October 1. 1920.] 



THE INDIA RUBBER WORLD 



Ocotillo Again to the Front 



IN November, 1916, The India Rubber World chronicled the 

 experimental ■work being done in extracting gum from 

 ocotillo in Arizona. The first work was not apparently 

 'Successful but that success is now assured is the assertion of 

 Daniel M. Bechtel, president of the Ocotillo Products Co., of 

 Indianapolis, which has just completed a large addition to its 

 works at Salome, Yuma County, Arizona. The plant was 

 started several years ago in an experimental way to obtain a 

 chicle-like gum from the ocotillo to use in a waterproofing 

 compound. A process of gasoline solvent-distillation was first 

 employed lor recovering the gum from the bark of the plant, but 

 this method left in the gum so much resinous substance that 

 a perfectly satisfactory cure could not be effected. So, too, 

 the process was rather crude and wasteful ; and, discouraged 

 by the small output and the relatively inferior product, the 

 projectors were often tempted to quit. 



At the outbreak of the World War, however. Dr. E. Cornelius 

 Weisgerber. a noted chemist, who had been put in charge of 

 the research and development division of the United States 

 Army and Navy, and who helped to originate valuable "smoke 

 screen," explosive, and pyrotechnic preparations, was directed 



periments at the desert works, he discarded the solvent-recovery 

 process and substituted that of destructive-distillation with sub- 



1 ut Ulijiillu i.N Its Ijksert Home 



to prepare a waterproof composition for painting concrete ships, 

 for coating concrete piling, and for lining the insides of hand 

 grenades. His attention was attracted to the possibilities of 

 ocotillo gum; and, taking up the earlier and incomplete ex- 



F.\CTORV OF THE OCOTILLO PRODUCTS Co., S.^LOME, ARIZONA 



sequent refinements. The result was the production of a rubber- 

 cellulose base preparation, which, after being sprayed on dry 

 concrete not only stopped all seepage but also overcame one 

 of the worst troubles of concrete ship builders, electrolytic 

 decomposition of the steel reinforcing. Concrete piling was 

 coated on the part most liable to disintegration, between high 

 and low water mark, and after a two years' test government 

 experts declared that neither sun, air, nor sea water had per- 

 ceptibly deteriorated the piling thus treated. 



The company is now equipped to take 100 tons a day of 

 ocotillo, which is gathered by Mexican laborers, who get $6 

 a ton for the shrubs delivered at the mill. The entire plant, 

 except a short root, is used. From the loading platform the 

 plants are hoisted to a chute, whence they are fed to a "hog," 

 which grinds them into small chips. The chips are then put 

 in a retort and decomposed by oil heat, and the volatile 

 pyroligneous acid passes like steam through pipes to condensing 

 vats underground, leaving the gums and tars in the closed vessel. 

 The gums are separated from the tars with suitable solvents, 

 and are sent to separate factories, while the liquor is shipped 

 to a third factory. The Arizona plant makes no finished 

 products. 



One ton of ocotillo yields 306 pounds of charcoal, 206 pounds 

 of tars, 130 gallons of pyroligneous liquor, and 173 pounds of 

 Kums. While the charcoal is said to be superior to willov: 

 or poplar charcoal for sugar-making, powder compounding, or 

 absorbing emanations from radio-active water ; while the 

 pyroligneous liquor is said to be rich in acetic and carbolic 

 acids, as well as wood alcohol, a synthetic oil rivalling linseed, 

 and other substances useful in the arts ; while the tars contain 

 a high percentage of creosote and have in the laboratories 

 yielded 104 fractions, including most of the dyes, drugs, and 

 synthetic preparations hitherto imported from Gennany; it is 

 from the gums that there is extracted, after supplying material 

 for lacquers, a substance said to equal first-class crude rubber, 

 identical with it chemically, and capable of perfect compound- 

 ing and vulcanization. This rubber content is 5 per cent of 

 the whole plant. 



A material practically akin to hard rubber or ebonite, it is 

 said, has been made from the residue of the tars and has 

 shown dielectric or insulating qualities equal to gutta pcrcha. 

 From this product the coinpany intends to produce a compound 

 for unbreakable talking machine records. The investigators 

 have also discovered a cellulose from which may be made non- 



