Cold emulsification is becoming standard practice in cosmetics manufacturing. Driven by the need to reduce energy consumption, preserve heat-sensitive actives, and work with natural thickeners that degrade under thermal stress, more producers are moving away from hot process manufacturing. The question is which mixing technology actually delivers stable, high-quality emulsions under cold process conditions. Rotor-stator homogenizers are the established choice, but their high shear profile creates limitations with viscous, structured, or particle-loaded formulations. This article presents comparative performance data for the FUNDAMIX® Vibro-Mixer against a rotor-stator benchmark, based on a study conducted by researchers from Hochschule Niederrhein and presented at DECHEMA 2024.
How Does Vibratory Mixing Perform in Cold Emulsion Processing?
Under controlled laboratory conditions, FUNDAMIX® produced stable cold process emulsions across multiple formulations tested. While rotor stator homogenizers generated smaller average droplet sizes due to higher shear forces, the vibration mixer consistently delivered emulsions with higher viscosities and stable multiphase structuring. This clear performance differentiation is highly relevant for cosmetic emulsification, where viscosity, texture, and stability remain core quality indicators.
Measured viscosities ranged from approximately 8200 to 8500 mPa·s, compared to roughly 6100 to 7400 mPa·s for the rotor stator benchmark. Depending on formulation, this corresponds to bulk viscosity levels exceeding those of rotor stator processing by more than 30 percent, highlighting a stronger structural buildup of the emulsion rather than finer droplet size reduction.
This higher viscosity correlates with effective structuring of the dispersed phase and efficient distribution of stabilizers such as xanthan gum or starch. Microscopic evaluation indicated well structured droplet systems with minimal signs of coalescence, demonstrating the ability of the vibratory mixer to generate stable emulsions even in the presence of pigments, scrubs, or other dispersed particles.
Another observation of strategic relevance for cosmetics R&D is the natural formation of W/O/W structures during single pot processing. The lower shear regime supports the development of multiple emulsions without collapse, enabling innovative sensorial profiles and controlled delivery concepts that typically require gentle processing conditions.
Formulation M-49: O/W emulsion, 0.7% xanthan gum, 3.0% starch (rheology additive), cold process (25°C/25°C), 200g batch
Why Is Vibratory Mixing More Energy Efficient and Scalable?
Energy consumption is a decisive KPI in modern cosmetic plants. In the comparative study conducted by Hochschule Niederrhein researchers (Pastewski et al., DECHEMA, 2024), power measurements recorded on identical cold emulsification formulations showed that the FUNDAMIX® Vibro-Mixer consumed 27 to 32 W, compared to 119 to 135 W for a rotor-stator homogenizer on the same recipes. This represents approximately four times lower energy input to produce a stable emulsion of equivalent quality.
Cold emulsification multiplies this advantage further. Conventional hot/hot processes require heating both the oil phase and water phase to 80°C before mixing. By working entirely at ambient temperature, cold processing eliminates this thermal energy cost entirely, on top of the mixing efficiency gain.
The FUNDAMIX® also ensures operational predictability by avoiding vortex formation, enabling high filling levels and stable batch operation across a wide viscosity range. For facilities implementing or expanding cold processing strategies, this creates a direct opportunity to minimize thermal energy demand while maintaining consistent product quality, supporting more flexible and modular plant layouts.
Moreover, the mechanical simplicity of the system, absence of rotating seals, and minimal maintenance profile align well with the hygiene and uptime expectations prevalent in cosmetics manufacturing.
Where Can Vibratory Mixing Create Value in Cosmetics Manufacturing?
With its characteristic flow behaviour and adaptability to sensitive formulations, the FUNDAMIX® offers compelling opportunities across various cosmetic processing steps. Its process stability, gentle shear profile, and efficient mixing dynamics align strongly with the industry’s move toward natural formulations, cold emulsification, and advanced texture engineering. In particular, the ability to form structured drop in drop systems contributes to enhanced emulsion stability and increased apparent volume, which is especially advantageous for cream based cosmetic products.
- Cold emulsification of creams, lotions, and serums using natural thickeners and biodegradable oils, benefiting from drop in drop structures that improve stability and yield higher apparent volume at constant mass.
- Pigment dispersion for scrubs, tinted formulations, and functional additives within structured multiphase systems, without risk of shear degradation.
- Suspension homogenization in high viscosity media where conventional impellers experience dead zones or require elevated energy input, while maintaining controlled phase distribution.
- Encapsulation or multiple emulsions, supporting advanced delivery mechanisms for actives through gentle processing and stable drop in drop formation.
FUNDAMIX® Vibro-Mixer during cold emulsification trials at Hochschule Niederrhein, 2024.
Cold Emulsification in Cosmetics: How to Cut Mixing Energy by 75% Without Sacrificing Emulsion Quality
| Parameter | FUNDAMIX® Vibro-Mixer | Rotor-Stator Homogenizer |
|---|---|---|
| Mixing principle | Oscillating perforated plate | High-speed rotating head |
| Shear profile | Gentle mixing conditions | High shear |
| Energy input (cold emulsification) | 27–32 W | 119–135 W |
| Resulting emulsion viscosity | 8,200–8,500 mPa·s | 6,100–7,400 mPa·s |
| Droplet size | Larger, structured | Smaller, uniform |
| W/O/W multiple emulsion formation | Yes, naturally in single pot | Not typical |
| Shear-sensitive actives | Well suited | Risk of degradation |
| Pigment and scrub handling | Intact particles preserved | Risk of shear damage |
| Vortex formation | None | Yes |
| Rotating seals | None | Yes |
| Maintenance frequency | Low | Higher |
| Cold process compatible | Yes | Yes |
Conclusion
The technical evidence positions vibration based mixing as a high potential technology for forward leaning cosmetics producers. While it does not replace high shear homogenization where ultra fine droplet sizes are mandatory, the FUNDAMIX® Vibro-Mixer clearly establishes its value in cold processing, high viscosity systems, natural formulations, and energy optimised operations. Its ability to produce stable emulsions, handle particle loaded systems, and maintain low energy input creates a compelling business case for both formulation labs and manufacturing plants aiming to modernize their processing footprint.
Finished emulsions on petri dishes. Left: FUNDAMIX® Vibro-Mixer. Right: rotor-stator homogenizer. The denser, more cohesive texture of the FUNDAMIX® emulsion reflects the higher structural viscosity measured across all tested formulations.
Frequently Asked Questions
What is cold emulsification in cosmetics manufacturing?
Cold emulsification is a process in which cosmetic emulsions are produced at ambient temperature, without heating the oil and water phases to the 80°C required by conventional hot/hot processing. It reduces energy consumption, preserves heat-sensitive actives, and is compatible with natural thickeners such as xanthan gum and starch that degrade under thermal stress.
How does a vibratory mixer compare to a rotor-stator homogenizer for cosmetics?
In independent comparative testing at Hochschule Niederrhein (DECHEMA, 2024), the FUNDAMIX® Vibro-Mixer consumed 27 to 32W versus 119 to 135W for a rotor-stator homogenizer on identical cold emulsification recipes, approximately 4 times lower energy input. Emulsion viscosities were 30% higher with the vibratory mixer, indicating stronger structural buildup. Rotor-stator homogenizers produced smaller average droplet sizes, making them better suited where ultra-fine droplet size is the primary requirement.
Can FUNDAMIX® handle pigments, scrubs, and particle-loaded cosmetic formulations?
Yes. The low shear profile of the FUNDAMIX® Vibro-Mixer avoids shear degradation of particles, making it well suited to pigment dispersion for tinted formulations, physical scrubs, and functional additives within structured multiphase systems. Microscopic evaluation in the DECHEMA study confirmed well-structured droplet systems with minimal coalescence in particle-loaded formulations.
What are W/O/W emulsions and can FUNDAMIX® produce them?
W/O/W (water-in-oil-in-water) emulsions are multiple emulsions in which water droplets are encapsulated within oil droplets, which are themselves dispersed in a continuous water phase. They enable controlled release of actives and distinctive sensorial profiles in premium cosmetics. The gentle shear regime of the FUNDAMIX® Vibro-Mixer supports natural W/O/W structure formation in a single pot without droplet collapse, a process that is difficult to achieve with high-shear rotor-stator equipment.
Is FUNDAMIX® suitable for scaling up cosmetic production?
Yes. FUNDAMIX® is available in four sizes (FM-1 through FM-4+), covering vessel volumes from 0.5 litres in the laboratory up to 12,000 litres in production. The geometrically similar mixing plates across all sizes ensure that mixing behaviour validated at lab scale transfers predictably to full production, with no vortex formation and stable batch operation across a wide viscosity range.
References
Pastewski, J., Lenters, L., Schultz, H. J., Wanninger, A.
Leistungsvergleich von Mischverfahren bei der Kaltherstellung von nachhaltigen kosmetischen Emulsionen.
Hochschule Niederrhein – University of Applied Sciences.
Presentation at the DECHEMA Annual Meeting, Fachgruppe Mischvorgänge, Schopfheim, Germany, March 7, 2024.
