From flat screen to 3D with Certottica
How do the nameplates on buildings stand up to attack from external agents and last over time? Because they are coated with a very hard and strong transparent film which is very easy to deposit on flat, hard surfaces by the PECVD process. But when this performance is requested for eyewear frames and jewelry, there is a multitude of problems because a uniform coating of film that unites strength and ductility has to be applied to objects that have complex convex and concave shapes and are made from a combination of different materials. It’s difficult, but not impossible. Backed up by a collaboration with Wood-k Plus, its Austrian partner in the Interreg IV project, and with Diener GmbH Plasma-Surface-Technology, Certottica took up the challenge and constructed a pilot system for achieving uniform coatings with a repeatable process for industrial production. For some time now the laboratory technicians at the Certification Institute in Longarone have been working with such research centers as Nanofab in the Veneto region to find a solution that would meet the mechanical and chemical requirements for complex objects like eyeglasses. However, it is thanks only to the development work carried out with Diener that the answer seems to be close at hand. The German company is located near Stuttgart, famous for being one of the areas with the biggest concentration of hi-tech applications for sectors that include vehicle manufacturing and electronic components. A place where the perfection of all details is a priority to meet the needs of development and where top-of-the-range vehicles and white goods undergo continual mechanical and climatic stress tests.
From a very hard film to one with greater ductility: eyeglasses are in the middle of this divergence because they require intermediate performance and excellent corrosion resistance, whereas jewelry tends toward vitreous coatings in quartz. Certottica has pursued this objective and has arranged for a machine specifically for research on eyeglasses and jewelry to be brought to its laboratories, where it was set up by the technicians in Belluno. The machine is a considerable size (see attached photo of the PECVD system installed at the Certottica laboratories): 60 cm wide, 2 m high and 1 m deep, with a 150-liter chamber where the mixture of gas condenses and coats the object placed inside it.
This machine and a much smaller one already available to the researchers and used for studying micro-cleaning and activation, make Certottica a center of excellence for researching the use of cold plasma. The 3 dimensions are no longer an insurmountable obstacle, but an achievable objective: the aim is to study the speed at which the film is made and at developing an eco-friendly process with low consumption of raw materials and reduced emissions for making coatings (quartz and silicone) that are totally biocompatible.
