Technical assistance
Is it possible to reverse the working bow with the balancing bow?
Yes! It is possible because they are exactly alike.
The wire elongation is too low. I have tried to increase the annealing current/voltage but I cannot obtain acceptable elongation values. What should I do?
It means that the maximum annealing temperature has been exceeded. Reduce the voltage in steps of 0.5V each time until reaching the desired elongation value.
Is it possible to convert a closed bow into an open bow?
No, it is not possible because the boring and the central groove designs are uniquely different.
The machine runs well at production speeds but wire(s) frequently break inside the drawing machine on start/stopping.
If the break repeatedly occurs on the same wire, check the dies. If the break occurs on different wires or at different wire sizes check the drawing emulsion conditions (concentration, PC, conductivity).
The wire colour becomes dark after some days after spool production.
The dark colour means oxidation. If the wire becomes oxidized after some days it means moisture on the wire after exiting the annealer. Check that it reaches the spool perfectly dry; if necessary, reduce the cooling water quantity and check that the drying air is dry and sufficient.
The wire colour is very dark on the spool just wound.
The dark colour means oxidation. If it appears during the process it means there is some oxygen in the annealing chamber (between shaft 2 and 3). At high speeds (higher than 10 m/s) the machine self-generates the steam. At slow speeds the steam or nitrogen supply unit will be activated to maintain the oxygen-free environment. If you run the machine at slow speed it is necessary that these units are working. If you run the machine at high speeds it is necessary to make sure that the chamber (plates) of the annealing zone is properly sealed and that there is no air infiltration. Check also the water in the tank under the annealing trough and the lack of turbulence.
Which oil do you recommend for bunch lubrication?
Some manufacturers use paraffin or paraffinic products which give good results but cause considerable mess in the machine. The main producers of oil for drawing have specific products for the bunch lubrication (e.g. Houghton 3415).
