Defects can arise in a product of a metal casting process from reactions occurring at a metal-mold interface. A method that reduces the defects uses an organic binder system by introducing a separate third component to a two-part polyurethane-based binder system used in the cold box or no bake process. The third part is added only after the first two parts are mixed with a refractory molding material to provide a shapeable foundry mix. The third part is an alkyl silicate, such as tetraethyl orthosilicate (TEOS), an alkyl orthoformate, such as trimethyl orthoformate (TMOF) or triethyl orthoformate (TEOF), or combinations thereof.

The object of the invention is a component system for producing a binder for metal casting on the basis of phenolic resins of the benzyl ether type and isocyanates containing non-polar solvents.

Foundry cores, which consist of a mould material mixed from a binder and a mould sand, as well as optionally added additives, that are moulded in a complex way or are optimised with regard to their quality and which are provided for casting cast parts, can be produced by: a) moulding the foundry core by introducing the mould material into a foundry core mould; b) hardening the mould material; c) removing the foundry core from the foundry core mould; d) heating the foundry core to a deformation temperature; e) deforming the heated foundry core by applying a deformation force to the foundry core; and f) cooling the foundry core.

The invention relates to a method for the layerwise construction of bodies comprising at least one novolac in a solid, free-flowing form; an isocyanate component and a first solvent as a liquid component to be printed, wherein the solvent according to a preferred embodiment of the invention also has a catalyst dissolved in the first solvent; a corresponding construction material mixture; a component system for producing the bodies by means of 3-D printing; and three-dimensional bodies produced according to this method in the form of molds and cores for metal casting.

The subject matter of the invention is mold material mixtures for producing molds or cores for metal casting, consisting of at least one refractory base mold material, a binder and an additive based on factice. The invention also relates to a component system, a method for producing molds and cores using the mold material mixtures or the component system respectively, and to molds and cores produced by said method.

A sand additive for use in a no bake foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wstite.

Molding material mixes that contain a polyurethane binder based on phenolic resins of the benzyl ether type and polyisocyanates are characterized by the inclusion of a polybutadiene derivative. In one case, the polybutadiene derivative has epoxide groups and hydroxyl groups. In another case, the polybutadiene derivative has succinic acid anhydride groups. Molds, cores and risers are produced using these molding material mixes. Inclusion of the polybutadiene derivatives results in a reduction of sand adhesions in the molding process.

The present invention relates to a phenolic resin for use in the phenolic resin component of a two-component binder system for the polyurethane cold box process, to a two-component binder system for use in the polyurethane cold box process, to a molding material mixture for curing by contacting with a tertiary amine, to the use of a corresponding phenolic resin, of a corresponding phenol component, of a corresponding two-component binder system or of a corresponding molding material mixture. The present invention relates, moreover, to an article from the group consisting of feeders, foundry molds and foundry cores, producible from a corresponding molding material mixture, to a process for preparing a phenolic resin, and to a process for producing an article from the group consisting of feeders, foundry molds and foundry cores.

The invention relates to a binder based on phenolic resins of the benzyl ether type and isocyanate compounds having at least two isocyanate groups, containing free phenol and free hydroxybenzyl alcohols in the polyol component. The invention further relates to mold material mixtures containing the binder and to cores, molds, or risers produced with the mold material mixtures and to the use thereof in metal casting.

Method of designing and manufacturing a distributor bar for use in a production line comprising a mixing head for providing a viscous foamable liquid mixture, a laminator with a predefined speed of at least 20 m/min, the distributor bar having a central inlet fluidly connected to a number of outlets via a main channel. The method comprises: choosing (3001) a geometry for the distributor bar and defining a set of geometrical parameters; assigning (3002) values to said parameters; creating (3003) a virtual model; simulating (3005) flow in said model by performing a Computational Fluid Dynamics simulation (CFD), taking into account (3004) a non-Newtonian shear thinning model; e) evaluating the simulated flow; building (2007) a physical distributor bar. A distributor bar, a production line, and a computer program product.