2.1. History, Working Principles and Types of 3D printing
2.1.1. History of 3D Printers
The conference organizers Alberto Corsín Jiménez and Adolfo Estalella state at the beginning of their invitation: “prototypes have acquired certain prominence and visibility in recent times”. (The long history of prototypes, Micheal Guggenheim,2006)
In 1920s, prototyping is become very important issue in developing manufacturing technology. Paper scales, wooden or clay models are used for describe inventors ideas. These methods are sufficient for these year but recent years, people want to constitute their ideas into being faster and more exact dimension. So, In 1980s, Rapid Prototyping technologies began ...view middle of the document...
This is in contrast to regular subtractive manufacturing. Traditionally, the prototype is constructed by cutting or machining raw material into a desired shape.
3D printing needs a CAD modeling by using a software such as AutoCAD, Solidwork etc. After the finished design, CAD model’s file is sent to the 3D printer to construct a mathematical model which involve coordinates or other specific details. Then, the construction material can be chosen according to our needs. Also, the material which is used, depends on the printer. It can be rubber, plastics, paper, polyurethane based materials, metals and more. There are different methods which can be used for constructing a scale. The method can be defined as
selective laser sintering, stereolithography, polyjet or jetted photopolymer, fused deposition modeling and laser fusing or laser powder forming.
2.1.3. Types of 3D printing:
Form of the starting material is classified by the RP classification.
1. Liquid class: Stereolithography STL
2. Solid class: Fused Deposition Modeling FDM
3. Powder class: Selective Laser Melting SLM, Selective Laser Sintering SLS
184.108.40.206. Stereolithography (STL)
3D Systems Inc. based on the work of Charles Hull announced the first extention RP technology in 1988. With using a directed laser beam to solidify the polymer, the Stereolithography is a RP process for assembling a solid plastic part out of a photosensitive liquid polymer.Stereolithography is an additive manufacturing process which uses a liquid ultraviolet formable photopolymer resin and an ultraviolet laser to build parts’ layers. For each layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin. The laser rays enables to construct layers by solidify resin. Polymerization occurs on exposure to UV light produced by laser scanning beam. Each layer is added onto the previous layers to gradually build the 3D geometry. This method enables more installations than any other RP method and resolution is higher. But the operation costs are very expensive due to material costs. Scanning speeds can be variable depends on resolution.
220.127.116.11. Fused Deposition Modeling (FDM):
The most widely used is a process known as fused deposition modeling (FDM). FDM is a RP process in which a long filament of wax or polymer is extruded onto surface for constructing new layers. FDM printers use a thermoplastics filament, which is heated to its melting point and then extruded layer by layer, to create a three dimensional object. The work head is controlled in x-y plane during each layer and then moves up by a distance equal to one layer in z-direction. The thermoplastic which extrude, is solidified and cold welded to the cooler part surface in about 0.1s. Part is fabricated from the base up, using a layer-by-layer procedure. The expenditure of the system and operating cost is very low but this system cannot be used for complex structures. Resolution of system drops at corners and it is...