Bill_Toge
Forum Replies Created
-
also, you’ll need a vacuum-sealed mixer as it’s very prone to aeration
-
@Doreen81 it has a boiling point of 247 °C at atmospheric pressure, so it’s not particularly volatile
-
that’d be because Alconox is anionic; a dilute solution of CTAC in hot water will do a better job
-
phenoxyethanol and benzyl alcohol are water-soluble, though sparingly so - very little of either will partition into the oil phase, so the answer is put them in the water phase
substantially water-soluble ethoxylated surfactants, e.g. SLES, can reduce the activity of some preservatives; they won’t deactivate them outright
regaring packaging, I’ve never seen any of these phenomena occur in practise; this appears to be one of those urban myths that has somehow become received wisdom despite not having a shred of evidence to support it
-
if you want higher viscosity you’d be best off changing your emulsifier system, since Tween 80 and Span 80 are both liquids at room temperature: try using Tween 60 and Span 60 instead
-
from my experience the variation in creams with mixed bases is most likely due to incomplete soap formation, and/or formation of metastable phases that eventually transition into the most thermodynamically stable phase over time
if you add the bases one by one rather than simultaneously, and adjust your process accordingly, the soaps can be formed in a more controlled fashion, and you’ll get much more consistent results
-
regarding point 6: while it is true that Annex II of the Cosmetic Product Regulations has over 1,300 entries, the vast majority have not been ‘banned’ as such, rather, they have been prohibited ever since there has been a unified regulation across the whole EEC (as it was back in 1976), and many are things you’d never use in cosmetics anyway
in some cases the prohibition has in effect restricted the usage of certain substances to medicines and medicines alone, as medicines have more rigorous requirements for safety testing
I would estimate the actual amount banned due to health concerns is somewhere between a few dozen and maybe 100 at most
even so, there is a system in place in which any health concerns must
reviewed by a scientific committee to the European Parliament before any
legislative action is taken, and they need very rigorous standards of
scientific proof before drawing a conclusion, making them a very effective anti-lobbying measure (see here for a selection of recent reports)still, post-normal science / propaganda cares nothing for hard facts - let’s hope it doesn’t spread into other mainstream journals
-
@zaidjeber not in Europe; it’s been banned from cosmetics there since 1979
-
@em88 what else do you have in the oil phase?
-
as challenge testing requires the services of a third-party microbiology lab, we tend to start the challenge test at 8 weeks; that way, we can be reasonably confident the product is stable before committing to (and paying for) the test
if the product type is genuinely unprecedented, and we have no stability records for anything similar, we hold off until 12 or 16 weeks
-
@Perry actually no, they didn’t; not least because the Advertising Standards Agency is very strict when it comes to dealing with transparently false claims, so to the best of my knowledge, there are no successful UK brands which make those claims
-
or better still, don’t claim things that are blatantly false
we’ve had customers who wanted “chemical free” products, and we’ve had to explain exactly why it’s not possible to have a genuinely chemical-free product in either the scientific or the legal sense
-
@Chemist5000 what is flowology? (apart from a linguistic abomination which botches together Germanic and classical Greek)
-
@Bobzchemist I’ve found gellan gum works well for this; it creates solutions that are immobile at rest but thin very readily under shear
-
@DRBOB even though it makes no sense whatsoever, and directly contradicts all forms of orthodox science and the 10 years of experience I have at the bench?
-
also: cryptography, which comes into play when the customer complains about the product and uses terms in a manner at odds with their generally recognised definition, so you don’t know what they’re talking about
e.g. when they use ‘pink’ to mean ‘undercooked / under-processed’ rather than ‘tinted red/purple’
-
@DRBOB is that 50% w/w, 50% w/v, 50% v/v or 50 mol%?
I’ve heard that tale repeated a number of times, but nobody repeating it has ever clarified which units they’re working in, or exactly why it works the way it claim it does
-
if you’re talking about physically creating a product from the raw materials, materials science, thermodynamics and fluid dynamics would be the main ones
in some cases (oxidative hair dyes, exothermic perms, soaps,
old-fashioned shaving creams) ‘simple’ chemistry takes one of the front
seats, in the form of acid/base neutralisation, saponification, or oxidative
polymerisationthe choice of packaging involves mechanical engineering and fluid dynamics
when the product physically interacts with the body, that’s mainly biochemistry and psychology
and when the product is manufactured and filled, that involves chemical engineering
so in short, quite a lot!
-
@ultraduy try finding the drop point of the oil phase, and form your emulsion 5-10°C above that
in general, unless you have a very high shear mixer (e.g. colloid mill or Ultra Turrax), 85°C is too high for W/O emulsions, as the water solubility of the emulsifier will decrease significantly as it cools, leading to the Ostwald ripening you’ve observed
if you have a very high shear mixer, the water droplets are much smaller, and are more firmly attached to the emulsion interface, reducing the chance of separation
@DRBOB how can it invert with no high-HLB emulsifier present? (without violating the laws of physics, that is)
-
can’t speak from personal experience, but the most foolproof way appears to be electrodialysis, as outlined in US patent 3616385
-
the watery feeling is most likely Ostwald ripening (water phase becoming physically detached from the emulsion); what temperature did you form the emulsion at, and what equipment did you use to form it?
-
@Lainee I meant what viscosity is it (it’ll be on the specification)
-
@DRBOB@VERDIENT.BIZ if it’s the same kind of “universal container” we buy (and it does look extremely similar), it’ll be moulded polystyrene
-
this is assuming of course the coffee beans in question come from C. Arabica; depending on the source, they could also be from C. Robusta
-
what grade of HEC are you using?