The Reasons For Frequent Wire Breaks In Multi-Head Wire Drawing Dies

Frequent wire breaks in multi-head wire drawing production are systemic process issues, mainly involving the following causes and countermeasures:

1.Raw material defects 

The oxygen content of the copper rod is too high (>6000ppm) or there are internal defects such as inclusions and bubbles. During stretching, stress concentration occurs, causing central cracking and wire breakage (the fracture surface is pointed and conical). 

The surface of the wire is oxidized or the hardness is uneven, reducing the ductility of the material.

2.Improper die configuration ‌ 

The drawing die arrangement is not designed in accordance with the surface reduction rate requirements. The sizing zone is too long or worn, causing the hole diameter to deform and increase the friction force.  

Insufficient surface finish of the die hole or poor design of the entry Angle results in wire scratches or internal cracks.

3.Process parameter imbalance ‌ 

Uneven tension control at each station: tension imbalance caused by pressure fluctuation of the wire storage wheel, instantaneous overload breaks the wire. 

Unstable annealing current: sudden increase in current melts the wire or causes a decrease in plasticity. 

Excessive stretching speed: exceeds the material deformation limit, especially when the synchronization of multi-head equipment is poor, it is more likely to break the wire. 

unreasonable stretching ratio distribution: Excessive deformation in a single pass (such as without using a bridge die for adjustment).

4.Lubrication and cooling failure ‌ 

Insufficient concentration of wire drawing fluid, abnormal temperature (above 35-45℃) or stratification of emulsion, leading to a decline in lubrication performance.

Metal shavings blocking the die or oil contamination, increasing the risk of surface scratches and wire breakage.

5.Mechanical failure of the equipment ‌ 

Wear or adhesion of copper powder on the tower wheel/traction wheel causes sudden changes in the tension of the unwinding/rewinding. 

Asynchronous transmission system: Wear of the main motor gears leads to speed mismatch between the constant-speed wheel and the traction wheel.