Home Cosmetic Science Talk Formulating Emulsion separation

  • Emulsion separation

    Posted by Melissafdodd on June 3, 2019 at 10:16 pm

    Please be gentle with me, as I am learning.  I have made a ” facial cleansing milk” which is basically a really lightweight lotion with a soapy surfactant.  I love it, and I have been using it for quite some time.

    I make a gallon at a time (masterbatch) without fragrance.  When I run out of it in my shower, I remove some and add the appropriate amount of fragrance (.25%).  I noticed separation, so I narrowed it down to what I thought the causes might be.  It isn’t a temperature issue, and it isn’t an emulsifier issue.  It is completely fine, until I add the fragrance.

    These are my questions:
    1) Do some fragrances just cause separation as a rule? If so, why?
    2) I mix my fragrance in with a stick blender.  Could this be “breaking the emulsion”?

    oldperry replied 4 years, 9 months ago 3 Members · 7 Replies
  • 7 Replies
  • oldperry

    Member
    June 3, 2019 at 10:19 pm

    1. Yes. Because they are oils and you’re trying to mix oils with water without enough surfactant to hold them together. But whether that happens or not depends on your formula, the ingredients and how you put it together.

    2.  Probably not but it depends on what’s in your formula.

    But no one can be of much help unless you share the list of ingredients in your formula.  It would help even more if you provide the percentages too. 

  • Melissafdodd

    Member
    June 3, 2019 at 10:27 pm

    I experimented with the formula and intentionally added more than the necessary amount of emulsifying wax to see if the fragrance still caused separation.  It did.  My fragrance is only used at .25% so it is literally several drops of fragrance to an 8 ounces bottle.  As long as I use it unscented, it doesn’t do this.

  • Melissafdodd

    Member
    June 3, 2019 at 10:48 pm

    Ingredients are: cocamidopropyl betaine, distilled water, emulsifying wax, sodium cocoyl isethionate, sunflower oil, castor oil, fragrance, sodium lactate, preservative

    The emulsifying wax is at 7%

    The sci is dissolved in coco betaine over heat, then the e-wax, sunflower oil, castor oil are added over heat.

    The water is heated separately with the sodium lactate and then combined with the oil phase.  

    I stick blend while hot and several times while cooling.  I stick blend again when temp is cool enough for the preservative to be added.

  • ngarayeva001

    Member
    June 4, 2019 at 5:41 am

    What is emulsifying wax?

  • Melissafdodd

    Member
    June 4, 2019 at 11:18 am

    Cetearyl alcohol and polysorbate

  • ngarayeva001

    Member
    June 4, 2019 at 12:27 pm

    …60 I assume. It’s not the best emulsifier. Also, it’s not clear how much oil you use, as you didn’t post the entire formula. As Perry said, you probably don’t have enough emulsifier, but without seing formula it’s impossible to say.

  • oldperry

    Member
    June 4, 2019 at 1:29 pm

    If you have 0.25% fragrance, you should try premixing it with 1% polysorbate 20 or 80 or some nonionic surfactant like that before adding to the main batch.

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