528 



THE INDIA RUBBER WORLD 



[August 1, 1912. 



On the general question of chemical coagulating agents. Dr. 

 Frank remarks : 



"Many products hiunchcd under attractive names, often con- 

 ceal behind them simple and well-known substances ... If the 

 price is suitable, trials should be made. The products obtained 

 by the use of new coagulants should not, however, be placed 

 on the open market, but should first be submitted to a testing 

 bureau. . . . Many attractive secret agents are, moreover, not 

 introduced for the purpose of deception, but because the in- 

 ventors are not acquainted with the materials used, thinking 

 with a stroke of the finger they can open the eyes of an industry." 



IV. MECHANICAL SEPARATION. 



In a certain degree there belong to mechanical methods of 

 separation those drying processes which are based on the me- 

 chanical separation of the serum from the rubber by porous sub- 

 stances, such as clay, wood, etc. But, as Dr. Frank remarks, 

 the real mechanical method for removing the rubber substance 

 from the latex is the centrifugal process, .'\part from all patents, 

 he considers the process of this kind most likely to be used 

 is that of Smith, shown at the London International Rubber 

 E.xhibition. which he regards as particularly suitable for Ficus 

 late.x. He adds that it also seems adapted for Hevea latex, but 

 in the latter case acid should be added previously to the cen- 

 trifugal action. .Although within moderate limits, the "Michie" 

 process has been employed in Ceylon, being a combination of the 

 centrifugal and centripetal processes. 



.'\nother mechanical process of separation is that used on a 

 large scale in the Dutch colonies, for the coagulation of Fictts 

 latex. The latex, after having been freed by straining from 

 mechanical impurities, is subjected to the action of a beater or 

 twirling rod, At one time this process was tedious, but it was 

 accidentally discovered that the addition to the fresh latex of 

 the thickened, creamy secretions from latex which had been 

 standing, n^aterially accelerated the separation, thereby render- 

 ing the process adaptable for use. The basis of this process had 

 Ijeen a number of years ago indicated by Eduardofif, in con- 

 nection with African vine latex. Still another interesting process 

 is that of Professor Daner for Castilloa, in which foreign sub- 

 stances (particularly those of an albuminous nature) are 

 separated by dilution. 



Electrical coagulation* in which the rubber is removed in the 

 form of a band, has also been adopted. 



THE FRANK-M.\RCKWAIJ) I'ROCESS. 



The process of Dr. Prank and Dr. Marckwald is based on the 

 simultaneous employment of dilution and heat, in conjunction 

 with suitable chemicals. It is founded on the injection of 

 latex in a thin jet into a much larger quantity of boiling water. 

 The separated portions almost innnediately thrown off are taken 

 out of the \vater, rinsed, and drawn through rolls with the ob- 

 ject of removing the water they contain and preparing them for 

 drying. The rinsed nr drawn slabs can, if desired, be blocked 

 while wet. 



Suitable acids are recommended for various kinds of rubber 

 (such as citric acid, purub, etc.), formaline being specially men- 

 tioned in connection with Fuiitiiiiiia. These acids are previously 

 added to the diluted latex. The active principle in this process 

 is the rapid and intense solidification, while the albumen is at the 

 same time separated. 



In Dr. Frank's opinion, this process is the most satisfactory 

 yet invented for Funlumia and Ficus. as well as, so far as ex- 

 perience goes, for Manihot latex. The latter coagulated .in East 

 Africa on a different system, has not jiroduced satisfactory 

 qualities of rubber. 



In view of its complicated nature, it is impossible to do more 

 than outline Dr. Frank's detailed and comprehensive treatment 

 of the subject of coagulation, as indicating what is already known 



regarding it, with a view to its further discussion. His investi- 

 gations and those of his associate, Dr. Marckwald, are still being 

 continued in that interesting field of research. 



SOUTH AMERICAN TRADE IN RUBBER GOODS. 



*This- system, Coclcerill'^, was dcjciibtd in 

 June, 1912, page 447. 



The Inui.\ Rvbbeb World 



FROM the views expressed in a recent article by the "Gummi 

 Zeitung," the progress made by Germany in South Ameri- 

 can markets, is largely due to the active efforts of the large 

 Hamburg export houses. The German rubber industry profits 

 by the generally good reputation of German goods. 

 To use the words of the j ournal. itself : 



"England is an important competitor in South Amer- 

 ica. The most important competitor with which the 

 German rubber industry will have, and, in fact, now has 

 to reckon, is, however, the American rubber industry. 



"While all that the United States is now doing in 

 South America is more or less of an occasional char- 

 acter, * * * this competition will very soon in- 

 crease. * * * Xhe American industry is in many 

 cases better situated as to delivery than that of Ger- 

 many. * * * It can use in a remarkable manner the 

 existing steam communications between the southern 

 ports of the United Slates and Venezuela, Brazil, etc." 



Bra'zil, it is added, offers the most extensive possibilities, 

 notably as to furnishing the rubber parts used in the construc- 

 tion of machinery, now being largely produced in that coun- 

 try. Automobile tires meet with a good and regular sale in 

 Brazil, the same remark applying to Argentina, Uruguay and 

 Chile. A steady demand likewise exists in all these countries 

 for solid motor-truck tires. The imports of motor vehicles by 

 South American countries notably increased last year. 



Rubber goods for electrical purposes come from various coun- 

 tries, while insulating material is chiefly imported from Ger- 

 manv, on account of tlie marked development of that branch of 

 German industry. 



-Vrgentina has developed agriculture in a marked degree, 

 which, it is remarked, affords an opportunity for the rubber in- 

 dustry to furnish certain accessories for agricultural machinery. 

 Rubber hose for purposes of irrigation are in regular demand, 

 the same condition? applying to other South American countries. 



Chile and Peru continue good customers of the German rub- 

 ber manufacturing industry. The opening of the Panama Canal 

 will naturalh' increase competition for the trade with those 

 countries. 



In this connection, it is of interest to recall the total figures 

 of American rubber goods exports to South America, as recorded 

 in the statistics published by The Indi.\ Rubber World in De- 

 cember, 1911 (page 119) : 



U. S. Exports of 



Rubber Goods. Population. 



Brazil $150,465 19.910,646 



Argentina 137,460 7.000,000 



Chile 72,110 3,249,092 



Uruguay 42,689 1,111,758 



Peru 36,122 4.500,000 



Colombia 23,017 4.500,000 



Venezuela 18,812 2,591,000 



Ecuador 13,237 1,500,000 



British Guiana 5,980 300,000 



Bolivia 2,053 2,267,935 



Dutch (niian.-i 919 70,007 



Paraguay 51 635,571 



Total $.S02,91S 47,636,009 



