Rapid prototyping is the process of quickly creating physical parts to use to test the appearance, fit, and / or functionality of a design. Traditional manufacturing processes can take weeks or months to establish, not to mention thousands of dollars. This is why rapid prototyping is so important. It not only saves time, but also money, in most cases.
Service providers
There are many companies that offer rapid prototyping services, and there are many services offered by them. Some of the popular services are discussed below.
Manufacturing types
There are two basic types of prototyping: additive and subtractive. Subtractive processes involve older techniques such as milling (including CNC milling). Machines start with an oversized block of material and gradually remove the material until the part is finished. Additive processes, such as 3D printing, are relatively new and work by creating layer upon layer of material until the part is finished. Both types of manufacturing can take hours or days to complete, but each process has unique advantages.
A rapidly growing process is called 3D printing. It is one of the newest and most affordable processes available. It is an additive process where the layers of material, usually a plastic or a photopolymer, accumulate one at a time for several hours to create parts. Some printers can even use real metal. There are several ways to create the layers. One involves an inkjet system, where a liquid photopolymer is sprayed onto a layer-shaped table and dried with ultraviolet lamps. Another system extrudes very small strips of plastic, such as a small hot glue gun, and a mechanical positioning system places the plastic in the correct areas to create a layer with the correct contour. Yet another system uses a laser to target a layer of dust to blend small areas together to create a layer with the proper contour. There are other systems, but this is a good description of this process.
Stereolithography (SLA)
Stereolithography, or SLA, is one of the oldest and most popular rapid prototyping techniques. It offers a good level of resistance, surface detail and cost. SLA is an additive process that involves a tub of liquid photopolymer. A laser system heals the appropriate sections of each layer.
Selective laser sintering (SLS)
Selective laser sintering, or SLS, is another popular service offering. It is generally more expensive and parts often have a rougher finish than the SLA, but there is a wider range of materials available, including metal, plastic, ceramic, and glass.
Urethane castings
When multiple rapid prototype companies are needed, it is sometimes more economical to mold the parts using a urethane casting method. Typical amounts involved are ten to one hundred. A master part is usually made using SLA and then an RTV silicone mold is created around it. Then the castings are made of urethane or polyurethane. These urethanes come in a wide variety of material and color properties, which can be of great benefit to the customer.
CNC machined plastic
Another service offered by some companies is mechanized plastic parts. CNC mills typically make parts from metal, such as steel or aluminum, but they can also be used to make prototype parts or low-volume parts from many different types of plastic.
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