Abstract: The present invention has solved the problems of conventional molding materials, and provides a hydraulic composition for additive manufacturing devices having high strength development, particularly high early strength development, and less generation of gas defect and graphite spheroidization defect. Specifically, the hydraulic composition for additive manufacturing devices of the present invention at least contains calcium aluminate. It is preferable that the hydraulic composition contain 0.5-10 parts by mass of gypsum with respect to 100 parts by mass of the calcium aluminate.

Abstract: A hydraulic composition for an additive manufacturing device, the hydraulic composition containing at least sand, an inorganic binder, and polyvinyl alcohol, wherein the hydraulic composition for an additive manufacturing device satisfies conditions (1) and (2). (1) The mass ratio of sand/(inorganic binder+polyvinyl alcohol) is 4 to 12. (2) The mass ratio of polyvinyl alcohol/inorganic binder is 0.1 to 0.4. The hydraulic composition for an additive manufacturing device also preferably satisfies condition (3). (3) The mass ratio of water/(inorganic binder+polyvinyl alcohol) is 0.30 to 1.30.

Abstract: A hydraulic composition for an additive manufacturing device has an excellent initial flexural strength development property and dimensional stability. The hydraulic composition includes 1.5 to 14 parts by mass of a polymer with respect to 100 parts by mass of an inorganic binder. In addition, in a hydraulic composition for an additive manufacturing device, the inorganic binder may contain 50 to 100 mass % of a calcium aluminate with respect to 100 mass % of the entire inorganic binder, and in a hydraulic composition for an additive manufacturing device the inorganic binder, may contain 0 to 50 mass % of rapid hardening cement with respect to 100 mass % of the entire inorganic binder.

Abstract: The present invention provides a hydraulic composition for an additive manufacturing device having an excellent initial flexural strength development property and dimensional stability, the hydraulic composition for an additive manufacturing device including: 1.5 to 14 parts by mass of a polymer with respect to 100 parts by mass of an inorganic binder. In addition, the present invention preferably provides a hydraulic composition for an additive manufacturing device in which the inorganic binder contains 50 to 100 mass % of a calcium aluminate with respect to 100 mass % of the entire inorganic binder, and more preferably provides a hydraulic composition for an additive manufacturing device in which the inorganic binder contains 0 to 50 mass % of rapid hardening cement with respect to 100 mass % of the entire inorganic binder.

Abstract: The present invention has solved the problems of conventional molding materials, and provides a hydraulic composition for additive manufacturing devices having high strength development, particularly high early strength development, and less generation of gas defect and graphite spheroidization defect. Specifically, the hydraulic composition for additive manufacturing devices of the present invention at least contains calcium aluminate. It is preferable that the hydraulic composition contain 0.5-10 parts by mass of gypsum with respect to 100 parts by mass of the calcium aluminate.