Overhead Stirrers: The King of Mixing Versatility

Published in Emulsifying, Homogenizing Mixing Suspending

Unlike other lab mixing equipment, Caframo overhead stirrers can tackle virtually any process due to their ability to handle large volumes over wide ranges of speed and torque. Moreover, there are countless impeller options available, allowing for all types of mixing from homogenization to solids suspensions. These qualities allow for simplistic scaling up and down with the same equipment. Dive into Caframo’s entire Overhead Stirrer lineup.

Volume and Viscosity of Samples

When choosing your lab’s mixing equipment, understanding the volumes and viscosities of your samples is imperative. One major advantage of Overhead Stirrers is their ability to mix volumes as small as 50ml all the way up to 100L, allowing one stirrer to be utilized over a wide range of processes. Likewise, Caframo Overhead Stirrers offer unmatched torque in the lab allowing viscous samples to be mixed with ease. Caframo’s BDC1850 is a torque leader, allowing for a maximum viscosity of 90,000 mPas.

Speed Matters

From keeping your sample in motion in laminar flow to creating homogenizations at high speeds in turbulent flow, Caframo Overhead Stirrers provide room for your processes to grow with speed ranges from 12 rpm to 6000 rpm. Caframo’s BDC6015 boasts the ability to mix from 40-6000rpm.

Impeller Options

With nearly limitless impeller options, Caframo overhead stirrer impellers blend, emulsify, suspend solids and offer more with unique designs for different flows such as radial, axial and tangential. Aside from impeller type, each impeller is available in multiple sizes and materials (stainless steel and PTFE), ensuring you have the perfect fit for your mixing vessel and ingredients in your application. Discover Caframo Impellers.

Versatility in Action

To give a real-world example of the versatility of Caframo Overhead Stirrers, we’ll walk through the details of a single application involving multiple processes in the cosmetics industry:

Production of a Face Cream

First, all aqueous ingredients are mixed with an axial blade at moderate speeds. This often includes water, thickeners, and humectants. The axial blade provides ample pumping action for this process. aqueous phase
Next, utilizing the same impeller and stirrer settings, the oil phase is prepared. This often consists of waxes and gums as well as an emulsifier.
Both the water phase and oil phase are combined with a dispersion blade at high rpm, which creates a perfectly creamy and consistent emulsion.
The emulsified mixture then proceeds to the cooldown phase where an anchor paddle is utilized to continually mix the emulsion at low rpm until it reaches room or near room temperature. At this time, temperature sensitive ingredients can be incorporated like fragrances, preservatives, and color. Finally, the pH is adjusted, and the formulated cream is packaged.



Jaszczur, Marek, Anna Młynarczykowska, and Luana Demurtas. “Effect of impeller design on power characteristics and Newtonian fluids mixing efficiency in a mechanically agitated vessel at low Reynolds numbers.” Energies 13.3 (2020): 640.
Brian James, “Mixing 101: Flow Patterns & Impellers”, 3 May 2022, https://dynamixinc.com/mixing-101-the-basic-principles-of-mixing-and-impellers/

Tariq Mahmood, Naveed Akhtar, “Stability of a Cosmetic Multiple Emulsion Loaded with Green Tea Extract”, The Scientific World Journal, vol. 2013, Article ID 153695, 7 pages, 2013. https://doi.org/10.1155/2013/153695

Gaurav Kumar Sharma, Jayesh Gadhiya. “Textbook of Cosmetic Formulations”, 2018, https://www.researchgate.net/profile/Jayesh-Gadhiya/publication/325023106_Textbook_of_Cosmetic_Formulations/links/5af22308aca272bf4257e507/Textbook-of-Cosmetic-Formulations.pdf