Shampoo Lumpiness and Separation Issue

Based on your shampoo formula and the description of it becoming lumpy (solid mixed with liquid) after one day, the most likely causes are related to the interaction between the ingredients, particularly the polymers and surfactants, or how they were mixed.

Here are the probable reasons:

1. Incompatibility between Cationic Polymers and Anionic Surfactant: Your formula contains two cationic polymers (Polyquaternium 10 and Guar Cat) and an anionic surfactant (Disodium Laureth Sulfosuccinate). Cationic polymers are positively charged, and anionic surfactants are negatively charged. They can strongly interact and form insoluble complexes or precipitates, especially if the concentrations or pH are not optimal for compatibility. This is a very common cause of lumpiness or separation in shampoo formulations.
2. Improper Hydration or Dissolution of Polymers: Guar Cat (Guar Hydroxypropyltrimonium Chloride) needs to be properly dispersed and hydrated to swell and thicken the solution evenly. If it wasn't fully hydrated before adding other ingredients, it can form undissolved lumps. Similarly, Polyquaternium 10 needs to be fully dissolved.

How to potentially fix or prevent this:

• For the current batch: It's often difficult to fully fix a batch once this kind of precipitation or lumpiness has occurred due to incompatibility. Mixing more might break up some lumps but won't resolve the underlying issue of incompatibility.
• For future batches (Prevention is Key):
  • Order of Addition and Mixing: This is crucial.
    • Properly hydrate Guar Cat first. Typically, you disperse it in a small amount of water or a non-solvent (like glycerin if you were using it, but not in this formula) and then add the bulk of the water while mixing vigorously to ensure it hydrates fully without clumping. Let it hydrate completely before moving on.
    • Add Polyquaternium 10 to water and mix until fully dissolved.
    • Combine the hydrated polymer solutions (if prepared separately) or add the other ingredients to the polymer solution.
    • Add surfactants (Disodium Laureth Sulfosuccinate and Cocamidopropyl Betaine) slowly to the polymer solution while mixing gently but effectively to avoid excessive foam.
    • Add NaCl (salt) solution last, slowly, while monitoring viscosity.
    • Add Phenoxyethanol (preservative) as per instructions, usually during the cooling phase if heating was involved, or at the end.
  • Check and Adjust pH: Measure the pH of your formulation. The optimal pH for compatibility of cationic polymers and anionic surfactants is usually in the slightly acidic range (e.g., pH 5.0-6.0). If your pH is outside this range, it can worsen incompatibility. You might need to adjust the pH using a dilute acid like Citric Acid solution.
  • Check Ingredient Compatibility: Ensure the specific grades of Polyquaternium 10 and Guar Cat you are using are known to be compatible with Disodium Laureth Sulfosuccinate. Sometimes specific suppliers provide compatibility data.
  • Review Concentrations: While your concentrations don't seem extremely high, the interaction is complex. If prevention steps don't work, you might need to slightly reduce the concentration of one of the polymers or the anionic surfactant in future trials.

In summary, the lumpiness is most likely due to an interaction between your cationic polymers and the anionic surfactant, possibly exacerbated by improper mixing/hydration of the polymers. Focusing on the correct order of addition, proper hydration/dissolution, and checking/adjusting pH in future batches should help prevent this.