

 to adhesion with the rubber. .As a ronscquencr nf this, spreading 



of a piece of the same gray goods treated with toron, the friction 

 of the first was IS pounds while the friction of the second was 

 24 pounds. Hence a 60 per cent increase in friction was realized 

 from the use of toron-treated fabric in the building up of the 

 tire. Fig. 1 shows this increase in friction. 



IMPROVED RESISTANCE TO DESTRUCTION BY FLEXING, 



.-\s is well known under the stress and strain, to which a re- 

 volving tire is subjected, owing to the roughness of the road, the 

 tire is being contniually contracted and expanded by an irregu- 

 larly acting torsional force which causes "flexing," It is probable 

 that flexing is the severest of the many adverse influences to 

 which a tire is subjected in actual use, and this flexing tends to 

 cause separation of the fabric, leading to bulging and blowouts. 



In a toron-treated tire the surface of the fabric ply is not only 

 uniformly attached to the rubber, but during vulcanization the 

 rubber flows between and around the threads of the fabric, pene- 

 trating them and bonding them to the next ply, as shown in Figs. 

 2, 3, 4 and 5. As a consequence the load of fle-xing is carried by 

 the rubber to a larger extent than in the older tire construction, 

 since it is more difficult to separate rubber from rubber than 

 rubber from gray goods. 



In flexing, the play of fiber on fiber of the fabric causes these 

 fibers to wear out. Resistance to this has been found to be 

 greater in the case of fa'bric made of Sea Island or of Egyptian 

 cctton than of American cotton, but it has now been shown that 

 when fabrics made from American peelers have been toron- 

 treated and built into tires they show a resistance to flexing equal 

 if not superior to that of tires built with Sea Island or Egyptian 

 cotton. From tests carried out on commercial vehicles it is 

 assured that fabric tires may be constructed and sold carrying 

 a guaranty of a minimum mileage of ten thousand miles, which 

 is a condition never before approached in this manufacture. 



PROTECTING THE FABRIC FROM OXIDATION AND ROT. 



Of nearly equal importance to the life of a tire is the prevention 

 cf its more readily perishable parts from coming in contact with 

 destructive agents. Cotton is very prone to oxidation and rotting, 

 especially when exposed to air and moisture, and particularly so 

 when warm. To prevent this the cotton is protected by its rubber 

 enclosure in a new tire. But in use the tire is continually exposed 

 inn anrl accidents nf the road such as cnntact with sharp 



becomes unnecessary and this expense is eliminated, moreover, 

 the friction is greatly increased. From actual tests of fabric tires 

 built by the same maker and of identical construction except, that 

 one was built of untreated gray goods, while the other was built 



'Laboratory cf W. B. Pratt. Inc., Hoston, .Massactnisctts. 



edges, which may cut into the fabric or cord foundation, and 

 through such perforations may enter air, moisture, dirt and or- 

 ganic germs such as the spores of moulds. Dirt acts as an abrasive, 

 .•\ir with moistiire brings about oxidation and the moulds as they 

 grow in a moist warm attnosphere rot the cotton. Warmth is 



