Dry Particle High-Impact Coating of Biopowders: Coating Strength

• Published in: Particulate science and technology 2009-07, Vol.27 (4), p.352-361
• Main Authors: Ötles, S., Lecoq, O., Dodds, J. A.
• Format: Article
• Language: English
• Subjects: adhesion; bio-powders; dry coating; Engineering Sciences; Nara hybridizer; strength; van der Waals
• ISSN: 0272-6351; 1548-0046
• DOI: 10.1080/02726350902993987

The aim of this study is to develop a fundamental knowledge on dry coating, to understand the coating strength of different bio-couples with a theoretical and experimental approach and how the dry coating is affected by the size of host particle and choice of dry particle coating equipment. For this purpose, we examine the feasibility of dry coating of two different particle size distributions of Cellets particles with talc using a Nara Hybridizer NHS-0, a 1 L Cyclomix, and a Turbula blender. Special care is required to choose suitable operating conditions in order to achieve surface modification without breakage phenomena. An experimental methodology based on a commercial granulometer is used to study the coating strength of the composites and allows us to study the influence of particle size. The conclusion is that the smaller the guest-to-host size ratio, the stronger the coating. This result is in agreement with the estimation of particle adhesion with the help of a van der Waals approach. The influence of the coating equipment is also studied. The Hybridizer leads with the chosen operating conditions to the stronger coating.