76 



THE INDIA RUBBER ^A/^ORI-D 



[December i, 1906. 



THE INDIA-RUBBER TRADE IN GREAT BRITAIN. 



By Our Regular Correspondent. 



IX marked contrast to the crowding and animation of the 

 vearlv motor shows held at Olympia Hall, London, 

 the recent Engrineering and Machinery Exhibition there 

 was very badly patronized by the public. It is not per- 

 haps surprising that the objects of interest as far as this 

 Journal is concerned were limited to packings 



THE OLYMPIA qJ- y^oQs sorts. We have heard a good deal 

 of the invasion of our market by American 

 packings in late years, this being due to some extent to our 

 rr. inufacturers emanating from firms who only took it np as 

 a side branch. We have some companies, however, now 

 who make a specialty of the packing business and who lay 

 themselves out to meet all modem requirements. Two or 

 three such companies were exhibiting in a comprehensive 

 scale at this Exhibition and their stands may be briefly re- 

 ferred to. The Dexine Patent Packing and Rubber Co., 

 Limited, hive works at Abbey lane. Stratford, in which the 

 necessar. aachinery is installed for washing, mix- 

 ing, and S' -ti. Ihec? — ' -J-..--™^- -= ^-xine was dis- 

 covered some nine year- e a combina- 

 tion of vulcanized India-rui/ljcr and .rredients 

 prepared by a special process. This is ra: commit- 

 tal language as far as the manufacture is concerned, but I 

 understand that the amount of rubber is very small in the 

 packings for high pressure steam purposes. For boiler gage 

 glass rings it is claimed that Dexine is much superior to 

 asbestos, and is at the same time considerabh" cheaper. In 

 the patent metallic boiler feed pump buckets the Dexine is 

 supplemented by an anti-friction wire gauze ; these buckets 

 are fitted back to back with an intermediate ring between 

 each acting as a support to both buckets on the forward and 

 backward stroke. Dexine is stated to with-' -' ' ' F., 

 and 300 lbs. pressure so that our engineers nee • far 

 as America to fill their requirements. Messrs. J anies A alker 

 & Co., of the Lion Works, West India Docks, London, had 

 : ■ irge assortment of their various packings, rubber valves, 

 Baiata belting, etc In the ■""''■■-- '--e' -"'nting for high 

 pressure steel wire gauze ;- sides with a 

 s{>ecial jointing material and ii; the • Lion sheet there is 

 a combination of woven wire asbestos and heat resist-r,? 

 material. To judge h\- the appearance of all the m 

 high pressure packings plumbago enters largely into th<.;„. 



C0MP.A.RED with the large number of proximate analyses 



of raw rubber which have been made in recent years but 



very little information is available as to the 



COMPOSITION composition of the fresh latex. This is no 



OF RUBBER LATEX. '^ , ,._ , , ^ 



doubt largely due to the difficult j- of effect 

 ing its transportation without coagulation setting in. With 

 regard to the amount of rubber in the Para latex the figure 

 of 32 per cent., which I found some 15 years ago agrees 

 very well with other analyses I have seen and it is well 

 known that the strength of the solution is variable. The 

 point, however, to which I wish to draw special attention 

 is the amount of nitrogenous or albuminoid matter in the 

 latex- Weber in his book quotes an anah-sis by Faraday of 

 Para latex showing albumen 1.90 percent, and a bitter nitro- 

 genous substance 7.13 per cent. Weber says that from these 

 figures the rubber would contain about 4.3 pyer cent, of al- 



PRIOE OF 

 RUBBER SOLUTION. 



buminous matter, an amount he considers highlj- question- 

 able. There is one rather curious point about this analysis 

 and that is that the figures for the nitrogenous matter are 

 identical with those given in Faraday's anaU'sis of Mexican 

 latex and quoted by Hancock in his book. Is it possible 

 that some confusion has arisen and that Faraday has been 

 credited with finding more albumen in Para latex than he 

 did find — that is. if he ever made a complete analysis of Para 

 latex, a point on which I have not at the time the oppor- 

 tunity of deciding. This apart, however. I agree with Web- 

 er that the figure is suspiciously high. Lascelles-Scott gives 

 the albumen as 2.71 per cent., though as he does not state 

 the source of the latex it does not go for much. Seeligmann 

 lumps the albuminous and mineral matter together as equal 

 to 12 per cent., which Weber says is altogether too vague. 

 Weber himself does not seem to have given any figures, 

 which is a pitj-, while mj- own analysis showed that the al- 

 bumen matter amounted only to 0.5 per cent, in the Para 

 latex. As the high quality of the Para rubber is due, to 

 some extent at any rate, to its freedom from such impurities 

 it seems of some importance to know what the figure really 

 is. I am not acquainted with any other figures than those 

 quoted, though I imagine that others must have been ob- 

 tained in recent 3-ears. 



If all rubber solution contained the same percentage of 

 rubber, and that of the same grade or quality, the price 

 of the product as sold by different mak- 

 ers might be more nearly uniform. A 

 glance, however, at the varj-ing prices 

 quoted indicates that the above conditions do not obtain, 

 and indeed it is now matter of common knowledge that the 

 one-time uniform standard of strength and quality has given 

 way in these latter days of increased application and in- 

 creased competition to a variety of standards set up by indi- 

 vidual manufacturers. Of course this procedure ma^- not be 

 without method. It may be taken that the strongest solu- 

 tion that can be made conveniently for ordinary use contains 

 21 per cent, of rubber. This strength is required for certain 

 purposes. The British war office, for instance, insist on at 

 least 18 per cent, of rubber in the solution supplied to the 

 .rriage department at Woolwich. Such strength, however, 

 j= quite unnecessary for use in connection with tire repairs, 

 II to 15 per cent, of rubber being quite enough. Solution as 

 low as 8 or 9 per cent, is regularl3- sold, as is also some which 

 has its lack of body made up b3- addition of rosin. But these 

 "- be recommended as being really in the interests of 

 ■•.y. African rubber has largely taken the place of fine 

 . rbber in late j-ears for solution making, and where the 

 product is sold at a corresponding reduction in price there is 

 little to be said against it. Now that solution making has 

 passed so largely out of the hands of the regular works into 

 those of the cy' ' :notor repair and outfit dealers, it is 



not surprising '. y alterations in procedure are to be 



noted. One of these is the use of recovered rubber ; not that 

 which is produced from old vulcanized goods but which is 

 got by special processes from certain forms of factory waste. 

 One such description of waste is the felt cuttings from the 

 tennis ball manufacture, the felt being faced with pure rub- 



