Bill_Toge
Forum Replies Created
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@johnb pen and paper is by far the simplest, most robust and least corruptible way for manufacturers to record lot numbers, times of addition, etc. while they’re making batches on the plant
also, in the lab we keep records of our formulas and methods in notebooks as a rule, since it’s a 100% guaranteed way of preventing them from being wiped out when our network crashes, burns and suffers a total systems failure after being ‘upgraded’ by an ‘expert’ ‘consultant’
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it all depends on how much previous experience they have creating oxidative dyes, how much manpower they’ve assigned to your project, and how high you are on their priority list
if they don’t already have one to hand, creating a reasonably stable base for the colours could in itself take 6-8 weeks
the water test, leave it in the sun test etc. are way above and beyond our normal procedures; that said, assuming they carry these tests out on seleced representative variants rather than all 22, I can’t imagine this testing would take up a huge amount of time
when we create oxidative hair dyes, our routine testing procedure consists of determining whether or not the colour can be applied evenly and consistently, how easy it is to apply, how easy it is to wash out, and how stable the formula is in the final packaging
I don’t know anything about your chemist’s background, experience, available resources or anything else, but I will say now that if we got a project like this tomorrow I’d quote the turnaround time for initial samples as 2-3 months, and that’d be a conservative estimate
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where did you read that?
neither of these materials are toxic or carcinogenic (from the tags I’m guessing that by “PEG” you mean PEG-20 glyceryl triisostearate)
there are alternatives, but they’ll make your product look and feel completely different
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I’ve got a few years’ experience in that field
what kind of dyes are they, i.e. are they direct or oxidative?
also, if they’re oxidative, are they liquids or powders?
in either case, formulating and testing different shades in the lab is the longest part of the process
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@johnb it’s not phototoxic if you use a furanocoumarin-free grade
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it is inevitable that legislative institutes on two separate continents, who generally don’t work with each other and have very different processes, will come to different conclusions about certain things
also, the European Food Standards Agency (who have the final say on what is or isn’t acceptable in food) doesn’t believe artificial colorants can cause hyperactivity either, simply because there’s no scientific evidence for it whatsoever; despite the best efforts of consumer pressure groups, they are still perfectly legal in this country
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most of these should work well:
http://www.gracefruit.com/additives/actives/preservatives/
1% w/w = 1% of the whole formula, weight per weight (i.e. 1 g per 100 g)
can’t really comment on the formula itself without seeing it in the flesh; on paper though, many aspects of it are typical of water-based styling pastes (similar wax/emulsifier levels, similar types of waxes used, etc.) and there’s nothing obviously wrong with it
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@Kara90 phenoxyethanol-based preservatives like Euxyl PE9010 and Liquapar MEP work well in this type of product; 1% w/w is a good starting level
I’d avoid potassium sorbate, not least because there’s a very high chance it’ll destabilise the emulsion and cause the product to separate (salts and emulsions don’t mix)
@crisbaysauli it’s an O/W emulsion, how can it not be water-based??
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@chickenskin if you want to create this kind of emulsion consistently and successfully, you really need a proper rotor/stator homogeniser, and a stator head with a fine screen
the screen size is critical; when I first started trying to make W/O emulsions in the lab I had no end of trouble using a 6mm screen, but it became much easier, and my products stayed stable for much longer, after we bought and fitted a head with a 1mm screen
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@SpicyKimchi a good deal of it is down to the media parroting bad science as gospel (most notably, a deeply flawed British academic study that claimed parabens cause breast cancer)
where other, more reliable studies are concerned, the media, as always, has shown a tendency to read the results across into an inappropriate context or not understand the studies at all
political pressure groups like the EWG do the same thing; despite their general lack of scientific credibility, they do have a talent for convincing influential people and certain legislators (e.g. in California) that they’re in the right
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the powder usually has some water in it as a remnant from the manufacturing process
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creating W/O emulsions is very much a question of technique as well as materials - you want to form your emulsion at as low a temperature as possible (so there’s little variation in emulsifier solubility as it cools, hence, less chance of the water phase separating), but you also want to form it above the drop point of your oil phase, so the two phases are still fluid
you also need a high-shear mixer with a fine screen on the stator head, e.g. 1 mm; the larger the screen, the higher the probability of failure
on the formulation side, you can help improve stability by using hydrogenated castor oil to gel the oil phase, and a polymeric co-emulsifier (e.g. PEG-30 dipolyhydroxystearate; Cithrol DPHS from Croda, Dehymuls LE from BASF)
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@becsmith that’s a very common misconception; the nature of the emulsion depends entirely on the nature of the emulsifiers, and the relative volumes of the two phases is irrelevant
or, to put it another way: there is no way that the system can in itself ‘determine’ the relative volumes of the two phases
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if it’s a powder, it’s concentrated (typically 95% w/w)
if it’s a liquid, it’s a dilute solution (typically 27% w/w)
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given that it mixes quite freely with oils, I don’t think you could claim that it’s genuinely oil-free
not with a straight face, anyway
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anything which can cause irritation to the eye - in other words, nearly everything!
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the oil will kill your foam; you’re best off using a water soluble derivative like Olivem 300
also, which polysorbate are you using? there are several different ones, and they all have very different properties
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yes, that is the expected standard for e.g. ISO 22716 - on the grounds that anything recorded in pen is much harder to alter after the fact
usage of Tipp-Ex and similar correctors is also frowned upon, for the same reason
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the strong cleansing effect is most likely because you’re applying more of the product than you would with a bar soap, and also because alkaline surfactant-based products are very efficient cleaners (this is why most household cleaners are alkaline)
alkaline products also tend to dry out and irritate the skin more than acidic or neutral products, and the fact that shaving leaves the skin vulnerable will exacerbate any irritation
the pH of your final product will depend on the degree of saponification, which depends on the ratio of bases to fatty acids
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they probably do, that’s how magnetic nail polishes work
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yes, but which order have you mixed them in?
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it sounds like the gum hasn’t been properly dispersed/hydrated
what’s your method of manufacture?
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yeah, that sounds about par for the course
at least they didn’t approve it, pay for all the testing, commit to an order and then bottle out at the last minute because they want more tweaks, which seems to be a favourite tactic among our customers
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I should think the brands without a listed preservative have very low water content, i.e. not enough to sustain microbial growth - this was how we preserved most toothpastes at my last place
also, do you have a mixer that can be run under vacuum?
toothpastes are very prone to aeration, and air is almost impossible to remove from them once it’s trapped; mixing them under vacuum is the easiest way to avoid aeration
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there’s no practical way to mix them other than heating, mixing until all the solids are melted, then cooling them back down again
and they’re both hydrophobic, so the mixture won’t get water condensing on it