PRODUCTION OF FIBER-REINFORCED CEMENT BOARD

摘要

PROBLEM TO BE SOLVED: To enable a milk carton waste paper to be utilized as a reinforcing fiber by formulating the fibers obtained by carrying out the dry-opening of the milk carton waste paper without removing the surface coating layer, and having a length not longer than a prescribed length, with a cement composition. SOLUTION: A milk carton paper is opened without removing the surface coating layer such as a film by using an opening machine such as a mill to provide fibers with <=3 mm lengths. A wetting agent in the proportion of 1-5 wt.% of the fibers is preferably added to the fibers at the time of the dry opening or after the dry opening to supplement water content of the fibers and to make the compatibility in a raw material good. The cement composition is formed by adding a silica component such as silica rock powder, a lightening agent such as pearlite, a thickener such as methylcellulose to a cement with a reinforcing fiber formulated therewith. The water of 20-100 wt.% based on 100 pts.wt. cement is added to and mixed with the cement composition, and the obtained mixture is pressure-formed by using an extruder. The pressure- formed product is cured and hardened to provide the objective fiber-reinforced cement board.