Abstract: A filter for filtering a liquid metal and to be received in a mold housing defined by internal side and face walls. The filter has a top wall and side walls extending downwardly from the top wall, the side walls being joined together at respective corners. The side walls extend downwardly towards distal end portions. The corners of the filter have a stiffness or rigidity that is higher that the remainder of the filter for increasing the strength of the overall filter and for helping the filter to maintain its shape and integrity throughout casting. The shape of the side walls allows an easy and consistent placement of the filter in the mold housing and ensures that the filter is maintained in place.

Abstract: A composition for preparing a rigidified fabric made of heat resistant fibers or threads of heat resistant fibers, preferably of woven threads made of heat resistant fibers, said composition comprising a mixture of a product A and a product B, the product A being obtained by polymerization of carbohydrate units, natural or synthetic, preferably a saccharide, and more preferably a sugar such as glucose, fructose, galactose, sucrose, maltose, lactose, etc.; and the product B consisting of at least one additive such as a binding agent. A method for preparing said composition, a method for preparing a rigidified fabric of heat resistant fibers, the method for the manufacture of filtering devices, filtering devices so obtained, their use for the filtering of metal, and installation and process involving said filtering devices.

Abstract: Disclosed is a free flowing dry back-up material which comprises: from 67 to 96% by weight of fly-ash; from 2 to 15% by weight of a heat sensitive binder such as boric acid; from 2 to 7% by weight of a non-wetting agent such as calcium fluoride; from 0 to 10% by weight of a heat expandable material, viz. a material expandable as a function of the temperature such as vermiculite or graphite; and from 0 to 1% by weight of a dust suppressant such as kerosene. This material which is useful in particular in the aluminum industry has the advantages of being water free and free flowing, such avoiding the use of vibrator to position it into a shell. It also has a low density and a low thermal conductivity. Moreover, it is organic free as compared to the existing materials which use an organic binder to ensure a low temperature set; and it sets at a temperature lower than 400° F.

Abstract: There is provided a filtration and distribution device for a molten metal, which is in the form of a bag having parts made of a solid heat-resistant fabric and open areas made of an open weave heat-resistant fabric. At least some of the parts made of the solid heat-resistant fabric are replaced by rigid parts made of a moldable or thermo-formable composite consisting of an open weave heat-resistant fabric embedded into a matrix made of a heat-resistant inorganic material compatible with the open weave heat-resistant fabric. Preferably, the open weave heat-resistant fabric forming the open areas of the bag, is made of yarns that are rigidified and protected by application thereto of a heat-resistant coating. This coating is preferably made of a heat-resistant inorganic material applied by spraying or dipping after the yarns are weaved. The rigidification can be achieved naturally or by thermal treatment.