Abstract: A binder for a foundry mould or core comprises an alkali metal salt of a polyvalent organic acid or a polymerized monovalent organic acid, for example sodium polyacrylate, and an alkaline earth hydroxide such as calcium hydroxide, together with a suitable solvent. Up to 80% of the calcium hydroxide may be replaced by a polyvalent metal oxide or hydroxide. The mixture may include small proportions of other materials, such as aluminum sulphate. It is important that the pH of the organic acid salt solution before mixing with the alkaline earth hydroxide should not be too high and it should preferably be between 5 and 8, in particular between 5.7 and 6.6.

Abstract: A process for casting metal which includes pouring the metal into or around a molded article obtained from a molding composition wherein the binder includes certain fulvenes and/or prepolymers thereof, and a metal salt catalyst. The metal is cooled, solidified, and separated from the molded article.

Abstract: An improved polyurethane binder system is provided which incorporates organic phosphorous compounds that impart longer bench life to the binders making them more useful for preparing moldable compositions such as foundry cores and molds.

Abstract: Mixing (a) a carboxylic acid, (b) a divalent or trivalent metal oxide or hydroxide and (c) a foundry molding sand in the presence of an aqueous solution of (d) a carboxyl-group-containing polymer or (e) water followed by shaping and curing can provide sand molds having sufficiently high green strength without contamination of the working environment. The molding sand composition has excellent processability, which means filling of shapes or molds with the sand can be done with ease. The sand molds manufactured in this way can be disintegrated by a simple procedure. Therefore the molding sand can be used over and over again and does not cause environmental pollution due to disposal of the molding sand.

Abstract: A novel process for preparing foundry cores or molds and binder materials used therefor are provided. The binder materials comprise (a) an alcohol-soluble phenolic resin, (b) a polyvalent metal hydroxide and/or oxide, (c) water, (d) an organic solvent, and (e) an alkali metal hydroxide. They are admixed with refractory particles, such as sand, and cured with carbon dioxide to form shaped foundry cores or molds. The process and materials of the invention bring about such advantages that curing may be performed with safe carbon dioxide, that shaped foundry cores or molds may be taken out from pattern immediately after curing, and that the products have a superior collapsibility after pouring a molten metal.

Abstract: A casting core for the creation of difficultly accessible cavities in castings of aluminum or of one of its alloys, produced from a water-soluble salt as base substance and burnt sugar as binding agent, and a process for the production of such a casting core wherein the base substance is mixed with burnt sugar in aqueous or organic solution, pressed in molds, and baked at elevated temperature.

Abstract: A rapid method for dehydrating a water-sand mixture containing sodium or potassium silicate to produce a strongly bonded sand core is disclosed. The silicate is mixed in a water/silicate ratio of 1.45-3.22:1 and is limited to 0.25-3% of the weight of the mixture. The core box is semi-foraminous and partially transparent to micro-wave energy whereby generated vapor is reduced due to the heated inner surface of the core box (some degree of lossiness) and due to some escape through limited core-box openings. The controlled supersaturated environment about the core serves to prevent micro-porosity and surface defects when controlled micro-wave energy is used to heat cure the mixture. To promote resistance to humidity after curing, the mixture may contain 0.5% zinc oxide, chromic oxide, or aminoaldehyde.