3D printing

3D printing is a technology that allows you to create three-dimensional objects by adding material layer by layer. Its development has represented a revolution in industrial manufacturing and in many other fields, as 3D printers are able to reproduce a three-dimensional model more quickly and easily by means of additive manufacturing, as opposed to traditional methods that required cutting, drilling, or sculpting the material. 

From 3D printing designs, these printers convert digital designs into physical objects. 3D printers can use various materials, of different properties, even in the same design, among them polylactic acid, high impact polystyrene, Laywoo-d3, acrylonitrile butadiene styrene, or polyethylene terephthalate, and even metals and resins, all of which have high strength but different physical properties.

3D printers enable faster, simpler, and lower-cost manufacturing than other traditional manufacturing technologies, and are also of great value to product designers and developers, who can create their models and prototypes more easily and economically. 

3D printing starts with a 3D printing design: a digital model in three dimensions that is created by using a computer-aided design (CAD) software, such as Tinkercad, Blender, or AutoCAD. Alternatively, an existing object can be scanned with a 3D scanner to create its digital replica.

Once the digital model is created, it is divided into very thin horizontal layers by a process known as slicing. This process is performed by a specific software called slicer, which translates the 3D printing design into instructions that the 3D printer can follow. The slicer software generates a file in G-code format, which contains the specific instructions for printing the object layer by layer.

The 3D printer deposits the chosen material layer by layer, moving the printhead according to the coordinates of the G-code file and adding the material where it is needed. There are different 3D printing technologies. The most common is Fused Deposition Modeling (FDM), in which a plastic filament is melted and extruded through a heated nozzle. Other technologies include Charles W. Hull's early model stereolithography, which uses a laser to solidify liquid resin, and Selective Laser Sintering (SLS), which uses a laser to synthesize material powder.

Once the printing is completed, the object may require post-processing, which may include the removal of support structures, sanding, polishing, or a painting process to achieve the desired finish. In some technologies, such as SLA printing, the printed object must be further treated with ultraviolet light to achieve its final strength.

In an early stage of development, 3D printing was primarily used for design and prototype development, but nowadays 3D printers are also used for the creation of final products in various areas, from the aeronautics industry to medicine, as well as being used in education or art.

These are some of the applications for which 3D printing is already being used:

• Medicine. In this field, 3D printers allows the manufacturing of prostheses specifically adapted to the anatomy of each patient; the creation of customized implants, such as bones and joints, that fit perfectly to the patient's body; the manufacturing of drugs, or the production of models for surgical practice.
• Aerospace industry. 3D printing is used for the manufacturing of spare parts; of unique or low-volume parts that would not be cost-effective to create with traditional methods, and for the production of customized tools and molds that optimize manufacturing processes.
• Automotive industry. This technology facilitates the production of customized or discontinued spare parts on demand, as well as the development of functional prototypes for testing and exhibitions.
• Engineering. The field of engineering has found in 3D printing an ally for the quick and economic development of prototypes for testing and validations before mass production, as well as for the manufacturing of customized parts.
• Construction. 3D printing is used for the manufacturing of complete structures or building components and for the production of detailed models for project planning and presentation.
• Art and fashion. In these fields, this technology can be used for the creation of works of art and sculptures, and the design and production of clothing, jewelry, and accessories
• Education. 3D printers facilitate the production of models for the teaching of complex concepts in sciences, in the technology branch, and art. It also allows students to create their own prototypes.

As other examples of 3D printing applications, Repsol uses this technology in different projects, such as the production of metal spare parts for its Petronor refinery, ecodesign projects, or the creation, together with the startup Recreus, of a fiberglass filament for use in these printers. It also collaborates with the NGO Ayúdame3D, which has already delivered more than half a thousand prosthetic arms made from recycled plastics in 55 countries, free of charge.