Lately, the most of watches brand that want to introduce in a so compétitive market, they put sapphire crystal on their watches. We also did it thus, because we like the transparence that offers this kind of crystal. sapphire’ Refractive index is of 1,775 while PMMA or Polycarbonate is of 1,5. Theoretically, this produce an increase of transparency in watch inside, but there are some factors that can give a good appearance with plexiglass crystal.
For instance, material thickness. Sapphire cristal with a big thickness offer a very good transparence but plexy is not so good with that. If a diver factory wants to build a watch with a high hermeticity, keeping the transparence, it can select a sapphire crystal with 5mm even more. Moreover dial can be viewed closer.
But, how can this property can be add in watches with plexy crystal. Easily, with domed crystal. Crystal domed has the property to bear big pressures with small thickness depending on its curvature. With bigger curve better supports the pressures. This property can be analysed in simulation program it will show a relation between
Moreover, in accordance with our new internal policy of mechanizing the most of possible components, we can do plexyglas or polycarbonate crystal in our workshop easily. That gives us the ability of design develop and manufacture all possible shapes for this kind of materials.