Production facilities rarely rely on single-stage machine operations. For example, progressive stamping dies sequentially form large batches of raw materials, which flow as blank strips through various tooling stations. It’s a high-volume process, in other words, one that incorporates punching, coining, and bending operations into a single line. Hence, the “progressive” descriptor. Peeking deep inside the equipment, we see the feed mechanism unrolling.
Unrolling the Raw Feed
Like a fully encapsulated process, one where the raw material enters and a finished product exits at the opposite end, progressive die stamping die stations pull in the feed medium. The high-volume process begins by using one or more profiled punches, which cut slugs from the metal. The cut blanks move, progressively, of course, towards the next station, where a lower and upper die snap the component into its intended shape. One successive operation after the next, the part is further refined. In fact, up to 20 different stations could be poised to whittle the component down further.
Precision-Based Parts Processing
It takes a sizeable investment to get this machine line up and running. However, once it’s operating, there are very few labour-related costs to pay out. On the flip side, that processing advantage can turn sour if there’s a misalignment error in the line. Even tiny dimensional error factors can cause a nasty end-product result, for those next to imperceptible flaws will accumulate as the part moves along the line. Ideally, every stage, every station, must be finitely adjusted so that each die cut, punch mark, and bend crease aligns just-so.
Incorporating Different Die Stations
One punch cuts a predetermined shape. Next, a folding station bends the metal once, a second folding station adds a radial bend that has a slightly different diameter, and then the second set of punch cuts is applied. There’s a shaving station, a stamping and coining machine, and a final finishing stage. All of these subsections operate incrementally, forming the part at speed into the desired profile. Extrusions, etching and embossing, coining and burnishing, all operations reserve a single stroke in the multi-stroke process.
To look at the equipment, it appears as a group of stamping stations, which lower and raise as a press. Under that press section, the various forming sections are timed to incrementally work the feed strip. Typically, those feed strips are discharged rapidly, but control elements, including pilots and blank positioning aids, are needed to keep the metal strips precisely positioned as they progress. Otherwise, progressive die stamping is a set-it-and-go equipment configuration, one that requires little user attention once it’s aligned properly.