Finish Cast Parts Faster and Improve Productivity With Ceramic Abrasives
By Kyle Thompson, product manager, Weiler Abrasives
Few industrial jobs are tougher than the tasks in a foundry’s cleaning room. High temperatures, heavy physical demands, and the need for constant attention to safety create challenging conditions for operators.
In this harsh environment, portable abrasives play an important role. These products are widely used in foundry cleaning rooms to remove gates, risers, flash, parting lines and other excess material that results from the casting process. These applications are necessary to bring the cast part into tolerance and make it suitable for its end use.
While numerous abrasive technologies can be used in foundry applications, using a ceramic abrasive can help get the job done faster — reducing operator fatigue and improving productivity.
Challenges in foundry finishing operations
The biggest challenges in foundry finishing operations stem from the difficulty of the environment and the physically demanding work. Foundries are typically very hot — with temperatures upwards of 110 degrees F — and operators work directly with molten metal. The parts are often still warm when they get to the finishing room.
Working in this demanding environment requires attention to three key factors:
- Safety issues necessitate constant operator vigilance to a variety of application elements. Proper personal protective equipment (PPE) is paramount. From respirators to protective clothing, all necessary PPE must be worn to protect the operator. In addition, the tool and grinding media must be correctly matched, and the orientation of the grinding product to the casting must eliminate the possibility of impingement, which can cause wheel breakage.
- Portable grinding with large tools and media in very harsh environments is physically exhausting. Finishing tools can weigh 5 pounds or more, with a few extra pounds of consumables on the end. Operator fatigue can lead to shortcuts, and shortcuts lead to accidents. Choosing abrasives that allow operators to grind faster while using less pressure helps reduce fatigue.
- In the current economic environment, finishing room operators are in short supply for many foundries. Therefore, their productivity is a critical metric in the overall output of the foundry. Faster-cutting abrasives result in shorter grinding cycles, which in turn, increase the output per hour of the foundry with a reduced risk of fatigue-induced accidents.
Abrasive options for finishing cast parts
There are many different abrasive product geometries available for finishing cast parts. These geometries are designated by type: Type 11 products are cup shaped; Type 27 products are disc shaped; Type 1 products are wheel shaped; and Type 16, Type 17 and Type 18 products are conic/plug shaped.
The physical size of Type 11 products makes them ideal for use on large castings or forgings that have significant amounts of excess material. Although cups are the most efficient way to remove material, they are not appropriate for many applications. In some instances, it is necessary to perform cutting operations while also grinding. In these applications, a Type 27 product is often the best choice for the work. In other applications, the operator needs access to part features that are too small to reach with larger products. When this occurs, cone- or plug-shaped abrasives are usually selected.
Each product type is suitable for different jobs inside a foundry, and product selection is often based on part geometry. For example, if a parting line must be removed from a part’s ID, an angle grinder with a 6-inch cup or a 9-inch Type 27 wheel won’t fit inside the part. But a die grinder with a cone that is 2 or 3 inches in diameter will fit into the space.
Traditionally, zirconia-alumina (ZA) abrasive grain has been used for finishing work on cast parts. When combined with the right bonding system for the application, the high durability of ZA grain provides fast stock removal and long-life in most finishing room jobs.
In recent years, ceramic grain technology has replaced conventional grains, like ZA, in industrial applications like roll grinding and gear generation. However, ceramic grain has not traditionally been available in a bonding system appropriate for portable foundry jobs. New technology is now bringing the benefits of ceramic grains to the foundry environment.
Benefits of ceramic abrasives
Because of the very fine microstructure of ceramic grains, they keep a sharp edge and maintain the ability to make a big chip as they break down. In foundries, where completing finishing jobs quickly is important, ceramic abrasives can get the work done faster. This results in less fatigue for operators and improved productivity and throughput in the operation.
In common product geometries like cups, ceramic products offer similar life as ZA-based products while generating 20% to 40% faster cut rate. This faster material removal translates to better productivity in the cleaning room and less operator fatigue.
In other products, like Type 27 discs, the bond system can be manipulated to reduce edge chipping. An anti-chipping bond system locks the grain rigidly in place and takes advantage of the grain’s low, specific cutting energy. This produces excellent grinding efficiency and uniform product wear, allowing operators to concentrate on the task at hand and not worry about constantly adjusting the angle of approach to maintain a good working edge.
Along with considering a ceramic abrasive for foundry finishing work, look for an abrasive that uses an anchored hexagon nut design. This secures the abrasive to the tool to increase safety and prevent product breakage.
Improve finishing in casting operations
In foundry finishing rooms, completing work quickly and safely is key. The faster the work gets done, the more parts get out the door — and the more the operation can take advantage of the valuable finishing room labor, which can be hard to attract.
Choosing an abrasive product made with ceramic grain for finishing room work helps operators get jobs done faster, which reduces operator fatigue and boosts productivity.