3D printing refers to the manufacture of digitally defined objects by the layered application and bonding of material. The term "3D printing" is often used colloquially as a synonym for additive manufacturing. Additive manufacturing methods contrast with subtractive ones, in which material is removed. An example of the latter is machining.
3D printing in the proper sense refers to the binder jetting additive technology. Other frequently used synonyms are generative manufacturing, layering manufacturing , additive manufacturing and rapid prototyping. Among the best-known 3D printing methods for plastics are selective laser sintering, multi-jet fusion, fused deposition modelling, stereo lithography and material jetting.
Manufacturing an object with a 3D printing method requires at least three steps:
1. The object is created digitally in a CAD file and converted into a format (such as STL) that the 3D printer can read
2. The object is printed in layers
3. The finished object is cleaned and reworked as necessary (polishing, coating, colouring, etc.)
The exact production technology depends on the printing method. There are many methods that are primarily distinguished by whether the material is added in the form of powder, molten plastics or fluid, and whether they are cured by light, air or bonding agent. Depending on application, plastics, metals, ceramics, concrete, food, or even organic materials can be processed with additive technologies.
3D printing is used for a wide and continuously expanding spectrum of applications. For the production of prototypes and models or for use in high-volume production, additive manufacturing is employed in a wide variety of areas, from art and design to the aerospace industry. In addition to simple user objects and toys, 3D printing technologies are used to print components for the architecture of complex geometries for devices in scientific laboratories and to manufacture stressed machine elements and replacement parts.
Industrial 3D printing is used for manufacturing prototypes, tools and volume parts. It uses materials that, depending on the industrial application in question, must meet special mechanical requirements such as flexibility, rigidity and wear resistance.
The use of 3D printing in industry has proven especially economical because models and small series can be created, tested, and adjusted for series production much more quickly that they can with usual methods. Unlike prototypes that map only the geometries of the planned component, industrially manufactured 3D printed models allow all mechanical properties to be tested on the machine.
3D printing services are frequently used for industrial prototype manufacture, since procuring an industrial 3D printer is not cost-effective unless the company in question possesses the necessary expertise and uses the printer regularly to manufacture models and series. 3D printing service providers usually have not only the necessary expertise, but also several 3D printers, allowing them to select the method best suited to the application in question. Depending on the method, it is also much more cost-effective to engage an external service provider because such methods as laser sintering involve the regular manufacture of large batches of parts for various customers, greatly lowering the production costs for individual parts and thus for individual customers.
In addition to manufacturing prototypes and small series, industry is relying more and more on 3D printing for tool manufacture for such procedures as injection moulding. Plastic, ceramic or metal – any large-series production mould can be additively manufactured. Unlike conventional tool manufacture, additive manufacturing allows moulds to be created quickly and simply based on a CAD file and added directly to the order. If modifications are necessary, they can be made with a few clicks, so the manufacture of a new tool is much quicker and more cost-effective than conventional methods allow.
3D printers are being purchased more frequently by private individuals so that they can print objects for private use and explore the capabilities of 3D printing. However, their options are limited by the costs, which remain high, and the quality of the materials used, which is generally low. There are industrial 3D printers for all types of additive methods; they can process a wide range of materials and are better suited to the requirements of industry.