Rapid Prototyping started out as a tool for large OEMs in aerospace, automotive, and consumer products. In the next few years, it may become standard procedure for plastics processors large and small.
You can use a variety of processes to obtain a rapid prototyped part depending on its final application. A simple formula helps ensure you obtain the part you expect: The Right Application plus the Right Process equals the Right Part.
Selective Laser Sintering (SLS) has become a reliable and trusted form of rapid prototyping due to its structural properties. It is particularly useful when the design is complex, custom, and needs to be functional or requires short run production.
In SLS a laser beam selectively fuses or sinters powder materials, nylon, or elastomer materials. It produces plastic or metal prototypes that closely match their molded counterparts.
The finishing time is reduced as the undercuts and overhangs are given support by the solid bed of powder which does not have to be manually removed, but the surface finishes are not as good as those produced through stereolithography. It requires no final curing, but the object is porous as it is sintered.
Once you have decided the SLS process is the best one for your part remember that there are only a select few materials available. However, those materials are as unique as they are special.
The most beneficial characteristic of SLS is how durable and functional the materials are. These materials include versions of the original DuraForm and DuraForm glass-filled (GF), which are nylon-based materials that create highly durable and functional plastic prototypes. Other materials available are Flex Plastic for elastomeric, rubber-like parts, and LaserForm, which makes metal prototypes.
The primary advantage of SLS is that it builds prototypes in nylon material. It is possible to make structurally functional parts such as living hinges, functioning springs, and snap fit components with nylon material. The process in itself is very simple and requires no molding or tooling. The nylon material used can be easily machined, drilled, and tapped unlike those used in sterolithography, which are brittle as they are built with liquid photopolymers and cured with UV light. They continue to cure once complete and as a result become more brittle as time goes on.
All of the selective laser sintering materials can be finished in multiple ways. They can be painted, plated, drilled, tapped, or even machined, which allows for a better appearance for these parts.
Having a good understanding of SLS limitations, plus knowledge about the available materials and how and when to use them, and knowing what the finish options are for your final part, will ensure that you get exactly what you need when you are ready to begin testing for form, fit and function.