Case study – Development of an instrumental method for testing cosmetic powder compacts

RHEONIS has implemented its expertise in instrument design, in the development of measurement protocols, in friction mechanics and its skills in image analysis in a medium-term study approach:

1. Bibliographic studies
2. Brainstorming and functional analysis
3. Mechanical design of a module adaptable to a rheometer
4. Preliminary tests
5. Implementation of brush loading and paper application protocols
6. Implementation of image processing protocols
7. Adjustment and validation on a range of brushes
8. Systematic trials & study of correlations
9. Interpretation of data and conclusions on the consistency of the test
10. Additional tests and validation

The test module developed to be adapted on a rheometer makes it possible to quantify the interactions between the compact and a brush, but also between the brush and an application medium. Complementary image analysis approaches make it possible to refine the interpretation of brush loading and deposit phenomena. The technique is functional for comparing cosmetic compacts, brushes and other devices. Improvements are possible to make it a predictive technique linked to sensory analysis.