142 



THE INDIA RUBBER WORLD 



[Uec 



of the war the Navy Department not only became the greatest 

 user of solution reclaimed rubbers, but admitted their advantages 

 without reservation. 



NEW USES FOR SOLUTION RECLAIM. 



This so-called solution process, a novel process for the utiliza- 

 tion of rubber waste, the Runge works was the first to bring 

 into use, not merely in Germany, but in the world. The process 

 yields by-products which in turn make it possible to employ 

 new methods of working in the manufacture of rubber products. 

 The Runge firm had, even before the war broke out, obtained the 

 patent rights for a series of processes which offer not merely 

 the possibility but the probability of introducing revolutionary in- 

 novations in branches of industry which are remote from the 

 rubber industry, and which before the war were not taken into 

 consideration at all as users of rubber. The scarcity of rubber 

 brought on by the war made it impossible to develop the possible 

 applications of these productions of the firm. But in the coming 

 days of peace the overproduction of the rubber plantations leads 

 to the expectation of ample provision for the German rubber 

 market, whether in the form of crude rubber or of rubber 

 waste, while other industries will have to contend with a con- 

 tinuous marked deficiency in the raw material that must be im- 

 ported from foreign lands. 



The prospects for the solution reclaimed rubbers making good 

 are much more favorable than they were before the war. The 

 matter is one which affects especially the processes for the pro- 

 duction of proofed fabrics, also linoleum-like flooring and other 

 necessaries for the building trade. The textile and linoleum in- 

 dustries are precisely the branches of industry which in the ap- 

 proaching days of peace for Germany will have to suffer greatly 

 from the lack of raw materials. 



THE FUTURE OF RECLAIMED RUBBER. 



In the opinion of the Runge works, Germany's consumption of 

 reclaimed rubber in the coming peace time will be uncommonly 

 great. If German economic experience with the employment of 

 reclaimed rubber, acquired during the war, is fully utilized, the 

 production of a given quantity of rubber goods will require only 

 half as much raw rubber as in the peace period preceding the 

 war, and the other half of the rubber will be supplied by re- 

 claimed rubbers, while the excellence of the product need not be 

 in any way inferior to that of the earlier peace goods. 



A natural prerequisite is that not only must rubber waste not 

 be exported, but it must also be imported. If for example, in 

 the preceding peace time the largest German rubber goods fac- 

 tory exported to England 8,800,000 pounds weight of worn out 

 automobile covers and received back in return 4,400,000 pounds 

 of reclaimed rubber, such a procedure will hardly conform to 

 the economic requirements of Germany. 



It is the belief at the Runge works that in the future German 

 economic life and the rubber reclaiming industry will have a 

 marked development. 



SOLUTION RECLAIMING PROCESSES. 



There are many reclaiming solution processes, several being of 

 other than German origin. 



Heyl-Dia Process (British). By this process ground rub- 

 ber is heated under moderate pressure in naphtha at a temperature 

 of not more than 120 degrees F. The naphtha is drawn off and 

 with it most of the sulphur. The rubber is then heated to over 

 350 degrees F. with a fresh solvent, when it dissolves. The 

 solvent is then removed and the sulphur washed and dried. 



The Basle Process (Swiss). This covers the use of various 

 ethers boiling at a temperature of about 100 degrees C. 



Zl;hl Process (German). Vulcanized waste is dissolved in 

 five times its weight of naphthalene at a low temperature. The 

 naphthalene is then distilled from the mixture with steam. 



Koener's Process (GrjiMAN). Waste rubber is heated with 



solvents such as benzene for a time, after which the solution is 

 further heated with water and the solvent subsequently distilled 

 off. 



Debauge Process (I-'rench). Tires arc soaked for two or 

 three days in xylol or other solvent, when the fabric can easily 

 be stripped away from the rubber. The rubber attached to the 

 fabric layers can be removed by a revolving wire brush, or by 

 digestion in vacuum with boiling xylol. The rubber is ground 

 while in the brittle, swollen condition produced by the solvent, 

 and the latter recovered from the rubber and fabric by steam or 

 dry distillation, in the latter case under reduced pressure. The 

 solvent may also be removed by washing with acetone or alcohol. 

 O'Neill Process (American). The caoutchouc is dissolved 

 out from vulcanized waste rubber by treating the waste in a 

 closed receptacle under about 60 pounds' pressure at a tempera- 

 ture below that determined to the rubber product (266 degrees 

 F.) in the presence of boiling resin spirit. The solvent is 

 removed from the dissolved and devulcanized rubber by vapor- 

 ation. The product is said to have all the characteristics of the 

 original rubber compound before vulcanization. 



De Villers Process (French). Rubber-coated waste fabric 

 is treated with boiling hot tetrachloride of ethane in two stages. 

 The free sulphur is removed by a brief treatment and the solu- 

 tion of the rubber is accomplished by a second extraction with 

 fresh solvent. After removing the fabric, the rubber is re- 

 covered from the solution by adding water and distilling off 

 the solvent with water ; or the solvent may be distilled dry, pro- 

 vided care be taken not to overheat the rubber. 



Compacnie Generai.e des Caoutchoucs de Terebenthine Pro- 

 cess (French, Canadian and Swiss Patents). Rubber is re- 

 covered from rubbered fabrics by treatment with ethane tetra- 

 chloride, heating the fabrics during this treatment, filtering the 

 resulting mass to remove the fabric, adding water to the filtrate 

 and heating it to drive off the water and solvent. 



Goldman Process (American). Rubber stock is recovered 

 from vulcanized rubber by bringing the latter in contact with a 

 solution comprising resin and a material obtained by the action 

 of dissolved resin on vulcanized rubber, and incorporating this 

 solution with the comminuted vulcanized rubber and removing 

 the solvent therefrom. 



Cox Process (American). Rubber stock is recovered from 

 vulcanized rubber by treatment in a resin solution together with 

 a solution of vulcanized gum in a resin solution. 



PoRzEL Process (American). Rubber waste is finely ground 

 and mixed with a rubber solution in the proportion of 2^ to 3 

 pounds of new rubber to each hundred of old, the solvent being 

 gasoline or carbon tetrachloride. The mass is reground, after 

 which the solvent and any contained moisture are removed as far 

 as possible, the temperature being kept below the vulcanizing 

 point, employing a partial vacuum if necessary. Molding and 

 vulcanization are affected with or without the addition of sul- 

 phur, which, when employed, is preferably dissolved in the rubber 

 solvent. 



Harris Process (German). Ground rubber scrap is heated 

 with a solvent such as chloroform, carbon tetrachloride, benzol, 

 etc., the inorganic matter is separated and the solution is treated 

 with hydrochloric acid, rubber hydrochloride is formed and is 

 either filtered off directly or is precipitated with alcohol or 

 chloroform in a vacuum. After washing with alcohol, ether, or 

 chloroform the rubber hydrohalogenide is heated with pyridin 

 under a reflux condenser for 12 to SO hours and the dark solu- 

 tion is poured into water and the regenerated rubber separates. 

 (German patents No. 267,277, November 28, 1912; No. 267,993, 

 December 29, 1912; and No. 267,994, January 21, 1914.) 



Hutz Process (German). This consists in reclaiming vul- 

 canized rubber scrap by treating it with hydrochlorines or the in- 

 termediate products obtained by the action of muriatic acid ort 

 glycerine. (German patent No. 268,843, December 24. 1912.) 



I 



