Straight from the workshop: Prétat, the forging specialist
An integral part of the FELCO Group for almost twenty years, the Prétat Company, is a hot forging specialist of aluminum and nonferrous metals. FELCO handles are forged within the premises at Cornol, within the Swiss Jura.
Forging represents a plastic shaping technique used to shape a piece which has been brought to a suitable temperature. However, Prétat takes forging to a whole new level."We do not limit ourselves to forging: as well as specializing in forging, we carry out additional work on items, such as manufacturing, treatments or polishing", specifies Alain Flury, CEO.
A multi-stage procedure
Initial operation, sawing the raw material (mainly aluminum, but also brass, copper, amongst others) arrives in the form of logs which are then cut into smaller pieces.
They are then heated in an oven, subsequently placed on the template (the lower part of the tool). A lubricant, which will propel the warping, is applied. It serves a dual purpose: without it, the piece will stick to the tool. At the same time, it helps the material enter those parts which are difficult to access. A drill is used on the transformed material: the punch (upper part of the tool) comes in contact with the piece.
"It is important to ensure that the two parts to the tool (template and punch) are never in contact with each other", emphasizes Alain Flury."The piece acts as a shock absorber. There is always surplus material which is known as"waste".
Brass and leather do not undergo heat treatment whereas aluminum does. At this stage, the material has lost all its mechanical characteristics. A thermal shock will serve to restore its properties. Heated to 450 degrees for two to three hours, the pieces are then suddenly dipped in a vat of cold water.
Fourth stage, cutting out. Cold presses (smaller than those used for the forging) are slowly lowered, controlled by an hydraulic system, and rout the piece. It is then blown using compressed air to remove the shavings and, where necessary, shaped.
The piece now boasts a perfect shape...however it is darkened by oxidation caused by the heating process. A chemical treatment (for aluminum), or ultrasound or roller treatment (for brass and copper), allow for the restoration of the original color.
For some clients, the operation ends here. This is the case with FELCO. Follow a final check, the items are packaged and transfered from Cornol to Geneveys-sur-Coffrane. Prétat clients are increasingly turning to manufactured items. A manufacturing workshop must therefore carry out multiple operations (tapping, milling, drilling...).
IT simulation
The tools are designed by the technical office. With the support of extremely advanced simulation software, engineers are able to test the tool before even building the prototype. This minimizes the time needed to finalize the template and punch, therefore costs for the client. This also allows for the refinement of the sales offer: the computer system determines the necessary force of the press.
FELCO, although an important client, is not alone
Founded in 1947 by Arthur Prétat and his two sons, the company became a public limited company in 1985. A few years later, in 1992, FELCO SA took interests in the capital of Prétat SA. In 1997, the company brought back all the shares.
At present, a good third of Prétat activity is accountable to FELCO The 85 employees also work for Vuitton, the coffee-machine company, ThermoPlan, Bosch, the Alstom Group...
It must be brought to attention that the turnover achieved and associated with FELCO has been in decline for a number of years. Would it be better for FELCO to find another supplier? No, Prétat's activity is growing...
SH