COMBINING ELEGANT APPEARANCE AND IMPECCABLE SURFACE QUALITY
Stereolithography (SLA) was the first rapid prototyping process and today still is one of the most widely used rapid prototyping technology. It can produce highly accurate and detailed polymer parts. Evonik is a leading manufacturer of modified resins for 3D printing, which will help you to harness the full power of the SLA technology. This is the prerequisite to leave rapid prototyping and enter rapid manufacturing.
The technique of stereolithography has been known for a long time and features a very high accuracy of the 3D printed object. It results in gorgeous looking models with impeccable surface quality. So it comes with no surprise, that typical applications in the industry include modelling Formula 1 racecar parts for wind tunnel testing. More mundane applications include the manufacturing of individualized hearing aids and dentures or investment casting in jewelry and arts.
SLA converts liquid materials into solid parts, layer by layer, by selectively curing them by vat photopolymerization. To initiate the curing process, a highly focused UV laser traces out successive cross-sections of a 3D object in a vat of liquid photosensitive polymer. The photopolymer hardens instantly when the UV laser touches it, forming the first layer of the 3D-printed object. Once a layer is completed, the platform is lowered by a distance equal to the layer thickness. The next layer is formed on top of the previously completed layer. This process is repeated until the build is complete. Afterwards, the 3D printed object has to be freed from possible support structures. Usually it is baked in a UV oven as well, to complete the polymerization.
Available for around 30 years, even nowadays SLA remains one of the most powerful and versatile of all techniques. It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available. However, cured objects change their properties over time and might be too brittle. This is why there are open challenges in optimizing material properties, namely mechanical strength and surface characteristics.
Using modified resins for 3D printing made by Evonik can help you to overcome many of these limitations. By using our nanosilica particle filled resins NANOCRYL® and NANOPOX® you can significantly reduce shrinkage resulting in improved edge sharpness and very high accuracy. By using ALBIDUR® you will add fracture toughness to your formulated product while generating a thermoplastic look and feel which is desired for many component parts.
Besides, a broad variety of mechanical properties can be improved when compounding fillers in resins. Evonik also provides high performing fillers, AEROSIL® fumed silica and AEROXIDE® fumed oxides which can help improve the mechanical strength as impact resistance or structural toughness or resilience.