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An Overview
Rapid tooling is an application of Rapid Prototyping that refers to using rapid prototyping technologies to produce prototyping or preproduction tools or molds This automatic building typically reduces the amount of time needed to produce such tools by less than 20% of the time needed in the typical manufacturing process. The cost of building tools in this manner can be significantly less costly than production tooling, however, these tools tend to have a shorter lifespan.
Rapid tooling is appropriate for difficult and complex geometries more easily handled by transferring the design of the tool directly from a design software application directly to a manufacturing process or technique. This process is especially suitable for simple tools due to the ability to more accurately represent such tools programmatically.
There are two types of rapid tooling are indirect and direct.
In indirect tooling, models created from the process are used as patterns to create the molds. These indirect tooling processes include:
- Vacuum Casting: The model is suspended in a vat of liquid silicone or room temperature vulcanizing (RTV) rubber. The mold that forms around the model as the rubber hardens is removed by cutting it in half and the model is removed leaving a cavity. . Tools produced by this process have very good accuracy. Epoxy and urethane materials can be poured into the cavity to product prototype parts.
- Sand Casting: A sand mold is built by packing a sand mixture around the model to form the mold cavity and pouring a casting liquid into the cavity. This technique is typically used for prototype or preproduction metal parts. When very limited quantities are needed the parts can also be used for production parts.
- Investment Casting: A ceramic shell is formed around the prototype wax model. The model must not expand during the autoclave process which hardens the shell in order to form the mold. The wax model is removed by melting leaving a cavity as the tool. Molten metal is poured in the cavity to form the part.
- Injection molding: A mold is formed by encapsulating the model with a composite or aluminum filled epoxy materal to form the tooling. The resulting tooling is used in the injection molding process.
In direct tooling, the tooling is produced directly from the prototyping process. Some available techniques for this process include:
- RapidTool: A metal mold is created using the SLS technology that can produce up to 50,000 injection moldings.
- Laser-Engineered Net Shaping (LENS): Creates metal tools from CAD data by using a laser beam to melt the area of the tool where material is to be added. The tool is built layer by layer by adding the desired material to the melted area. This process is only applicable to tools with simple, uniform cross sections.
- Sand Molding: Sand molds are constructed directly from CAD data.
Disclaimer
DPT may not provide some of the services and/or techniques presented in the Knowledge Center. For a full list of services we do offer, please visit our rapid prototyping page.
