Rapid prototyping is a special form of prototyping and enables the fast fabrication of physical models. This approach has its roots in manufacturing engineering. The generic term refers to the process of quickly producing demonstration material using construction data.
Computer-aided design data, also known as CAD data, provides the basis for printing three-dimensional prototypes. The rapid prototyping machine converts this data, which contains computer-aided designs. Based on a cross-section of the desired product, the 3D printer then builds up the object layer by layer from shapeless material, taking advantage of the different physical and chemical effects.
The use of 3D printing technology is becoming more widespread and also opens up new possibilities for the production of spectacle frames. To print bespoke eyewear in 3D, some individual data is required. First, a camera scans the patient’s head and face. This can be done either in the store or online on special websites and takes only a few minutes. Using this data, a frame can be created which is an ideal fit for that person’s face. The customer first chooses the frame style from a variety of different templates. In addition to selecting the frame colour(s), it is also possible to personalise the frame by adding text to the temples. This information is then digitally adjusted to the 3D frame model, customising the width of the nose bridge, temple length and full frame size to fit the wearer’s individual head form with pint-point precision. Once the scanned data including frame colour and model has been sent to the 3D printer, it is possible to create a truly bespoke, one-of-a-kind frame that is a perfect fit.
Polyamide (PA) is the most commonly used material in 3D printing. Polyamide as well as the well-known nylon are both classified as thermoplastics. The polyamide used in 3D printing is a fine powder. To create a 3D print, a very thin layer of the powdered material is spread onto a build platform. A laser beam then scans the surface, selectively sinters the powder and solidifies a cross-section of the part. When the entire cross-section is scanned, the building platform moves down one layer thickness in height. When the printing process is complete, unsintered powder is removed and you have a spectacle frame all set for the finishing touches.
Benefits of 3D printing with polyamide (with nylon):
• The natural colour of polyamide is white and can therefore be tinted.
• The printing process produces no harmful printer dust.
• Polyamide does not contain any toxic chemicals and does not react with the body.
• It is as strong as cast iron.
• The material is semi-flexible and thin areas can be bent to a certain extent without suffering damage.
3D printed frames weigh about 30% less than standard acetate frames and offer greater stability. In addition, the scratch-resistant structured surface of the frame is insensitive to dirt. However, the key advantage of 3D printed spectacle frames is the possibility of adjusting them during production to the individual and unique head form and facial features. This technology is particularly ideal for spectacle wearers with very flat noses who have only had a limited choice of frames available to them until now. The fact that the 3D printed spectacles can be custom-made locally, that is to say within the relevant country of the spectacle wearer, is often another incentive to purchase them. What’s more, they can express their individuality and style by personalising the 3D printed frames, e.g. by adding text to the temple. Superior wearing comfort combined with innovative design – 3D printed spectacles chime with the spirit of the times and focus on a promising technology.
Sustainability plays a major role in the production of spectacle frames with 3D printing. Since the entire production process can be carried out at the same location, long distance transport is eliminated. Furthermore, unlike other manufacturing processes, 3D printing does not produce any waste. The frames are made to order, thus avoiding excess production and protecting the environment. In a nutshell: 3D printing enables resource efficient production.