Gravity mold casting

Gravity Mold Casting Gravity Pulls It Down... 

Permanent mold casting is generally similar to die casting, except that gravity rather than pressure is used to fill the mold cavity. This process is employed where larger, or heavier, section castings are needed. Mold costs are still high, so this process is economical only in volume as well. 

Molten metal is poured under gravity into a pre-heated die, where it solidifies. The die is then opened and the casting ejected. Also known as permanent mold casting (see 1.3F). 

Sand molds are gravity fed whereas the metal moulds used in permanent mold casting are either gravity fed or by using air or gas pressure to force metal into the mold. Sand castings and permanent mold castings are made from alloys that respond to heat treatment. 

This reactor contains at least two solid phases, two Hquid phases, and a gas phase. The flows are largely driven by gravity caused by the density differences of the soHd and Hquid phases. Taconite and coke are admitted at the top of the reactor and O2 at the bottom. Liquid Fe and slag are withdrawn at the bottom of the reactor. The Hquid iron is either cast into ingots in molds or directly passed from the reactor through rolling mills to process it into sheets. 

The method of prepg CP-1B consisted of vibrating casting powder into a mold, introducing the nonvolatile, liq expl solvent by gravity thru... 

Finally, in the reaction injection-molding (RIM) process, low-viscosity reacting monomers or prepolymers are intimately mixed just before being injected into a hot cavity, where they react further and solidify. The RIM process, then, is a variation of the casting process, where highly reactive liquid systems are injected quickly, rather than being allowed to flow by gravity, into complex shape cavities, where they quickly react and solidify. 

This method is ideally suited to the casting of spherical shapes, but the outer shape may be modified with the use of special techniques. Normally, metal molds are used and plastic is poured into the rotating mold that may spin about a horizontal, inclined, or vertical axis. The centrifugal force, even though minor relative to gravity, improves both homogeneity and accuracy. 

Aluminum castings can be produced with all conventional casting processes. For mold making, only sand casting and gravity casting (under reservation) can be used because of the relatively low quantities required. 

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