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THE INDIA RUBBER WORLD 



[December i, 1908. 



Hard Rubber at the Marseilles Exposition. 



WHILE the International Exposition at Paris, in 1900, pre- 

 sented comparatively little in the way of hard rubter 

 and allied products, a notable change was apparent at 

 the Marseilles Exposition this year, owing to the development of 

 electrical science meanwhile. Hard rubber was represented on 

 this occasion in such a manner as to suggest that it has become 

 an almost indispensable substance in every branch of economical 

 activity, 



In this article reference is made to the productions of one of 

 the most important hard rubber manufacturing concerns in 

 existence, the rubber works of Dr. Heinr. Traun und Sohne, 

 of Hamburg, Germany, formerly the Harburger Rubber Comb 

 Co. This concern had, indeed, at the Paris Exposition, in the 

 hands of their Paris representatives, a small, but qualitatively 

 interesting collection of hard rubber goods on exhibition ; but 

 at the Marseilles Exposition very important progress was 

 demonstrated. 



The firm of Traun, whose prominence in the hard rubber 

 manufacture has been recognized for upward of 50 years, fol- 

 lowing the requirements of the times, have created in their 

 factories a special and exceptionally complete technical depart- 

 ment at the head of the various divisions of which specialists 

 have been placed. The activity of this firm extends direct to 

 the electrical field proper, as well as to auxiliary materials and 

 apparatus. Included in the first are the strong current branch, 

 dynamo and motor construction as well as the transmission of 

 electrical energy; the minimum or weak current branch, teleg- 

 raphy, the telephone, the field of wireless telegraphy, the auto- 

 mobile branch, and finally the Rontgen or X-ray technique. In 

 the second division one finds the extensive field of chemistry, 

 which, in its electrolytice apparatus, as also for the further ex- 

 ploitation and completion of the chemical products, can no 

 longer dispense with hard rubber as the sole material, which 

 is, in the highest degree, resistant to chemical agents, and at 

 the same time workable. As a further phase of technical utility, 

 exists the field of hygiene. Here the beauty, the cleanliness and 

 the chemical resistance of the material unite to ensure its 

 permanent employment. 



In dynamo construction it is primarily the production of the 

 very solid and high heat resisting hard rubber qualities, the 

 "eisen gummi" (iron rubber), the "resistent" the different 

 "isolasts" and the "ferro-isolast" by the firm of Traun that 

 has won for their products prominence in this difficult field of 

 the insulation branch. Here, in addition to the normal black 

 hard rubber, the utilization of which for ordinary tempera- 

 tures and loads, retains unimpaired, its importance in dynamo 

 construction, the material in question shown either in partially 

 manufactured form, as sheets, rods, tubes, etc., ranging from rods 

 of millimeter in size, to sheets of 100 mm. in thickness and 

 rods of 100 mm. in diameter ; also as furnished parts, for instance, 

 armature insulation, back-connection boxes, terminal blocks, base 

 plates for interrupters, safety cases in all sizes, distributing 

 boxes, plug contacts, cases for measuring devices of all kinds, 

 "ideal" rubber protective tubing for motor cable, brake and light 

 connections, and incandescent lamp sockets and switches. More- 

 over are to be noted the complete insulations for commutators 

 (controller rollers) for electrical street and trunk railroads, as 

 well as magnetic spark extinguishers made of iron insulated 

 with "eisen gummi." Finally may be mentioned the cases and 

 interior insulation devices for measuring instruments of the most 

 complicated character, as well as the variety of storage battery 

 boxes running into thousands of types. 



One is impressed with the multitudinous forms of bell or cup 

 insulators, the employment of which, with tensions of a few 



hundred volts, as simple bells, and at higher voltages, for multi- 

 plex bells, is still very popular. Compared with porcelain, the 

 hard rubber bell has the advantage, with otherwise equal electrical 

 properties, that the accumulation, within the inner edge of the 

 bell,, of spider-webs, etc., is prevented, the sulphur in the hard 

 rubber being objectionable to insects, which greatly simplifies 

 the work of keeping insulators clean on long circuits. In the 

 case of portable circuits — field telegraph lines, for instance — hard 

 rubber has almost superseded the porcelain insulator. Every 

 type of insulator for electric street and trunk railways is repre- 

 sented ; spherical and bolt insulators, caps and cones, rotary in- 

 sulators, buckle insulators, for very high traction loads, ham- 

 mer insulators, section interrupters, and the like. 



Wireless telegraphy could hardly have attained its present 

 success without hard rubber. For example, there are powerful 

 inductor fittings, the hard rubber tubes of which have walls 15 to 

 25 millimeters in thickness, by means of which it is possible to 

 produce the electric sparks of the enormous length necessary for 

 the transmission of the wireless energy ; attuning coils of gigantic 

 proportions, coils for variable self-induction, condensers, antennae 

 transmission tubes, and special insulators, which insulate the 200 

 millimeter long sparks in the transmitting devices. 



The automobile branch was represented at the Marseilles Ex- 

 position in a manner to show the most recent development in 

 this field. While the part played here by the hard rubber in- 

 dustry in automobile construction is largely confined to the elec- 

 trical features, there is to be, nevertheless, the display of steering 

 wheels, setting levers, etc., covered with hard rubber for pro- 

 tection against heat or cold. In the motor vehicles operated 

 by explosion, the most important feature in hard rubber is the 

 electrical ignition apparatus, for the parts of which the highest 

 degree of electric insulation and capacity for resisting elec- 

 tric perforation, the greatest heat resisting capacity and least 

 liability to wear, are demanded. The large number of dis- 

 tributing discs, with the numerous metal contacts, so difficult to 

 vulcanize in, the contact coils, carbon holders, plug contacts, 

 in their fine finish, delight the connoisseur. 



The great spark inductors and their apparatus, used in the 

 Rontgen or X-ray branch, have already been mentioned. New in 

 this field are the protective devices against the effects of the 

 Rontgen rays, for which purpose, permeable and electrically non 

 conducting substances are homogeneously combined, or com- 

 pounded, with substances that absorb such ray. By this means 

 it has been found possible to produce aprons, masks for Rontgen 

 lamps, etc., that protect the operator. 



One of the most important fields for the hard rubber industry 

 is offered by chemistry. Here the electric current and its 

 necessary insulation, distribution, and transmission, in connec- 

 tion with the employment of enormously powerful currents on 

 the one hand, and the production of substances that exercise a 

 destructive effect on most formable materials, 'has furnished a 

 previously unexpected field for the use of hard rubber. The 

 electric requirements have already been referred to above, but 

 the rubber-coated metallic kettle for boiling, stirring and as- 

 sembling purposes and the rubber-coated iron stirring appa- 

 ratus working in it, the hard rubber conductors to carry off the 

 resultant products and the branches, bends, T and elbow pieces 

 with the cocks, slides and valves necessary therefor, are a sight 

 in themselves. To this must be added the hard rubber pumps 

 of every description, made wholly of hard rubber, or in which 

 the parts coming in contact with acids or alkalies are coated. 

 Dr Heinr. Traun und Sohne received the highest award at 

 Marseilles — the grand prrx — for their exhibit of manufactures 

 used in the hard rubber industry. 



