Home Cosmetic Science Talk Formulating Very small scale powder mixing machine

  • Very small scale powder mixing machine

    Posted by docsimple on October 4, 2017 at 8:05 am

    I am working in the 10-30 gram range right now and I’m looking for a better way than the hand held mortar and pestle. A couple mineral foundations looked great until applied. The colors were still streaking after i had spent a few minutes working it.

    This is unacceptable! I demand the highest level of homogenization, and also I’m lazy. I want to be able to get fully mixed powders but the homogenizing mixer I bought requires liquid. This will work fine for a very many things but for the straight minerals I want to be able to create samples using a minimum of raw materials. Clearly this is a short term goal to get formulations prior to production, so I am trying to find the least expensive way to go about this. A few hundred would be ok if I know i could thoroughly mix 10 grams. Seems silly but I want to be able to run dozens of test samples. I’d rather buy a mixer that works for this than buy a ton of raw materials I may not end up moving forward with. I have been scouring the internet but I cant find something appropriate for this small a scale with powders.

    Maybe I’m just showing my lack of experience here, but is there a tool for this? The kitchen Items I saw looked inappropriate and the overhead mixers would be for larger quantities. I saw the IKA turret but the vials are single use…. that would add up quick! If they had a reusable head it would be ideal. Anyway, I’m praying someone else has had this issue and is willing to share an answer :)

    Bobzchemist replied 6 years, 8 months ago 6 Members · 16 Replies
  • 16 Replies
  • Bobzchemist

    Member
    October 4, 2017 at 4:47 pm
  • docsimple

    Member
    December 12, 2017 at 10:44 pm

    wow, just saw this. Talk about not responding :)

    all valid ideas. I’m super cheap and like to make trials on the scale of 1-10 grams. I hate waste. Would this one work on that scale? It seems to me the solids would just end up caked on the bootom:

    https://www.amazon.com/KitchenAid-BCG211OB-Blade-Coffee-Grinder/dp/B00CT9XZMA/ref=lp_14092831_1_11?s=kitchen&ie=UTF8&qid=1485433335&sr=1-11

    realistically I’m dreaming of this:
    http://exaktusa.com/dispersion-equipment/basic-models/trm-basic-exakt-50i/

    but that is way down the line!

  • Bobzchemist

    Member
    December 13, 2017 at 7:21 pm
  • em88

    Member
    December 14, 2017 at 7:46 am

    Use sieves! Blending at high speed will not lead to homogenization and of course the mortar will not do the job properly. You have to put the powders in a specific order based on density and quantity to achieve the good mix. 
    As I said, use a proper sieve for the particle size of the powders you have and sieve the powders several times. 

  • Bill_Toge

    Member
    December 15, 2017 at 12:29 am

    in the lab we use a miniature coffee grinder (bought from the local supermarket for the princely sum of £10) for high-shear airtight mixing of powders - we don’t use it for colour cosmetics, though, so there’s no guarantee it’ll grind the pigments effectively

  • belassi

    Member
    December 15, 2017 at 4:51 am

    What em88 said. I tried to use a coffee grinder to reduce oatmeal to use in a shampoo. It is impossible to get all the particles the same size. You have to use sieves. (In the end I gave up and just hydrolysed it, that fixed that.)

  • jeremien

    Member
    December 15, 2017 at 10:43 am

    You can ask to Santa Claus the Ika Tube, there is turrax unit tubes available … 500$ the basic version 

  • em88

    Member
    December 15, 2017 at 2:23 pm

    A small lab scale V-blender would be a good choice for powder mixing/blending but you are looking for a very small quantity of powder to mix. 10-30 g of powder should take about 5-10 min to mix if you use sieves. 
    Forget about the mortar. While you use the mortar, in the same time you reduce the particle size of the powder. 

  • Bobzchemist

    Member
    December 16, 2017 at 12:30 am

    I’m going to point out something that you probably don’t want to hear.

    In the 20 or so years I worked in commercial color cosmetics R&D/manufacturing, no one ever made less than a 50-gram batch, and that was only in special circumstances. 99% of the work was done in 100-gram batches or larger.

    Why? Because making smaller batches distorts the processing so badly that it’s almost impossible to scale up any batches smaller than 50 grams. On top of that, for batches less than 100 grams, you need to weigh your colorants to three places (0.001 grams), which is a pain in the butt.

    If you never plan on making any batches larger than 30 grams, or if you don’t care about batch-to-batch repeatability, this won’t be an issue for you. But, if you are planning on eventually making larger batches, 10-30 gram batches are just wasting your time - you will have to repeat the whole color-matching process anyway when you make a larger batch.

  • docsimple

    Member
    January 20, 2018 at 4:42 am

    I looked at that IKA drive. Too much for the tubes but would work great. I have a homogenizing mixer but I’m not sure I can use dry material with the mixing blades.

    Bob, I’m not doing color in these formulations. I like to make the product and test physical characteristics until I like it and then scale updo colors.

    In my 10 years as an R&D formulation chemist my test runs ran from the 10’s of lbs to the 1000’s. Fortunately that wasn’t my money. Even a successful test costs $$

    This is my first time working with cosmetics. I get the methodology but I find I am re-inventing the wheel quite often. Every other field I started with a mentor, quite grateful for this site!

  • em88

    Member
    January 20, 2018 at 9:18 am

     I have a homogenizing mixer but I’m not sure I can use dry material with the mixing blades.
    What kind of mixer do you have?
    Powder blenders are based on mixing powders by making them flow. If your powders do not have good flowability, mixing them is difficult. The best way to blend small quantities of powders with poor flowability is by using sieves. 

    Just curious, what wheel are you re-inventing? It is most likely someone else did it before you. 🙂

  • docsimple

    Member
    January 20, 2018 at 8:02 pm

    I’m making all few different products but trying to start on hand creams and liquid foundations now. This thread was originally based on blending materials for pressed foundations.

    Polytron 1600e
    http://www.speciation.net/Database/Instruments/Kinematica-AG/POLYTRON-PT-1600-E-economical-benchtop-homogenizer-;i2214

  • Bobzchemist

    Member
    January 21, 2018 at 1:33 am

    The major point I was trying to make applies to color and any other product. In my experience, scale-ups start to fail when there’s too much difference between steps.  Usually, the geometry/rheology/energy input of the systems is too far from being similar to scale-ups when I start with batches that are too small, below 100 grams or so.

  • belassi

    Member
    January 21, 2018 at 5:18 am

    What minimum would you recommend, Bob? I normally run experiments at 500g for a first attempt, and 1Kg when I think it’s about right. I try to make a balance between wasting raws and getting reasonable accuracy.

  • em88

    Member
    January 22, 2018 at 8:27 am

    @Belassi, that is very reasonable. I do start with 200g first attempts and than increase to 500g, 1-3kg, 30kg and so on 

  • Bobzchemist

    Member
    January 23, 2018 at 2:56 am

    200g or 500g is fine, depending on the formula. 100g is iffy, and less than 100, at least for me, creates problems even if only scaling up to 500g

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