Measuring and managing variables for sheet metal forming success

Keeping the many variables associated with metal forming under control allows a company to produce quality parts consistently. supermatros / iStock / Getty Images PlusL

Forming sheet metal components successfully and efficiently requires managing many variables, including the properties and conditions of your materials, equipment, and processes. When you’ve managed them well, you can build quality components, minimize resource expenses, and optimize employee contributions. But a single misbehaving variable can lead to quality failure.

To ensure the variables in your operation are working together well, you need to measure each one and understand its acceptable operating range. Statistical process control offers a process to measure variable operating values against upper control limits and lower control limits. Suppliers of manufacturing equipment and materials understand and publish the usable operating range of their products. Experienced professionals and laboratory research can enhance supplier-provided information about how manufacturing materials respond to the demand of your operations and component geometries.

Some of your variables can be measured directly and accurately in real time. Strokes per minute, ram speed, and cycle profile are probably already measured by your equipment. For example, your press should have a strain gauge on the load frame that measures the force exerted by the press through the stroke. With tonnage monitoring, you can identify unbalanced loading, inadequate lubrication, variations in material mechanical properties, tool wear, errors in shut-height adjustments, and splits and wrinkles.

Some variables, like a material’s tensile properties, are typically estimated and assumed. The mill performs destructive testing on the ends of the coil and reports the results, among other characteristics, on the mill certification delivered with the coil. However, rolling mill operations introduce variations in properties across the length of the coil, and the destructive testing provides properties only for the location tested.

Nondestructive testing is an alternative for determining properties across a larger sample of the coil. This process uses observed relationships between magnetic and mechanical properties to determine tensile properties. While not a direct measure of tensile properties, nondestructive tests can be useful in getting a broader profile of mechanical properties across a coil.

Smart manufacturing includes tools to measure many of these variables to evaluate their effect on quality production. It also gives you the opportunity to predict issues and alert staff.

With smart manufacturing tools, you can readily identify correlations and investigate causes and effects among manufacturing variables and production events. Proper use of these tools requires several commitments:

The number of variables that influence forming success makes sheet metal forming incredibly complex. As OEMs incorporate more grades and types of sheet metal in their products, the complexity of forming will continue to increase. And as battery electric vehicles become more prominent, lightweighting will continue to drive further innovation in materials.

Now is the time to develop your monitoring and analytical strategies. These strategies will help you better understand the implication of your decisions and make your workforce more adaptive to the inevitable changes.

Forming sheet metal components successfully and efficiently requires managing many variables. To ensure these variables are working together well, you need to measure each one and understand its acceptable operating range.