676 RUBBER 



calendering machines in the large factories in Europe. 

 Crepe of any desired width can then be made. 



Holes in Crepe. The presence of holes in crepe, which 

 apparently reduces its market value solely on account of 

 the fact that the rubber is bought on appearance, is really 

 due to not finishing the rubber on smooth rollers; the 

 rubber should be folded on itself so that the holes are 

 closed up during the final finishing process. 



Yellow Patches in Pale Crepe. In the pale crepe now 

 made by the addition of sodium bisulphite, the mottled 

 yellow and wjiite appearance is usually due to adding the 

 solid substance or a concentrated solution which is not 

 properly mixed with the latex, or possibly through the 

 addition of the bisulphite salt after the coagulating acid, 

 so that proper admixture becomes impossible. 



Over-smoking. The appearance attributed by buyers to 

 " over-smoking " may be caused by prolonged smoking 

 after the rubber is dry, a process which has been recom- 

 mended by the chemists of the Rubber Growers' Associa- 

 tion as improving the quality of the rubber, or it may foe 

 due to the use of a fuel, the fumes from which are rich 

 in tarry products, such as coconut husks; in the latter 

 case a mixed fuel should be used. 



Packing of Rubber. 



Although it is difficult to give any satisfactory advice 

 on the subject of packing, it is undoubtedly a fact that 

 even the best of the present cases, such as the Venesta 

 case, is unsatisfactory for the higher grade plantation 

 rubbers, which ought not to require rewashing in the 

 home factory. The unpacking recently of a large number 

 of samples of rubber contained in a number of different 

 cases, received from estates for the London Rubber 

 Exhibition, has demonstrated the fact that even with the 

 greatest care a considerable amount of sawdust, fine 

 splinters, and debris becomes incorporated with the 

 rubber, which must in many instances necessitate the 

 rewashing and maceration of rubber which had been 

 packed in a perfectly clean condition on the estate. This 



