3D Printing: you may have one in future

3D printing or Additive Manufacturing is a technique which is improving day by day. As the name suggests, 3D printing refers to the technique of manufacturing solid objects by supplying a digital pattern. Just like a 2D printer prints text or photos sent to it by the computer, a 3D printer reads in computer designs and manufactures the products implied by those designs. A 3D model of the object is supplied to the printer. Such 3D models are developed using Computer aided Design(CAD) tools.

A small statue of Mario generated using a 3D printer

Unlike traditional object manufacturing(pottery,shoe making,clay modeling and what not), where objects are created by taking initial building material and then removing parts from it to get the final object(in short, Subtractive modeling), in 3D modeling, objects are built by adding small quantities of the building material(Additive modeling). The 3D design of the object is broken down into cross sections of different thicknesses.This thickness depends upon the object to be created as well as the technology to be used for 3D printing.The 3D printing device takes this design and then produces every cross section as suggested by the design and creates the final object by adding the next cross section to the previous. Hence, the overall object is built by building single layers of the object and adding them to each other as they are built. These layers of the manufacturing process correspond to the cross sections specified in the design.

The aforementioned process is the core of all 3D printing technologies but the manner in which the layers are produced and how the layers are added to one another distinguishes the various technologies.A broad categorization of the techniques goes below:

Molten Polymer Deposition : Uses a molten polymer and beads of some thermoplastic material. A movable nozzle, whose movement is controlled by the Computer Aided Manufacturing(CAM) software, is used. The nozzle releases the thermoplastic beads to produce the layers. These beads harden immediately after the nozzle deposits them. The movable nozzle deposits these beads in the way the layer should be formed and then releases molten polymer to seal this layer to next layer that will be built upon it. e.g: Fused Deposition Modeling(FDM) technology.

Granular Materials Binding: Small granules of the building material are fused together by heating them. When one layer gets built up, another layer of granules is fused on to the first layer and hence no need of layer binding here. e.g : Electronic Beam Melting(EBM) used for making metal parts, CandyFab for making confectionery and inkjet 3D printing used for making colored 3D objects.

Photopolymerization : A liquid polymer that turns solid on getting exposed to some light, is used. The liquid polymer is kept in a container and is exposed to the light in a controlled manner.A build plate is used to separate a cross section of the polymer from the rest of it. The light projector's position and coverage area are controlled so that only desirable portion of the polymer over the build plate gets exposed. In this way, a layer gets formed. Then the build plate moves downwards and another layer is formed similarly. At the end, the remaining liquid polymer is released from the container and the object is acquired.e.g : Stereolithography (SLA)

A model of a sport shoe generated using 3d modeling

3D printing is used for prototyping, where a small model of actual object is made, or for creating artifacts that will actually be put into use.3D printers can be used to produce jewelery,artwork,metal models, artistic confectionery etc.  The 3D printer generates an object which is exactly similar to the 3D model supplied. Hence the printer allows one to create multiple similar copies of same design. 3D printing is perfectly complemented by 3D scanning. Hence, instead of creating 3D models of some real life object manually, one can simply use a 3D scanner to create a 3D model of  that object and once you have the model, just imagine how easy it is to build multiple copies of the same.

A bicycle model generated using 3D printing