Compacted laminated stone faced stair tread mfr - comprising double pre-compacted asbestos base layers

摘要

Board comprises several prepressed base layers of long fibre asbestos cement which are subjected to an inter second prepressing operation at a higher pressure than the first, but lower than the final compaction pressure when several asbestos backing layers are press-bonded to a natural stone pref. marble facing plate. The inter compacting operation eliminates the need for multiple compacting at the final laminating pressure. The boards are used for high bending stress and torsion resisting building plates for making up into stairs etc. in the building ind.