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Stereolithography is a type of rapid prototyping used to manufacture 3D objects from a digital model exported in a standard format, the format STL (STereoLithography).

Several processes are based on this production method, such as direct metal laser sintering (DMLS), selective laser sintering and photopolymerization.

Selective Laser Sintering or SLS TM

In selective laser sintering, a carbon dioxide laser with low relative thermal energy is used to raise a variety of thermoplastic and metallic powders at the temperature of diffusion to a solid or sintering state.

This process is used to quickly develop objects with an extremely complex geometry that are functional and lasting, as well as a vast range of other applications.

The advantages are numerous:

• Detailed parts and assemblies
  
• Wide range of materials: plastics, metal parts, etc.
  
• Possibility of highly flexible integral hinges and snap fasteners
  
• High stress tolerance and thermal resistance
  
• Cost-effective, small production runs
  
• Used in presentations, demonstrations and video reproductions
  
• Dimensional accuracy to one-thousandth of an inch
  
• Quick delivery for most parts and models

Photopolymerization or SLA TM

An ultraviolet laser is used in this process an as a photoinitiator in the polymerization of the materials being used.

With this technique, models with extremely complex geometry may be quickly developed with a remarkable aesthetic look.

The advantages are also numerous:

• High-quality surface finishing
  
• Accuracy to one-thousandth of an inch
  
• Range of resins that vary in rigidness, colour, clearness and thermal resistance
  
• Possibility of cost-effective, small production runs
  
• Use in presentations, demonstrations and photo-reproductions
  
• Quick delivery for most parts

Room Temperature Vulcanization or RTV

In this process, liquid silicone rubber is poured around a master. The resulting mould is withdrawn from the master and hardened, and then may be used to produce parts in cast urethane.

This technique is used to produce a large quantity of prototypes at a relatively low cost.

The other advantages are:

• Detailed operational prototypes and visual models
  
• Production of cast urethane offering a wide range of rigidness, thermal resistance, colour and texture
  
• Accuracy to one-thousandth of an inch
  
• Possibility of cost-effective, small production runs
  
• Parts delivery usually in two or three weeks

If you would like to learn more about rapid prototyping, please visit:

www.wohlersassociates.com