110 



The Uniformity of -Fine Habd Paea. 



In my opinion the sole reason for the uniformity of Tine Hard 

 Para is the law of averages. Each ball of Fine Hard Para probably 

 takes from one to two months to prepare and thus any daily variation 

 of the latex in concentration, etc., or any variation in the temperature 

 or other conditions of the smoking process employed, are averaged. 

 This indicates at once a method for rendering plantation rubber 

 more uniform in bulk, viz., the mixing together in each case, of 

 rubber prepared on different dates. 



Having summarized the causes of variability in plantation Para 

 rubber and shown the principal factors which have an influence on 

 the problem and stated the probable reason for the uniformity of 

 Fine Hard Para, it can easily be seen what remedies should be 

 adopted to secure uniform results. It is obvious that the problem is 

 not excessively diflicult on any one estate for one type of rubber, but 

 that considei'able difficulties arise in the endeavour to make all 

 estates carry out a similar practice. 



In considering the problem of variability we must at once 

 realize that uniformity can only strictly apply to one type of rubber. 

 Thus thin pale crepe is intrinsically distinct from smoked or plain 

 sheet and as long as there is a market demand for this grade, which 

 will probably be always, since this type of rubber has created its 

 own market for specific purposes for which no rubber of darker 

 colour could be employed, it is impossible for estates to make one 

 uniform product, since thin pale crepe, from its mode of preparation 

 will almost certainly always have a different rate of cure to smoked 

 sheet. It might be suggested that this type of rubber be made as 

 the sole first grade. The answer to' this is that thin pale crepe is 

 almost always inferior to smoked or plain sheet in tensile properties 

 and hence should not be used for articles in which strength rather 

 than colour is a desideratum. 



It is thus evident that for present demands we must prepare at 

 least three and probably four grades of plantation rubber, that is 

 either two first grade and one second grade or two first grade and two 

 second grades. The probability is that four grades is the minimum, 

 since it does not seem desirable from our researches to combine all 

 lower grades. The best solution is probably the preparation of pale 

 crepe and one other first grade and the preparation of two lower 

 grades as follows : No. 1 lower grade crepe to consist of lump, 

 skimmings and picked scrap, and No. 2 lower grade crepe of bark 

 shavings plus earth scrap. 



It is not proposed here, however, to deal with lower grades but 

 with first grades only, although in one respect, the question of 

 " lump " rubber or cup and bucket coagulations, is of interest, as 

 will be seen later. 



