The object of the invention is a method for the layered construction of bodies comprising refractory molding base material and resol resins as binders having, in addition to phenol, ortho- and/or para-substituted phenols as monomer structural elements and three-dimensional bodies produced according to this method, and a binder for 3-dimensionally constructing bodies, in particular molds and cores for the metal casting.

A structure for manufacturing castings, containing an inorganic fiber, a layered clay mineral, and an inorganic particle other than the layered clay mineral and having an organic content of 5 mass % or lower or having a mass loss of 5 mass % or lower when heated at 1000° C. for 30 minutes. The inorganic particle preferably contains one or more selected from obsidian, graphite, and mullite. The inorganic fiber preferably contains carbon fiber. The inorganic fiber preferably has an average length of 0.5 to 15 mm. The layered clay mineral preferably contains one or more selected from bentonite and montmorillonite.

A foundry mix includes a major amount of a foundry aggregate and an effective binding amount of a binder system. The binder system cures in the presence of sulfur dioxide and a free radical initiator. The binder system may include (1) 10 to 70 parts by weight of an epoxy novolac resin; (2) 0.5 to 10 parts by weight of resorcinol; (3) 20 to 70 parts by weight of a monomeric or polymeric acrylate; and (4) an effective amount of a free radical initiator. Notably, (1), (2), (3) and (4) are separate components or mixed with another of said components, provided (4) is not mixed with (3) until a foundry mix is to be created, where said parts by weight are based upon 100 parts of the binder system.

A no bake process is provided for preparing a foundry shape. A major amount of an appropriate foundry aggregate, especially a sand that has been mechanically-reclaimed, is mixed with an amount of halloysite tubes. A binder system, especially a water-based binder, such as an aqueous alkaline phenolic resole resin, is added to the mixed aggregate and halloysite, and a liquid co-reactant for curing the binder is also added. By intimately mixing the components, a foundry molding compound is formed and it can be placed into a mold or patter to cure into a foundry shape. When removed from the mold or pattern, the foundry shape can be used to cast molten metal.

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.

A no bake process is provided for preparing a foundry shape. A major amount of an appropriate foundry aggregate, especially a sand that has been mechanically-reclaimed, is mixed with an amount of halloysite tubes. A binder system, especially a water-based binder, such as an aqueous alkaline phenolic resole resin, is added to the mixed aggregate and halloysite, and a liquid co-reactant for curing the binder is also added. By intimately mixing the components, a foundry molding compound is formed and it can be placed into a mold or patter to cure into a foundry shape. When removed from the mold or pattern, the foundry shape can be used to cast molten metal.

The binder coated refractories comprises the refractory aggregates and the solid-form coating layer which comprises the sugar group as the binder and which is provided to the surface of the refractory aggregates. According to this, the sugar group is used as the binder for bonding the refractory aggregates. Further, even if the sugar group is thermally decomposed, the sugar group emits the carbon dioxide and the water. Therefore, there is little likelihood of emitting the harmful gas. Therefore, it is possible to reduce the environmental pollution. Further, the sugar group is thermally decomposed easily. Therefore, it is possible to manufacture the casting mold having the good breaking property.

A method for additive manufacturing is provided, including: mixing a hardener with a sand material, so that the hardener is evenly coated on a surface of the sand material, and then spraying a binder through a nozzle, reacting the binder sprayed through the nozzle with the surface of the sand material evenly coated with the hardener to harden a sand mold. Therefore, the problem of nozzle clogging may be overcome, and a solid with a particle size of less than 0.6 μm may be obtained by the additive manufacturing. In addition, the hardening speed can be adjusted according to the size of the sand mold. Compared with a general sand mold product, the hardening speed may be increased and the storage life of the binder may be prolonged when the sand mold has a large size.

A description is given of a binder system, intended more particularly for use in a process from the group consisting of polyurethane cold-box processes and polyurethane no-bake processes.

The present invention relates to a mold material mixture for producing moldings for the foundry industry, in particular for producing foundry molds, cores or feeders for the foundry industry, which comprises A) one or more pourable, refractory fillers, B) a binder system comprising i) formaldehyde, a formaldehyde donor and/or precondensates of formaldehyde and ii) an amino acid. The present invention additionally relates to the use of amino acids in a mold material mixture for producing moldings for the foundry industry or for producing moldings for the foundry industry, a process for producing a mold material mixture and a process for producing a molding for the foundry industry.