Decemhkr 



1906.] 



THE INDIA RUBBER WORLD 



79 



THE PRODUCTION OF PLANTATION RUBBER. 



ROBBHK MACIllNHKY A I' I'KKAOENIYA. 



AT tile CeylDii Rubber Kxliibition a feature on tlie pto- 

 grani wliieli proved of exceptional interest was en- 

 tilkd " A Demonstration of Rubber RIacbinery, " in 

 wliich Mr. Herbert Wri^jlit operated or explained 

 the use of each piece of nieclianisui on show for facilitatinj^ 

 the preparation of rubber from lalex. This did not embrace 

 rubber tapping tools which were publicly tested, also Ijy Mr. 

 Wright, on another day, on rubber trees in the garden at 

 Ileneratgoda. 



Mr. Wright began with Macadam's latex strainer, pouring 

 into it a pailful of latex charged with mechanical impurities. 

 The latex flowed into a bag to which a centrifugal motion 

 was given, and the clean latex issued through a pipe at the 

 side, while tlie impurities remained in the strainer cloth. 

 Considerable ipiautities of latex could be handled in 30 to 

 5.) minutes. In tliis experiment, 2,'i gallons were strained 

 in p, minutes. 



Xext came Brown & Davidson's settling tank, designed 

 for the accumulation of latex in large (piantities. This was 

 provided with a drip tin by which a few drops per hour could 

 be added of dilute ammonia or formalin, this being thor- 

 oughly mixed with the late.x through the turning of plates 

 within the tank. The machine used in Mr. Wright's dem- 

 onstration had been filled eight days before with latex, which 

 was still in a good state for coagulation. Latex from trees 

 of varying ages, collected on different days or the same day, 

 can be mixed in the same tank, with the result that rubber 

 of a uniform standard is prepared. The same apparatus may 

 be used for smoking rubber, the fuel used being wood with 

 creosote added, the smoke being so introduced as to come 

 into close contact with the latex. 



The demonstrator now used the Michie-Oolledge machine, 

 by which latex was coagulated in i '.' minutes. After the 

 machine is set in motion there is originally a centrifugal 

 and subsecpiently a centripetal motion incurred. But it 

 seems necessary, in order to effect coagulation, to use some 

 acid. Mr. Wright pointed out there was also to be seen at 

 the exhibition rubber coagulated by the ordinary method of 

 putrefaction. The latex is allowed to accumulate. It under- 

 goes decomposition. Acids are formed and the rubber clots 

 or coagulates. 



There was an extensive disjilay of rubber washing and 

 macerating machinery. The Federated Engineering Co., 

 exhibited two sorts of rollers ; Brown & Davidson four 

 michines, on different lines ; and Walker, .Sons & Co., a 

 small machine. In all these machines the principle is to 

 subject the rubber to a tearing and stretching process, and 

 while in that condition, to wash it with a strong current of 

 water, either hot or cold. When it has been thoroughly 

 wiished the rubber may be passed between other rollers and 

 turned out in crepe and other form.?. All the various ma- 

 chines referred to were put in motion at one time. 



A machine for expressing moisture from rubber, exhibited 

 by Walker, Sons & Co., was next operated. This is practi- 

 cally a mangle placed horizontally. Once the moisture is 

 practicallj' expelled, the complete drying can be effected 

 (i) in a curing house, (2) in vacuum chamber, or (3) in a press. 



Specimens of rubber were prepared by all the various pro- 

 cesses, including two small specimens of l)lock, such as was 

 exhibited so successfully by the Lanadron estate. Practically, 

 Mr. Wright delivered a lecture, during which latex collected 

 during the preceding 12 days was put through all the vari- 

 ous processes described, beginning with the centrifugal 

 straining machine and ending with the making of a 

 " blork " nf rubber. 



AU'.i/^/) or pa'//j:s. 



Bfst iiuplcinent or series t>f iniplenienls for lapping PaiA Irtts 

 (21 coiiipelilors) — (a) Paring : Gold iiiedid, !•;. 1). IJowman ; silver 

 medal, C. O. Macadam, (h) Pricking: Cold medal, W. T. Miller ; 

 silver, E. D. Bowniaii. 



Best inslruiueiit for tapping CasUlloa trees (12 competilyrs) : 

 Gold medal, C. O. Maca<laiii. 



Best iuslrunienl for Ceara trees ( 13 competitors) : Silver medal, 

 C. O. Macadam. 



Best instruiiieiit for raiiil)iiiij> { /■iciis) trees (8 coni])etilors) : No, 

 award. 



Best in.struiueiit for tap])iiig liigh parts of trees : No award. 



Best apparatus for assisting the flow of latex : Silver medal, 

 Brown & Davidson. 



Best apparatus for ceutrali/ing latex from separate trees. No 

 award. 



Best apparatus for storing latex before coagulation : No award. 



Best sample of preserved li(jui(l lalex : No award. 



Best method of coagulating latex : Gold medal, Walker, Sons & 

 Co. ; -silver medal, W. J. Bird (Duckwari e.slale). 



Best melhod of preventing putrefaction of rubber : Gold medal, 

 Brown & Davidison (smoking ajjiiaralus). 



Best apparatus for recovering rubber from bark shavings, or for 

 macerating rubber plants : Gold medal. Brown & Davidson ; silver, 

 p'edeiated Engineering Co. 



Best rubber washing machine : Gold medal, Brown & Davidson ; 

 silver, Federated Engineering Co. 



Best method of protecting rubber trees during tapping : No 

 award. 



Best plan for curing house : Gold medal, Kelway Baniber. 



Best method of packing rubber for export : No award 



Best method of vulcanizing, hardening, or coloring rubber : Gold 

 medal, Kelway Eaniber. 



Preparation of block rubber : Gold medal, Brown iS: Davidson. 



Strainer ; Gold medal, C. O Macadam; gold medal, Kelway 

 liamber. 



THE STRENGTH OH PI ANTATION RUBBER. 

 I.v a lecture at the Ceylon Rubber Ivxhibition .Mr. C. K. 

 Smithett, one of the judges sent out from I<ondon, said that 

 the high price paid for plantation rubber in the London mar- 

 ket was due to its purity. But in point of strength fine hard 

 Para was still superior to the plantation product. How that 

 strength could be obtained without reducing the standard of 

 purity was a question for the planters to settle. But the 

 question struck him : Were they tapping their trees too 

 early ? He knew there was a desire to get into the market 

 as soon as possible, and he feared that tapping at 6 years and 

 even less might be a mistake. Forest rubber trees on the 

 Ama/.on were not tapped until 30 years of age, and at this 

 exhibition some of the rubber which received the highest 

 awards was from trees from 10 to 15 j-ears old and upward. 

 Bad reputations were hard to be got rid of, and it would not 



