340 



THE INDIA RUBBER WORLD 



[July i, 1904. 



SCIENTIFIC VULCANIZATION METHODS. 



BY CHARLES J. TAGLIABUE. 

 II. — AUTOMATIC CONTROL OF TEMPERATURE. 



IN every branch of rubber manufacture, uniformity of product 

 is possible only by maintaining accurate control of vul- 

 canizing conditions. In practice, dependence is placed on a 

 heater man who is left to his own judgment to regulate the 

 heat by hand, basing his adjustments of the steam inlet and 

 outlet on thermometer readings. With such a system only 

 approximate results are possible. 



Long experiment has resulted in the development of a scien- 

 tific system of automatic time and temperature control, where- 

 by, once adjusted, the vulcanizing process is perfectly regulated. 

 This is known as the " Tagliabue system." Its proper applica- 

 tion necessitates correct plans of piping and ample steam sup- 

 ply to insure its uniform and rapid distribution to all parts of 

 the heater or press, and the instant removal of the air, wet 

 steam, and condensation. 



The leading feature of the " system " is the Pressure Gover- 

 nor, which is an apparatus for throttling the steam valve, not 

 in accordance with the initial or boiler pressure as in ordinary 

 regulation, but in accordance with the pressures inside of the 

 heater or press. The mechanical features of the apparatus aie 

 so simple and few that derangement is scarcely possible, or, if 

 it takes place, it can be quickly remedied by any mechanic or 

 engineer. 



When the governor is set for the desired temperature or 

 pressure, it is necessary only to turn on the steam and the 

 heater practically takes care of itself. As there is a definite 

 equivalent in degrees of temperature for every pound of pres- 

 sure of saturated steam, it is only necessary to provide weights 

 for the governor which will give control at any desired degree 

 of heat, and as all the observations are made with the ther- 

 mometer, it is virtually temperature control. 



It is true, at the beginning of the cure, when the cold heater 

 is started, that the temperatures and pressures do not corre- 

 spond, but this period is not counted in as part of the actual 

 curing time. As soon as the heater becomes thoroughly 

 heated, and the condensation of the steam is again normal, the 

 temperature and the pressure will be found to agree absolutely 



and invariably. Thus the actual time of curing should be 

 measured from the time the heater has reached its maximum 

 temperature. 



Time is equally important with temperature in vulcaniza- 

 tion, and should be as exactly regulated. The usual method is 

 to mark on the heater or other convenient place the length of 

 cure, or time when it should end. This time having elapsed, 

 the heater man is supposed to shut off steam and blow off the 

 heater. The Tagliabue automatic system shuts off the steam 

 at the expiration of the cure, and if desired also operates a 

 blow off valve, to blow out the steam. This, in conjunction 

 with the temperature controlling device, makes the process of 

 curing practically automatic and positive. 



The diagram illustrates the arrangement of the entire system 

 as applied to a properly piped heater. The system is pneu- 

 matic — i. e., compressed air is the motive power for operating 

 the controlling valves. The air compressing outfit of the sys- 

 tem consists of a small steam air compressor A 1 and air storage 

 tank A, mounted on a suitable stand. The compressor is pro- 

 vided with all the necessary lubricators, the steam supply is 

 %" and the exhaust y&" . The tank is supplied with pressure 

 gage, and from the top is taken the main air supply line A*, 

 subdividing into the branch lines A*, supplying the pressure 

 governor B, and the time device C. The air pressure required 

 is 15 pounds or more. To maintain this pressure constant the 

 controlling valve A- is placed on the steam line to compressor, 

 and connected to storage tank as shown. This valve can be 

 adjusted for any required air pressure, and will control the sup- 

 ply of steam to the compressor, so that the desired pressure of 

 air will be maintained, with a minimum use of steam. As the 

 amount of air used by each device is small, this compressor 

 will furnish the air for quite a number. The air intake to com- 

 pressor is placed out of doors, and should be located away from 

 the steam vapor or dust. This compressor requires little steam, 

 and never stops. If properly supplied with oil it will take care 

 of itself. In the bottom of the storage tank is a blow off valve, 

 A a , for blowing off at intervals accumulated water and oil. 



The pressure governor £ is provided with a flange for secur- 

 ing it to the wall near the heater or press. The lever is hung 

 on knife edges and is as accurate as a scale beam as it rests on 

 a rubber diaphragm in the circular base. Above the lever is a 



SVsfe««V^^^^\^^\^l«fe5!%3*£ 



TAGLIABUE AUTOMATIC SYSTEM OF TEMPERATURE AND TIME CONTROL. 



