Proper Procedure and Timing for Adding Carbomer to Adjust Viscosity

The addition of Carbomer to adjust viscosity involves three critical phases to ensure a clear, smooth, and stable gel:

1. Dispersion Phase

Carbomer should be added to the Water Phase early in the process.

• Procedure: Slowly sprinkle the Carbomer powder into the water while mixing at a moderate speed to prevent the formation of "fish eyes" (clumps).
• Tip: Using specialized grades like Carbomer 940 (EasyDisperse™) or Carbomer U10 (EasyDisperse) significantly speeds up this process as they are designed to wet and disperse quickly.

2. Hydration Phase

Once dispersed, the polymer needs time to fully hydrate and uncoil.

• Duration: Allow 15–30 minutes of mixing or standing time. Skipping this can lead to inconsistent final viscosity or a grainy texture.

3. Neutralization Phase (The Thickening Step)

Carbomer is naturally acidic and will not thicken until it is neutralized to a pH of approximately 6.0–7.0.

• When: This is typically done near the end of the formulation process after other ingredients are incorporated. However, if you have acid-sensitive ingredients, you should neutralize the Carbomer first.
• Neutralizers: Common alkalis used include Triethanolamine (TEA). Add the neutralizer slowly while stirring gently until the desired gel consistency is achieved.

Key Considerations:

• Electrolyte Sensitivity: Standard Carbomers can lose viscosity in the presence of salts, minerals, or certain plant extracts. For formulas with high electrolyte content, Carbomer Ultrez 30 is recommended as it offers superior electrolyte tolerance.
• Shear Sensitivity: Once the gel has formed (after neutralization), avoid high-shear mixing (above 2,500 rpm) as it can permanently break the polymer chains and cause the gel to become liquid.

For more options on gelling agents, you can browse the Carbomer category in the catalog.