Wire Breakage during drawing process

I'm new in this magnet wire line. Currently we have an old in-line enamel machine and facing wire breakage during drawing process.
We have 2 kinds of pay-off wire:

a)Our own rod-breakdown machine drawn 2.51mm annealed oxygen free copper wire and
b) Supplier rod-breakdown machine drawn 2.60mm annealed oxygen free copper wire.

Chances for wire breaks during drawing process in the enameling machine:

a) = 4 per day
b) = 0 per day

We compared both wires, for:

1) Elongation: a) 39% b) 42%
2) Breaking tensile strength: a) 22.15 kgf/mm2 and b) 19.24 kgf/mm2
3) Maximum breaking tensile strength a) 25.83 kgf/mm2 and b) 26.47 kgf/mm2

I'm all new in this with no reference book or personnel.

I tried to use b) wire. It run smooth without breakage for days until finish 1 m/t pay-off, and then I must change to a) wire. It breaks 4~5 time per day in drawing, before the final drawing dies. Then I changed back to different lot of b) wire and it runs smoothly again.

No changes in drawing die sequence, drawing lubricant %, machine settings, line speed when running both types of pay-off wire.

What else I can check, to prove one is better than another.

Thanks and Regards
KY CHAN

Hello lschan,

You have proven the inferior quality of your own rod-breakdown, machine drawn, 2.51mm, annealed, oxygen free copper wire. No doubt you have some kind of foreign, likely small metallic inclusions in your breakdown copper wire. They made it through your rod breakdown but not through your secondary drawing operation.

Think of your secondary drawing operation as a copper wire quality control device.
We recommend you purchase:
Nonferrous Wire Handbook, Vol. 2 www.wirenet.org/waistore/productdetail.cfm?productid=13
Nonferrous Wire Handbook, Vol. 3 www.wirenet.org/waistore/productdetail.cfm?productid=14
Regards,

Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com
519 641- 3212