Developments in the Manufacture of Copper Wire

This paper describes a new copper rod and wire mill located at t h e Western Electric C o m p a n y ' s Plant at Chicago. It includes a brief survey of t h e copper rolling a n d wire drawing art at the time the investigation was s t a r t e d ; a s u m m a r y of tests made in varying the practice in rod rolling a n d wire drawing; a n d an outline of t h e work done by t h e Western Electric C o m p a n y engineers in developing a n d designing new types of wire drawing machinery. T h e rod mill is converting 225 pound wire bars into rod in fourteen instead of t h e usual eighteen passes. This is accomplished by making heavier reductions in t h e first four passes while the copper is hot. T h e new wire mill incorporates m a n y novel features, a n d t h e wire drawing machines are more compact in design and of considerably higher speed than those in general use. T h e design of t h e wire mill was undertaken following a comprehensive survey of wire drawing processes and equipment used in this c o u n t r y and abroad. P a r t of this survey consisted of a s t u d y of t h e m a n u f a c t u r e of diamond dies, it having been found t h a t dies suitable for high speed drawing required a differently shaped " a p p r o a c h , " a b e t t e r polish, and a shorter " l a n d , " t h a n those which were available for low speed work. T h e economies in floor space and plant investment due to t h e use of more compact and higher speed machinery are outlined. Some of the o u t s t a n d i n g features in plant arrangement which contribute to more efficient operation are discussed in t h e concluding pages.