The Grandvillars plant (France) is the largest wire drawing plant in Europe with a capacity of over 75,000 tonnes.
LISI AUTOMOTIVE masters the quality of its wire through vertical integration. This wire rod is used to manufacture cold forged parts, such as screws, nuts, safety components, spacers... in LISI AUTOMOTIVE'S European cold forging plants.
The main steps in the preparation of wire are:
- Treatment of the wire
- Wire drawing
- Heat treatment or annealing
The main wire preparation operations are:
- Acid pickling (HCl)
- Flood rinsing
- Zinc phosphating
- Soaping (lubricant)
LISI AUTOMOTIVE is particularly mindful of protecting the environment through applying ongoing improvements to its processes:
- Of a chemical nature (elimination of oxides and soot from annealing)
- Of a mechanical nature (reduction of polluants)
This operation enables the perfect calibration of the wire’s diameter to the optimal manufacturing conditions for cold forging:
- Calibrating the wire’s diameter to ± 0.02 mm
- Work hardening the surface in order to facilitate shearing (skin pass)
Heat treatment or annealing
This operation enables the metal to be softened so that it can be deformed during forging (spheroidised annealing).
Preparation sheet steel coils
Sheet steel coils and strips are used to produce fasteners and fastener components by high speed stamping. In order to prepare them at the right quality and size, LISI AUTOMOTIVE has its own rolling mill, with cold rolling, heat treatment and coil slitting :
- Cold rolling enables to get the right thickness and flat steel surface qualities for stamping
- Heat treatment in a controlled atmosphere
- Slitting to get right sized coils, enabling a wide range of part numbers and small production runs to be produced more economically