Aerosol Coating

Beneq develops aerosol coating equipment and processes for thin film coating applications. The two aerosol coating processes we offer are Beneq proprietary technology and with that, unique.
 

Development of aerosol methods within Beneq started with nHALO^®, a flame-based nanoparticle generation process originally developed for coloring art glass. Beneq has turned it into an industrial large-scale processing technology with several applications in development. The second aerosol process is nAERO^®. nAERO was developed to fill the rapidly escalating need for a flexible, tunable and alternative thin film coating method for advanced coatings on glass. The driving application for nAERO is transparent conductive oxide (TCO), which is in high and ever-growing demand within the solar (photovoltaic) industry today.

nHALO - flame-based aerosol coating

Beneq Hot Aerosol Layering Operation, nHALO, is based on the combustion of gaseous and atomized liquid raw materials in an atmospheric oxy-fuel flame. This evaporation-gas condensation method produces nano-sized particles of metal oxides, e.g., TiO₂ and Al₂O₃, noble metals, e.g., Ag and Pd and combinations thereof, e.g., TiO₂-Ag. The flexibility in the raw material feeding gives the freedom of incorporating raw materials with very different vapor pressures. A turbulent flame provides for efficient mixing of the raw materials, leading to homogeneous nanoparticles. Rapid quenching and a short residence time produces particles with a narrow particle-size distribution. The size of the nanoparticles in the nHALO process depends mainly on the precursor mass feed rate. The produced material has little effect on the mean particle diameter and particle size distribution. The schematic below shows the basic setup for nHALO nanoparticle generation and coating – all in one process step.

nHALO can be used to modify the surface layer of a substrate by allowing the nanoparticles to diffuse into the material matrix, or to produce a coating by depositing nanoparticles on the surface only. Particles produced by nHALO range in size from 5 to 200 nm in diameter (primary particle size), depending on the precursor composition and process parameters. After synthesis, the particles can be directed to collection or direct deposition on a substrate, as in the case of glass coloring and coating.
 

nAERO - aerosol-based aerosol coating

In the nAERO process, the coating precursors are fed into a deposition chamber as liquid droplets and the droplets are directed towards the surface of the glass substrate to be coated. The primary droplet size and size distribution is of paramount importance for the resulting thin film. The glass substrate is brought to the coating process at such a temperature that the thermal energy of the glass substrate is able to vaporize the droplets close to the surface of the glass substrate to be coated, before the droplets contact with the surface of the glass substrate to be coated. The schematic below presents the basic setup for nAERO coating.

 

The main benefits of the nAERO process are that it combines the advantages of spray pyrolysis and CVD in such a way that the challenges commonly associated with these methods are avoided. In short, nAERO offers:

• High thin film growth rate
• Efficient use of raw materials
• Minimal detrimental process-related particle formation
• Suitable for different kinds of applications, both in- and off-line
• Designed for use in normal air pressure

The nAERO process has successfully been implemented both for the production of TCO coatings (for low-e and PV applications) and for self-cleaning coatings.

More information

Download Aerosol Coating Technology brochure (pdf).