December 1, 1915. 



THE INDIA RUBBER WORLD 



119 



they will find that the most systematic method is really the 

 easiest in the long run, and that not only its faithful maintenance 

 permits the tracing of a complaint to an individual purchase of 

 raw material, but — what is even more important and perhaps 

 otherwise unattainable — its systematic procedure creates a more 

 favorable shop condition in which there is greater economy, 

 fewer irregularities and delays, and greater assurance of a more 

 uniform final product. 



.A.nothcr important item in shop management that adds to the 

 scientific or systematic handling of materials has to do with a 

 method of determining the time of issuing and the quantities 

 of shop and raw material orders. It has been called "periodic 

 ordering," but it might more truly be named stock budgeting, 

 for it requires the predetermination of possible manufacturing 

 requirements over a convenient interval of time, and the bulking 

 of the necessary shop and raw material orders therefrom. A 

 three months' period has been found most satisfactory in one 

 plant, but other shops may find a longer or shorter period of 

 greater advantage. The essentials of its successful operation are 

 to divide the year commensurately into periods, to use good 

 judgment in the estimation of advance requirements from past 

 records and future indications, and to carry the schedule through 

 unaltered after the orders have once been issued. If a change is 

 believed necessary after it is too late to make an alteration, a 

 supplementary order can be put through as a special, or the 

 deficienc.v — or excess — can be remedied in the planning of the 

 requirements for the next period. Advance period estimates 

 should be made to allow sufficient time for the washing and 

 drying of crude rubber, the resting of mixtures, etc. The de- 

 velopment of several periods has to be experienced before this 

 method is completely installed, and in some shops it may re- 

 quire even longer to make adequate adjustments of stock, space, 

 and equipment ; but the method is very flexible in its application 

 to wide variations in shop conditions, and its advantages, aside 

 from those of financial budgeting, are steadier labor and shop 

 conditions with the elimination of rushed and inactive inter- 

 vals, because an advance knowledge of work to be done within 

 a period makes possible a more economical assignment, the 

 elimination of excessive stock, space, and equipment require- 

 ment witli the resulting minimum investment of capital, and the 

 steady and frequent production of a semi-perishable product with 

 an advance knowledge of the expected dates of completion. 



Lack of space in a general article like this prevents the ex- 

 planation of other large betterments for the control and handling 

 of raw materials, such as strict stock-room control and the 

 routing of operations, and complete cost and overhead expense 

 accounting systems with comprehensive monthly and yearly 

 summaries. Suffice it to say here, however, that all these sys- 

 tems and methods have been worked out from a conception 

 of Taylor's Scientific Management, partially applied to the rub- 

 ber industry, and their superiority over present methods, or lack 

 of methods, in the average rubber shop is in every way more 

 economical and desirable. 



When the handling of materials has been thus standardized 

 and the materials themselves made as uniform as possible, then, 

 and not until then, the control of processes can be improved. 

 Rubber mills, calenders, and tubing machines can be successfully 

 equipped with comparative temperature measuring instruments 

 and roll-spacing gages so that the variables of heat and handling 

 can be controlled and standardized for each kind of mixture 

 with reasonable accuracy. Press curing in molds with both 

 steam and temperature indicators has usually attained a higher 

 standard of accuracy than other operations, but there is still 

 much more room for improvement in the use of better presses 

 and molds, and more adequate tools for ejecting and cleaning. 



Open steam vulcanizing is usually controlled by clocks, steam 

 gages, and pyrometers or thermometers. The steam experts 

 say that pressure varies directly with temperature, and that with 

 gages and temperature indicators of equal accuracy and sen- 



sitiveness cither instrument will indicate the true heat conditions 

 within the vulcanizer. And yet the rubber worker knows that 

 under the most uniform conditions and with the same tempera- 

 ture indication on either the gage or thermometer, he is obliged, 

 for a good cure, to alter the time of cure to suit the use of "live" 

 or "dead" steam ; the former condition produced by a slightly 

 opened exhaust valve to permit the continual escape of a small 

 amount of steam and water, and the latter by an exhaust which 

 passes through a steam trap. The rubber worker also knows that 

 the curing directions in an autoclave where heat is externally ap- 

 plied to a sealed pot containing water are very diflferent from 

 those required for the same material in the same mold in the usual 

 tank vulcanizer which is heated by the injection of steam through 

 a valve with the ejection of water of condensation through a steam 

 trap or slightly opened exhaust valve. The writer has yet to hear 

 of a satisfactory scientific explanation of these phenomena and 

 until it is forthcoming, the open steam vulcanization of soft rub- 

 ber goods will continue to produce the present uncertain results, 

 in spite of the strict observance of uniform conditions with which 

 rubber manufacturers now endeavor to surround this important 

 operation. 



\\ ith materials and machines standardized, specific instruc- 

 tions can be worked out and put into concise form, so that the 

 workman can follow^ them just as a machinist follows his blue- 

 print or drawing. 



It has been the writer's experience to develop and apply most 

 of these suggestions for the betterment of rubber shop and prod- 

 uct conditions, and the results obtained have more than com- 

 pensated for the effort involved. One representative experience 

 may serve to illustrate : In a calendering operation a gang of 

 eight workers were turning out an average of 400 units a day. 

 They were experienced, and it was believed that only automatic 

 machinery could lower the costs of the operation. Xevertheless. 

 three years later, after the installation of most of the improve- 

 ments above outlined and without automatic machinery, they 

 were averaging 600 units per day, with one less worker— an in- 

 creased production of SO per cent, with 12 per cent, less labor. 

 The more uniform quality of the material delivered to the calen- 

 der, and the more favorable shop conditions, had resulted in 

 fewer interruptions and in the production of a larger quantity 

 of usable finished product. 



It is the writer's firm belief that if these higher standards of 

 mechanical practice and precision, with more scientific methods 

 of controlling processes and handling materials, as above out- 

 lined, are adopted, it will be entirely possible to put many rubber 

 articles on the market with a guaranteed advance date — molded 

 in the article or indelibly stamped on fool-proof packages — 

 which will tell positively just when the rubber manufacturer's 

 responsibility ends, as in the case of the kodak film industry. 

 It will then be the concentrated incentive of the manufacturer 

 not only to endeavor to advance the date as far ahead as pos- 

 sible, but also to see to it that the product is so well made that 

 under normal usage it will not have to be returned for credit 

 before the expiration of the guaranteed date. 



When such a condition shall have been reached, the rubber 

 industry will be beyond the cause for the complaints of the 

 present unhappy consumers of rubber products, and its position 

 will be alongside of, and not behind, the higher developments 

 of other industries. Such a consummation need not await the 

 millennium, for its accomplishment by the industry, as a wliole, 

 but only the awakening of the individual rubber manufac- 

 turers to the opportunity that is before them. 



RUBBER ENZTHES. 



It is generally admitted that enzymes are the cause of tlic tack 

 in rubber. Dr. Uttee states that they can be destroyed by heat- 

 ing the latex or even the gum for 15 minutes at 176 degrees 

 Fahrenheit. 



