Cosmetics and personal care

Cosmetic and personal care powders present a processing challenge that most other sectors don't share: the same powder needs to flow freely enough to fill compacts, hoppers and dosing systems reliably, yet consolidate well enough to hold together as a pressed product that survives transit and consumer handling. Fine pigments, talc carriers, surface treatments, and binding agents all influence where a powder sits on this spectrum – and small batch-to-batch variations in particle size or moisture content can shift it significantly.

Dynamic testing with the Powder Flow Analyser captures flow, cohesion, segregation and caking behaviour under conditions that reflect real manufacturing environments. Texture Analyser tests measure the mechanical strength of pressed compacts and surface hardness – the properties that determine whether a finished product performs in the consumer's hands. Together, they provide a complete picture of both processability and product quality.

• Face powder is the most cohesive sample of the three by a considerable margin, with a Cohesion Index of 41 – more than double that of the other two. Despite becoming somewhat easier to move at higher speeds (speed ratio 0.46), the absolute level of cohesion remains high enough that the practical symptoms are sticking, poor initiation of flow, and inconsistent feeding rather than speed-related packing changes. Its caking behaviour is also notable: it consolidates dramatically under load, producing a relatively compact column – which means that after any period of storage or dwell under pressure, restarting flow reliably will require adequate pre-conditioning.
• Baby powder and Foot powder occupy a similar cohesion and speed-dependence band – both with CI around 16 and speed ratios of 0.40, meaning both become modestly easier to move at higher speeds. Where they diverge is caking: foot powder develops a substantially stronger cake (mean cake strength ~198 g vs ~135 g for baby powder) despite similar bulk and flow characteristics. For a formulator or production engineer, this means similar filling and conveying behaviour but meaningfully different storage and shelf stability risk – foot powder is more likely to exhibit hard lumps or discharge problems after prolonged storage, particularly in humid conditions.

Powder Flow Analyser – dynamic behaviour

Texture Analyser – strength, surface feel, and durability

Powder problems are driven by movement, stress, and time. Dynamic flow and strength-based testing reveal behaviours that static tests cannot capture.