| 摘要 |
PURPOSE:To provide a process for producing an asbestos-free extrusion-molded article having little cracks and warpage. CONSTITUTION:Solid materials composed of ordinary Portland cement as a hydraulic binder, wollastonite or pulp as reinforcing fiber, crystalline fine quartzite, methylcellulose as a thickener, etc., are mixed with each other in dry state, a liquid material such as water is added thereto, the mixture is mixed and kneaded and a panel is extrusion-molded from the mixture. The panel is subjected to primary curing under saturated steam pressure at 40-80 deg.C. 15 Panels are stacked one upon another, cured in an autoclave according to a prescribed procedure and cooled while lowering the pressure until the absolute pressure in the autoclave reaches 1atm. After discharging drain from the autoclave, the autoclave is deaerated with a Nash pump, etc., while keeping the molded article in the autoclave to effect the uniform cooling of the article. The panel can be cooled uniformly in the autoclave by this process to suppress the generation of cracks and deformation of the panel. |
