CHAPTER XI 



THE MANUFACTURE OF RUBBER GOODS 



THE principal processes employed in a rubber 

 factory begin with the washing and drying of the crude 

 commercial samples, which require thorough cleansing 

 in order that technically pure rubber may be obtained. 

 From this point two series of operations diverge, 

 which may be distinguished as wet and dry processes 

 respectively. In the former the rubber is dissolved 

 in naphtha or benzene, and is then deposited from the 

 solution in moulds or on cloth. The articles so formed 

 are subsequently vulcanised, often by the cold process, 

 i.e. the action of sulphur monochloride. The bulk of 

 the larger and more solid goods are manufactured by 

 a dry process. In this the rubber is first masticated 

 or kneaded, in order to bring it into a suitable condition 

 for the next operation, that of mixing, in which various 

 filling and diluting materials are intimately distributed 

 through the substance of the rubber, together with the 

 sulphur required for vulcanisation. The mixed rubber 

 is then moulded or forced or built up with layers of 



