Precision glass molding is an established replicative manufacturing technology for mass production of glass optics. However, compared with injection molding of polymer optics, the production costs are still high, mainly due to longer cycle time. Two scale-up strategies of glass optic production can be applied to reduce the production costs per lens, namely multi-cavity molding and wafer scale molding. However, the efficiency of these two scaling strategies depends on a variety of factors. It is complicated to determine which scaling strategy should be used for the serial mass production of glass optics. In this study, the two scaling strategies will be introduced at both the technical and the economic level respectively. At the technical level, the molding environment, manufacturing accuracy, suitable lens geometries, and the technology readiness level of two scaling strategies will be compared. On the economic level, the productivity and production costs will be analyzed in detail. The goal is to develop a guideline for industry partners, which can be applied to determine the optimal scaling strategy. Furthermore, the concept of digitalized glass optics production, which is established by Fraunhofer IPT, may offer more potential to the scaling of glass optics compared with conventional optics production.
Fraunhofer IPT has developed an innovative software concept for a digitalized glass optics production by means of precision glass molding and the belonging process chain. Thus, production data is used comprehensively and can be exploited conveniently for process development, production ramp-up and serial production. One striking innovation is the possibility to run part-specific simulation leading to a “Digital Twin” of every lens produced. The benefit for business is to enable advanced process developments, acceleration of production ramp-up and improved productivity in serial production. The concept is briefly introduced in conjunction with the current development state. Three possible use-cases for digitalized optics production are given and the paper concludes with further development steps necessary to implement the concept.
Compression molding of precision optics is gradually becoming a viable manufacturing process for low cost high performance optical elements. In this process, a glass preform in the form of gob or disk is heated rapidly above its glass transition temperature then pressed between two optical mold halves to finish dimensions. The molded lens is first cooled slowly then at a fast cooling rate to room temperature to complete the process. For more than a decade, the authors have conducted a collaborated research in glass molding using both experiments and numerical modeling. In this presentation, we will discuss the recent work in molding of both conventional glass optics and extreme high temperature glass optics – fused silica material. In addition, development of graphene like coatings for precision glass molding will also be described.
The use of chalcogenide glass in the thermal infrared domain is an emerging alternative to commonly used crystalline materials such as germanium. The main advantage of chalcogenide glass is the possibility of mass production of complex shaped geometries with replicative processes such as precision glass molding. Thus costly single point diamond turning processes are shifted to mold manufacturing and do not have to be applied to every single lens produced. The usage of FEM-Simulation is mandatory for developing a molding process for complex e.g. non rotational symmetric chalcogenide glass lenses in order to predict the flow of glass. This talk will present state of the art modelling of the precision glass molding process for chalcogenide glass lenses, based on thermal- and mechanical models. Input data for modelling are a set of material properties of the specific chalcogenide glass in conjunction with properties of mold material and wear protective coatings. Specific properties for the mold-glass interaction such as stress relaxation or friction at the glassmold interface cannot be obtained from datasheets and must be determined experimentally. A qualified model is a powerful tool to optimize mold and preform designs in advance in order to achieve sufficient mold filling and compensate for glass shrinkage. Application of these models in an FEM-Simulation “case study” for molding a complex shaped non-rotational symmetric lens is shown. The outlook will examine relevant issues for modelling the precision glass molding process of chalcogenide glasses in order to realize scaled up production in terms of multi cavity- and wafer level molding.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.