无石棉维纶纤维水泥板的工艺原理与特性

研究用高模量维纶纤维与改性维纶纤维代替石棉制造无石棉纤维水泥板。这两种纤维的弹性模量虽显著低于石棉,但与水泥基体间有较好的界面粘结,故仍起增强作用。探讨了用抄取法制作无石棉维纶纤维水泥板的工艺原理,其中主要有维纶纤维的均匀分散、减少过滤过程中水泥粒子的流失、控制纤维水泥浆的过滤速率、调正抄取机的工艺参数、板坯的补充加压,采取合宜的蒸养制度等。所制成的维纶纤维水泥板具有以下主要特性:(I)横、纵向抗折强度与弹性模量低于石棉水泥板,但变形能力高于后者。(2)抗冲击强度高于石棉水泥板。(3)容重低于石棉水泥板。(4)与石棉水泥板一样,具有较好的不透水性、抗冻性、不燃性、耐热水性与机械加工性。

TECHNOLOGICAL FUNDAMENTALS AND CHARACTERISTIC OF NON-ASBESTOS VINYLON CEMENT SHEETS Vinylon Cement Sheets

High modulus and modified vinylon fibres are used as substitutes for asbestos to make non-asbestos fibre cement sheets. Though the Young's modulus of these fibres is much lower than that of asbestos, they still give reinforcing effect on cement matrix due to their good interfacial bond with the latter. Several technological fundamentals for producing non-asbestos vinylon cement sheets by Hatschek process are dis- cussed, Such as homogeneous dispersion of the fibres, reducing the loss of cement particles in filtration, con- trolling the main technological parameters of the Hatschek machine, additional pressing the green sheets, adopting the optimum steam curing regime etc, The non-asbestos vinylon cement sheets have the following characteristics: (1) their longitudinal and transverse bending strength are lower than that of asbestos ce- ment sheets, but deformation capacity is higher than that of the latter. (2) their impact strength is higher than that of asbestos cement sheets. (3) their bulk density is lower than that of asbestos cement sheets. (4) their watertightness, frost resistance, non-combustibility, hot water resistance and machinability are the same as that of asbestos cement sheets.