Cosmetics and personal care manufacturing covers a wide spectrum of product types, moisturising creams, body lotions, shampoos, conditioners, sunscreens, shower gels, and deodorant sticks, each with distinct formulation requirements. What they share is the need for precise, repeatable mixing: stable emulsions, fully hydrated thickeners, uniformly dispersed actives and UV filters, and consistent viscosity from batch to batch.
For New Zealand manufacturers operating across natural skincare, contract manufacturing, and personal care supply, choosing the right cosmetic mixing equipment is a significant process decision. This article covers the mixing challenges specific to cosmetics production, the role of high shear technology, and the Silverson mixer range — supplied in New Zealand by Advanced Packaging Systems (APS).
Silverson High Shear Lab Mixer
The Mixing Challenge in Cosmetics Manufacturing
Conventional agitators and paddle mixers are inadequate for the range of mixing operations required in cosmetics production. Several problems arise in practice:
- Stable emulsions are difficult to achieve. Oil-in-water (O/W) and water-in-oil (W/O) emulsions require sufficient shear energy to break the dispersed phase into fine droplets and stabilise the interface. Conventional agitators produce coarse, unstable emulsions that separate on standing.
- Thickening and suspending agents form agglomerates. Carbopol®, Veegum®, xanthan gum, and hydroxyethylcellulose must be hydrated uniformly — a process that requires shear to develop the desired rheological properties. Without it, lumps form that are difficult to break down subsequently.
- Insoluble UV filters agglomerate in suspension. Titanium dioxide (TiO₂) and zinc oxide, the primary UV filters in mineral sunscreens, require high shear dispersion to achieve uniform UV protection and a cosmetically acceptable, low-whiteness finish.
- Process times are excessive. Achieving homogeneity with conventional agitation typically requires multiple passes, or extended mixing cycles that reduce throughput and increase energy consumption.
High shear mixing addresses all of these limitations through the same fundamental mechanism: a precision-machined rotor/stator workhead operating at high speed to apply intense hydraulic and mechanical shear at the point of mixing.
Silverson Mixer with a custom-built tank
How High Shear Mixing Works
Silverson high shear mixers operate on a three-stage rotor/stator principle. The high-speed rotation of the rotor blades creates powerful suction, drawing liquid and solid materials into the centre of the workhead. Centrifugal force then drives the material outward through the precision gap between rotor and stator, applying intense mechanical and hydraulic shear. Processed material is expelled radially at high speed into the body of the mix while fresh material is continuously drawn in, maintaining the cycle.
This reduces processing times by up to 90% compared with conventional agitation. A comprehensive range of interchangeable workheads — emulsor screens, square hole high shear screens, disintegrating heads — allows a single machine to perform emulsification, homogenisation, dispersion, dissolving, and particle size reduction by changing the workhead between operations.
Donna-Klare Cream
Cosmetics Applications by Product Type
Creams and Lotions
Most cosmetic creams and lotions are O/W or W/O emulsions. The oil phase typically contains cetyl alcohol, stearic acid, and fat-soluble actives; the water phase contains emulsifiers, thickeners such as Carbopol® or Veegum®, and water-soluble actives. The two phases are combined under high shear at temperatures of 45–85°C depending on formulation and viscosity.
Silverson high shear mixing produces stable, fine emulsions with droplet sizes achievable below 5 microns — a level of fineness that improves skin feel and active ingredient delivery. At production scale, formulations developed at laboratory scale on the Silverson L5M-A transfer directly without reformulation, as all Silverson equipment is built to the same rotor/stator tolerances. For a practical example, see the APS case study on Silverson lab mixers in face cream manufacturing.
Shampoos and Conditioners
Surfactant-based formulations require thorough blending of ingredients with widely varying viscosities. Carbopol® and hydroxyethylcellulose (HEC) must be fully hydrated without forming agglomerates — one of the most demanding mixing operations in personal care production. Lumps that form during thickener addition with conventional agitation are difficult to break down subsequently and produce an inconsistent product.
The Silverson Flashmix is particularly well suited to this application: it draws powdered thickeners directly into the mixing zone under vacuum, hydrating them instantly without aeration or dust. Fragrance oils, conditioning actives, and colour are then incorporated in the same vessel.
Sunscreens and UV Protection Products
Mineral sunscreens present a specific dispersion challenge. TiO₂ and zinc oxide are insoluble, high-density powders that agglomerate readily in suspension. Without high shear dispersion, agglomerates produce uneven UV protection and a visible white cast. Silverson’s rotor/stator workhead breaks down pigment agglomerates to sub-micron levels, producing a uniform dispersion that is cosmetically acceptable and consistent in SPF performance across the batch.
Body Washes, Shower Gels, and Liquid Soaps
High-surfactant systems with carbomer thickeners require careful thickener incorporation. Conventional agitation causes carbomer to form lumps as it contacts the aqueous phase. Silverson high shear mixing disperses and hydrates carbomers uniformly in a single pass, producing the correct rheology without additional reworking.
High-Viscosity Formulations: Deodorant Sticks and Body Butters
Deodorant sticks, wax-based balms, and dense body butters become semi-solid or highly viscous on cooling. These require a mixer that maintains shear intensity at elevated viscosities while ensuring uniform distribution throughout the vessel. Silverson Bottom Entry Mixers, used in conjunction with a slow-speed anchor stirrer or scraper unit, are designed specifically for this requirement. The Bottom Entry mixer provides high shear homogenisation at the base of the vessel while the anchor stirrer distributes the homogenised output uniformly through the batch.
Silverson Ultra Mix Bottom Entry
Silverson Mixer Selection for Cosmetics Production
Four Silverson mixer types are used in cosmetics and personal care applications, with selection depending on batch size, product viscosity, and process requirements.
High Shear Batch Mixers
The standard production mixer for creams, lotions, shampoos, and gels. Suitable for batch sizes up to approximately 1,500 litres. Available on mobile floor stands for flexible batch production, with sealed units available for pressure or vacuum operation. Interchangeable workheads allow emulsification, homogenisation, dispersion, or powder incorporation within the same vessel.
High Shear In-Line Mixers
Suited to high-volume production and continuous or semi-continuous processes. Self-pumping and aeration-free, the In-Line mixer processes material as it flows through the mixing head, eliminating the need for separate transfer pumps. Can be retrofitted to existing process pipework. Multi-stage units and Ultra Sanitary variants are available for applications requiring enhanced hygienic assurance.
Silverson Flashmix
The Flashmix is the preferred solution for rapid incorporation of large volumes of powder ingredients — thickeners, actives, pigments — without aeration or dusting. Powder is drawn directly into the mixing zone from the bag or hopper under vacuum, dispersing and hydrating instantly in the liquid phase. Minimised cleaning requirements and easily automated operation make it well suited to high-throughput personal care production.
High Shear Bottom Entry Mixers
Mounted at the base of the mixing vessel, with a capacity range of 5 to 2,000 gallons. Constructed in 316L stainless steel with single or double mechanical shaft seals, and available with explosion-proof motors and cGMP/USDA-compliant specification. Typically used in conjunction with an anchor stirrer or scraper for high-viscosity products. Ideal for deodorant sticks, body butters, and wax-emulsion personal care products.
Planning a processing or packaging project?
Speak with Advanced Packaging Systems about equipment selection, line integration, and local support in New Zealand.
- Local technical and commercial support in New Zealand.
- Obligation-free advice on equipment and line fit.
- Useful next steps, even if your project is still early-stage.
Silverson Cosmetic Mixing Equipment in New Zealand
Advanced Packaging Systems is the New Zealand distributor for Silverson, providing local support for mixer selection, application advice, commissioning, and ongoing supply of workheads, replacement parts, and accessories. APS supplies Silverson laboratory-scale equipment to universities and R&D facilities throughout New Zealand.
APS holds the Silverson L5M-A Laboratory Mixer in stock in Auckland, available for a trial, on loan. For new product development and scale-up, APS can advise on the appropriate production mixer type and configuration for a specific formulation and batch size requirement.
View the full Silverson mixer range at APS or contact APS to discuss your requirements.
