Rapid Protyping Technologies

This is a description of the various rapid prototyping and additive manufacturing technologies.

Stereolithography Apparatus (SLA) uses a UV laser to trace a cross section of the product model layer by layer across the top of a vat of liquid polymer. This hardens a thin layer of the material. As each layer is traced, the object is lowered slightly for the laser to trace the next cross-section of the object in the polymer, solidifying that layer and bonding it to the previous layer. This is done layer by layer until the object is formed. Manufacturers:
3D Systems
Selective Laser Sintering (SLS) uses a laser to fuse (sinter) a thin layer of powdered material into a solid object. After each layer is completed, a thin layer of the powdered material is spread across the top for the fusing of the next layer. It is good for fine detail and thin-walled parts. Manufacturer:
DTM Corporation
Fused Deposition Modeling (FDM) uses a temperature-controlled head to extrude and deposit thermoplastic material based on CAD cross-section slices. The material starts in a semi-liquid state, bonding to the previous layer, and then hardening. Manufacturer:
Solid Ground Curing (SGC) prints each CAD cross-section slice on a glass photomask using a electrostatic process like a photocopier. A UV light shines through the mask onto a thin layer of polymer, hardening the exposed resin. Liquid resin is vacuumed off and liquid wax which a later removed is spread onto any spaces. This layer is is cooled to a solid and then milled to thickness. Repeating the process with the next layer builds up the part. Manufacturer:
Cubital America
Laminated Object Manufacturing (LOM) start with a thin layer (4 to 8 mils) of sheet material and use a laser to cut the first CAD pattern (based on a part cross-section). A blank sheet backed with a dry adhesive is then rolled across the cut layer and heat bonded. The cutting process begins again on that sheet. The process build parts with relatively thick walls. Manufacturer:
Inkjet Technology deposits tiny droplets of hot liquid thermoplastic in the desired pattern, layer by layer. Droplets of this or another secondary material generate any support structure (which is later melted away, dissolved or physically removed). Manufacturers:
3D Systems
Direct Shell Production Casting (DSPC) produces ceramic casting molds for metal casting using a layered printing process depositing a liquid binder onto a layer of ceramic powder. After the mold is “printed”, it is then fired. These molds will handle any metal and are more accurate than those from sand casting. Manufacturer:
Direct Metal Deposition (DMD) uses a CNC laser to fuse layers of metal powder. The resulting prototypes made from H13 tool steel, aluminum and other metals are meant to be used for production. Manufacturer:
Precision Optical Manufacturing
PMD flat wire metal deposition technology uses an energy source such as a laser, to fuse a solid metal flat wire to a substrate. Manufacturer:
H&R Technology, Inc.
3D Printing is a term applyng to various technologies for machines that often operate in an office setting. Manufacturers: