90 BELL SYSTEM TECHNICAL JOURNAL 



siderable difficulties in designing a suitable cleaner were experienced, but 

 ultimately the use of alternating current together with an alkaline cleaning 

 bath, was found most suitable. The wire passing to the machine comes in 

 contact with the surface of a cleaning solution for a short distance. Electri- 

 cal contact with the wire is made through guide rolls and the current flows 

 from the wire through the solution to the container. Originally a mixture 

 of cyanides was used as the cleansing agent and the current flow was held 

 to about 8 amperes per square inch surface at 12 volts. Recently a more 

 effective non-poisonous cleansing agent has been developed by using sodium 

 ortho silicate and ivory soap. The passage of the current in either case 

 heats the solution and liberates a rather violent evolution of gas at the 

 surface of the wire. With the soap solution a foam is built up which is 

 continually floated off, carrying the grease, copper, dust, etc. to the sewer. 

 This method keeps the cleaner from concentrating the dirt and consequently 

 eliminates frequent cleaning both of the cleaner and the screen on the 

 cylinder which formerly used to get plugged up with particles of grease 

 carried over from the cleaner by the wire. 



Embedding the Wire in the Pulp 



From the cleaner the wire is guided into the cylinder machine. It is 

 extremely important at this point that the wire be guided into the center of 

 the small sheets and at such a point on the periphery of the drum that some 

 pulp is deposited below and some over the wire. After passing around the 

 cylinder the wire travels along with the felt and pulp through the presses 

 and finally emerges at the last press embedded in a small sheet of wet paper 

 (Fig. 6). It was found that poor pick-up of the fibers often occurred unless 

 the surface tension of the water was lowered by some means. Ordinary 

 soap is used for this purpose. Approximately ten pounds per thousand 

 pounds of pulp are dissolved in the storage tanks to give effective results 

 and to smooth out the pick-up to give a high degree of uniformity to the 

 weight of pulp per unit length of wire. 



Polishing 



Polishing of the insulation on the wire is brought about by passing the 

 wire and pulp sheet over polishing blocks which are rotated rapidly around 

 the wire as an axis. Three blocks are used and are so placed that the wire 

 is slightly deflected from its course as it passes first over one block, then the 

 second and finally the last (Fig. 7). The rapid rotation of the polishing 

 head produces a light rubbing action on the sheet which is rolled down 

 without tearing and results in a good round smooth wrapping of wet paper 

 about the wire. With the wire running at a linear speed of 130 feet per 



