Metal casting silicone rubber

Indirect tooling methods are many. Examples include cast aluminum, investment metal cast, cast plastics, cast kirksite, sprayed steel, spin-castings, plaster casting, electroforming, room temperature vulcanizing (RTV) silicone elastomer (Chapter 2 Silicone Elastomer), elastomer/ rubber, reaction injection, stereolithography,338 344 (Table 17.4), direct metal laser sintering, and laminate construction. 

Precision duplication, durability, and metallic beauty have made antimonial alloys, such as pewter and britannia metal, desirable for decorative castings. Several different tin—base and lead-base antimony alloys are used in the jewelry industry. These alloys are typically cast in rubber or silicone molds. 

As mentioned earlier, the insert parts can be produced by any apparatus. This can be extmsion with subsequent cutting, injection moulding, two or multiple colour (also two or multiple component) injection moulding, press moulding, punched and bent metal sheets, cast iron, sintered metal, ceramics in any shape, cut glass, etc., or moulded or extruded silicone rubber (as in catheters and insulators). 

Alternatively, a simpler approach and a less costly way may be beneficial depending on the type of prototype needed. One may consider CNC machining of a metal, wood, or solid plastic model. Machining plastic must be done with very small cuts to avoid residual stresses and distortion however. If the material to be used in the final product is a polymer another approach is to make a wood or metal pattern. Then make a silicone rubber mold by pouring liquid rubber over the pattern in a box. -" Then make prototype castings with a resin-Uke polyurethane. A silicone mold can make up to 20 parts before it begins to deteriorate. 

Zinc is used in multiple applications. It is widely employed for galvanizing steel and iron against rust. It is also used for die casting and forming alloys including brass and bronze. This lustrous blue-white metal is hard/brittle at ambient temperatures. It is malleable at 100—150°C, conducts electricity and heat, is anticorrosive, and has a relatively low melting point (419.5°C). Zinc is the fourth most common metal today. Adhesives recommended include nitrile-epoxies, epoxies, silicones, cyanoacrylates, and rubber-based adhesives [21]. 

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