| 摘要 |
PURPOSE:To obtain the titled foamed material having low specific gravity, light-weight and excellent heat insulation, by adding a foaming agent and water to glass and/or natural glassy mineral powder, preforming the obtained composition, placing the preformed product on a calcining mold having a specific shape and calcining and foaming the preformed article. CONSTITUTION:100pts.wt. of glass and/or natural glassy mineral powder (e.g. silas) is compounded with 0.1-5pts.wt of a foaming agent (e.g. Si3N4), 0-50pts. wt. of water and 0-10pts.wt. of a binder (e.g. PVA) and the obtained composition is pressed under a pressure of >=0.1kg/cm<2> to form a preformed article 2 having a concave surface 21 having similar or somewhat larger curvature than the convex face 121 of a calcining mold 1. The preformed article 2 is placed on a convex face 121 of the calcination mold 1 directing the concave face 21 of the product toward the convex face 212 and is foamed by calcination. The calcination mold 1 is produced by mounting a protrusion ridge 12 having an upper convex surface with a semicircular cross-section on a supporting plate 11. |
