Manufacturers using additive manufacturing techniques produce eyewear frames in a completely new way by printing them out layer by layer.
While some 3D-printed frames are standardized designs shipped finished and ready for display on opticians’ optical boards, and others are made to order by taking precise digital measurements of patients’ heads, the way they are printed is all relatively the same using the selective laser sintering process (SLS). A powdered nylon polyamide material is melted with a laser and distributed layer by layer until a solid, three-dimensional frame is created.
Because the printing process is additive, meaning that the frame is built up by subsequent layering of the material, there is little waste, making the overall process more sustainable than typical frame manufacturing. Other benefits include on-demand production and reduced inventory, and for those systems that include facial scanning, an additional benefit is made-to-measure customized fitting.
In a category all its own, 3DNA is a system for creating customized eyewear that incorporates three-dimensional facial scanning technology to take a 360-degree image of a patient’s head. Then, rather than using 3D printing, the frame is assembled by hand using semi-finished blanks of raw material and hinges processed by the company’s equipment. The company states that “3DNA utilizes all the promise of 3D-printed eyewear,” which it describes as “local manufacturing, on-demand production, reduced inventory, customization, made-to-measure fitting and independence,” but “without any of the drawbacks,” which the company states as “color limitations, rough surface texture, bendable-plastic feeling, lack of comfortable fit to facial contours and quality gap between 3D-printed and traditionally made eyewear.”
Bellinger House of Denmark, which 3D prints its Blac+ eyewear line, described its additive manufacturing process in detail: “The Blac+ process begins with designing and drawing our Blac eyewear in 3D. We then proceed to SLS (selective laser sintering), which uses a laser to melt the PP22 powdered material in three dimensions. As the laser contacts the powder bed, it raises the material to its sintering temperature, repeating the process one thin layer (0.1mm) at a time. After the laser process is finished, the fronts are peeled from the leftover powder, which is reused to make sure that nothing is wasted. The frames are tumbled and thoroughly polished by hand, and the coloring is added to the material.”