Processing vacuum casting

One essential difference between casting and molding processes is that pressure need not be used in casting (although large-volume, complex parts can be made by low pressure and/or vacuum casting methods). Another difference is that the starting material is usually in liquid form rather than the usual solid plastic used in other processes. There is also the difference that the liquid could be a monomer rather than the plastic used in most other processes and in turn the monomer is converted to a polymer/plastic (Chapter 1). 

Vacuum castings, the more basic processes, such as vacuum casting in silicone molds, also have their place and a range of gun-applied TS polyurethane resins introduced by Axson, France, avoids the need even for the casting machine. Martello Design has developed a polyurethane injection process, Thin-RIM, complementary to its existing vacuum casting method, which allows features and wall sections down to 0.5 mm to be produced. 

All, even nonadditive, manufacturing processes or process chains that support to make tools, tool inserts, dies, and molds faster and cheaper than it was possible with traditional tool making but for a lower production outcome. The term includes aU kinds of copying or secondary rapid prototyping processes like vacuum casting. 

Duplication of prototype master models (made by special techniques such as laser stereolithography, laser powder sintering, LOM etc.) in polyurethane or epoxy resins by the vacuum casting process within the scope of rapid prototyping . 

Vacuum casting is a variation of sand casting, is used for aluminium alloys and is known in the industry as V-casting. The process uses dry... 

Vacuum Casting. A slip casting (q.v.) process in which the casting rate is increased by applying a vacuum to the outside of a porous mould. Cf. pressure casting. 

Moving potentially one step further from rapid prototyping to low volume production the vacuum casting process uses a master model, possibly derived from a SLA process, to make a silicon tool. The... 

There are several other batch processes. Vacuum bag and resin injection techniques have been used for specialist application but these are not used extensively in commercial practice. Centrifugal casting has been used for the manufacture of pipe sections but this is again a specialised area. Filament winding (Fig. 3) is essentially a batch process but by good engineering and well planned layout, pipes and tanks made by the filament winding process can be produced... 

There are two typical cathodes composite cathodes and thin-fllm cathodes. Composite cathodes are fabricated by a process of casting, coating, or printing slurries. Fabrication of thin-fllm cathodes usually involves vacuum techniques. 

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