METHOD OF MANUFACTURING FRONTWARD ASBESTOS CEMENT SLAB Russian patent published in 2004 - IPC

FIELD: manufacture of building materials.

SUBSTANCE: manufacture of pressed asbestos cement slab suitable for facing front wall panels comprises composing asbestos blend, crushing asbestos fibers, thoroughly stirring asbestos and cementing substance in water to form homogenous paste, which is further completed with additional water to give asbestos-cement slurry used for molding asbestos-cement sheets by removal of most water contained in slurry and imparting required dimensions and shape to sheets. The latter are then compacted and binding agent contained therein is allowed to harden so imparting required mechanical strength. Compaction is accomplished by raising pressure to 600 MPa during up to 50 min so developing specific pressure to 212 kg/cm² and holding product at maximum pressure for up to 15 min. End products are stored.

EFFECT: increased bend strength to 300 kg/cm² and higher due to increased length of asbestos fibers in asbestos blend and increased frost resistance of products to 150 alternate thawing-freezing cycles.

1 tbl, 3 ex