144 



RUBBER. 



Stoves Nos. i to 4 require a i N.H.P. boiler, and Nos. 5 and 

 6 require a 2 N.H.P. boiler. 



The number of square feet of rubber at each charge is 

 calculated on the shelves being about 2\ inches apart in each 

 case. This is suitable for crepe, biscuit, or worm rubber, and if 

 required for drying rubber in blocks, the distance apart of the 

 shelves will be increased to suit the sizes of blocks used. 



We may state that the areas given refer to one side of the 

 shelves only on which the rubber is placed, and does not take 

 into account the drying surface of the underside of the shelves. 

 The inspection fittings of this apparatus enable the operator to 

 watch the progress of the drying. The stoppage of the flow of 

 water driven off from the rubber indicates when the process is 

 complete. 



BRIDGE'S VACUUM DRIER. 



Another form of a vacuum drying plant is shown in Fig. 32. 



PACKING RUBBER FOR EXPORT. 



The importance of keeping rubber dry and protecting it from 

 bright light during the time which elapses between manufacture 

 and despatch to market will be apparent from the preceding 

 remarks. Good stout wooden cases should be used in packing, 

 as rubber contracts in transit, and when the cases containing it 

 are roughly handled the sides are liable to be knocked out. 

 Ordinary tea-chests with an iron rim have proved satisfactory. 



Carefully grade all rubber ; light and dark coloured samples 

 of each grade should not be mixed. To prevent the danger of 

 contaminating sound with " tacky " rubber they should be kept 

 separate. No packing material such as paper should be used 

 which is liable to adhere to the rubber. in transit, and the interior 

 of cases should be free from loose splinters, shavings, saw-dust, 

 &c., for a similar reason. To prevent dust and dirt entering the 

 cases and adhering to the rubber, wax-paper might be beneficially 

 employed. 



The loss in weight of plantation rubber in transit varies 

 between \ and \ per cent. 



" Fine Para " is usually received in packages weighing from 

 280 to 300 Ibs., but brokers suggest that packages of plantation 

 rubber should weigh from i to 2 cwt. each. 



