JUNE - 2022AEROSPACEDEFENSEREVIEW.COM8Where traditional forming processes meet their limitations, additive processes­also known as 3D Printing­pick up the slack: on the basis of a digital three-dimensional blueprint, material is applied in layers on a base surface. After each application the surface is lowered by a fraction of a millimeter and another layer is added. Very soon a three-dimensional structure is produced that corresponds exactly to the digital specification--with no need for special molds or extensive post-processing.Plastics are durable, easily fusible, offer many possibilities with their properties, and are ideally suited for this cutting-edge technology. With polyamide 12 (PA12), Evonik is one of the world's leading suppliers of powders for 3D printing having delivered the first polymer powders for additive manufacturing as early as 1996, setting standards for plastic materials that are still valid today. With a variety of innovative high-performance materials ranging from reinforced to flame-retardant and elastic materials, we are bringing the 3D printing industry a decisive step closer to series production.Many people think 3D printing is a competitor to well established processes like injection molding. This simplistic approach does not factor the many possibilities this technology allows and will likely not be successful. If it is to be widely adopted, it needs to find its market space where its makes sense. It enables more freedom in design and opens new opportunities for designers and engineers to develop lightweight components with new functions. To make the most out of it, one needs to completely redesign the parts for 3D printing so that they will have the best properties where they are most needed. A component that is reinvented for 3D printing often has little in common with the original part. Whereas an injection-molded part must be heavy and massive so that it can withstand great stresses, an equivalent 3D-printed part can have a seemingly filigree design consisting of arches, struts, and honeycomb structures. It can withstand stresses just as well as the injection-molded part but weighs only a fraction as much. These possible weight reductions coupled with relatively low production runs needed, make additive manufacturing a very interesting technique for aircraft construction. In medical technology, another factor plays a role: no two people are alike. Therefore, prostheses, aids or even surgical devices must be individually measured and adapted. 3D printing is used to create small drilling and sawing aids for knee operations or hearing aids, for example. More recently, custom made implants are being made possible by fused filament fabrication using VESTAKEEP® i4 3DF implantable filament.3D PRINTING IS EVOLVING FROM A NICHE PROCESS TO HIGH-VOLUME MANUFACTURING TECHNOLOGYBy Alex Sant'Anna, Director, Additive Manufacturing & Material Solutions ­ Americas, EvonikAlex Sant'AnnaIn My Opinion
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