Deep drawing

What is deep drawing you may ask? It is an advanced manufacturing method that demands a great deal of experience and knowledge as well as a well-developed range of machinery. Ingelsten & Co was set up 1937 and has subsequently built up a solid bank of knowledge and experience within precisely deep drawing.

What is deep drawing?

Deep drawing is used to manufacture a product with seamless, complex shapes. A tool-related manufacturing process where the metal is stretched, or extended between two tool-halves, to create the prospective product's shape.

Within deep drawing we often talk about drawing ratio. I.e. , the ratio between the drawing punch's diameter d and the blank disc's (the circular blank's) diameter D.

The material's properties and its tensile strength are also important to include in the calculation when producing the deep drawing process.

The drawing ratio and the material's tensile strength then determine the manufacturing process. The following factors and procedures have to be included in the calculations.

• Material properties
• Size and shape of the blank to be used
• Number of drawing stages and drawing ratio between the stages.
• Pressing forces and drawing speed for specific moulding.
• Tool design, tool material and lubrication.

Tool material and lubrication are important in order to avoid material transferring from the product to the tool. This is in order to reduce friction between product and tool, and to thereby obtain a better surface finish on the product and a longer service life for the tool.

In deep drawing, the material is subject to forces and stresses arise in the material. The material is deformed plastically or elastically depending on the amount of stress. It changes from elastic deformation to plastic deformation at the material's yield point. With plastic deformation, strain hardening takes place. The material becomes extremely hard to work with and higher stresses are required to further deform the material.

So, for some materials, stainless for example, the art is to mould the material by means of deep drawing with as few production stages as possible, without needing to relieve the stress in the material between the different deep drawing stages. To manufacture the product more quickly, more efficiently and with higher quality.

The most common examples of deep drawing are probably the beer or soft drinks cans we buy. Or the kitchen sinks we have at home. The material must have good shape properties with regard to yield point and ultimate tensile strength in order to cope with tough stresses and to avoid breaking during the deep drawing process.

Customer case: Westal

Here is an example of how we were able to use deep drawing to make Westal's production process more efficient. Westal manufactured a lamp housing for recessed outdoor roof lighting.

Previously:

• Cutting three pieces of sheet-metal
• Bending three pieces of sheet-metal
• Welding the pieces together
• Surface treatment/protection to prevent the housing rusting

Now:

• Deep drawing with surface treated sheet-metal 

Result:

• Cheaper
• More effective
• Higher quality and surface finish
• Fewer production stages 

Ask US whether deep drawing is the solution for YOU. It doesn't cost anything to ask.