Asbestos-free sheet material for spiral-wound gaskets

摘要

Non-asbestos flexible sheet material suitable for use in the manufacture of spiral wound gaskets is made by dewatering on a water-permeable conveyor a layer of aqueous slurry and compressing and drying the dewatered layer, the aqueous slurry employed being one that contains the following ingredients in the following proportions by dry weight: china clay 20-50% mica or chlorite 20-50% graphite 10-40% cellulose fibres 2-10% vitreous fibre in wool form 2-10% synthetic organic polymer binder 2-10%.