Mixing HPMC in Liquid Soap: Preventing Separation
Question
How should HPMC be correctly mixed into a liquid soap base to prevent separation and achieve a homogeneous texture?
Answer
Advice on Mixing HPMC into Liquid Soap
It sounds like you're experiencing separation when adding a pre-made HPMC gel into your liquid soap base. This can happen because surfactants in the soap base can interfere with the proper hydration and dispersion of HPMC.
The recommended method for incorporating HPMC into liquid soap formulations is to fully hydrate the HPMC in the water phase before adding the surfactants or the liquid soap base.
Here is a suggested mixing order:
- Prepare the HPMC Gel: Disperse the HPMC powder in hot water (80-90°C) or a suitable solvent like Glycerin or Propylene Glycol until fully dispersed. Then, add this mixture to cold water (below 20°C) while stirring continuously until a clear, homogeneous gel is formed. Ensure the HPMC is completely hydrated.
- Combine Phases: Once the HPMC gel is fully formed, slowly add your liquid soap base (which contains surfactants and other ingredients) into the HPMC gel phase. Stir gently but consistently to avoid excessive foaming.
- Mix Until Homogeneous: Continue stirring until the entire mixture is uniform and no separation is visible.
By hydrating the HPMC completely in the water phase first, you allow it to build its gel structure without interference from the surfactants, which helps prevent separation and ensures a stable, homogeneous liquid soap.
