Sunday, April 24, 2011

HLB system: Work this one out!

Now you try it! Here's a recipe (originally found in this post) on which you can practice your mad HLB figuring out skills!

BODY BUTTER FOR ITCHY WINTER SKIN WITH MINIMALLY PROCESSED INGREDIENTS
WATER PHASE
25% water
10% aloe vera
10% chamomile hydrosol
10% witch hazel
2% hydrolyzed protein
5% tamarind seed extract
3% glycerin
0.5% allantoin

OIL PHASE
10% soy bean oil
7.5% cocoa butter
7.5% mango butter
7% emulsifier*

COOL DOWN PHASE
0.5% chamomile extract
0.5 to 1% preservative
1% fragrance or essential oil blend

Please refer to this PDF for information on your emulsifier and oil values.

Remember the steps to finding out the HLB value of your ingredients.
1. Which ingredients have an HLB value?
2. How much of each ingredient is in the total recipe?
3. Divide this by the total oil phase to get a percentage.
4. Multiply the percentage by the HLB value. Add them together to get the HLB value of your oil phase.

And remember the steps to finding out the HLB value of your emulsifiers.
1. Find a low HLB emulsifier and a high HLB emulsifier.
2. Work on the percentages to find a total that is very close to the HLB value of your oil phase.
3. Rejoice!

I'm going to suggest you use glycol distearate (HLB 1) and ceteareth-20 (HLB 15.2) as your emulsifiers, but you can use others. It's just those are the ones I'm using and it will be easier to compare your notes with mine if we're using the same emulsifiers!

All right! You're on your own! Feel free the post your results in the comments. There isn't a prize or anything - just the satisfaction of knowing you got it right! Join me tomorrow to see if you got it right!

5 comments:

Katie said...

I got an HLB value of 7 for my 25% oil phase. If I use 55% of glycol distearate and 43% of ceteareth-20, I get a total of 7.086. To get a total of 4% for my emulsifyer though, my math doesn't quite work out. I get 2.2% of glycol distearate and 1.72% for the ceteareth-20 for a grand total of 3.92. Is it better to go slightly higher in my total HLB value (using 45% of cet.-20 instead of 43% would give me a total of 7.39 instead of the 7.086)in order to make the final percentages of each add up nicely to 4%? At 55% glyc. dist. and 45% cet.-20 I will end up with a nice even 4% at the end but I'll be going higher than 7 for the total HLB value. It may just be "splitting hairs" though! Which number do you think is more important to get "on the nose"?
Happy Easter!
Katie

Susan Barclay-Nichols said...

Hi Katie! Thanks for playing along! Your emulsifiers must total the amount you're going for, so if you're trying for 4% emulsifiers, they must total 4 (so for instance, 2% of one, 2% of another - 1.5% of one, 2.5% of another). If you're going for 5%, you need both emulsifiers to total 5% (so 2.5% for one, 2.5% for the other, and so on). It is vital that you have a total of 4% or 5% for the emulsifiers. If you have less, then you risk your product failing!

I promise this isn't a trick question - it is possible to get 4% or 5% emulsifiers very close to the required HLB value.

Sorry for being cryptic, but I don't want to give it all away until tomorrow so others can play along!

Katie said...

Poo! I can get 4% with 60% glycol disterate and 40% ceteareth-20, but my HLB value is only 6.68, not quite close enough to 7. My brain cells are on strike! I'll have to wait for the magic answer! : )

Susan Barclay-Nichols said...

I'll give you a hint...Our emulsifiers don't necessarily want to work with us to produce nice round numbers like 60% or 65%! Try going a little higher or lower with the percentages and see if it works out.

Katie said...

Okay, I'm going with 62% glycol distearate and 40% ceteareth-20 for a grand HLB total of 6.7 (close enough) and 2.48% glycol distearate and 1.6% ceteareth-20 = 4.08%
And that's my final offer! : )