1.9 BALLISTIC PARTICLE MANUFACTURING (BPM)

 

• Developed by BPM technology

 

• Sprays material (wax) in 0.002” drops at rates of 12,500 drops per sec to build up slices

 

• The elevator drops as slices are formed

 

• Variable slice thickness is set by changing the flow rate

 

• Part material supports are made from water soluble wax (polyethelene glycol) and are removed after completion by placing the model in water

 

• The BPM personal modeler is $35,000

 

• Incremental fabrication is a ballistic particle method developed by Incre Inc. but molten metal is used instead.

 

 

1.9.1 Sanders Prototype

 

• This methods uses two thermoplastic materials the positive having a higher melting temperature. The materials are distributed by a head that will melt and deposit either material (much like an ink jet printer head doing multiple colors). A raster scan is used to build up layers until the final composite part is done. The lower temperature material is melted away to leave the inner part.

 

• This method is very good for small parts, and produces parts in engineering materials.

 

• There are two commercially available units,

 

 

 

 

1.9.2 Design Controlled Automated Fabrication (DESCAF)

 

• Invented in 1986 by Efrem Fudim

 

• Marketed by Light Sculpting Inc.

 

• Uses photomasks of layers to develop sections.

 

• Exposes the parts to UV light, and develops the photomask

 

• Requires about 40 sec/layer

 

• Expected specs.