Featured End User 1 - Weld Removal
Weld Removal and Paint Prep
Cage Welding Area
The old process was to use a 4-1/2 and 7" 40 and 50 grit Aluminum Oxide Resin Fibre Disc for weld and penetration removal on hot rolled and cold rolled material. The current process is to remove welds, depending on the length and width, with the A/O Resin Fibre Disc and finish with a Medium Nonwoven Disc on any surface going to the paint booth. We used the ARC brand 40 grit 7x5/8”-11 Zirconia Flap Disc, removing welds at a 3 to 1 time savings along with much longer life of at least 5 to 1 over the Resin Fibre Disc. This will create much less change out time along with a faster grind and superior finish. We also used a 7" Extra Coarse Nonwoven Disc to remove all weld penetration marks and found the product not only removed the weld, but also gave a similar finish to the Medium Nonwoven Disc currently used. This eliminated the Resin Fibre Disc step, saving time with a product that lasts longer than the Medium Nonwoven Disc. The operator and manager both agreed that they could cut their usage by 8 to 1 over the Medium Nonwoven Disc currently used.
Booms Area
We used the ARC brand, 40 grit 7x5/8”-11 Zirconia Flap Disc for rapid weld removal, but the Extra Coarse Nonwoven Disc worked extremely well in weld penetration removal and surface conditioning before the powder coating process. The operator and manager agreed it was a big time saver - at least 4 to 1 - but the results were much better than before and they expect the product to look much better after paint.
Plant 2
Currently using a 36 grit A/O Resin Fibre Disc on a simple HRPO weld removal operation. We used the ARC brand, 40 grit 7x5/8”-11 Zirconia Flap Disc, which was faster than the Resin Fibre Disc by 4 to 1, providing a better finish and lasted 5 to 1 with less time to remove the discs.
Paint Prep Area
The weld removal area was currently using a 36 grit A/O Resin Fibre Disc to remove the weld, then sending the material to a separate booth for a finish with a 40 grit disc for paint prep. We used the ARC brand, 40 grit 7x5/8”-11 Zirconia Flap Disc that removed the weld much faster with better life of 5 to 1. This saved time in production and change out. The 40 grit weld removal left a finish that would take much less time and possibly eliminate the 40 grit step, which could save a large amount of time and money in that area.
Weld Removal Summary
During our testing it became quite clear that a standard Zirconia product was the best choice for weld removal. The abrasives worked best on hot rolled plate and cold rolled sheet products. The Flap Disc produced rapid stock removal along with a paintable scratch pattern. All responses were positive and all workers were impressed with the product's performance. As a result of the positive tests we decided to test and quote our standard Zirconia Resin Fibre Disc to replace all 3M and Norton Resin Fibre Discs. ARC ABRASIVES offered a substantial cost savings and good performance with the ARC Zirconia Resin Fibre Disc, as well as a good cost savings and process improvement with the Flap Discs.
Stainless Steel Weld Removal and Surface Finishing
Stainless Steel Bins and Spreaders
We worked in two separate areas that stainless steel welds were removed and the material was conditioned. The current process was to use a 36 grit A/O Resin Fibre Disc and finish with a combination of Coarse, Medium and Fine 7" Hook and Loop Discs to refine the scratch pattern to an acceptable level. We used the ARC brand, 60 grit 4-1/2 x 7/8” Zirconia Flap Disc that removed the weld material much faster, and lasted much longer at a rate of 5 to 1. We then used a Fine Nonwoven 7" Hook and Loop Disc to refine the 60 grit scratch lines. The product worked well but could not remove the tooling marks from the press. We then incorporated a Medium and Fine Nonwoven Disc to get satisfactory results. This completely eliminated the Coarse Nonwoven step, saving 10 minutes per part. We started with a finer grit that removed the weld quickly. Because of the construction of the Flap Disc, this saved us time in the surface finish steps in both areas. The suggested product was well received as a time saver.
Stainless Steel Weld Removal and Surface Finish Summary
The use of a 60 or even 80 grit Flap Disc is the key to cut at least one step out of the grit progression to produce an acceptable finish. This is a process improvement as well as a cost savings for the 7” Hook and Loop product that is currently used from 3M.
Burr Removal and General Grinding
Oxide and Burr Removal
We have changed the 3M 1 x 1 x 3/16" Unitized Wheel to a new ARC brand, 1 x 1 x 3/16" Unitized Wheel in the Fargo plant. The ARC wheel has shown increased performance, nearly 3 to 1, compared to the 3M wheel. This was accomplished with the same speed of oxide and burr removal with a cheaper price compared to the 3M wheel. We also tested, and have put in place, a process improvement for the same area for plate material, 1/4" and above. ARC has provided a 1 x 1 x 1/4" 120 grit Interleaf Wheel that provides quick removal of the oxide and burr with a superior finish. Combined with the speed of removal, the product can last upwards of 15 to 20 times longer, compared to the 3M wheel at this time.
Back Stand Belt Grinders
Belt grinders located in many of the welding stations are currently using 60 and 80 grit Ceramic Belts. Ceramic was created because the fracture rate of the grain creates a constant sharp edge and even material removal. This is an advantage in harder material, such as stainless steel and cold rolled material in the Rockwell C range. This creates a much cooler surface and is an advantage for sheet product of 20 gauge and above. For general purpose material removal and shaping on stainless plate sheet, cold rolled and hot rolled pickle and oil, a standard Zirconia product will perform just as well or better. The product has an even breakdown in the grain and an aggressive cut. The best advantage is pricing - This Belt has a cost of 30 percent less with the same performance as Ceramic.
Burr Removal and General Grinding Summary
We have seen substantial cost savings due to the use of Zirconia Belts that have shown a 50% reduction in price with superior life. Combined with the process improvements and cost savings of the Unitized and Interleaf Wheels for oxide and burr removal, these areas could show a 50% reduction in abrasive use for calendar year 2009.
