3D Printing is a technique of additive manufacturing developed for rapid prototyping compared to traditional subtractive manufacturing process. We mainly use three main technologies for 3D Printing – FDM (Fuse Deposition Modeling: modeling by melting), the stereolithography (SLA, an UV light is applied over a layer of solidified liquid plastic) and selective laser sintering (a layer of a laser sinters powder). This article is strictly on 3D Printing and we will not discuss about the 3D Printers.
Basics About 3D Printing
3D printing can produce a real objects : An operator draws the object on a screen using a tool for CAD (Computer Aided Design). The 3D file obtained is sent to a specific printer that performs the slicing and removing of the raw material or solidifies the material layer by layer for the final piece. The principle is quite similar to that of a conventional 2D printer; filing glue are also identical to the desktop printers. This stacking of layers creates a volume.
According to the process a variety of materials can be used like plastic (ABS), wax , metal , plaster of Paris and more. Applications can range from the industrial like car production, aircraft, consumer goods etcetera to visualization of projects, verification of ergonomics for architecture or design studies. This technique is currently (2013) limited as the use of materials are not suitable for intensive use and therefore only produces prototypes, sometimes in scaled size, but the use that will be made ??in the future for more extensive usage. Some see the advent of 3D printing as third industrial revolution.
Arthur C. Clarke wrote of a “machine to replicate” in the 1960s, machine that would replicate objects as printed books, which would have a profoundly positive effect on society, “humanity will adapt as in the past “. In 1972 , in the cartoon Tintin and the Lake of Sharks, Professor Calculus invents a three-dimensional copy machine immediately coveted by Rastapopoulos to make duplicate works of art stolen in major museums. These were thoughts.
Current Application and Examples of 3D Printing
Unlike Computer-aided Manufacturing (CAM) or the traditional methods we use for production – Cutting, Drilling, Casting and Molding Metals, 3D Printing can only handle materials with the following specifications:
- Transparent, translucent or opaque materials
- Electrical insulators and conductors
- Rigid or flexible, elastic or brittle
- Pasty, hard, abrasive
- Magnetically inert
The field of medicine also take 3D printing, with the creation of a bone-like material and the creation of custom prosthetics and exoskeletons. Shapeways, based in the United States offers a 3D printing online service for individuals and businesses. The French CADvision is the leader in 3D and system of direct digital production printers distribution, with particular targeting the professional world. Sculpteo has launched the first mobile application to generate 3D files directly from a smartphone like the iPhone. All technologies are based on cutting the 3D virtual object in 2D slices of very thin layers. These thin slices are placed one at a time by fixing the previous, which reconstructs the real object. There are different types of technologies. The main ones are:
AM or ALM (Additive-Layer-Manufacturing) : Additive Manufacturing (AM) is defined by ASTM as the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies. Synonyms are additive fabrication, additive processes, additive techniques, additive layer manufacturing, layer manufacturing and freeform fabrication. The additive term describes the technologies that can be used anywhere in the product life cycle, from pre-production (i.e. rapid prototyping) to full scale production (also known as rapid manufacturing) and even for tooling or customization post-production applications. Examples of AM technology are fused deposition modeling and laser sintering.
FDM (Fused Deposition Modeling) : This technique consists of a resin (usually plastic) melt through a nozzle heated to high temperature. A small wire melt the plastic, with a diameter of the order of a tenth of a millimeter. This wire is placed and will stick by remelting of what has been previously deposited. The Fused Deposition Modeling is a trademark owned by the inventor of the deposition technology filament fusion Stratasys.
FTI (Film Transfer Imaging) : Covered layer of transparent photopolymer resin film is placed in front of the machine integrated with video projector, the image is projected on the 2D section will ‘cure’ the resin. The output tray is raised thick while the transparent film is returned to the cartridge to receive a new layer of liquid resin, the image of the 2D section is projected above and so on. The thing is well reconstructed layer by layer.
MJM (Multi-Jet Modeling) : This technique involves depositing a layer of resin (plastic acrylate or polypropylene) liquid in the same way that ink jet printer with a thickness of 2/100 4/100 mm.
SLA : This technique generally uses a special sensitive resin to be treated by ultraviolet rays. At the end of each 2D layer, an ultraviolet light treatment is done on the resin.
SLS (Selective Laser Sintering) : This technique is similar to stereolithography, but powder is used (instead of a liquid photopolymer). A powerful laser solidifies the powder surface and agglomerates them . A new layer of powder is then spread and the process begins again.