3D printing, as a newly emergent technology, has now been widely considered as the most significant technological breakthrough of the twenty-first century. The technological evolution of the 3-D printer has made a new means of open design capable of accelerating production/development of very complex structures accurately. This review critically examines types of 3D printing and focuses on possible areas of improvements.
3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. It isalso known as rapid prototyping, is a mechanized method whereby 3D objects are quickly made on a reasonably sized machine connected to a computer containing blueprints for the object. The 3D printing concept of custom manufacturing is exciting to nearly everyone. This revolutionary method for creating 3D models with the use of inkjet technology saves time and cost by eliminating the need to design; print and glue together separate model parts. Now, we can create a complete model in a single process using 3D printing. The basic principles include materials cartridges, flexibility of output, and translation of code into a visible pattern. 3D Printers are machines that produce physical 3D models from digital data by printing layer by layer. It can make physical models of objects either designed with a CAD program or scanned with a 3D Scanner. It is used in a variety of industries including jewellery, footwear, industrial design, architecture, engineering and construction, automotive, aerospace, dental and medical industries, education and consumer products.
3D Printing Technologies
Different technologies are available to print different kind of 3D objects.
2.1 Stereo lithography –
Stereo lithographic 3D printers (known as SLAs or stereolithography apparatus) position a perforated platform just below the surface of avat of liquid photo curable polymer. A UV laser beam then traces the first slice ofan object on the surface of this liquid, causing a very thin layer of photopolymer toharden. The perforated platform is then lowered very slightly and another slice istraced out and hardened by the laser. Another slice is then created, and thenanother, until a complete object has been printed and can be removed from the vatof photopolymer, drained of excess liquid, and cured.
2.2 Fused deposition modelling –
It is an additive manufacturing technology commonly used for modelling, prototyping, and production applications. FDM works on an "additive" principle by laying down material in layers; a plastic filament or metal wire is unwound from a coil and supplies material to produce a part. Various polymers are used like Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), Polylactic Acid (PLA), High Density Polyethylene (HDPE), PC/ABS, Polyphenylsulfone (PPSU).
The process of printing can be summarised as
1 – Nozzle ejecting molten plastic
2 – Deposited material (modelled part)
3 – Controlled movable table.
The technique fuses parts of the layer, and then moves the working area downwards, adding another layer of granules and repeating the process until the piece has built up (shown in figure). This process uses the unfused media to support overhangs and thin walls in the part being produced.
2.3 Selective laser sintering (SLS) - This builds objects by using a laser to selectivelyfuse together successive layers of a cocktail of powdered wax, ceramic, metal,nylon or one of a range of other materials.
2.4 Multi-jet modelling (MJM)- This again builds up objects from successive layersof powder, with an inkjet-like print head used to spray on a binder solution thatglues only the required granules together.
Figure 1: Fused deposition modelling technique
3D Printing Capabilities
This modern technology has created numerous newpossibilities in various fields. The list below details the advantages of 3D printingin certain fields.
1. Product formation is currently the main use of 3D printing technology. Thesemachines allow designers and engineers to test out ideas for dimensional productscheaply before committing to expensive tooling and manufacturing processes.
2. In Medical Field, Surgeons are using 3D printing machines to print body partsfor reference before complex surgeries. Other machines are used to construct bonegrafts for patients who have suffered traumatic injuries. Looking further in thefuture, research is underway as scientists are working on creating replacementorgans.
3. Architects need to create mock-ups of their designs. 3D printing allows them tocome up with these mock-ups in a short period of time and with a higher degree ofaccuracy.
4. 3D printing allows artists to create objects that would be incredibly difficult,costly, or time intensive using traditional processes.
5. Research on 3D printers to print buildings effectively and efficiently are still in process.
It is nearly impossible to reduce all the component of adjacent triangle. However we can improve the quality of the product and time required to print the 3D object at the cost of price. Major factors that can affect the quality and speed of printing involves
Design of 3D printers can be altered which may involve
More number of degrees of freedom to improve the accuracy or quality of the printed object.
Less weight of moving components to improve the dynamics of printer.
Software algorithms written for pattern of printing the object
Commands to the printer’s robotic arms are decided by embedded algorithms written for printers. For every printing, which is done layer by layer, there may be number of ways to deposit material on each layer. These ways known as trajectory planning must be optimise to get high quality printed object meeting the good dynamics as well.
Motor assembly used to provide various movement of the arms of printer
Type of motor used for motion of arms can be exploited to get optimised quality of the object and printing speed. Instead of traditional stepper motors, servomotors may also provide good performance. Further PID or State Space models can be used to stabilize the printer in best possible time. This will increase printer speed as well as quality of printer.
Electronic circuit complexity
However this factor affects less but can’t be ignored when optimising speed parameter. Highly complex circuit will increase the time of printing.
3D Printing technology could revolutionize and re-shape the world. Advances in 3D printing technology can significantly change and improve the way we manufacture products and produce goods worldwide. If the last industrial revolution brought us mass production and the advent of economies of scale - the digital 3D printing revolution could bring mass manufacturing back a full circle - to an era of mass personalization, and a return to individual craftsmanship.
There is lot of scope to exploit the mechanical design,software design, Electric motor assembly and electronic circuitry to improve the quality of product as well as to reduce the printing time of 3D objects.
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