Article by: Perry Romanowski

This is the next in our series about all the equipment you need to set up a cosmetic lab. The first was about containers and the second about weighing equipment.  This article will be about the equipment you need to create your batches. The main piece of equipment is a lab mixer. 

Factors influencing mixer type

Your mixer is one of your most important pieces of equipment when setting up a cosmetic product lab. If you have done any searching on the Internet you’ve probably gotten the advice that you can use a hand mixer or immersion blender. While this may be true, this is not the proper way to make cosmetic products. Immersion blenders are fine enough for the kitchen but to make working, stable formulas you are going to need proper mixing equipment.

Here are a few things to consider when choosing a proper mixer.

What types of products will you be making?

There are numerous types of cosmetic products that you can make from liquids to gels to emulsions. You want to have a mixer that is versatile enough to handle as many different types of products as you’ll make.  Some things to consider.

Product viscosity. If you are going to be making very thick products like gels and creams you’ll need a mixer that has enough torque to move the solution. Stick blenders and magnetic stirrers will just not work for most cosmetic formula applications.

Formula sample size — One of the things I see people doing wrong is that they make batches that are too small. Even if you are going to make a product for yourself a 100 g batch is just too small for most purposes. This is because it is too difficult to weigh to the right accuracy but more importantly, it is too difficult to get proper mixing without incorporating too much air. Air in batches is not good. Laboratory overhead mixers are designed to process up to a certain amount, usually specified in liters. Examples: 35, 100, 150 and 200 liters. Since viscosity issues enter the equation in direct proportion to volume both must be considered when picking a mixer.

For most cosmetic labs ideally, you’ll have two types of mixers.  One that works for batch sizes of 5000g or less and one that works for batches up to 5 or 10 gallons.

Mixing speed.  The maximum mixing speed your stirrer can achieve is another thing to consider when picking a mixer. You want to have a device that can start slow (to avoid splashing contents all over the place). Then you can adjust the mixing speed after it starts.  A variable mixer speed control is important. Examples are stirrers operating from 50 to 500 RPM, from 40 to 2,000 RPM and 20 to 700 RPM. This should be adequate for most cosmetic product labs.

Other mixer features. There are a number of fancy mixer features you can get such as programming time and schedules plus digital RPM displays. Related to stirring time is an automatic shutdown if the stirrer motor overheats or is subjected to an overload due to viscosity increases. They have mixers with programmable control panels that allow you to adjust the torque, mixing speeds, and even keep digital or printed records.  None of this is of much use to a cosmetic formulator. It may be nice to have if you can afford it, but it’s not really necessary.

Mixers for Cosmetic Products

We’ve had a number of good discussions about cosmetic mixers in our forum and I would encourage you to go read through those. This will give you practical information about mixers which people currently use in their labs.

Industrial mixer for small scale formulator

Laboratory equipment set up

I mentioned earlier that some people use kitchen equipment to make their cosmetics. This may be fine enough for DIYers and hobbiests but this is not the right equipment to use in a professional cosmetic lab. Even a hobbiest would be better served by getting proper equipment and avoiding things like stick blender, immersion blender, food processors, blenders, and hand mixers. Making cosmetics might be like cooking but it isn’t exactly like cooking.

Overhead mixers

Click for more info

The best type of mixer to get for a cosmetic lab is a center-stir, overhead mixer. An example is the Scilogex mixer shown in the picture to the right.

This mixer has all the specifications that you would need for a lab and you’ll be able to make a wide variety of types of products. Although this type of mixer will only be suitable for small to medium sized lab batches. If you want to make more than 5000g batches, you’ll need a more heavy-duty mixer. For a less expensive (but less durable / versatile option) you might try the Mophorn Overhead stirrer,

If you are looking to make small sized production batches then you’ll want something larger with more torque. Something like an open-drum mixer would work.

Homogenizers

While an overhead, center stir mixer will work for most formulas, if you are making larger scale emulsions you may want to invest in a homogenizer. Something like this homogenizer would work for a lab. The reason you need a homogenizer is because when making emulsions you need to create tiny droplets of the internal phase. The more mixing, the more energy, and the smaller particles you can achieve. The key is that you do not want to incorporate any air into your emulsion however. This is why a homogenizer is superior to a stick blender.

Mixer blades, paddles and impellers

The mixer motor is only one aspect of your mixing setup. The other important piece is the mixer blade also known as the impeller. We’ve written an entire article in factors to consider when picking a blade and I encourage you to go see the cosmetic stirrer recommendations.  When I formulate I mostly use a paddle mixer like the one in the picture to the right. But propeller mixers, X-mixers and spatula blades can all work for different types of formulas.

Other mixing equipment

In addition to the mixer motor and impeller you’ll also need various equipment like the following…

  • Stands to hold the mixer above the mixing container
  • Clamps to secure the mixer (and container) to the stand
  • Platform to set the container. This could just be the counter, top of a hotplate, or water bath.

Getting a mixer is a key piece of equipment to outfit your cosmetic lab. You may be tempted to skimp here to save money but don’t do it. You will be using this mixer often and you don’t want to get something you have to replace every few months. Price does make a difference.  However, sometimes you can think outside the box and save a good amount of money. For example, in our forum one of our formulators listed a whole DIY cosmetic mixer project where you can make a decent mixer for a fraction of the cost. Another option is to look to a different industry. Sometimes lab equipment has the same specs but costs much more.  Not sure why, it’s just marketing I guess.  But here is an excellent mixer (called a drill press) you can get for a good price.
Whatever you choose, remember if you want to be a professional, you should get professional equipment.

What mixer do you use? Leave a comment below.

In the next part of this lab set-up series, we’ll cover heating and cooling equipment.

About the Author

Perry Romanowski

Perry has been formulating cosmetic products and inventing solutions to solve consumer problems since the early 1990’s. Additionally, he has written and edited numerous articles and books, taught continuing education classes for industry scientists, and developed successful websites. His latest book is Beginning Cosmetic Chemistry 3rd Edition published by Allured.

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