Consequently, many foundry managers are skeptical about trying new, slightly more expensive, products that claim to deliver longer lasting performance. However, foundries in the Pacific Northwestern United States that are using the patented pouring, filtering, and riser basins made of DuraTech, formally known as Super-Slick-Plastic, are reporting savings up to $4,000 annually for their efforts. That could offer new cost cutting potential for others using green sand and flaskless molding.

    One such foundry is the Durametal Corp., Portland, Oregon. The no-bake sand caster supplies stainless steel and white steel for the pulp and paper industry. As part of its operation, the company produces between 500-600 pouring basins a day, using a silica sand mix with a urethane binder.

    Durametal had been using a urethane and fiberglass core box to produce no-bake sand basins, but surface wear from sand erosion necessitated frequently outsourcing the core box for repair and resurfacing.

    Then in 1993, the company elected to try a new basin pattern made of DuraTech Originally developed for the aerospace industry, the plastic is environmentally - friendly, and is made of light-weight polyurethane. The plastic can be molded onto metals, or easily machined, and it withstands temperatures up to 200 degrees F (93 C). Its standard hardness is rated at D-75 Durometer, though custom sheets can range in Durometer hardness from A-60 to D-75.

    In practical application, Durametal has found that the six cavity box produced more than five years ago still remains in service, and while the DuraTech pattern has produced in excess of 1 million pouring basins, it has required virtually no maintenance.

    Consequently, because this product has proven itself to be the most wear resistant plastic developed for this application, Durametal estimates this "new" plastic pattern is saving the company about $4,000 each year it's in service savings now exceed $20,000.

   In addition to the cost savings, Durametal foundry workers have cited other benefits to using the new plastic basin molds. They weigh about half as much as the previous basin molds, and because the plastic can be machined or molded into thin wall sections, the lighter weight boxes are more manageable.

   Other Northwest foundries, including Eagle Foundry Company, Varicast, and Roemer Electric Steel Foundry Company, have experienced similar results with their DuraTech core boxes.  They also report that the draw from the patterns is good, and that virtually no release agent is required.  This provides additional savings.

    Adolf's Pattern Shop, Portland, OR, has developed several styles of filter basin molds.  One of the largest basins available (Box #554) can deliver up to as much as 1,500 LB (680 kg) of filtered steel, 2,000 LB (907 kg) of iron, or any other type of metal. All of the basin patterns can be used with, or without, square or circular ceramic foam filters of various sizes.  Used without a filter, some of the basin patterns are suitable for use as a straight riser. With a filter, the same pattern can also create a recessed break-off riser. Adapter rings give extra flexibility to some basin patterns. They allow the pour opening to be reduced or enlarged.  Some basin styles can be used with a sand saving insert.

    In addition to providing a variety of standard basins, the company will create custom patterns in a variety of sheets, blocks, rods, or tubing.

    While the plastic has been proven to offer cost saving durability for basins, it's also been used to create an American Foundrymen's Society approved test bar pattern. That indicates that the material could potentially provide additional savings to foundries electing to use the material for other types of patterns and core boxes.