Ot-roBER 1, 1918 



THE INDIA RUBBER WORLD 



crepe, and prove that the process is capable of producing rubber 

 of excellent quality." 



Eaton's tests show the remarkable uniformity of the sample 

 of crepe rubber, considering that they represent the produce of 

 old and young trees ; of pure latex and latex diluted with water, 

 and of rubber made on different days. The rate of cure was 

 found to be more rapid than in the case of the standard sample 

 of crepe, a result attributed by Eaton to the absence of acid. 



The figures given by Eaton show that this method of coagula- 

 tion affords, at least, rubber equal in all respects to the best 

 now being produced by acid coagulation and of greater uniform- 

 ity. The point upon which stress requires to be laid, however, 

 is that it is a process, and seemingly the only practical one, by 

 which the coagulum may be allowed to mature for the length of 

 time essential for eliminating the differences that otherwise re- 

 sult from unstandardized subsequent treatment. 



For the production of "standard" rubber the bulked latex 

 from a day's tapping requires to be placed in the coagulating 

 tanks, as described above, and allowed to remain undisturbed 

 for a fixed time, which it is suggested, should be three days. 

 Under these conditions no putrefaction occurs and the coagulum 

 remains perfectly white, except for a slight surface darkening. 



Judging by the considerations advanced above, the rubber so 

 produced, whatever the source, or whether finished as crepe or 

 sheet, would show no variations in the time of heating required 

 under standard conditions for correct cure, while the vulcanized 

 material would possess the maximum attainable textile strength. 

 The cure would be substantially quicker than that of Para 

 under similar conditions, but this is an advantage, as it enables 

 the manufacturer, while heating for the same length of time, to 

 vulcanize at a lower temperature, which is all to the benefit of 

 the finished material. 



The result of the general adoption of the above described 

 method of operation would be the production of a plantation 

 raw rubber as uniform in its vulcanizing properties as fine hard 

 Para, and one affording at least an equally satisfactory product. 



CHEMICAiri»ATENTS. 



THE UNITED STATES. 

 pROCESS OF Making a Substitute for Whiting.— A product 

 * known as artificial whiting manufactured by processes similar 

 to those employed in the conversion of natural chalk into whit- 

 ing, precipitated chalk, or other forms of calcium carbonate. 

 With such artificial whiting, either during or after its manufac- 

 ture, an organic salt or soap is incorporated. 'The whiting if 

 neutral is made to contain free alkali or lime and an organic 

 derivative is added which will convert the free alkali or lime 

 into a salt or soap. Such addition may consist of oleic acid, 

 tannic acid, benzoic acid, or any of the higher organic fatty acids, 

 or a phenol, such as carbolic acid, or alpha or beta naphthol. 

 (Herman B. Kipper, Solvay, New York. United States patent 

 No. 1,264,392.) 



VuLrANizATioN OF RuBBER. — A method of acclerating a vulcan- 

 izing process which consists in adding to the rubber mixing an 

 accelerator comprising caustic alkali dissolved in a hydroxy- 

 organic compound forming a solvent which is not decomposed 

 by the alkali. The solvent specified is glycerol or glycol. (Doug- 

 las Frank Twiss, Sutton, Coldfield, England, assignor to The 

 Dunlop Rubber Co., Limited, Westminster, London. United 

 States patent No. 1,271,810.) 



Process of Vulcanizing Rubber Shoes. — The articles are 

 heated by the application of a heating medium applied to one 

 side while maintaining the opposite side free from contact with a 

 condensable heating medium, and when the article has been 

 sufficiently heated to prevent condensation thereon, then subject- 

 ing the opposite side to a condensable heating medium at a vul- 

 canizing temperature. (Charles E. Bradley, assignor to Misha- 

 waka Woolen Manufacturing Co., both of Mishawaka. Indiana. 

 United States patent No. 1,271,?43.) 



LABORATORY APPARATUS. 



FILTERING TUBE. 



'T^HE apparatus shown was designed particularly for han- 

 ■*• dling those precipitates whose solubilities necessitate great 

 economy with the liquid used for transferring and washing. 



A straight glass 

 tube, having a stop 

 cock at its middle 

 point, is sealed to a 

 carbon filter tube. 

 The latter is fitted 

 with a two - hole 

 rubber stopper. The 

 stem of a Walter 

 crucible - holder 

 passes through one 

 hole of the stopper 

 while the other 

 contains a right- 

 angled exit tube. 

 The connection 

 leading to the suc- 

 tion pump is in- 

 tercepted by an 

 ordinary T-tulie. the 

 free end of which 

 is joined to a short piece of rubber tubing as an air inlet. 

 In operation, the perforated crucible G with prepared asbestos 

 felt, is set in collar W. Once adjusted, the suction needs no 

 interruption throughout the filtration. When cock S and clamp 

 M are closed, the tube C serves as a small filter flask. When 

 Clamp M is opened and pushed past the shoulder onto the 

 tube T, atmospheric pressure is restored within the apparatus; 

 then on opening cock S, portions of the filtrate can be de- 

 livered into the original beaker. ("Journal of Industrial and 

 Engineering Chemistry," by permission Chemical Director, E. I. 

 du Pont de Nemours & Co.) 



DYNAMOMETER. 



The illustration shows the type of dynamometer used in the 

 so-called "barbecue" test for determining the adhesion of soft 

 rubber to hard in solid 

 truck-tires. It consists of 

 a calibrated elliptical 

 spring which flattens 

 under the strain applied to 

 the end loops, thus im- 

 parting motion to the indi- 

 cating mechanism in the rear of the dial. The instruments have 

 an extra pointer winch is loose and which remains at maximum 

 strain after load is released. Capacities vary from 500 to .S.OOO 

 pounds. (John Chatillon & Sons, New York.) 



.-^ 



FISH SCALE RUBBER. 



The "Scientific .\merican" devotes much space to the success 

 an inventor has attained in compounding fish scales and rub- 

 ber. According to the tale, the compound vulcanizes and 

 forms a tougher product than has previously been discovered. 

 It is a thousand to one that fish scales as a compounding ingre- 

 dient are no better than hundreds of other ingredients already 

 in use. The fact is, anything dry can be incorporated with rub- 

 ber, and the mass vulcanized. The test is what sort of a plastic, 

 if any, can be produced from fish scales without rubber. If 

 alone, they do not sheet and show resilience, the resilience found 

 in the rubber and fish scale combination comes from the rubber 

 and from nothing' else. 



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 you receive. 



