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My oil phase consists of

Lanolin Wax

Stearyl Behenate

Cetyl Alcohol

Stearyl Alcohol

Peg 40 Hydrogenated Castor Oil

Petrolatum

GMS

Caranuba Wax

Our calculated required HLB came to 10.7237

My emulsifiers consist of:

Cetyl Alcohol - 31.7622 % of emulsion

Stearyl Alcohol - 31.7622 % of emulsion

Peg-40 Hydrogenated Castor Oil - 28.6885% of emulsion

GMS - 7.7868 % of emulsion

Pemulen - (No HLB, Did not include in my percentage, should I have?)

After calculating the percentages of our emulsifiers, we realize that the HLB of emulsifiers is 14.1583, way out of range to keep our emulsion stable.

Now, this is where I am stuck. I understand how to calculate 5% increments if I had 2 emulsifier ingredients, however I have four. How do does calculating differ when you have four emulsifiers?

My thoughts -

A. If I replace the Stearyl Behenate (HLB of 8.4) with Tribehenin (HLB of 4) in my oil phase, will this help bring balance to my emulsion?

B. Do I have too many emulsifiers? Should I only have two, rather than four?

C. Do I calculate the stearyl and cetyl alchohol as part of the oil phase as they are acids/esters AND count them as part of surfactants/emulsifiers when calculating, or do I calculate them separately? In other words, are Cetyl Alcohol and Stearyl Alcohol considered emusifiers/surfactants, or should I only be looking at them as part of my oil phase?

D. Should I have calculated the pemulin into the percentage of emulsifiers when calculting the HLB of my blend of surfactants.

E. It seems like there are more high HLB esters/emulsifiers than low, and in W/O emulsion I am aware we want it to be on the low end, preferably using emulsifiers with an HLB of 4-6. Really, outside of the GMS (HLB of 3.8) everything is above a 6. We also know that the HLB of our emulsifiers should match or be very close the the HLB of our oil phase.

Do I simply adjust the percentage of emulsifiers until the HLB is as close to 10.7 as possible? Do I try to add another emulsifer with a lower HLB such as oltheth-2?

F. We have our formula at 60% Water. We have tried at 55% and 50% with no major improvements. Is 60% ideal?

G. We both lab and inline rotostator mixers for homoganizing, but are unsure if we should be going high shear or low, thoughts?

Conclusion: Please Help! I have hit a wall and could really use the knowledge found here. I appreciate all comments and considerations, please feel free to educate me or correct me in any way. If more information is needed, I will happily provide it.

## Comments

How do does calculating differ when you have four emulsifiers?"This is a percentage equation.

w = emulsifier 1 HLB

x = emulsifier 2 HLB

y = emulsifier 3 HLB

z = emulsifier 4 HLB

W% + X% + Y% + Z% = 100%

I won't look up the exact emulsifier values but here is how you would do it. Suppose you have the following emulsifier values

w = 6, x = 8, y = 11, z = 14

We'll go with your emulsion percentages

W% = 31.7622

X% = 31.7622

Y% = 28.6885

Z% = 7.7868

HLB = w*W% + x*X% + y*Y% + z*Z%

HLB = (1.91) + (2.54) + (3.16) + (1.09) = 8.7

Now, suppose you change the emulsion percentages

W% = 50

X% = 30

Y% = 15

Z% = 5

The new HLB value of your emulsion is...

HLB = 6*0.5 + 8*0.3 + 11*0.15 + 14*0.05 = 7.75

Hope that makes sense.

The HLB Values of my emulsifiers/surfactants and percentage of emusifiers used are:

W - Cetyl Alcohol - HLB of 15.5 - 31.7622 %

X - Stearyl Alcohol - HLB of 15.5 - 31.7622 %

Y - Peg- 40 HGC - HLB of 14 - 28.6885%

Z - GMS - HLB of 3.8 - 7.7868%

Plugged into the equation we see:

(31.7622/100) x 15.5 + (31.7622/100) x 15.5 + (28.6885/100) x 14 + (7.7868/100) x 3.8 = 14.1583

Given that the HLB of my emulsifiers equals 14.1583 and the HLB of my oil phase equals 10.7237, I'd simply have to adjust percentages of W,X,Y,Z Accordingly to match my oil phase.

How do you determine the right percentage to plug in? I can do trial and error, but guessing feels like throwing darts at a board while blindfolded.

Do you think this is the single cause of my emulsion problem, or are some of my other questions pertinent as well?

Thank you for your help Perry, I appreciate your knowledge

But I think you're missing something. If you already have Stearyl Behenate in your formula, that should be included in your emulsifier calculation.

Also, Cetyl Alcohol and Stearyl Alcohol are co-emulsifiers. Since they have such a high number they aren't really primary emulsifiers in most cases.

If you just start with your oil phase. You need an emulsifer for an oil system of HLB = 10.7

So, a good place to start would be an emulsifier system with an HLB 9 and one with HLB 11.

PEG-7 Olivate HLB = 11

PEG-40 Sorbitan Peroleate HLB = 9

But you can still experiment with different ratios of the emulsifiers you are using. When it comes down to it, you have to experiment with what is going to be stable. The HLB system gives you a starting point.

Regarding Cetyl & Stearyl Alchohol, that's exactly what we were thinking, and it seems to imply that do not need to be calculated into the HLB ratio of our emulsifier blend.

Do I need to consider Cetyl & Stearl as a part of my blend of emulsifiers? Or do I consider them part of the oil phase only? If they are only a part of the oil phase, it would leave us with 2 emulsifiers; GMS at an HLB of 3.8 and Peg 40 HGC at and HLB of 14 as my current blend, giving a quite a range. Could I technically then adjust the percentage of the these two to 35% GMS and 65% Peg 40 HCO? This would give an average HLB of 10.283, however, I'm not sure this would work.

Regardless, we may be too far from the 10.7, still require something between 9 and 11 as you said. I will see what I have in house to test, or order in one of the two you suggested.

In the mean time, I have been thinking that replacing the Stearyl Behenate (hlb of 8.4) with Tribehenin (hlb of 4) would also improve the emulsion as the majority of our emulsifiers are on the high end of the HLB spectrum. Do you agree with my thinking here?

Thanks!

Thanks!

You should remove the two fatty alcohols from your emulsifier system when calculating.

and chemically compatible with it, you should be OKalso Pemulen is ionic, so it doesn't have an HLB

fatty alcohols are not emulsifiers; they are surface-active, but the hydrophilic part of the molecule is too small for them to act as effective emulsifiers

neither PEG-40 hydrogenated castor oil nor GMS are particularly effective emulsifiers in combination; we used to manufacture a product with this system which was notorious for being difficult to mix, prone to separation during cooldown, and turning out visibly different nearly every time it was made; it sounds like this is what's happening here

I'd suggest adding ceteareth-20 to your emulsifiers, that should make the phases easier to mix together, and hopefully resolve your issue

Two questions:

1. If we add the cetereth-20, would we be able to consider that and the gms as our emulsification system and adjust percentage of each to reach a balance within +1?

2. Or does the peg-40 HCO still remain calculated as the part of our emulsifier system?

I will try adding some cetereth-20 and see what happens!

Could you clarify what you meant by saying I am calculating using the required value?

Thanks!

Stearyl Alcohol - HLB of 15.5

These are required HLB for those two fatty alcohols. You will need and emulsifier with that HLB value to emulsify each of those fatty alcohols.