408 



THE INDIA RUBBER WORLD 



March 1, 1921 



photographs. Three classes of rubber come to the factory for 

 treatment: (1) rubber to be remilled ; (2) rubber to be re- 



Brothcrs. l.imitrd. Si ii :^JI^, rr 



"Coolie Lines" or Native Quarters 



treated, and (3) rubber to be packed for export shipment. 

 Class 1 comes in various forms, such as balls, sheets, crepe. 



scrap, kimps, etc. It all contains a certain amount of bark, dirt 

 and other foreign matter. 



Class 2 is mostly ribbed smoked sheets, often mouldy or badly 

 treated in the first place. The mouldy sheets are washed and 

 hung in the smokehouse — and the same with the sheets that have 

 been improperly treated. 



Class 3 is bought in bulk lots of crepe or other sheets and is 

 selected according to established standards. When this has been 

 done it is packed for shipment without further treatment. 



Class 1 material is received at the store room, selected there, 

 taken to the milling room for recreping and then hung in the dry- 

 ing room. When dry the sheets are taken to the storehou.se, re- 

 selected, and finally stored in the house set aside to receive rub- 

 ber ready for shipment, and there packed. The milling process 

 consists of passing the rubber through two-roll mills while a 

 continuous spray of water is played upon it, thus washing out all 

 dirt and foreign matter. 



The typical factory shown in the illustrations is complete in 

 all details with ample "godown" buildings on the premises. It 

 is built for service and utility and is equipped, not only for eco- 

 nomic treatment of rubber, but for the comfortable housing of its 

 coolies, as the long row of "coolie lines" will testify. In its con- 

 struction and installation, too, much good taste has been dis- 

 played, as will be seen by the somewhat ornate and elaborate 

 entrance shown in the illustration. It stands out in striking con- 

 trast to the unadorned and austere appearance of most United 

 States factories. 



The Peachey Vulcanization Process 



OUR RE.\DERS are already acquainted with the Peachey process 

 for the vulcanization of rubber through descriptions already 

 published in these columns.' Further interesting practical 

 details are found in a recently published paper on this process by 

 S. J. Peachey and A. Skipsey" from which the following has been 

 abstracted. 



The authors concede that while a vulcanized rubber of excellent 

 quality is yielded by the Goodyear process yet this method pos- 

 sesses certain disadvantages, viz.: (1) It necessitates the con- 

 tinuous use of steam both as a heating agent and as a medium 

 for exerting pressure on the goods under treatment to avoid the 

 development of porosity ; (2) it is a comparatively slow process ; 

 (3) it restricts the manufacturer in his choice of filling and color- 

 ing agents. The manufacturer thus has to depend chiefly on 

 inorganic compounding materials and a limited range of mineral 

 pigments. The majority of coal-tar dyestuffs are destroyed or 

 modified by the action of sulphur at 140 degrees C, hence delicate 

 tints are practically unobtainable with the usual process of vulcani- 

 zation. 



The new process removes these restrictions and renders possi- 

 ble new technical and artistic eflfects in rubber goods. The dis- 

 covery of the process resulted from an investigation on the be- 

 havior of rubber towards different forms of sulphur. Sulphur is 

 remarkable for the number of allotropic forms which it is capable 

 of assuming. In all three states of aggregation — solid, liquid and 

 gaseous — sulphur appears to toe capable of varying its molecular 

 complexity. An attempt was made to compare the action of these 

 different forms of sulphur on rubber. This attempt was inter- 

 rupted by the discovery that the interaction of sulphur dioxide 

 and hydrogen sulphide produces momentarily a form of sulphur 

 which rapidly combines with rubber at the ordinary temperature, 



^The India Rubber World. May 1 

 •Journal of the Society of Chcmi 

 January 15, 1921, page 5T. 



1920, page S32. 

 ical Industry, Volume XI.., No. 



yielding an effective vulcanization. The reaction between the two 

 gases must take place in contact with the rubber or no vulcaniza- 

 tion results. The sulphur is active only at the moment of libera- 

 tion, and it is fair to assume, therefore, that the effect is pro- 

 duced by atomic sulphur. 



In applying the new process the rubber is exposed alternately 

 to the action of sulphur dioxide and hydrogen sulphide. The 

 gases readily diffuse into (probably dissolve in) the rubber, and 

 there interacting produce active sulphur which immediately com- 

 bines with the rubber at the ordinary temperature, yielding a 

 product wholly comparable with that obtained by the Goodyear 

 hot process. Evidence is accumulating to show that the product 

 is actually superior in strength ; this may be explained by the fact 

 that the depolymerization of rubber produced by heat is avoided 

 in the new process. 



The process appears to be of fundamental importance for the 

 following reasons: 



(1) It is a true sulphur vulcanization— as distinct from the 

 sulphur chloride vulcanization produced by Parkes' "cold cure." 



(2) It eliminates the use of heat and to a great extent the use 

 of mechanical pressure. 



(3) It employs two gases, both of which can be produced on a 

 large scale at a very cheap rate. 



(4) It is rapid in action. 



(5) It enables the manufacturer to employ organic filling agents 

 which cannot be used in conjunction with the hot process or with 

 the Parkes process (most organic materials are attacked and de- 

 stroyed by contact with sulphur chloride). 



A number of cheap and highly durable materials may be fabri- 

 cated from various wastes in this manner and employed as floor 

 and wall coverings, for boot and shoe manufacture, and for fancy 

 leather goods and upholstery work. Further, in numerous manu- 

 facturing processes unconnected with the rubber industry the 

 process renders possible the use of rubber as a binding agent for 

 fibrous and granular materials as an alternative to the resins. 



