O'TOBER i, 191S.] 



THE INDIA RUBBER WORLD 



rubber. 

 ;w rubbe 



sball hav 



stretchij 

 iigth. 



treart shall be made from and i 

 taining at least 70 per cent by 

 sulphur shall not exceed 8 per ( 

 Compound shall contain no red 



tread rubber shall be 



im set of 25 per cer 



and holding for 10 minutes. Res 



• the per cent of elongation over 



ion— These 

 Mid containi 

 or plantatio 

 by weight 



shall be made from and have 

 ig at least 85 per cent by volun 

 a rubber. Sulphur content shal 



T)e 



c) Sidewall- 

 stics of a con 

 best quality 

 th; - 



Tde from and ha 

 nm of 65 per cent by 

 - Iph 



the char 



ubber shall be use-l. 

 .800 pounds per sqi 

 2 to 11 inches) and 

 e free of ingredient 

 (d) The total suli 

 oer cent of the \v 

 lanufactuier desires 





for 



shall not 

 rubber used. _ No reclaimed 



.11. 1 .1 :..;: ;;iuim elongation of 450 per cent 

 mm set of 25 per cent. The compound shall 

 to rubber trade as "oil substitutes." 

 ,ny of t!ie above compounds shall not exceed 



new rubber used except as follows: if the 

 Ipliur bearing fillers, thereby causing the total 



of the weight of new rubber, he may do so 

 a sample of the finished unvulcanized stock. 





be spir 



•ally wrapped according to standard 

 utside showing size, type and name 

 ■ tag or label in colors of red, white 



red. first four months of calendar 

 lemlar year; blue, last four months 

 lied bv square, triangle and round 

 ipproximately 2 inches in diameter. 



cars shall be packed as specified by 

 nent, the specifications covering this 



SpEciFir.\TioN No. 1071. 

 CORD CONSTRUCTION. 



(t) As so. 



2. Type. 

 shall be of i 



straight side i 



3. CONSTEI 



manner that 



1 in accordance with this specification 

 designed for the standard S. A. E. 

 inches or 38 by 7 inches. 



(b) All cord material to be of the best quality combed Sea Island, 

 •or Egyptian cotton or its physical equivalent. 



(c) All cord fabric must be thoroughly dried according to standard 

 manufacturing practice, before it is started through the operations of 



(d) The usual methods of inspection used by tire companies in com- 

 mercial practice to discover defects in each roll of cord fabric, shall be 

 employed, and tests to determine the tensile strength of cords shall be 

 made in the individual cords taken from each roll. These tests shall be 

 made in the following manner: 



The individual cords shall be tested in a fabric testing machine in which 

 the distance between crips is approximately 10 inches, which grips separate 

 at ihe rate ol '11 inches per minute. The results shown must be up to 



he cons. 



:d with 



ot r, bead slrelehuig o 



( i) Two chafing sti 



square yard, shall be 



each side of the tire a 



chafing strip shall exte 



ig) There shall lie 



cords which shall h<- 



this cushion shall be .( 



fh) Over the cush 



-open-weave fabric such 



on both sides with a 



properties of a nature 



ire manufacturers in the constri 

 ir as they are sufficient to precli 

 wing off the rim when under p 

 of fabric weighing not less than 



cha 



ign 

 used. Each chafing strip must extend upward on 

 ,t least 154 inches from the heel of the bead. One 

 nd at least 54 -inch above the other. 



a cushion of rubber compound applied over the 

 ivider than the breaker. The minimum gage of 



ion there shall be at least one breaker strip of 

 as is used in standard commercial practice, coated 



rubber compound having the physical and chemical 

 to form a perfect union between the cushion and 



'Tthe 

 George B. Wells, 



tread when the cure is effected. This breaker strip shall have a minimum 

 width of S'A inches. 



Breaker shall be made from the best quality Sea Island or Egyptian 

 cotton or its physical equivalent and shall weigh not less than 10 ounces 

 per square yard. 



(i) The tread of the tire shall not be less than i^-inch thick, 54-inch 

 of wdiich shall be the minimum thickness for the part of the tread under 

 the middle of the non-skid portion. 



(j) The sidewall of the tire shall have a minimum thickness of .0625- 





Tests. (a) Cross sectional diameter 

 e recommended weight and load sched- 

 E. shall not be less than 7.25 inches. 



between sidewall and plies shall average 14 

 ng the standard friction test. 



cushion and plies shall average 16 



(b) Tire 

 per square 

 cretion of the inspector. 



(c) The minimum strength of the tire shall be 3,500 pounds. This 

 "strength factor" is the product of the number of cords per inch meas- 

 ured at the tread at right angles to the cords; times strength of individual 

 cord as taken from the cord tire; times the number of plies. 



(d) The strength of the union between breaker and tread and between 

 breaker and cushion shall average 32 pounds or more per inch, using the 

 standard friction test. 



(e) Strength of the ur 

 pounds or more per inch, 



(f) Strength of the ur 

 pounds or more per inch, using the standard friction 



5. Road Te.sts. Any manufacturer bidding on orders for government 

 business must be prepared to meet the following testing conditions: 



(1) No tires are to be given consideration by the Government unless 

 the company submitting the bid tenders an affidavit stating that they main- 

 tain and properly check up tests on cars to properly test their pneumatic 

 tire product and that these cars deliver an average of 8,000 tire miles 



(2) The cars, speed, loads, and road conditions must be such that the 

 tires are properly tested and the Government mav appoint an inspector to 

 see that the above conditions are complied with. 



(3) A successful bidder must supply an affidavit before delivering any 

 tires to the Government stating that the tires to be delivered are practically 

 duplicates in construction and material of tires which he has previously 

 tested properly and a sufficient number of tires satisfactory to the ATotor 

 Transport Service, at least six tires, have averages on the rear wheels of 

 at least 5.000 miles. 



6. Lining. The inside of each tire shall be properly lined in accord- 

 ance with the standard practice of tire manufacturer. 



7. Flaps. A flap of the size 38 by 7 shall be furnished with each tire 

 as in standard commercial practice. 



8. Compounds, (a) Tread— The tread shall be made from and have 

 the characteristics of a compound containing at least 70 per cent by vol- 

 ume of the best new rubber. Content ot sulphur shall not exceed 8 per 

 cent by weight of the new rubber used. Compound shall contain no re- 

 claimed rubber. Minimum tensile strength of tread rubber shall be 2,600 

 pounds per square inch and shall have a minimum set of 25 per cent. 

 Set test shall be made by stretching 2 to 10 inches and holding for 10 

 minutes. Rest sample for 10 minutes and then measure the per cent of 

 elongation over the ori.ginal length. 



(b) Friction and Cushion— These shall be made from and have the 

 characteristics of a compound containing at least 85 per cent by volume 

 of best quality new wild or plantation rubber. Sulphur content shall not 

 be more than 8 per cent by weight of new rubber used. No reclaimed 

 rubber shall be used. 



(c) Sidewall — The sidewall shall be made from and have the character- 

 istics of a compound containing a mi^iimum of 65 ner cent by volume of 

 the best quality new wild or plantation rubber. Sulphur content shall not 

 be more than 8 per cent of weight of new rubber used. No reclaimed 

 rubber can be used. Compound shall have a minimum tensile strength of 

 1,800 pounds per square inch and a minimum elongation of 450 per cent 

 (2 to 11 inches) and a maximum set of 25 per cent. The compound shall 

 be free of ingredients known to the rubber trade as "oil substitutes." 



8 per cent of the weight of new rubber used except as follows: if the 

 manufacturer desires to use sulphur-bearing mineral fillers, thereby causing 

 the total sulphur to be over 8 per cent of the weight of new rubber, he 

 may do so, but shall submit for analysis a sample of the finished unvul- 

 canized stock. Such stock shall not show a sulphur content in the acetone 

 extract of over 8 per cent of the weight of new rubber used. 



9. Inspection. The Motor Transport Service reserves the right to 

 make any inspection, test, or analysis necessary to insure the product meet- 

 ing all requirements of this specification. 



10. Packing, All 

 practice and properly labelled 

 of manufacturer, and marked with either tag or label in colors of red, 

 white or blue which will denote as follows: red. first four months of cal- 

 endar year; white, second four months of calendar year; blue, last four 

 months of calendar year; years to be designated by square, triangle and 

 round labels or tags — tags or labels to be approximately 2 inches in diam- 

 eten Tires shipped for origitial equipment of cars shall he packed as 

 specified by customer. In the case of oversea shipments, the specifications 

 covering this shall be applied. 



SPECIFICATIONS FOR PNEUMATIC AUTOMOBILE TIRE 

 CASINGS. SIZE 40 BY 8. 



Specification No. 1072. 



COED CONSTRTICTION. 



1. General, (a) Pneumatic automobile tire casings manufactured in 

 accordance with this specification shall be of cord construction of the size 

 known to the trade as 40 by 8. 



(b) The tire must give satisfactory service under a load of 3,650 pounds, 

 when inflated to 110 pounds per square inch. 



(c) Tires to he free from all defects and fully guaranteed as to material 



(d) Tires shall be of the standard commercial non-skid design of the 

 manufacturer furnishing the same, or of rib tread design as specified on the 

 order. In the case of a manufacturer using more than one non-skid tread 

 design, selection of the design to be adopted is at the option of the Motor 

 Transport Service. A small section of the tire shall be submitted for ap- 

 proval before contract is let.^ 



(e) All tires shall be branded with the manufacturer's name, size of 

 tires, serial number, and the tires shall be plainly marked with either tag or 

 label in colors red. white or blue, which will denote as follows: red, first 

 four months of calendar vear; white, second four months of calendar year; 

 blue, last four mtmths of calendar year; years to be designated by square, 

 triangle and round labels or tags — tags or labels to be approximately 

 2 inches in diameter. 



(f) .^s soon as possible it is desired that all tires be marked with the 



