By George Nikolopoulos, Regional Sales Manager
Carbopol is a registered trademark of the Lubrizol Corporation for a family of polymers that are used as thickeners, suspending agents and stabilizers. They are utilized in a wide variety of personal care products, pharmaceuticals and household cleaners. Most Carbopol polymers are high molecular weight acrylic acid chains, usually crosslinked, and are available as powders or liquids.
In the cosmetic industry, Carbopol is used as a thickener in lotions, creams and gels. It is also used to stabilize, suspend, and control the release of pharmaceutical products. At low concentrations, suspensions flow easily with a slippery feel. At higher concentrations, high viscosity varieties form gels that are pseudoplastic. At rest, the batch has a very high viscosity and resistance to flow. When shear force is applied by a mixer or pump, the apparent high viscosity is reduced.
The typical powder is very light and fluffy, forming clouds of airborne dust if not handled carefully. It tends to float on water, requiring a good vortex to wet out. Once wet, it swells quickly creating high viscosity. Different varieties produce varying viscosities, but most are used below 1% concentration. The crosslinked polymers are not actually water soluble, but swell into hydrated spheres that give the product its rheological properties.
As with gums, Carbopol forms clumps commonly known as fisheyes, if not mixed correctly. The Rotosolver is a top entry high shear mixer that is widely used to disperse these materials quickly, eliminating clumps without damaging the polymer with overshear.
Check out these videos to see how our sanitary high shear mixers work on Carbopol and another water soluble gum, carboxy methylcellulose (CMC). Both are difficult to disperse and hydrate, but no match for the Rotosolver high shear mixer.