We have a nickel product line that is spooled onto 5 lb spools after strand annealing. When it goes onto the spool it is tight and looks perfect.
After five or six days the wire is loose.
What is the correct lay and tension formula?
Is there another variable that has to be address?

Thanks,
rab

good day Wire..

Not sure if this will help, but a while back we had roughly the same situation, when we packaged spools from a cold weather climate but when we shipped to a warm weather climate, the spools looked great when they left but when they arrived they were all messed up. We found out that the spools in cold areas shrank at traverse length, and when the they did arrive at the warm climate, the spools would expand, making for a mess of wire.

So we experimented with tension and found we needed to increase the tension by 10% beyond where we started at, also find out from your customer how they are paying off the spool, whether a smooth pull or a jerking pull, and also, if they are applying tension to the spool prior to paying it off.

To answer one of your questions we found that the pitch of the wire should be around 1.5% the diameter when spooling.

Hope this helps somewhat.

Hello,

I wonder if your nickel strand is too hot when rewound on to the 5 pound spools after annealing. The hot wire would heat the spool and then the combined (hot) wire and spool would slowly cool to room temperature. This is not unlike sending a (room temperature) combined wire and spool to a colder climate.



In that thread the magnet wire folks thought the winding pitch should be around 1.1 times the wire diameter. Constant winding tension (drum to flange) is also very important.

Kindest Regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com