• Formulating

  Most common method used to reduce viscosity in commercial shampoos?

  Posted by Gunther on May 19, 2018 at 10:19 pm

  While salt is technically feasible
  Is it commonly used?
  Any shampoo performance drawbacks from too much salt? less foaming?

  What about the other viscosity-lowering alternatives proposed below
  Alcohol? too drying?
  Propylene glycol?
  Polysorbate 20? less foaming

  After a certain amount of salt has been added, the viscosity peaks and any more salt will actually reduce the viscosity rather than increase it. This type of curve is useful for adjusting the viscosity of the product. Some formulators purposely exceed the curve in order to reduce the stringy character of the formula. Stringy flow can also be corrected by adding a little polysorbate 20 or propylene glycol to the formula. However, these materials will reduce the viscosity as well, which is why they are added in very low quantities such as 0.1-0.5%.

  Reducing Viscosity

  One way to reduce the viscosity and stringy character of the formula is to go over the peak of the salt curve and reduce viscosity by adding an excess amount of salt. This will also reduce the stringy flow property of the formula. Other techniques to reduce viscosity include adding alcohol (denatured ethyl alcohol) and /or glycols (propylene glycol). Surfactants with higher ratios of hydrophile (bulky hydrophilic group and relatively smaller hydrophobe) such as xylene sulfonates will also reduce the viscosity. Certain nonionic surfactants such as polysorbate 20 also tend to reduce the viscosity of anionic surfactant based formulas. Another important aspect of viscosity modifiers is the feel (and any other modification for example to the lather profile) of the formula, that they introduce. Temperature/viscosity and pH/viscosi-ty curves are also important selection criteria for viscosity builders. Relatively flat curves would be preferable. In other words you would want the formula viscosity to remain relatively unchanged when the temperature or pH changes during storage or use.
  https://www.happi.com/contents/view_features/2009-09-02/the-formulation-basics-for-personal-cleansers

  OldPerry replied 5 years, 12 months ago 3 Members · 2 Replies
• 2 Replies

• 

  DAS

  Member

  May 19, 2018 at 10:30 pm

  Xilene sulfonates and glycerin. Some nonionics too, fatty alcohols can work in some cases.

  Using too much salt?. I don’t think you will find that in a comercial shampoo, at least not in a decent formula. 

• 

  OldPerry

  Member

  May 22, 2018 at 7:49 pm

  Fragrance can also reduce viscosity.
  Adjusting pH may also be used to reduce viscosity

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