PULP INSULATION FOR TELEPHONE CABLES 3 



have demonstrated that it compares favorably in stabiUty and per- 

 manence with the well established manila fibre. In the case of pulp 

 insulated cable which is discussed in this paper the raw material used is 

 100 per cent of this wood fibre. 



The present day ribbon paper insulating machine as developed by 

 the Western Electric Company is essentially a rotatable hollow tapered 

 spindle centrally mounted on and integral with a light weight disc 

 about 15 inches in diameter. The wire to be insulated passes through 



Fig. 1 — Ribbon paper insulators. 



the spindle over a capstan and to the take-up spool. The insulating 

 paper wound into a pad or disc is slipped over the spindle and sup- 

 ported by the metal disc. This whole assembly is arranged to rotate 

 rapidly around the wire and feed the paper ribbon from the periphery 

 of the pad through guides so as to form a continuous spiral wrapping 

 around the wire which is advanced at a definite speed by the capstan. 

 The speed of rotation of the spindle is approximately 3300 R.P.M. 



