Case study – Instrumental method development for the study of cosmetic powder compacts and brush interactions
Internal R&D project
Project duration: 6 months
Cosmetic powders compact are usually handled with a brush or finger and the covering properties is commonly studied through sensory analysis.
We developed a scientific method based on mechanical and optical techniques for the study of powders compacts dynamic response to “brush-like” constraint and the understanding of brush/compact interactions. The system is implemented on a rheometer apparatus.
Steps for the development of an instrumental scientific method for the study of brush loading and compact application
RHEONIS holds combined expertise regarding instrumentation design, measurement protocols development and physical interacial sciences, that proved useful for this medium-term project.
- Literature study
- Functional analysis and brainstorming
- Mechanical design of a specific expertimental system on rheometry
- Preliminary testing
- Study of brush loading protocols and loaded-brush application on paper
- Development of image processing routines
- Adjustment and validation on various brushes
- Systematic study and correlations analysis
- Data interpretation and conclusions on the internal validity of the test
- Complementary trials and validation
Systemic stocks chart
Scientific method for the analysis of powder compacts with respect to brush-like constraints
The testing system is mounted on a rheometer, allowing a fine control of applied constraints and measured responses. Interactions between the compact and the brush (loading and friction) can be quantified, but also the unloading of the brush on an application support. Combined mechanical and optical analysis allow various refinements of the interpretations, leading to a this method to be used as a predictive tool of sensory analysis of powders compact application.
The strengths of this innovative experimental approach
Apparatus and protocols validated
Implemented on rheometry systems (thus open for transfer)
Adapted to powder compacts study and application systems independently
Adapted for objectification of sensory analysis
Last Updated on September 29, 2021 by Vincent Billot