A method of manufacturing molds and cores suitable for producing fiber composite bodies or cast parts of metal or plastic from a mold base material and a multicomponent binder by 3D printing includes pretreating the particulate mold base material with at least one silicon-organic compound having a polar hydrophilic end and a nonpolar hydrophobic end, forming a layer of the pretreated particulate mold base material, and applying the binder or at least one component of the binder in liquid form to the layer, wherein b. and c. are repeated.

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), where said parts by weight are based upon 100 parts of the binder system.

A binder system for refractory materials used in sand casting processes, especially two-part polyurethane-based binder systems used in the cold box or no bake process, has less metal-mold reaction when a separate third part is used. 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.

A foundry mix includes a major amount of a foundry aggregate and an effective binding amount of a binder system. The foundry 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.