Any operation that involves stamping or metal forming typically has to deal with rough edges and surface finishing. Traditionally, there’s been a tension between quality and productivity—it’s hard to pull a die to sharpen it when you have a production target to hit. Push the die too far, and you can end up with a marred surface in addition to the usual raised edges.
Rotary brush technology has changed that, as we recently learned from Scott Coyle, sales manager at Timesavers, LLC. Check out the video below:
Deburring vs Finishing
Although deburring and finishing involve similar processes, there are important distinctions between them. Generally speaking, it’s possible to deburr an edge without finishing the adjacent surface. Deburring deals with the removal of the unwanted raised edges caused by previous operations. Burrs fall into one of two categories: mechanical burrs, which can result from shearing, stamping or folding; and thermal burrs, also known as slag or dross, which can be caused by welding and laser or plasma cutters.
Finishing refers to the broader category of modifying the surface of a workpiece to remove scaling, pitting, enhance its quality or prepare it for coating or painting. Finishing machines are also used for calibration and stock removal to achieve higher material removal rates and decrease variations, as well as edge rounding.
Wet vs Dry Deburring & Finishing Machines
Job shops utilizing dry deburring and finishing machines are typically grinding similar materials, such as carbon steel. These machines have a lower capital cost and require less maintenance in the long term, however they also require dust collection, which tends to increase their footprint.
In contrast, wet deburring and finishing machines are more useful for grinding a variety of metals, such as steel and aluminum. Since powdered aluminum is highly flammable, the sparks from grinding steel in the same machine pose an ignition risk. That’s why wet machines spray coolant on workpieces. This has the added benefit of clearing debris and cooling the part.
Both machine types require regular cleaning and inspection, with particularly close attention to tension levels, pinch rolls and bearings.
Grinding & Finishing Abrasive Types
The three most important attributes for an abrasive are:
- Type: coated, non-woven, etc.
- Grade: very fine, 120 grit, etc.
- Composition: ceramic, aluminum oxide, etc.
Abrasives can be broadly grouped intro three categories: belts, discs and brushes.
Abrasive belts run on a continuous loop and are best for removing vertical burrs, but they also tend to roll excess material over workpiece edges, creating lateral burrs which then have to be removed. Abrasive discs are used for small or sensitive parts, including those made from cladded or galvanized materials. Like discs, abrasive brushes work well on small and sensitive parts, but they’re also better at edge rounding.
Rotary brush deburring can remove burrs from the edges of a part without altering the profile of the surface. For example, rotary brush deburring can deburr a polycarbonate sheet without removing protective coatings or films. However, with different adjustments, the same rotary brush deburring machines can also be used to create a random orbit finish on surfaces.
Check out the video above to learn more, or visit the Westway Machinery website.