What is deep drawing?
Emprotec works on the forming of parts by cold drawing of sheet metal.
The process transforms a flat piece of metal into a hollow, three-dimensional part. This involves progressively forcing a metal sheet into a die using a press.
At each stage, the part is progressively formed deeper into the die: this is what is known as deep drawing.
The aim is to form parts with deep cavities while preserving their structural integrity.
This type of forming is carried out on a transfer press fitted with a drawing tool comprising:
- A punch, which has the internal shape of the part to be produced,
- A die, which supports the material and gives it its final external shape,
- A blank holder, which presses the blank against the outside of the die to ensure an even flow of metal.
Emprotec has transfer presses which, thanks to side bars fitted with grippers, carry out simultaneously all the drawing operations needed to produce the final part.
A single press is all that is needed to complete the entire drawing sequence.
The main benefits are optimised holding of the part between the different stations (compared with a press line) and a high production rate.
As these relatively high rates cause the parts and tools to heat up, soluble oil is sprayed to absorb the heat.
Advantages
A process offering very good dimensional accuracy while keeping costs down
Drawing offers many advantages, both in terms of cost and part quality, thanks in particular to the wide variety of materials that can be processed and to the very nature of the process which, by ensuring streamlined manufacturing, avoids the costly additional operations that other techniques may require.
This technique allows relatively low cost prices and very high production rates. Emprotec's production capacity ranges from 900 to 1,800 parts per hour, depending on their size and complexity.
The work hardening resulting from the deformation imposed on the sheet gives the finished part mechanical properties superior to those of the blank. These high properties make it possible to lighten the parts. The surface finish of an as-drawn part is far superior to that of cast parts. The appearance of deep-drawn parts is therefore much better , and finishing work such as polishing is less extensive and, above all, less costly.
Materials
A variety of materials to meet every need.
Emprotec works with different materials according to the technical specifications given by the customer and the recommendations made by its design office.
Steels
Modern rolling techniques make it possible to obtain very thin steel sheets with a clean, smooth surface, a uniform surface and a range of mechanical properties suited to the requirements of drawing.
These sheets are classified into three categories:
- Commercial quality sheets
- Drawing quality sheets
- Special drawing quality sheets
Copper
Unalloyed with any other element, red copper has excellent extra-deep drawing qualities, often superior to those of brass or special steel.
Stainless steel
Stainless steel has excellent formability, owing to its outstanding mechanical properties. Thanks to a high strength-to-weight ratio and its unique elongation and work-hardening characteristics, it can meet many requirements for complex shapes.
Brasses
The most common brasses are 60/40 and 72/28.
This grade (72% copper and 28% zinc) is used to manufacture cartridges and cases, avoiding annealing operations.
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Your trusted partner in deep drawing. Emprotec supplies you with high-quality technical parts, combining expertise, innovation and compliance with customer requirements.
ISO 9001 certified company.
Parc d’activités Alpespace
401 Voie Galilée
73800 Sainte-Hélène-du-Lac
France
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