In our STEIN series “Seizing Opportunities,” we share our knowledge about strategies companies can use to achieve long-term success. Additive manufacturing, also known as “3D printing,” is one of the key technologies of Industry 4.0: How far has the technology come? How can it be applied in stone-processing businesses, and what are its limitations?
With ever-improving print quality and falling prices, additive manufacturing (also known as generative manufacturing, rapid prototyping, or 3D printing) is increasingly establishing itself in the creative crafts sector as well. Even in some natural stone processing companies, 3-D printers are already being used to produce models, templates, samples, or prototypes, as well as one-off pieces or small batches. What are 3-D printers capable of today, what processes, possibilities, and limitations exist, and when are 3-D printing service providers a viable alternative?
Unlike conventional manufacturing, additive manufacturing processes do not create objects by reshaping, cutting, or machining a workpiece, but are built up layer by layer from a liquid, powdered, or solid raw material—such as plastic, synthetic resin, ceramics, metal, or many other materials—using chemical and/or physical processes. Objects made of different materials or colors, as well as movable functional models, can be produced in a single operation. The objects can also be transparent or elastic. The manufacturing quality depends on the accuracy and surface finish, which in turn depend on the three-dimensional print resolution in the X, Y, and—most importantly—Z directions (layer thickness) of the output device.
The model data is typically generated using CAD and modeling software, and in some cases also via 3-D scanners. Virtually anything can be printed: plastic and metal structures as well as delicate designs or solid components made of STEIN or concrete materials—with or without steel, fiberglass, or textile reinforcement, and with or without the addition of recycled materials. Mechanical or electrical components, medical implants, shoes, clothing, jewelry, and playable musical instruments are now printed just as readily as food or habitable houses.
3-D printed objects can be custom-designed, modified, and printed immediately. They can be reproduced multiple times and, in small batches up to a certain quantity, are more cost-effective than conventionally manufactured products. This is particularly true for complex objects, as the cost-effectiveness of additive manufacturing increases with the complexity of the object’s geometry. 3-D printing is also more sustainable, as it uses only the material required for printing—though this material is not always environmentally friendly.
Additive manufacturing offers virtually unlimited creative and design freedom: For example, objects with undercuts, cavities, and other features—which cannot be produced using conventional methods or can only be produced with great difficulty—can be realized. Components can be partially engineered with specific mechanical or thermal properties to ensure that forces and stresses are optimally dissipated. The main limitation of additive manufacturing is production time, which cannot keep pace with mass production. Printing costs are also high. Although prices are currently falling, particularly for home and desktop printers, the costs for high-end printers and printing materials (between 60 and 400 euros per kilogram) are unlikely to change significantly in the medium term.
If specific surface quality requirements must be met, manual or machine-based post-processing is usually necessary (milling, grinding, painting, etc.), as the surface texture is always more or less rough. For stability reasons, delicate components should have a minimum wall thickness (approximately one millimeter). In certain printing processes, overhanging parts require a support structure that must be removed later.
Read more in STEIN 2/2020.
