Film coating scaling

Table 12 Parameters for film coating scale-up evaluation...

As with ah thin-film PV technologies, the projected manufacturing costs of a-Si H ahoy PV modules fah rapidly with annual manufacturing volume, ie, MWp /yr. The primary driver of this volume cost reduction is the volume—cost relationship of commercially available thin-film processing equipment. Thin-film coating machines often have capacities equivalent to 3—5 yr, so that manufacturing economies of scale are more fully realized at the... 

Discontinuities in conducting oxide film or scale or discontinuities in applied metallic or non-metallic coatings. Exposed substrate (provided that this is more electrochemically active than the coating). 

The FPI principle can also be used to develop thin-film-coating-based chemical sensors. For example, a thin layer of zeolite film has been coated to a cleaved endface of a single-mode fiber to form a low-finesse FPI sensor for chemical detection. Zeolite presents a group of crystalline aluminosilicate materials with uniform subnanometer or nanometer scale pores. Traditionally, porous zeolite materials have been used as adsorbents, catalysts, and molecular sieves for molecular or ionic separation, electrode modification, and selectivity enhancement for chemical sensors. Recently, it has been revealed that zeolites possess a unique combination of chemical and optical properties. When properly integrated with a photonic device, these unique properties may be fully utilized to develop miniaturized optical chemical sensors with high sensitivity and potentially high selectivity for various in situ monitoring applications. 

Since the majority of film-coating operations around the world utilize aqueous coating processes, it is often useful to apply thermodynamic models to the process. In this way, the development-scale process can be fundamentally characterized, based on application of the first law of thermodynamics, as suggested by Ebey (6), allowing more accurate predictions for operating... 

Unlike the processes described elsewhere in this book, the film-coating process is inherently much more complex, since the list of parameters that contribute to overall success is, potentially, exhaustive. Thus, the complexities of the scale-up process are potentially more challenging. In basic terms, these three components of the film-coating process all contribute, in a very much interactive manner, to the overall success of the process ... 

Considering the processing fundamentals of this dry process, almost all of the issues associated with the scale-up of more traditional film-coating processes are eliminated, and the key objective is to feed tablets directly from the tablet press into the electrostatic coating operation, and thence in to packaging. Thus, once the process is defined in terms of coating one tablet, it is replicated an appropriate number of times in order to coat all of the tablets in the batch. 

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