August i, 1902.] 



THE INDIA RUBBER WORi-D 



351 



chine over to the opposite side, and by the time he is through 

 with that, the other table is ready for him. The power re- 

 quired to run this machine is, of course, only nominal, as it is 

 only applied to the cutting knife. Certain machines are placed 

 in the trade on a royalty, while others are sold outright. In 

 connection with this article are shown leading types of cloth 

 cutters, operated by power and by electricity. 



AN AMERICAN THREE ROLL WASHER. 



THREE ROLL WASHERS AND GRINDERS. 



Most of the washing, mixing, and grinding of rubber is 

 done on two-roll mills, upon the same principle as when 

 the rubber industry was in its infancy, although in the United 

 States, to be sure, a greater product has been secured by in- 

 creasing the size of the rolls and speeding the mills up. It is 

 a curious fact that while the three roll washer is an American 

 invention, the three roll grinder is English. The washer is the 

 invention of Mr. Maurice C. Clark, superintendent of the 

 Joseph Banigan Rubber Co. (Providence, Rhode Island), and 

 is built by both the Farrel Foundry and Machine Co., and the 

 Birmingham Iron Foundry. The comparison of 

 the amount of work done by the three roll washer 

 as against the two roll, is exceedingly interesting. 

 One three roll washer will crack up and wash in a 

 day about 5000 pounds of Paid fine rubber, 4000 

 pounds of Paid coarse, Caucho, or Assam, and 

 3500 of low grade Africans, such as thimbles, Ben- 

 guelas, etc., or would equal the work of five or six 

 ordinary two roll washeis, the three roll machine 

 using not over 50 horse power, while the line of 

 two roll washers would use about 150 horse power. 



The English three roll double acting mixing and 

 grinding mills were invented and patented by 

 Joseph T. Wicks, the well known India-rubber 

 expert. This type of mill is fitted with one slow 

 and two friction rolls, the manner in which they 

 operate being well shown in the illustration. All 

 three of the rolls are piped for water and steam, 

 and the mill is opened or closed by moving the 

 slow roll backward or forward. 



In mixing, the rubber is first placed on the slow 

 roll. The compounds are then used in the usual 



manner, and the batch cut and handled just as it would be 

 in ordinary mixing, the difference being that, with two friction 

 rolls, practically twice as much mixing is done in a given time. 

 According to the inventor's figures, a 112 pound batch, which 

 it would take 30 to 40 minutes to fix on an ordinary two roll 

 mill, will be thoroughly mixed in 15 to 20 minutes on a three 

 roll. It has also been found that the rolls can be kept cool 

 more easily on this type of mill than on the two 

 roll. As there are many kinds of stock that should 

 be mixed as quickly as possible, it would seem that 

 this mill might be found very useful. This same 

 three roll system is applied to warming mills, re- 

 fining mills, and for waste rubber grinders. 



It is of interest to know that the inventor and 

 patentee has long been in the rubber business, and 

 is an acknowledged expert. He was at one time 

 connected with William Warne >Sr Co., Tottenham, 

 England ; was later manager of the great factories 

 of Charles Macintosh & Co., Manchester ; was with 

 Maurel et fils, Boulogne sur Seine, France ; and 

 was mill and laboratory manager to the Dunlop 

 Pneumatic Tyre Co., Aston, Birmingham. Mr. 

 Wicks's rubber machinery is built by the old house 

 of James Bertram & Son, Limited, Edinburgh, Scot- 

 land. 



VULCANIZING RUBBER SHOES UNDER PRESSURE. 

 For some time past ex-Governor A. O. Bourn, 

 of the Bourn Rubber Co. (Providence, Rhode 

 Island), one of the pioneer manufacturers of rub- 

 ber shoes in the United States, has been conduct- 

 ing a series of experiments with a view to shorten- 

 ing the time of vulcanization where the dry heat is used, and at 

 the same time bettering the product. Instead of the ordinary dry 

 heater he uses a jacketed vulcanizer into which the shoes are 

 run on specially constructed cars. One of the early results of 

 his experiments was the discovery that the time of vulcanization 

 was much shortened when the air in the vulcanizer was com- 

 pressed. This, however, meant an air compressor and more or 

 less expense. He secured his interior pressure, therefore, by 

 employing a dry vaporizing material which, under heat, liber- 

 ates a gas that exerts powerful pressure upon the rubber sur- 

 faces and at the same time neutralizes thesulphurousand other 

 vapors that have always been more or less a source of trouble 



WICKS'S PATENTED THREE ROLL MIXER. 



