Molding Sand


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molding sand

[′mōld·iŋ ‚sand]
(metallurgy)

Molding Sand

 

a mixture of sand, clay, and highly refractory materials, such as chamotte and asbestos, together with a binder, used for making single-casting and semipermanent molds.

Both natural and synthetic molding sands are used. Different molding sands are used for the casting of pig iron, steel, and nonferrous metals. Molding sands may also be classified as facing sands, black, or floor, sands (for backing and filling), and all-purpose sands. Molds are classified as green-sand, dry-sand, skin-dried, and chemically hardened molds; those in the last category may be hardened by carbon dioxide, or they may be self-hardening. The properties of a molding sand—formability, strength, gas permeability, refractoriness, and collapsibility—depend on the combination of materials used and the way in which the materials are mixed. Recycled sands may also be used as molding sand. Special production equipment is used in the manufacture of molding sands.

References in periodicals archive ?
The results of compressive strength and permeability of twelve molding sand mixture experiments based on general factorial design with four levels of content and three levels particle size of rice husk are listed in Table 1.
This test is used to determine the percentage of moisture in the molding sand. Moisture in molding sand affects the plasticity of the clay bond, which controls most sand-related defects.
The cone jolt toughness test is a good tool to evaluate the ability of a prepared molding sand to resist breakage (toughness).
As a result of the downward-moving riser, the molding sand under the riser is well compacted, and the casting has a perfect contact surface.
This course covers the components of the sand conditioning system that is used to prepare molding sand mixtures.
The properties of molding sand mixtures give an indication of the quality of the molding sand mixtures.
The practice of using one molding sand with multiple metal types (pouring aluminum and copper-base with the same sand system) is becoming popular in the casting industry for both ferrous and nonferrous facilities.
The size of the sand grains in your molding sand mixture is a critical element in the quality of the castings you produce.