Additive manufacturing or 3D printing is a process of making three dimensional solid objects from a digital model. 3D printing is achieved using additive processes, where an object is created by laying down successive layers of material.

3D printing is considered distinct from traditional machining techniques (subtractive processes) which mostly rely on the removal of material by methods such as cutting and drilling.

Industrial 3D printers have existed since the early 1980s, and have been used extensively for rapid prototyping and research purposes. These are generally larger machines that use proprietary powdered metals, casting media (e.g. sand), plastics or cartridges, and are used for many rapid prototyping uses by universities and commercial companies.

The use of additive manufacturing takes virtual designs from computer aided design (CAD) or animation modeling software, transforms them into thin, virtual, horizontal cross-sections and then creates successive layers until the model is complete. It is a WYSIWYG process where the virtual model and the physical model are almost identical.

Methods of 3D Printing

There are several ways to do 3D printing differing mainly in the way layers are build to create the final object.

Selective laser sintering (SLS) uses a high power laser to fuse small particles of plastic, metal, ceramic or glass powders into a mass that has the desired three dimensional shape.

Fused deposition modeling (FDM): The FDM technology works using a plastic filament or metal wire which is unwound from a coil and supplies material to an extrusion nozzle which can turn the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism, directly controlled by a computer-aided manufacturing (CAM) software package.

Stereolithography (SLA): The main technology in which photopolymerization is used to produce a solid part from a liquid is SLA. This technology employs a vat of liquid ultraviolet curable photopolymer resin and an ultraviolet laser to build the object’s layers one at a time. For each layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin. Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to the layer below

USES: Applications include design visualization, prototyping/CAD, metal casting, architecture, education, geospatial, healthcare and entertainment/retail.

Other applications would include reconstructing fossils in paleontology, replicating ancient and priceless artifacts in archaeology, reconstructing bones and body parts in forensic pathology and reconstructing heavily damaged evidence acquired from crime scene investigations.

Some recent achievement in field of 3D printing

Dutch doctors successfully fitted an 83-year-old woman with an artificial jaw made using a 3D printer. This operation, the first of its kind, could herald a new era of accurate, patient-tailored artificial transplants

British-Italian researchers demonstrate a giant 3D printer capable of constructing a full-sized house in a single 24-hour session. The machine, which uses sand and a chemical binder as its working material, printsstructures from the ground up, including stairs, partition walls and even piping cavities

Researchers at the Vienna University of Technology (TU Vienna) have made a breakthrough in 3D printing, with a machine that can print at the nano-scale and is orders of magnitude faster than previous devices

Engineers at Virginia Tech build the world's first 3D-printing vending machine, which allows any member of the public to rapidly print objects on demand by submitting a blueprint to the machine

American researchers use a 3D printer to build a sugar framework for growing an artificial liver. The sugar structure simulates a human vascular system, allowing artificial blood vessels to be grown to support the liver.

An American gunsmith produces the world's first functional 3D-printed plastic firearm.

Scenario in India

India is relatively new to 3D printers and with increasing initiatives by local assemblers and domestic manufactures; the 3D printers are available at affordable cost to consumers. The location of research and development bases of most of the manufacturing and engineering companies present a wide opportunity for rapid adoption of 3D printers in the country.

Indian market is sensitive towards prices of 3D printer technology. Utilization of 3D printers on commercial scale is yet to develop on large scale due to expensive nature, lack of awareness, and scalability of machines. These aforementioned reasons inhibit market growth in India.

As of 2013, electronics application leads the market (volume share of 24.1%) followed by automotive (21.2%), medical (15%), industrial (13.8%), aerospace (10.8%), architectural (5.2%), and educational (3.0%). India 3D printer market revenue is projected to reach $46 million by the year 2019.

Indian market for 3D printers have more potential in commercial segment including healthcare sector, architecture, educational, art & craft, and other 3D printing service provider companies. Special purpose applications, extent of customization, use in organ replacement, customized footwear designs, interior decoration, furniture modeling, educational models, fashion & apparels, animation & gaming, and chocolate and drug printing are some of the niche applications of 3D printers in Indian market.