Design of a modular structured plant construction for glass etching based reducing molten salts (SaltEtch)
Holger H. Stühff
Fon: +49 4152 88 55 950
1. May 2017 to 31. July 2019
Project Management Agency
Karlsruhe Project Management Agency (PTKA)
Etching of glass components on basis of reducing molten salts
Processing glass fibres is a basic technology to manufacture both passive and active optical components. Main applications of these components are optical communication networks as well as sensor elements. The optical fiber technology is a field of ever-growing significance for communication and sensors. An important technology to produce fiber optical components and actually state of the art is etching glass fibres with hydrofluoric acid. However, that technology limits the surface structuring in the micrometer range as well as the component reliability and additionally requires high safety measures. A quality leap could be the development of a new production process for glass fibers on the basis of molten salts. Currently, there is no adequate industrial-suited plant technology, which could provide glass components etched by molten salts in a sufficient quantity viable on a worldwide mass scale. The objective of the SME innovative project is therefore the design of a plant technology for etching glass based on molten salts.
For many glass components are surface structuring etching processes necessary. An example is the reduction in diameter of glass fibers. Until now, these etching processes usually are based on aqueous hydrofluoric acid solutions. Serious problems of these technology are on the one hand the structuring capability limitations in micrometer range, the process reliability as well as the progressive damage of fibers after the end of the etching process. On the other hand, stand a high environmental pollution and high safety requirements. A quality leap could be the development of a new production process for etched glass fibers on the basis of molten salts for which is currently no adequate industrial-suited plant technology no available.
Tasks and goals
The objective of the project is the design of a new and modular plant technology for etching glass components based on anhydrous molten salts. The focus is a flexible process management and a high etching accuracy. Via the new developed procedure, the mechanical and optical quality compared to conventional etched components can be raised significantly.
The consortium consists of two project partners, Stühff GmbH (SME) and Fraunhofer Institute for Reliability and Microintegration IZM (research institute). The procedure is structured in three steps: Step 1 Preparation, Step 2 Process patterns and laboratory samples and Step 3 demonstrator. Thus, the partners have to work out the requirements initially. In doing so, they focus on the procedural and design framework conditions. Based on this, components for the plant technology and the process control of the system periphery will be designed, which lead to a first demonstrator to validate the etching process. In addition, the calculation and optimization of process engineering solutions and design solutions has to be checked by computer aided simulations. The knowledge gained from this process is then once again used to realise, check and optimize the procedure and the manufacturing concept. With these results, a demonstrator will be built, which should show the technical feasibility of the procedure. The combination of system periphery and different etching chamber configurations allows to show custom-specific requirements during the demonstration phase.
Results and application potential
The target result is a successful demonstration of a new plant concept. The strategic objective of the company is to develop the demonstrated plant concept further and get a determinant market position with its own modular structured product. Target clients are fiber and component manufacturer for fiber technology. Furthermore, requirements that exceed the fiber based data communication should be fulfilled. There is a great need for compact plants for etching and strengthening glass. On condition that the project can be realised successfully, it should perspectively also be possible to etch areal components with molten salts. The usage of reducing molten salts will increase the product quality massively, whereby the safety measures could be reduced caused by the elimination of hydrofluoric acid. From the outset the marketing concept focusses international costumers.
Projectpartner and -tasks
Stühff GmbH, Geesthacht
Plant design: Development of the plant technology, the industrial manufacturing process and the process controller for the plant periphery
Fraunhofer Institute for Reliability and Microintegration IZM, Berlin
Research institute: Development of the procedural basics of the etching process and the model-based process control