TREATMENT FOR TEXTILE INSULATION 



237 



is a second motor for circulating the air within the head. The main 

 drive motor is connected so that it rotates the wiping dies continu- 

 ously so they will not freeze up, and the take-up reel and the capstan 

 are operated through a hand clutch. Six passes of wire w^ere decided 

 upon as giving better control of the coating than afforded by four 

 passes. Electric heating elements were selected as being compact and 



Fig. 6 — Cellulose acetate wire coating machine. 



easily controlled. In the schematic view, Fig. 7, are shown the method 

 of air supply, the circulation of the air within the drying chamber, 

 and the exhausting of the acetone-air mixture. 



In making a commercial installation of the new machines, it was 

 necessary to go into the questions of preparing and circulating the 

 cellulose acetate solution, recovering the acetone, and making the 



