Abstract: A foundry mold or core is prepared by mixing with a foundry aggregate a polyisocyanate, a polymeric addition product of a phenol and a further material comprising aromatic hydroxyl groups, forming the mixture to the required shape and causing or permitting the polyisocyanate to react with both the addition product and the further material to bind the aggregate. The addition product may be prepared by reacting an unsaturated hydrocarbon with a phenol. The hydrocarbon may be comprised by a mixture of terpenes. The further hydroxy material may be a bisphenol or phenolic resin.

Abstract: A carbon fibre reinforced carbon article is prepared by wrapping carbon fibre cloth around a carbon fibre reinforced carbon core and then depositing elemental carbon on the core and in the cloth to bond the cloth to the core, leaving substantial interstices in the covering layer of cloth.

Abstract: In a foundry binder comprising a polyisocyanate and a polyhydroxy composition, the polyisocyanate is modified by reaction with a drying oil. The composition is useful in a "cold box" process.

Abstract: A foundry composition for use in forming foundry moulds or cores comprises an aggregate mixed with a binder which includes a polyisocyanate, a polyfunctional phenol and an aliphatic polyol with the weight of the phenol exceeding that of the polyol. The composition may be used in a "cold-box" process.

Abstract: A final mixing chamber for mixing together previously separately prepared mixtures of foundry sand/binder and foundry sand/catalyst which are delivered to the upper end of the final mixing chamber having a discharge aperture in its lower end and a vertical rotatable shaft extending centrally through the chamber with blades fixed thereto. Some of the blades extend radially from the shaft and are made up of mixer blades which direct material downwardly and deflector blades which deflect material upwardly, while the remaining blades are scraper blades which are attached between adjacent ones of the other blades at their extremities so as to scrape the internal surface of the chamber.

Abstract: A method of, and apparatus for, mixing foundry sand, resin binder and catalyst, wherein sand/resin and sand/catalyst mixtures are prepared separately in continuous mixers and conveyed to a final mixing chamber having a vertical high speed rotating shaft with downwardly inclined mixer blades and upwardly inclined deflector blades.