Provided is a method of producing foamed sand (s) for forming a sand mold. The foamed sand (s) includes sand particles (p) and foam (f) adhering to surfaces of the sand particles (p). The foam (f) contains water glass (b), water (w), and a surfactant (c). According to the method, an aqueous surfactant solution (e) in which the surfactant (c) is dissolved is frothed to generate froth (d) from the aqueous surfactant solution (e). Then, the generated froth (d), the water glass (b), and the water (w) are kneaded with the sand constituted by the sand particles (p).

A method for inorganic binder casting, comprising: selecting a Shape-Forming Material based on pre-determined manufacturing and shape characteristics, selecting a casting shape based on pre-determined design characteristics, and forming the Shape-Forming Material into a mold. The mold is coated with an inorganic binder solution at a pre-defined weight ratio and is dehydrated the Shape-Forming Material. The method further comprises pouring a hot liquid metal into the mold and allowing said hot liquid metal to cool to form a molded part. The Shape-Forming Material may be washed from said molded part with a solvent, the inorganic material and Shape-Forming Material reclaimed, reused, and the Shape-Forming Material reformed to a mold. The method further comprises recreating a liquid inorganic binder solution using the reclaimed inorganic material and recoating the Shape-Forming Material with the reclaimed inorganic binder solution.

The foundry sand binder supply apparatus of the present invention comprises a hopper for storing a binder therein, a binder transfer device for transferring the binder, a binder measuring and discharging device disposed beneath a distal end of the binder transfer device, and a binder supply amount control device. The binder measuring and discharging device comprises a measuring container for receiving the binder therein, a load cell for measuring the weight of the binder inside the measuring container, and a discharge device for discharging the binder from the measuring container. The binder supply amount control device is operable to control the discharge device to discharge the binder from the measuring container by a predetermined amount less than the whole amount of the binder inside the measuring container, and control the binder transfer device to supply the binder into the measuring container by the predetermined amount of the discharged binder.

A water supply and kneading system for green sand, including: a weighing hopper that stores green sand that has been weighed; a kneading machine that kneads the green sand and water; a sand loading means for releasing the green sand in the weighing hopper into the kneading machine, or shutting off the release; a water supply device that supplies water to the green sand in the kneading machine; a moisture sensor that includes a pair of electrodes and measures the moisture content of the green sand stored in the weighing hopper by measuring an electric potential difference between the electrodes; and a kneading control device that controls the amount of water supplied by the water supply device and controls the sand loading means on the basis of the output of the moisture sensor.

A mixing and adjusting method for foundry sand includes calculating a total supplied water amount until a compactability (CB) value of mixed sand becomes larger than a lower limit value of a target CB value range, determining the total supplied water amount as a predetermined amount of water associated with an electric resistance of the foundry sand, and determining a ratio of a variation in the CB value corresponding to an additionally supplied water amount from the additionally supplied water amount during an additional water pouring and the CB value of the mixed sand.

Provided is a method of producing foamed sand (s) for forming a sand mold. The foamed sand (s) includes sand particles (p) and foam (f) adhering to surfaces of the sand particles (p). The foam (f) contains water glass (b), water (w), and a surfactant (c). According to the method, an aqueous surfactant solution (e) in which the surfactant (c) is dissolved is frothed to generate froth (d) from the aqueous surfactant solution (e). Then, the generated froth (d), the water glass (b), and the water (w) are kneaded with the sand constituted by the sand particles (p).

The method of manufacturing a core of the present disclosure includes the steps of blending dry regenerated sand, wherein the foundry sand utilized in the production of the core is sand regenerated by a dry process, wet regenerated sand, wherein the foundry sand is sand regenerated by a wet process, and new sand in a predetermined ratio, and producing a core from the blended sand. The blending ratio is as follows: dry regenerated sand, 49 wt % to 95 wt %; wet regenerated sand, 1 wt % to 49 wt %; and new sand, 1 wt % to 5 wt %.

A sand core making machine that includes a hopper having a hollow body with an inner surface delimiting a passageway for a material used in the manufacture of a sand core. The hopper includes a plurality of breaker assemblies with each breaker assembly having at least one string. The ends of a string are attached to corresponding attachment points of the inner surface of the hollow body, such that the strings are arranged in a flow passage of the material. At least two breaker assemblies are spaced apart such that the two breaker assemblies interact with each other to break lumps of the material supplied to the hopper when the hollow body is shaken.