Forum Replies Created

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  • Bobzchemist

    Member
    May 6, 2015 at 3:46 pm in reply to: Sugar Scrub

    In formulas like this, there usually aren’t stabilizers/suspending ingredients. You just have to put in enough sugar that there’s no room for it to fall to the bottom. The larger the sugar crystals are, the easier this is.

  • Bobzchemist

    Member
    May 6, 2015 at 3:42 pm in reply to: issues with solid sunscreen stick

    It does, actually. Too many home crafters feel that they should be able to throw together a sunscreen just as easily as they can make salad dressing.

    So, I will return to your questions and hopefully be more helpful. It takes a lot of shear force to properly disperse zinc oxide, so if you can’t afford an expensive high-shear mixer, your best bet will be to use a pre-dispersed mixture. Generally speaking, using a mixture will not give you much, if any, room for other oils. You will have to melt your waxes and butters, mix, and then add the ZnO dispersion. This should get rid of your yellowing problem.
    The funnel-shaped hole in the stick can be gotten rid of by one of two methods - either fill from the back (which is how lipsticks are poured) or fill from the front, but pour in enough extra material that you can cut off the excess and have a perfectly smooth surface.
  • Bobzchemist

    Member
    May 6, 2015 at 3:31 pm in reply to: Formaldehyde concentration

    There is no formal limit on formaldehyde set by the FDA, as far as I know. The general rule about selling a safe product applies, which means that you’d need to do extensive safety testing to prove the safety of anything over the 0.2% level set by the CIR.

    The State of California has effectively banned this ingredient (Prop 65).
  • Bobzchemist

    Member
    May 6, 2015 at 1:04 am in reply to: issues with solid sunscreen stick

    In the US, sunscreens are OTC pharmaceuticals. As a professional, it would be irresponsible of me to help you do this (outside of a FDA registered facility), or even recommend that you do so on your own.

  • Bobzchemist

    Member
    May 5, 2015 at 10:03 pm in reply to: issues with solid sunscreen stick

    The zinc oxide is a pigment, so it isn’t soluble - the best you can do is a suspension. The yellowing in some areas is a sign that you do not have a uniform suspension. As a result, the SPF value of your stick will be quite variable, so I wouldn’t count on it delivering sun protection, if I were you.

    The hole in the center is just physics - wax and wax blends shrink as they cool. There is no way to avoid it.
  • Bobzchemist

    Member
    May 5, 2015 at 6:05 pm in reply to: Color matching

    There is one other method to evaluate color - although this is for mass only - put three drops on a microscope slide, cover with a second slide, and gently squeeze the two slides together, then evaluate visually.

    The drawdown method comes closer to the skin results. You don’t need a fancy applicator (although they do help with consistent drawdowns) Use a wide, flexible, stainless steel spatula for your drawdown, and do it on a Leneta drawdown card. http://www.leneta.com/index.html 
    Remember - standard always goes in the middle, the batch you’re adjusting goes on either side.
  • Bobzchemist

    Member
    May 5, 2015 at 3:12 pm in reply to: Konjac root powder

    @belassi, if you really have powdered roots, maybe you need to find out how the Glucomannan is extracted from the root?

  • Bobzchemist

    Member
    May 4, 2015 at 1:21 pm in reply to: Emulsion or binder for soap shavings to liquid soap?

    OK then my first question is - How much scrap material are we talking about? Secondly - what is the formulation for the soap that you  have shavings from? Thirdly - what are you planning to do with the liquid soap, i.e. is it for personal use or do you want to sell it? And lastly - what sort of processing equipment do you have available to you?

  • Bobzchemist

    Member
    May 4, 2015 at 1:30 am in reply to: Emulsion or binder for soap shavings to liquid soap?

    I don’t think anyone here can recommend doing this. If you need liquid soap, why not make it from scratch?

  • Bobzchemist

    Member
    May 1, 2015 at 8:48 pm in reply to: Long Term Heat Stability

    Sounds to me like you’re getting a good portion of your viscosity from the crystalline wax network formed by the cetearyl/cetyl, which typically breaks down at 40C. Your only option to fix this, aside from increasing the cetyl alcohol, would be to increase your viscosity through another mechanism, using gums, for example.

    Viscosity from cetearyl/cetyl is built up the most by slow cooling, which allows the wax crystals the maximum amount of time to grow. It is minimized by rapid cooling, so once you build up your viscosity with other ingredients, you’ll be able to get similar viscosities at RT and at 40C by cooling your batch as rapidly as possible.
  • Bobzchemist

    Member
    May 1, 2015 at 7:26 pm in reply to: W/O/W Double Emulsion for slow fragrance/extracts release

    You can search for a liquid crystal emulsifier and find more, but these are common:

    Olivem 1000 by itself or plus Olivem® VS Feel;  Montanov 68; Arlacel™ LC

    Also look at Pemulen for another way to emulsify
  • Bobzchemist

    Member
    May 1, 2015 at 7:10 pm in reply to: Help! Starting my own line. Canada? Chemist????
  • Bobzchemist

    Member
    May 1, 2015 at 5:25 pm in reply to: Help! Starting my own line. Canada? Chemist????

    HAPPI puts out a yearly directory.

    There are several companies in BC, but none in Alberta, sorry.
  • Bobzchemist

    Member
    April 30, 2015 at 6:20 pm in reply to: Konjac root powder

    Perhaps something like this would be a better choice for experimenting with Konjac?

  • Bobzchemist

    Member
    April 30, 2015 at 6:06 pm in reply to: Konjac root powder

    First, get a water content from a couple of grams, then see if it’s flammable. That way, you’ll at least have some ammunition when you talk to the supplier. 

  • Bobzchemist

    Member
    April 30, 2015 at 1:46 pm in reply to: Should aloe vera be banned?

    @Bill_Toge, you’re probably right - but this time I have more ammunition to call them on their hypocrisy. Also, the California Prop. 65 regulations are rigid and inflexible - there is likely no way to avoid any aloe-containing product eventually having to carry a Prop 65 warning.

  • Bobzchemist

    Member
    April 30, 2015 at 1:41 pm in reply to: W/O/W Double Emulsion for slow fragrance/extracts release

    For a multiple emulsion, the emulsifier layers around the W/O droplets (discontinuous phase) have to be strong enough to keep the water in them from merging with the water of the continuous phase. As @Iaskedbetter said, none of the Tween range will be able to do this.

    This is a very, very complicated and difficult way to get a timed-release fragrance product. Have you looked at other emulsion systems first and already determined that they are unsuitable? LC emulsions would probably do what you need with far fewer hassles.
  • Bobzchemist

    Member
    April 29, 2015 at 10:14 pm in reply to: Should aloe vera be banned?

    Our point is that there have been a number of ingredients that are not available for use in cosmetics any longer due SOLELY to data from mice. In some of those cases there has been  explicit evidence that the material does not cause cancer to humans - but the materials were banned/forced off the market anyway. In fact, in one of those incidents, the material in question was actually a component of human skin - but mouse carcinogenicity was enough to both drive it out of cosmetics and off the market, and also to prompt many lawsuits against manufacturers that were using it. I believe some companies even instituted voluntary product recalls.

    So, the interesting part is going to be watching if there is the same sort of witch-hunt and media frenzy about an ingredient that is universally beloved by the “natural is always and forever better” crowd. 
  • Bobzchemist

    Member
    April 29, 2015 at 6:11 pm in reply to: Should aloe vera be banned?

    True, but there have been a number of cosmetic raw materials banned, or effectively banned, just from a hint that they might be carcinogenic in any way. It will be interesting to see what happens here.

  • Bobzchemist

    Member
    April 29, 2015 at 5:54 pm in reply to: Should aloe vera be banned?

    Wow - this is going to be a dilemma for the “natural is always safe and better” crowd.

  • Bobzchemist

    Member
    April 28, 2015 at 2:32 pm in reply to: Natural Replacement for Butylene Glycol & Propylene Glycol

    Also, ADM makes a completely “natural” (i.e. 100% vegetable derived feedstock) Propylene Glycol.

  • Bobzchemist

    Member
    April 27, 2015 at 11:18 pm in reply to: Natural Replacement for Butylene Glycol & Propylene Glycol

    Agree with Zemea as the best alternative.

    How do you define “natural”?
    Do you know what it means for something to be called “organic” in this context?
  • Bobzchemist

    Member
    April 27, 2015 at 1:47 pm in reply to: Summer Work Experience

    OK, I asked you to connect, and I see you accepted.

    I think the first thing you need to do is join the LinkedIn group Society of Cosmetic Scientists:
    which is primarily a UK/EU group, but has members from all over.
    When you can, post your internship request there.

    The next thing to do is to join the LinkedIn group Society of Cosmetic Chemists:
    which is primarily a US group, but also has members from all over.
    When you can, post your internship request there also.

    Lastly, go over to http://www.scs.org.uk/ and apply for membership, or just check on their job vacancies.

    The growing trend in the US is that summer work for college students has pretty much diminished to unskilled positions. Spots are still available in labs, but they are largely unpaid internships.
  • Bobzchemist

    Member
    April 27, 2015 at 4:22 am in reply to: Summer Work Experience

    Are you on LinkedIn?

  • Bobzchemist

    Member
    April 24, 2015 at 3:08 pm in reply to: Natural Private Label Companies

    First, you are going to need to define what “natural” means to you.

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