ZIRCAR Alumina Insulations Types ZAL-45 and ZAL-45AA "All-Alumina" boards are high strength, uniform, rigid, refractory structures composed of alumina fibers and high purity inorganic binders. Both have an optimum fiber density of 45 lbs/ft³ (0.72 gm/cc), fine open pore structure and excellent thermal insulating properties. Type ZAL-45 has superior hot strength and dimensional stability to 1650°C (3000°F) and withstands intermittent use to 1700°C (3192°F). Type ZAL-45AA has superior resistance to chemical attack and dimensional stability to 1550°C (2822°F).
The homogeneous microstructure and consistent binder distribution allow these materials to be machined to tight exacting tolerances with ordinary shop tools and equipment. Their superior machineability and dimensional stability plus low heat capacity make them ideal for use as setters, supports and process fixtures in both continuous and batch firing furnaces