Simple Solutions That Work! Issue 12

PRODUCT SOLUTION BACKGROUND Isotherm tile feeder linings. Isotherm is a lightweight ceramic bonded insulation material which has no binder and is fired at 1350 °C. This means there is no gas produced during casting and allows them to be placed very close or even on the casting surface without causing any defects or sand burn on. They also have a Modulus Extension Factor of 1.52 compared to the typical 1.2 MEF performance of fibre board on large feeders. This means that isotherm feeders are typically 45% smaller than the equivalent fibreboard feeder. NEW CASTING METHOD Through the use of our software, discussion and calculation we were able to reduce the cast weight to approximately 28.5 tons, by making the following changes. 1. Resizing the 6 main fibreboard feeders with isotherm feeders saved 300kgs/ feeder = 1800kgs 2. This also resulted in much cleaner feeder necks avoiding flame deflection and cutting damage. 3. Removal of the inside wall padding = 1700 kgs. This was done by placing ingates in the bottom of the casting and creating two small isotherm feeders at the ingates, which avoids both shrinkages due to ingating and erosion/burn on in this area. The weight of these feeders was absorbed by simplification of the gating system. 4. In order to remove the padding it necessitated a line of chills along the inner wall to meet the integrity standard required. However, this also avoided any risk of machining into the centre line area and the associated defects, while reducing machining time by approx. 3 hours. 5 BACK TO BASICS Continued on next page