Ammunition box project

Introduction

An manufacturer, active on the International market, is producing since 1950 mechanical components, containers and special boxes for Avio and Defense sector.
All the production process take place inside the Company, from sheet metal to final product including:

• Decoiling and cut to length
• Stamping
• Bending
• Welding
• Painting

Most of the equipment is aged.

Problem

The global market is a challenge, the income of new international players disturb the leadership of this manufacturer that now has a real problem: stay competitive with the ammunition boxes production, from which is depending the 50% of the company turnover. Approximately 900.000 boxes per year. In order to do that, the management identify the solutions for cost reduction:

• Reduce the human factor.
• Increase the productivity.

Situation analysis

Аmmunition box production involves: decoiling, bending, welding and  painting.  The bottle neck has been identified: resistance welding of the box bottom cover. Actually a seam welding machine AC current, is welding the bottom, positioned on a turning tooling. The process takes 48sec, loading unloading not included.

The best solution Finding

CEMSA company developed a new concept of machine:

• Using the indirect welding configuration.
• Adopting the Medium Frequency technology 1000Hz (one transformer only).
• Providing the last release in CNC motion control.

Conclusion

The combination of the above described improvements, cut down the cycle time to 21sec. Additionally the benefit of the medium frequency was consisting of:

• Energy consumption reduced of the 30%, compared with the same machine  using AC current.
• Welding heads and copper parts heating, minimized. With a consistent benefit of consumables duration itself.

Definitely the target was achieved, The manufacturer can divide the production cost on a higher number of pieces produced. The competitiveness is safe.