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THE INDIA RUBBER WORLD 



[Dlce.mber I, 1904. 



THE "SWEATING" OF CONGO RUBBERS. 



TO THE Editorof The India Rubber World : Since the 

 publication of my letter in your journal of October i 

 (page 3) I have had numerous letters from different parts of 

 the world referring to the same, many of them asking ques- 

 tions regarding crude rubber. I think the best way to answer 

 them is through the same medium as before, which I do as fol- 

 lows : 



When criticizing Congo rubber, 1 do so from a manufac- 

 turer's point of view only. The great trouble with which the 

 factory has to contend is that the quality is not constant- 

 neither is the elasticity. To-day we are paying anywhere from 

 80 to 97 cents a pound for the grades known as " tresses," La- 

 pori, Aruwimi, etc. Practically speaking, as far as the manu- 

 facturer is concerned these are all in the same family, 

 and are used in the same way, dried and seasoned in 

 the same temperature, and so on. Now we buy. say 

 10 tons of " tresses " ; they are clean, have a beautiful 

 appearance, and a very small shrinkage, say 5 to 8 per 

 cent. The results are highly satisfactory, and we call 

 upon our broker for some more. He informs us that 

 he has some of the same lot, actually the same. Again 

 we buy. and we have a feeling that we are all right, and 

 that this last lot will fully equal the first, but some day 

 our foreman informs us that the goods are not curing 

 well, don't look well, don't feel as good as usual, and 

 in short, that something is wrong. 



We commence to investigate, and we gradually 

 work back, through the curing process, mill room, 

 compound room, reclaiming department, and finally 

 the washhouse. We ask the foreman here if there is 

 anything wrong with the rubber; he says "No," but 

 we investigate lor ourselves, and we note that here 

 and there in the drying room the sheets are falling ; 

 the temperature is correct, but the rubber is not. Upon 

 examination of a fallen sheet, at the fracture, we find 

 it quite soft and mushy; it shows decomposition. Upon open- 

 ing up a bag, we see evidences of the rubber having sweated. 

 Now I am not quite sure that " sweated " is the correct term ; 

 of course I can only look at it from the factory end, as I men- 

 tioned before, and here is the way the whole thing appears to 

 me. 



The latex is gathered into a receptacle and a process of co- 

 agulation is carried out, either with the aid of chemicals or 

 heat ; sometimes, as we read it, it is with aid of the heat of 

 the human body, etc., and I think that it is right here that the 

 trouble commences ; the coagulation is not perfect, not abso- 

 lutely complete. The edges of the receptacle are allowed to 

 retain non coagulated latex, and this is smeared more or less 

 on the balls, etc., of the correct article ; this I should imagine 

 is not noticeable at the time, owing to the whole mass being 

 more or less sticky, consequently it passes. It is now baled up 

 and starts on a long journey to liurope, and during the voyage 

 this non coagulated mass begins to " sweat " and decompose. 

 On its arrival the rubber is found to be " more or less sticky " ; 

 that is, the non coagulated mass has resolved itself into a soft 

 sticky mass, resembling some of the rubber substitutes. 



01 course this may be caused by exposure to the sun, but 

 owing to general appearances, I am not inclined to that theory. 

 That this " sticky " mass shows decomposition is easily proved 

 by the absence of elasticity, also the absence of any swell or 

 expansion when dissolved in benzine. 



In conclusion, I think that if some of the men who are re- 

 sponsible for the first stages could visit some of the factories 



in America or Europe, they would quickly be able to figure out 

 the why and wherefore of these troubles and so eliminate 

 them. Yours truly. A, D. THORNTON. 



General Supcrinlendenl, The Canadi.in RubbC' Co. of Montreal. 

 Monlical, Canada, Nov. 14, 1904, 



A MODEL MOLDED GOODS DEPARTMENT. 



No other rubber factory in the world has so large or so 

 thoroughly organized a department for the manufacture 

 of molded goods as has The B. F. Goodrich Co. (Akron, Ohio)- 

 The illustration herewith shows one end of the press room, in 

 which there is a battery of 200 hydraulic presses, all built for 

 and equipped to turn out small work. These presses are run 

 in three sections, the division turning on the temperature 



THE GOODRICH MOLDED QOODS DEPARTMENT. 



maintained in each. They are set so that all of the piping is 

 easily within reach, thus avoiding any unnecessary lifting of 

 the molds, while behind each press is a pipe through which 

 fresh air is forced, driving away the heat and the fumes that 

 usually conspire to make the workman's task exceedingly dis- 

 agreeable. In connection with this press department is a 

 completely equipped machine shop where new molds are made, 

 the average being about seven a day for 300 working days. 

 The system prevailing through this department is ideal and 

 has resulted in so large a business that recently another de- 

 partment of 50 presses has been added, with the prospect that 

 that also in time will undergo notable growth. 



THE NEGLECT OF BICYCLE TIRES. 



[from "the HICYCLINO world," NKW YORK,] 



I3RACTICALLY all of the manufacturers who make auto- 

 mobile tires also make bicycle tires. A number of them 

 are spending considerable sums in national mediums in adver- 

 tising the automobile tire. The fact should suggest that they 

 might help their business, and incidentally the cycling inter- 

 ests, did they in ever so small a way include in such advertise- 

 ments the mere fact that they make bicycle tires also. 



One of the attractions of the grounds of Girard College, in 

 Philadelphia, during the past summer, was a " rubber forest,' 

 comprising eighteen fine specimens of Ficus elastica, of un- 

 usual size for greenhouse plants of this species. 



