1 64 RUBBER AND 



In fact, from the fluctuations in market price of the 

 different forms of plantation rubber, it may be concluded 

 that manufacturers have not yet arrived at a unanimous 

 preference for any particular method of preparation. 

 At successive auctions the market may be headed by 

 pale crepe, block rubber, smoked sheet or by some other 

 form. From the planter's point of view, creping and 

 vacuum drying are probably the most convenient 

 methods. It may therefore be useful briefly to recapitu- 

 late the successive processes gone through in an 

 up-to-date factory in which these processes are employed. 

 Although objections have been made to both these 

 processes on account of their effect on the mysterious 

 quality known as nerve, yet both are closely similar 

 to some forms of treatment which the manufacturer 

 himself employs. It seems probable therefore that 

 objections to these methods will fade away as soon as 

 large bulks which have been " worked " to an equal and 

 known extent can be put upon the market. 



Creping and Vacuum Drying. 



In a typical factory then, the spongy mass of rubber 

 derived from the acidified latex is fed into the first 

 washing machine. The rubber is passed repeatedly 

 through this machine under a stream of water, and 

 finally emerges as fairly thick crepe. This crpe is 

 passed through a second machine in which the rollers 

 are closely set, and is converted into a continuous strip 



