Ill 



The problem therefore with whieh we have to deal in connection 

 with the preparation of first grades, is whether we are going to be 

 content to produce pale crepe and smoked sheet as carried on at 

 present or to endeavour to substitute another and an improved type 

 of rubber in place of smoked sheet and it is this problem primarily 

 with which I propose to deal briefly, leaving the subject open for 

 discussion, after bringing forward the salient facts in support of a 

 new method of preparation. 



It would probably be preferable to state at once that the 

 proposed method of manufacture is that which we have styled 

 " slab " rubber, in lieu of sheet. 



Our researches have shown that whereas smoked sheet cures in 

 about 2| to 2f hours under the conditions employed, "slab" rubber 

 cures in about Ij hours or less than half the time. Apart from this, 

 " slab " rubber is about 20 to 25 per cent, superior in tensile properties 

 to crepe and generally superior to smoked sheet. The advantages to 

 the rubber manufacturer of this type of rubber are therefore obvious. 

 Whether a manufacturer would be prepared to pay a premium for such 

 rubber however remains to be seen and for the present it is taken for 

 granted that such rubber would merely fetch the ordinary top market 

 prices obtained for smoked sheet. We, therefore, have to consider its 

 preparation entirely from the producer's point of view (assuming of 

 course that it is not going to fetch a lower price on the market, as 

 it probably would do if judged by appearance only). What are the 

 advantages we must ask ourselves of any alteration of existing 

 methods. Some planters may be very conservative in this respect 

 and prefer a laissez-faire policy, but I venture to suggest that, 

 especially at this time, we have no more right to adopt such a policy 

 in our commerce and industry than we have in the conduct of our 

 military affairs and I therefore assume that all planters are alive to 

 the necessity of a change if it can be shown that such a change will 

 produce an improved product. 



We have now to consider the possible forms in which such a 

 type of rubber can be prepared, taking note of the advantages and 

 disadvantages of each method of preparation. 



There are only three possible forms in which such rubber could 

 be prepared for the market, viz. (1) virgin " slab " containing about 

 20 per cent, of moisture, (2) in the form of crepe, (3) in the form of 

 dry block. 



Of these forms the most suitable when everything is taken into 

 consideration, is the first. The only disadvantage of shipping virgin 

 " slab " is that extra freight has to be paid on about 20 per cent, of 

 water. 



The pre-war freight on rubber was about ^d. or say 2 cents 

 per lb., while the present rates are about Id. or say 4 cents per lb. 



