Monday, June 11, 2012

3D Printer Raw Materials

3D printers utilize different types of raw materials. Following are my personal thoughts on two different raw material types.

Filament ABS, PLA:
- Mainly used in RepRap derivate printers.
Relative low cost printer design. Utilizes low cost extruders. Printed objects have continuous layers, improving rigidity and smooth look.  Depending on the nozzle width, the build speed can be considerable increased in trade off lowering the detail of final object.

Uniform and perfect circle filaments are required for high quality results.
Difficult to align layers. Difficult to control the extruded plastics thickness. Bubbling may occur.
Supporting the design is not that easy, either another extruder is required with a water soluble plastic is used or the gap can be filled with loosely build plastic.  Stringing is also another problem.
The object printed would deform while being printed due to temperature differences. The bottom platform can be heated and the extruded plastic is hot, however the plastic in between is exposed to the ambient temperature. Due to these temperature differences warping is inevitable depending on the shape of the object. Heated platform is required for larger ABS prints.

Powder Plastic (I don’t know the exact plastic composition):
- Mainly used in high end 3D printers.
Plastic powders unlike filaments can have higher tolerances in manufacturing. No support material is needed while the powder serves as the support. No heated platform is required. Less warping occurs due to less temperature deviation. Consistent printed unit volume results in consistently high quality prints. Parallel processing can be easier to implement compared to filament based printers.

Higher cost of printer design. Laser sintering, thermal print heads or inkjet technologies are utilized in these printers making them difficult to develop for low budget startups.
Unless multiple lasers are used printing object with laser sintering is slower compared to large nozzle filament printers. Because focused laser beam can only melt small regions compared to large size of nozzle. It is expensive to manufacture very fine plastic powder (2-3 micron).