188 



THE INDIA RUBBER WORLD. 



(March I, 1911. 



REFRIGERATION IN RUBBER MANUFACTURE. 



THIS was the title of a paper conimimicated to the Inter- 

 national Refrigeration Congress held last October at 

 Vienna. From the translation of it whicli appeared in 

 La Rcvuc Generate du Froid for December, 1910, published at 

 9 .'\vcnue Carnot, Paris (17) we give herewith the following 

 fairly exhaustive summary of its contents. 



There are two applications of refrigeration in the rubber 

 industry, one in connection with the manufacture of fine cut 

 sheet and the other with the recovery of naphtha from spread- 

 ing machines. With regard to England the most extensive 

 and widely distributed application of these freezing processes 

 is found in the various card cloth factories in Lancashire and 

 Yorkshire as in these w-orks the freezing machinery is very 

 generally installed for the double purpose of condensing the 

 naphtha from the spreading machines and of consolidating the 

 •circular rubber blocks preparatory to their being cut into sheet. 

 In these works, however, as in the few large rubber works 

 -where fine cut sheet is produced, there is considerable varia- 

 tion in the details of the refrigeration machinery and process 

 adopted. 



With regard to cut sheet, a moderately low temperature 

 suffices for perfect solidification of the block to the core. If 

 the temperature is too low the block would be of uneven con- 

 sistency, as the sudden solidification of the outside would pre- 

 vent the cooling of the interior which would remain soft and 

 unfit for cutting. The best way of freezing a block is to put 

 it in the open air in winter weather, but as the British winters 

 are ver>' variable and as the demand for cut sheet is general 

 throughout the year, all the factories have found it necessary 

 to employ refrigeration, and nowadays there are no summer 

 stoppages in England at works where this was not uncommon 

 in the past, as the modern procedure includes refrigeration of 

 the work rooms. The author disclaims any intimate knowledge 

 of the state of affairs regarding refrigerating on the Continent 

 or in America, and does not claim that present-day procedure 

 in England represents the latest improvements, though he 

 claims that English cut sheet still holds the premier position a, 

 to quality. Alteration in refrigerating procedure might pos- 

 sibly be advantageous as regards economy, but he does not look 

 for any improvement in the quality of the product. 



It is not unnatural that the author should feel compelled to 

 show some reserve with regard to giving details of the pro 

 cedure at the factories, but even in the absence of full details 

 the descriptions which follow are of interest, .^t the india- 

 rubber works of Messrs. Chas. Macintosh & Co., Limited, of 

 Manchester, the freezing of the blocks was effected for many 

 years by immersion in the well-known mixture of ice and salt. 

 Now, however, the firm have a very complete installation 

 which includes an ammonia machine for freezing the blocks 

 and also a sulphurous acid machine for cooling tlie large work- 

 room in which the cutting machines are placed. The ammonia 

 machine is situated in a chamber insulated with charcoal, and 

 the blocks stand herein for a period of lime which represents 

 a considerable saving compared with the ice and salt method. 

 The workroom is also insulated with charcoal and kept at a 

 temperature of about SO degs. Fahr. during the summer months, 

 the water dripping on the knives being also cooled. Sheets, of 

 which 160 go to the inch, are now being cut in summer in this 

 room. At the card clothing works of Messrs. Horsfall & Bick- 

 ham, at Pendleton, Manchester, the arrangement is rather dif- 

 ferent. Here the artificial freezing of blocks was initiated about 

 40 years ago, the plant being designed also for the recovery 

 of naphtha. The freezing machine is after Siddeley & Mac- 

 kay's patent, in which ether is used, and was put in by the 

 now defunct firm Arrowsmith, Siddeley & Co., of Liverpool. 

 These machines in the various card cloth factories give a 

 uniform recovery of SO to 60 per cent, of the naphtha used. 



Fur freezing llie blocks a wooden tank, 12 ft. square, is set 

 into the ground and is well insulated by sawdust. The tank 

 is filled with brine circulating from the refrigerating plant, 

 and the circular blocks are put into tightly tilting iron cases 

 fixed in the tank. The brine pipes passing througli the cutting 

 room assist in reducing its temperature. 



At the card cloth factory of Messrs. John Whiteley & Sons, 

 of Halifax, Yorksliire, a branch of the English Card Clothing 

 Company, an ether machine is used for freezing the block* 

 though the proess adopted differs somewhat from the two to 

 which reference lia.-; been made. II. L. Terrv. F. 1. C. 



•THE INDIA RUBBER WORLD" HERBARIUM. 



■ I 'HE illustration shows some of the many specimens uf leaves 



■* and Howers of rubber producing trees which were pressed 



and mounted in the Botanic Gardens. Trinidad, by a botanist 



who is specializing on rubber producing sjiecies They are 



From "Tiik I.xiua Rubber WnRi.n" Herbarti'm. 



mounted on Bristol board, 12 x 18 inches, are glass covered and 

 framed. They are notable as being exceedingly perfect and 

 form the nucleus of a new feature of The India Rubber 

 World library — a rubber herbarium. The species shown in the 

 illustration embrace the following well-known rubbers : 



No. I. Cryptostigia grandi- 



Aora. 

 No. IT. Tievea Brasiliensis. 

 No. III. Castilloa elastica. 

 No. IV. Funtuinia elastica. 



No. V. Landolphia Kirkii. 



No. VI. Ficus elastica. 



No. VII. Mimuso/'s glohosa. 



No. VIII. Manihot Clacmii. 



The United States consul-general at Hong Kong states that 

 an official report estimates the number of Para rubber trees under 

 cultivalion in Cochin China at over 1,000.000. of which about 

 15,000 are being tapped. 



