Portable sand tester provides accurate, repeatable results. (Case history).

Process improvement for sand systems involves recognizing the problems and then implementing the standard process improvement cycle technique of plan, do, check and act. Each step of the process improvement cycle involves monitoring sand property data for a molding line at specific instants. Improvement is accomplished with quick, consistent, timely data collected at minimum cost (without a trained sand technician).

The Hartley Sandman is a portable sand laboratory that meets and satisfies these needs within the constraints of cost, time, repeatability and accuracy. Because of its compact design (52.5 x 28 x 40 in.) the tester can be moved easily to van us locations within the foundry.

The equipment tests the following green sand properties: compactability, green compressive strength, deformation, moisture and permeability. From these measured values it calculates the available bond, working bond, muller efficiency and toughness. The complete set of tests takes 4-5 mm (depending on the composition of the sand), with results printed out or fed directly to a laptop or desktop computer for data tracking, graphing and statistical analysis. The testing does not require a trained technician, only someone to collect the sample and riddle the sand. All tests are performed exactly the same way; hence, there is reduced experimental error. It takes a sand technician 15-20 min to perform the same tests. The collected data provides the foundry with fast information on current conditions of molding sand and records and charts the data in dedicated Windows-based PC software. The tester minimizes the personnel costs to obtain data and gives a sufficient number of tests to infer statistical significance in a short time.

Frazier & Frazier, an iron foundry in Coolidge, Texas, and Wacasco Foundry, a brass foundry in Spindale, North Carolina, both employ the portable sand tester for sand sampling to keep a closer tolerance on molding sand to reduce castings defects. Both Frazier & Frazier and Wacasco Foundry use test results to monitor trends on their molding sand. This data is used to analyze what corrective actions to the sand system are required if collected data drifts outside the upper and lower control limits. Production cost reductions were achieved by performing more tests without trained personnel and by making sound decisions due to the increased number of tests.

Jim Casey, Quality System Director at Frazier & Frazier, commented, "The performance of the Sandman has decreased the manpower needed for testing, while increasing the number of tests." Robbie Deese, Quality Control Engineer of Wacasco Foundry, commented that he "is very pleased. It helps maintain the quality of sand, it has instant results and the consistency of the tests is excellent."