Edmund Herman

Setting the processing variables is different between the net shape and non-net shape processes. While non-net shape variables have to be programmed constantly to change the tool's position in space to follow the unique shape of the part being made, the shape of the part for the draw forming net shape process is built into the die.

The relationships among part geometry, tool geometry, and control of the processing inputs are significantly different between the net shape and non-net shape processes.

The connections between product conditions and product input variables for draw forming must be made through the intermediary transformation characteristics: plastic strains and displacements. So all product requirements must be redefined as the changes (or transformations) required of those two characteristics.

Advanced technology in the metal stamping industry has rendered obsolete traditional methods of selecting, specifying, and supplying material. Using modern technology to quantify materials can reduce the occurrence of material variation exceeding the die and process capabilities and make die development a much more efficient process.

In draw forming, measurement and quantification are essential to ensuring part quality for the customer. However, the product requirements and the product input variables have different metrics and different conceptual meanings, which seems to defy direct engineering. Three processing variables can be adjusted during production to ensure the part is formed correctly.

Draw forming is one of the net shape processes, and, as a result, many of the technology advances in the general field of manufacturing have not been as beneficial to draw forming as one would expect. All too often, such advancements as lean manufacturing, statistical process control, just-in-time, and six sigma, have not resulted in benefits for draw forming.