It’s possible to build objects directly in three-dimensional space. Direct three-dimensional techniques are three types
- Shape generation through point by point
- Shape generation through surface by surface
- Shape generation through simultaneous creation of whole object.
Beam Interference Solidification (BIS)
This method was patented by Formiographic Engine.
In this process, using material is a photosensitive transparent liquid plastic (Monomer).
When monomer subjected to a laser beam of a particular frequency, it reaches a reversible metastable state and no bonding reaction takes place. But when a part of liquid that is already in a metastable state is hit by another laser beam of a specific frequency, polymerisation of metastable state takes place, resulting in the solidification of voxel (Volume Picture Cell) at the intersection of the two beams. By moving the two laser guns in a particular way, the volume of the desired object can be generated voxel by voxel.
Ballistic Particle Manufacturing (BPM)
This process undergoes layer-by-layer application.
In the direct three-dimensional approach, the part building is achieved by shooting of molten droplets on top of each other. The two piezoelectric inkjet printing nozzles are guided by manipulators to deposit the molten droplets according to need from any direction instead of using an array of such inkjet nozzles as done in the layer-by-layer approach.
Six axis robots can be used for the purpose. One of important advantage of this approach is the elimination of support structures.
Direct Metal Deposition (DMD)
The University of Michigan, Ann Arbor, has commercialized a laser machine for generating three-dimensional metallic parts.
Metal powder is supplied which is melted by a high power laser beam and functional metal part can be generated. The deposit head is guided by a manipulator.
Holographic Interference Solidification (HIS)
A three-dimensional image is projected in a vat containing a photosensitive liquid monomer and a whole three-dimensional surface gets solidified as a whole.
The holographic film for projecting the image is created with a CAD system. A system based on this principle has been developed by Quadtec Pry., Melbourne.
The long standing desire of manufacturing engineers to produce solid parts directly from the design data stored in a computer seems to be on the verge of realization.
Current methods of generative manufacturing are used for prototyping.
The generative process will also play a very major role in manufacturing microparts.
Advantage of generative manufacturing process
- No tools and fixtures are required.
- No restriction on geometry of the parts shape exists.
- Composite parts and assemblies can be produced in one go.
- The process is very suitable for computer integration.
- Small batch production of complex parts is economically viable.
These process are also responsible for bringing bottom-up approach in the manufacturing scenario and can considered to be the forerunner of the ultimate process of manufacturing by self-assembly of material.