Fig. 4. Wide fl uctuations in compactability at one molding line were solved in October 2012 with the installation of a new piece of equipment.
is added via a mixer and when it stops, sometimes extra clay falls into the auger. Years ago, Grede-St. Cloud had installed a slide gate to prevent that from happening, but it was discovered the slide gate stopped working. Once the slide gate was fi xed, the variation in live clay amount went back down. After keeping tabs on its live clay
variations for some time, Grede-St. Cloud moved to a mass balance system in which it calculates based on a formula
of how much clay will be lost when running a specifi c job. T at calculation is used to determine how much new clay will be added for each job. T is calculation is made for every job that runs through the facility. It has proven to signifi cantly reduce variation in the methylene blue clay test results (Fig. 6).
Watching Size Distribution A third key independent variable
to measure is the size distribution of
washed green sand. Size distribution is not as easy to control because new sand is a product supplied by a vendor, not something you can change in-house. But metalcasting facilities should try to control size distribution because it has a big eff ect on the sand system. Size distribution can be expressed
through: • AFS Grain Fineness Number (GFN). • Surface area. • Percent fines.
Why the world’s foundries trust Gradmatic
Our environmentally safe furnace lining solutions drive productivity while protecting workers from silica dust over exposure. Te Gradmatic Refractory Installation and Vibration System lines furnaces from 1 to 70 tons.
Less labor and material costs Denser, longer lasting furnace linings Increased tonnage per lining improves profitability Improved workplace conditions protects workers Cuts respirable silica dust from 4 to 10x lower than OSHA approved levels!
Gradmatic Refractory Installation Systems
We’ve been making foundries safer since 1993 See us at Booth 910, Metalcasting Congress
Learn more:
gradmatic@muskoka.com • 705-762-0945 •
www.gradmatic.com March 2015 MODERN CASTING | 35
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92