126 



THE INDIA RUBBER WORLD 



[ I >J .<_■! M m I! 1. l'»l 1 



The Work of the Bureau of Standards on Rubber. 



THE constitution of the United Static gives to Congress the 

 right to fix the standards of weights and measures. 

 Whether this provision ol the constitution was neces- 

 sary to justify the institution of the Bureau of Standards at 

 Washington need not be discussed, but it may be cited as the 

 authority for the action of Congress in providing for this bureau. 

 There has been confided to it the charge of all 

 the standard weights and measures in possession 

 of the federal government, or at least such of 

 them as are the standards from which our weights 

 and measures are derived. 



In connection with the standardization of 

 weights, measures and apparatus of many kinds 

 there is a large amount of work conducted along 

 other scientific lines, including mechanical, chem- 

 ieal and electrical. Along what are known as 

 nit. re practical lines a great number of tests are 

 made on a wide variety of materials, particularly 

 those used in government supplies. Among the 

 articles so used and tested are many kinds of 



rubber g Is. 



In many eases this bureau acts as the examining chemist for 

 the departments which purchase the supplies. In doing this they 

 have a broader idea than the ordinary chemist who is endeavor- 

 ing to protect his client only, for the bureau tries to work with 

 the manufacturer as well as with the purchasing agent so as to 

 help the maker to produce the best goods as well as to provide 

 those that are best suited for the government's use. The private 

 consumer ordinarily wants to get the best goods and is not dis- 

 turbed if others — particularly if they are competitors — get an in- 

 ferior quality. Nor does the ordinary purchaser endeavor to 

 help the manufacturer who furnished the goods. But this bureau 

 believes it good policy to help the manufacturer, so as to secure- 

 desirable products for the government. 



In pursuing this policy much work has been done on the prepa- 

 ration of suitable specifications which shall be at the same time 

 just to both parties and allow the most economical article that 

 is adapted to the purpose. 



In the rubber line one notable instance of co-operation of this 

 bureau with manufacturers and consumers is us work with the 

 Joint Rubber Insulation Committee. Mr. J. B. Tuttle of the 



Fig. No. 2. Apparati - in Determine Bursting Pressure. 



■ acted with the committee, and its proceedings were re- 

 published for general distribution with the approval of the 

 bureau. 



In 1912 Reprint Xo. 174 from the bulletin of the Bureau of 



Standards Vol. 8, No. 3 was published, entitled "The Deter- 

 mination of Total Sulphur in India Rubber," It was by C. A. 

 Waters, associate chemist, and J. B. Tuttle, assistant chemist. 

 A pamphlet entitled "The Sampling of Rubber Goods," was re- 

 printed in the "Journal of Industrial and Engineering Chemistry," 

 with the permission of the director of the bureau of 

 Standards. 



Circular Xo. 38 of the Bureau of Standards, published for dis- 

 tribution in 1912, is entitled "The Testing of Mechanical Rub- 

 ber Goods." and the second edition was published in April, 

 1913. This contains notes on the sources of supply and collec- 

 tion of rubber, rubber substitutes and reclaimed rubber, as well 

 as descriptions of the processes of manufacture, also physical 

 testing of rubber, chemistry of rubber and regulations regarding 

 tests. Most of the apparatus used by the bureau in the work is 

 here illustrated, as well as the methods used in testing. 



Fig. No. 3. Testing Machine Operated by Steam < r Water. 



In performing the chemical analysis there is no special ap- 

 paratus used not found in most laboratories, but the extractors 

 are always the most important feature of rubber analysis. Fig- 

 ure Xo. 1 shows the Wiley Soxhlet extractor as modified by 

 Ford. 



Figure No. 2 shows a hand testing apparatus for determining 

 the bursting pressure of hose. Figure No. 3 illustrates a testing 

 machine operated by a steam or water cylinder. Back of the 

 machine is a press for cutting samples. Figure No. 4 shows a 

 band press and sample cutter with the cut sample beside it; 

 while Figure 5 shows a set of rubber mills geared to. and oper- 

 ated by, a motor. The mills include a cracking mill, a mixing 

 mill and a three-cylinder calender for making frictions, etc. The 

 mixing mill and the calenders are arranged for steam and water 

 circulation through the rolls. This apparatus has just been put 

 in and it is expected that some very valuable experimental work 

 will be accomplished with its aid. The India Rubber World 

 has obtained from the bureau a description of their methods of 

 chemical testing which follows in full. 



