January 1, 1915.1 



THE INDIA RUBBER WORLD 



227 



new mats, hose, toys, and goods not absolutely necessary have 

 also been scrapped and reclaimed. The same source also affirms 

 that stores of hard rubber goods ready for export were con- 

 demned and ground to dust and remanufactured into electrical 

 parts, for military use. 



In this connection the kite German prohibition of the export 

 ■ 'i hard rubber goods in any form takes on an added interest. 



The following are included in the list of articles forbidden ex- 

 port by Germany: Caoutchouc, guttapercha, balata; waste rubber; 

 oil caoutchouc for proofing; surgical instruments, with exception 

 of obstetrical and dental; rubber for rubber hose, bandages, etc.; 

 cable for military and general purposes; goods out of soft 

 i. >ut. Ii'ii. , with the exception of guttapercha paper and certain 

 products of guttapercha for asbestos goods. Special permits must 

 be obtained if it is desired to export any of these articles, and no 

 permits will be granted on hose, tubes, tire covers and tires. 



Among rubber goods to which attention lias been given in 

 Germany for the war are drinking bottles, tobacco boxes and 

 other articles to help the German soldiers withstand the hard- 

 ships of war. Recent additions to the military kit include "gutta 

 percha paper" for the treatment of sore feet. This article is 

 displayed in the druggists' windows, accompanied by a show 

 card calling attention to its merits, and stating that its applica- 

 tion does not involve disuse of the feet. It is wrapped around 

 the feet before putting on the socks, so that the sore places are 

 fully covered, thus relieving the friction caused by the socks in 

 marching. 



In addition to the regular articles needed by soldiers, there 

 are a number of specialties which have been taken up in Ger- 

 many, such as sleeping bags, ear protectors, and head, ear and 

 nose bandages. Caps, including the "Mensur" style, which have 

 been in the hands of bandage makers and druggists, are also 

 now receiving the attention of the rubber trade. 



The "Vogufa" Rubber Goods Factory, of Pausa, Vogtland, 

 Saxony, has patented a substitute for rubber shoes in the form 

 of a protector made of strong rubberized fabric, to be worn in 

 the shoe over the stocking. Small openings on the upper part 

 prevent the stoppage of perspiration. Even when the shoes are 

 broken it protects the foot from moisture and cold. 



A GERMAN VIEW OF SHOE MANUFACTURE. 



A GERMAN manufacturer writes as follows in the columns 

 of the "Gummi-Zeitung" on the subject of vulcanizing 

 rubber sh< ies : 



Of all factory made rubber articles, rubber shoes claim the 

 greatest attention. Not only is the utmost care required in the 

 selection of the raw materials and in the compounds, but it is 

 particularly the vulcanization which can lead either to the pro- 

 duction of a first class article or of the reverse. 



In spite of the use of tried compounds and suitable grades of 

 crude and reclaimed rubber, the following defects may be pro- 

 duced in the finished shoes by defective vulcanization : 1, Porosity 

 of the soles ; 2, blistering of the uppers ; 3, sub-vulcanization and 

 the consequent exudation of sulphur; 4, super-vulcanization or 

 so-called "scorching" ; 5, metallic appearance of the varnish. 



Porosity almost exclusively arises from moisture in the raw 

 materials. Therefore, crude and reclaimed rubber must be first 

 dried by heat. Whiting (or like substances) can be dried in a 

 special stove, being then carefully protected against moisture 

 during storage. Tars, pitches or oils are first superheated in 

 order to remove all volatile components. It is considered ad- 

 visable before use to obtain laboratory tests of the separate ma- 

 terials for moisture. That even with such precautions porous 

 soles may be turned out, may arise from using crude rubber 

 with too high a resin content or which is decomposed. 



The blistering of the uppers is usually due to the presence of 



moisture in the fabrics used. It is consequently recommended to 

 first boil these fabrics thoroughly in vats, and to dry them care- 

 mil 



I mkr-vulcanization and the consequent exudation of sul- 

 phur, pro ided the compound has been rightly prepared, arises 

 merely from a mistake in curing. Shoes with this defect are not 

 bad merchandise, though the flaw renders them unsalable to the 

 line trade. Super-vulcanization or "scorching" causes the shoes 

 unmerchantable, and may be caused by a defect in the 

 plant, or by carelessness of the operator. Super-vulcanized shoes 

 tear at the edges, break in the uppers and crack in the varnish. 



Metallic brilliancy in the varnish of the upper is caused by the 

 heating pipe not being tight, by which means moisture is allowed 

 to penetrate during the vulcanization; or by the atmospheric air 

 being too damp at the time of admission. The vulcanizing cham- 

 ber ought, therefore, to be heated before use. 



The following method of vulcanizing shoes, the result of many 

 years' experiments, has been found to produce articles of good 

 and regular quality. A horizontal vulcanizer is used, of about 

 8 feel in diameter and 32 feet in length; the heating coils, each 

 acting separately, being built in as usual. At the back end of 

 the vulcanizer in the lid, as well as in the side walls, are spaces 

 for the recording thermometers. 



In the interior of the vulcanizer at the highest and lowest 

 points pipes are inserted, reaching from the back wall. These 

 are provided with small openings (1/25 to 1/6 inch) toward 

 the inside of it. Between these two pipes are placed at a higher 

 level two other pipes ; the suction and pressure pipes of the 

 rotary mechanism driven by a small motor. The hot air is thus 

 continually drawn from above and forced back into the oven, 

 where it is distributed through the perforated pipe. Uniformity 

 in the suction or pressure of the air must be tested before the 

 apparatus is placed in operation. Sheets of metal are hung be- 

 tween the pipes and the shoes in order to prevent too direct a 

 radiation of heat and to distribute the pressure of the air. The 

 fans of the rotary mechanism should revolve at the rate of 260 

 to 300 revolutions per minute, and the drive must be sufficiently 

 forcible to absorb and introduce the air with rapidity at a pres- 

 sure of 22 to 29 pounds per square inch. 



At the beginning of the vulcanization the air first introduced, 

 which is charged with the fumes of varnishes, etc., is allowed 

 to escape into the open; fresh air previously heated and dried 

 being admitted. During the process of vulcanization the rotary 

 mechanism is allowed to revolve several times in a reverse direc- 

 tion to ensure the absorption of the air and its re-introduction 

 from above. By hanging maximum thermometers at various 

 points of the vulcanizer the highest temperature arrived at can 

 be recorded for future reference. 



This system of vulcanization is said to give a thoroughly uni- 

 form product, and to prevent claims in regard to defects in man- 

 ufacture, which were formerly unavoidable. 



PLANTATION FIRES. 



A fertile source of danger on plantations arises from the neglect 

 of planters to extirpate the "lalang," which is found between their 

 trees. The government of Cochin China has addressed a circu- 

 lar to the colonial administrators of the country, compris- 

 ing the above view and adding that there is absolutely no risk 

 of fire on the plantations visited, wdiere they are carefully kept. 

 This danger, however, exists where the planter fails to de- 

 stroy the grasses and merely lets them dry where they lie. In 

 such a case the least spark will produce a conflagration. 



In conclusion it is impressed on the colonial agents that it is 

 advisable to call the attention of planters to this source of possi- 

 ble danger. 



A book for rubber planters— Mr. Pearson's "What I Saw in 

 the Tropics." 



