Saturday, August 3, 2013

Weekend Wonderings: Thickening a liquid soap with Crothix, a new surfactant thickener, solubility of allantoin, heating shrink bands,

The summer semester is over, and it's time to start studying for my mid-month final exam. I have two weeks of holiday time at the end of the month, and for at least one of those weeks, I'm planning to putter around the house and play in the workshop! I'm running out of everything again, and I really need to play with my new supplies at some point!

We held craft group outdoors to play with some fragrances, and the kids made these amazing fragrance misters with all kinds of neat scent combinations, most of which I'll be posting over the next few weeks. It's an easy recipe - up to 2% fragrance oil, up to 2% polysorbate 20 (equal amount to the fragrance oil), 0.5% to 1% preservative, and the rest in distilled water. Thanks to Voyageur Soap & Candle for donating something like 200 of these little misters! The kids had a blast!

In this post on modifying a conditioner into shaving lotion, Michael asks: If I am using all natural products and crothix how should I formulate? I am using water, organic castille soap, vegatable glycerin, baking soda (sodium carbonate), essential oil, macadamia nut oil, olive oil, germall, and liquid crothix 1%. How long do you mix crothix for? My product was watery. I'm going to use tap water next time. I used alkaline water for this batch. I want the consistency to be a little thicker. It's too runny when it comes out of the foam bottle. Do you add crothix by w/w or by v/v? I added crothix by total volume of formulation. so my total volume was 620 mL and I added 6.2mL of crothix (1%)

Crothix won't work with liquid soap as it needs a pH range of 5.0 to 9.0, and castille soap has a pH of about 10. A soap has to have a pH of 8 or higher - alkaline - in order to be a soap. If you reduce the pH below 8, it de-saponifies and becomes a bunch of oil and water again. (Click here to see what happens if you mix vinegar - an acid - and castille soap together. Ick!) You could reduce the pH slightly to something like 8 or 9 with some citric acid, for instance, but you'll need a pH meter to see where to stop.

As an aside, I saw spellings for castille with one l and with two. I am choosing the two ll version - castille - but would like to hear from Canadians if this is the spelling we use. 

Please don't use tap water because you don't want to worry about the metals found in it that can mix with your product. Always use distilled water so you don't have to deal with anything other than a nice neutral - around pH 7 - solvent.

Everything we do is by weight, never by volume. You might have used 1% Crothix by volume, but that isn't 1% by weight. I can't find the specific gravity of Crothix - how much it weighs per millilitre - but it isn't going to be 1 ml equals 1 gram. If you have something like water - which is 1 gram per 1 ml - at 99 ml and you add 1 ml Crothix, you don't have 1% Crothix. You could have 0.5 grams of Crothix or 1.5 grams of Crothix.

So the short answer is that you can't use Crothix with this product unless you lower the pH, and you can't really lower the pH without ruining the castille soap, so I'm afraid I don't know what to suggest about thickening it. And we always do everything by weight because it's more accurate.

As a quick aside, I just picked up this thickener from Voyageur Soap & Candle, Ritathix DOE thickener (INCI: PEG-120 Methyl Glucose Dioleate, Methyl Gluceth-10), a thickener that is supposed to be able to thicken non-ionic surfactants like decyl glucoside. I can't find a data sheet on it anywhere as it seems like it was just introduced in mid-June, but I did find this suggested recipe using this ingredient from Personal Care Magazine. I will be trying this out during my two weeks of holiday at the end of this month!

From Happi: Applications: Surfactant systems, facial washes, cleansers
Use Levels: 0.5-3.0%
Comments: A liquid based surfactant thickener that has the ability to thicken in very precise increments. A cold process ingredient that can be added during any phase of the manufacturing process and can be used to fine tune batch viscosity. Can be used in clear surfactant systems and does not need to be neutralized.

In this post Chemistry Friday: Why do we care about mixing and solubility?, Clare asks:  I dream of making The Ultimate Moisturiser for my grumpy pernickety skin. Everywhere says that allantoin can be used up to 2%, but if the solubility at room temperature (and all products are going to end up at room temperature) is only 0.57%, surely it's impossible to use more than that? Why is the usage rate always stated as up to 2%? How do we know that other extracts or actives are soluble up to their maximum usage rate? I don't want to spend lots of money on lovely ingredients only to waste them if they won't dissolve at the recommended usage. Can you help explain?

I think the reason we might see it suggested at up to 2% is that this isn't just about solubility in water. Allantoin is more soluble in glycerin and SLS than water (see this brochure). Lotioncrafter also has a great PDF on the topic with some suggestions about how to use it at more than 0.5%.

To find out the solubility of an ingredient, ask your supplier. Ask them if the up to 2% (for instance) is for water or other things. Ask for a data sheet. If they can't provide you those things, consider going to another supplier who can answer those questions. It's hard to do searches for things like extracts because we have no idea which manufacturer makes it, unlike doing a search for something like a surfactant or an oil, and one strawberry extract could be very different than another. This is why we turn to our suppliers for help!

We don't want to waste our ingredients adding more than we should, but you will be using them up a lot faster than you expect! I think facial moisturizers are the hardest things to make because it really is about getting a good base recipe and tweaking it quite a lot, so my suggestion is to make 100 gram batches and not anything larger, adding one thing to each batch so you can isolate a certain ingredient. Use each product for at least ten days as it can take quite some time to know whether our skin likes something or not. If you have any serious reactions, stop immediately.

Let us know how the moisturizer turns out!

Related links:
A couple of notes about acne, break outs, and sensitive skin
Comedogenicity: What the heck does that mean?

In this Weekend Wondering post, Maiti asks: I've recently begun making lotions based upon your recipes. Thank you for everything that you do! My question is this: I am worried about customers at farmer's markets opening my lotion jars and sticking their dirty fingers in my product. I'm switching to flip-top bottles in my next set. But for now, I've got screw-top jars. I want to shrink wrap them to keep people out. But that requires heat from a hair dryer to shrink the plastic wrap around the jar. Will that affect the lotion?

I don't think it will, but I also don't sell my products, so it's something I haven't tried. Given these shrink bands are intended for this very purpose, I would think those things would be accounted for by the manufacturer. Looking at these shrink bands from Voyageur Soap & Candle, they mention shrinking them with a heat gun without mentioning any cautions, so I would think things are fine. You aren't exposing it to a lot of heat for very long, so my instinct is to tell you not to worry too much as long as you are heating it just long enough to shrink the band.

Experienced vendors - what do you think?

Join me tomorrow for more Weekend Wonderings!

9 comments:

Jane said...

I use a heat gun to heat the shrink bands on my lip balms. The plastic reacts to the heat so quickly that my products are not under the gun long enough for them to heat up much at all. The lip balms stay solid and firm. I do not worry about the heat affecting the quality at all.

LeKenda said...

I have used shrink bands on my products and the process takes mere seconds with a heat gun- I mean like a max of 5 seconds! In addition I have shrink band items and open them months later when they didn't sell and the products were perfectly fine (the consistency was fine and free of yuckies- yes I checked, lol)

Alexis said...

Michael, I've done some experimenting with crothix pastilles and hard soap. 12% crothix pastilles and 33% dri-pak soap flakes (rest water & preservative) will yield an incredibly hard mass that is something else to behold...

But I don't think you need crothix (liquid or pastilles) to thicken this. I'm not sure if you're using NaOH castille (hard soap) or KOH castille (liquid soap). If the soap you have is hard, you can grate about 2 ounces of it and add 2 to 8 oz of distilled water (or other ingredients total) and heat it in a pot (double boiler) or slow cooker. Once everything is melted/blended, you can dip a spoon in it then dip the spoon in ice water or put the spoon in the freezer for a few minutes to see if the viscosity is where you want it.

If you're using liquid, then what is sold on the market has already been diluted - or that's my understanding anyway. I've researched making liquid soaps, and from what I've read they are very thick and must be diluted about 40% to be viscous enough for pouring. So in this case you would have to heat it to evaporate the water.

I think it is worth trying just using the glycerin instead of water and see how you like it. 1) glycerin is a byproduct of the soaping-making process and it might blend better and 2) it's a humectant. You may not need to add any oils since most soaps (hard or soft) are super fatted to neutralize all the NaOH or KOH.

I have not experimented with how much water or glycerin can be added to soap for the pH to drop below 8. Germall Plus has a pH effectiveness range of 3 to 8.

Iamnotarobot said...

Suggestion for selling items that use a tester product - small disposable spoos that potential customers can use to scoop out product then throw away. Keeps open jar products clean!

Most DIY tutorials on Pinterest are not formulated correctly nor do they use proper emulsification or preservation. A pinch of this and a pinch of that is not accurate, nor measuring in teaspoons. Scales are not expensive to buy.

Mommysoaper said...

I have been using liquid crothix for a while to thicken my liquid soap though my liquid soap is a blend of different oils, not 100% olive oil. The crothix thickens up the liquid soap nicely. I do not thicken my liquid soaps that I put into foaming dispensers, I actually thin it with distilled water until it dispenses in a nice stable foam. Didn't realize crothix had a ph restriction, though it still seems to work fine for me.

Krystal said...

Another option (that I've used) is to put some electrical tape (I have black lids/clear jars so used black tape) around the seal of the jar, it keeps people out! Having a tester is also a great idea!

7slaper said...

Dear Susan,
The link to the allantoin brochure sadly doesn't work; it gives a HTTP 404 error.

Ive been using allantoin in the heated water phase, not knowing there were other options. Thusfar it never gave me problems, but it's good to know that there are other ways to incorporate it.

Your information is valuable as allways! Thank you for that.

It happens that suppliers don't know a thing about the ingredients that they're selling. IMHO due to the fact that especially (small) web shop owners don't need to be qualified for the specific branche of products they sell, unlike the owners of a real life shop. E.g. a tobacco shop owners needs to know everything about tobacco, the making of cigars, the various tobacco plants, which leaves are used, possible hazards etc.

People see the gap in the market, become distributors for big firms like Brambleberry, thus being plain resellers without any or lacking knowledge.
Despite that, we're happily buying from them, because they bring the ingredients we're craving for, within reach. (I'm talking about Europe)
The bigger suppliers provide us with the necessary information and often more!

I love shrink wrap! Use it for almost every product I make. For soap: hygenic, keeps them fresh.
For jars, lipbalm tubes, airless dispensers, you name it.
It gives the products a clean, new and professional charisma and it keeps your labels clean.


Mugi said...

Hi, an new to soap making and have been given the the following ingredients to use: sulphonic acid, common salt, coastic soda and ungerol. however, i have failed to make the soap thick even when i use CMC. Please help recommend how i can make my soap thick. thanks

7slaper said...

Firstly, if you list your recipe, it is easier to help you.
Is it a syndet soap or a soap made by saponification of oils and Potassium hydroxide?
What is the preservative you used? Some surfs may react differently than you'd expect.
You say you're new to soapmaking; I wonder where you got the information on the chemicals you mention.
Ungerol is more commonly known as SLeS; Sulfonic acid is mailnly used in toilet cleaners and other harsh detergents, almost always with the addition of salt(NaCl). It is a foam enhancer.
CMC (carboxymethylcellulose) works on two aspects, the first is to prevent deposition of heavy metals; the second is to disperse the dirt.
It makes soap flakes more pliable, but if it affects the viscosity of liquid soap....?
Anyhow I have the impression that you are talking about industrial household soap making (at home) rather then about cosmetic soap making. :)