chemicalmatt
Forum Replies Created
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@Abdullah I would characterize this as adequate for the purpose. This is a low torque/low shear mixer but you can compensate with your homogenizer. Looks like a 0.75hp motor, ought to be OK for 50GL (200L). I like the stabilizer ring.
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@tecnico3vinia, Synthalen W600 (acrylates copolymer from 3V Sigma) will do the job nicely once neutralized. No more separation anxiety.
Ultrez-10 will crash when your surfactants are added. -
Your mathematics are correct. This will incease pH - guaranteed. Now there’s one way to find out the answer to your other question: try it and find out.
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@Rimbaud16 this is exactly what @ketchito describes: HDPE will soften, become less rigid and implode when many oils are stored inside. Castor Oil is notorious here too - just your (bad) luck. Switch to PET or BOPP to get out of this mess as suggested. Those appear to be the “soft touch” PE. If that is the case then there are “soft touch” BOPP bottles out there. BTW, this is especially acute in Chinese-made HDPE containers.
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The silicone situation is currently acute. Back-orders of 8 -10 weeks not unusual. Prices 200% mark-up not uncommon either. Try A&B Specialty Silicones in Illinois for an alternate source, they use Bluestar (NV) base materials and do a fine job at low costs.
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You are looking at a 50GL (200L) jacketed 316SS vessel with a 3-5hp gear-driven side-sweep agitator, plus a clamp-on or imbedded 1.5 - 3.0hp turbine mixer, preferably gear-drive but direct drive will do. A flush-fit bottom ball or gate valve and a Wilden M8 style double-diaphragm pump, some Tygon 1.5 in hose and 304 or 316SS sanitary fittings and you are on your way. Add some VF power invertors for controls for good measure. Assuming you are using low-pressure steam then a board rating of 25psi should be fine. Be advised the smaller kettles are the hardest to source on the used market. You may find many 1000 - 2000 GL kettles with that set-up all over the world, but a 25 - 100GL one? Be patient or have one fabricated.
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@Karo_lina This is too vague a question to answer effectively I am afraid. You’ll need to divulge the physical form, all constituents, outcome desired….much more than here. Be advised the term “active ingredients” is confusing for us veteran formulators. What activity is inferred?
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The paddle blade will approximate it if you are using a 600ml beaker. Honestly, counter-rotating a 316SS spatula with a strong right arm while the impellor (3-blade propeller in this catalog) runs at low speed works best for me. For larger batches use a KitchenAid blender at the lowest speed and the planetary attachment.
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Respectfully @Pharma, and I do respect you, your advice is unsound. Lactic acid/sodium lactate at pH 5.0 - 5.5 is by stoichiometric definition a buffer system and HAS been proven to maintain a urea-bearing system at a pH 5.0 - 5.5, the sweet spot for stability minimizing decomposition into ammonia and biuret. I’ve discovered in my research on rice starch that is was shown - as was potato starch - to stabilize urea solutions at that pH too. The research paper mentioned that as a side note not as a breakthrough idea. Upon reading this the little light bulb went off inside my head: another means of stabilizing urea, how cool is that!. Since then I’ve formulated 20% urea creams using the classic lactate buffer approach backed up by 3.0% rice starch and have seen nothing but success. @Graillotion is exhibiting the same romance with triethyl citrate that I have. I think I’ve enabled her and perhaps an intervention may be needed.
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Tromethamine (TRISamino from Angus Chemical) Use 80% of the amount calculated for TEA99%. Especially if you are formulating with stearic acid/TEA in lotions & creams.
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Trying to understand here…purpose? If this is a formula then the purpose of NaOH is to keep that carbonate from fizzing away as CO2.
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@Graillotion - kudos for the 411 on rice starch vs. silicone elastomers. You rock! @Perry :smiley: late night on ‘XRT no doubt, where the swingers and jogglers listen?
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@Stivtoo Inconsistent results: it would appear this is not a mixing/processing issue but a chemistry problem. Without knowing exact concentrations, I’ll posit that you are relying solely on the BTMS as emulsifier, the sorbitan stearate is only a builder, so you’ve reached the limit of oil load capacity. I’ll bet if you added 1.0% ceteareth-20 or ceteareth-25 to your oil phase this will come together, but that is only a guess. BTW, if you add BTMS directly into water phase at 80 - 85C, melt & mix, then the ceteareth-20, then the oil constituents in order you can have a one-pot mix.
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Silica! Works like a charm.
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MAtching that silicone elastomer’s sensorial property is a tough task. Other than the perflourethers that one is the best for “velvet”. If you can get hold of esters readily, try making an ester cascade effect with two or more. Cetyl palmitate/trimethylolpropane triisostearate/isononyl isononanoate for a start will provide a satiny cushion.
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Good for you @Mondonna, been there and done that myself many years back in the lean days. Without Amazon or Ebay I took a trip to the aquarium supply shop to get the lamp. Anyway, you want to test at 285 - 340nm for UV-B and far UV-A where most of the action is. Most blacklights emit nearer to 285nm if I remember.
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My choice would be cetyl alcohol alone in most formulations. Where you have GMS, stearic acid, sucrose stearate, etc. etc. mainly C18 moities, the cetearyl would behave better.
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I do not think CMIT/MIT will deposit, especially at 10ppm. Polyquats must form coacervates with the surfactants and those coacervates must bring with them only whatever they can associate with, dimethicone being the most dependable.
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@Abdullah That mass ratio is the ideal (“classic”) ratio for building cleansing products like shampoos and body washes. Floor cleaners, laundry detergents, hard surface cleaners are a different story. The “classic” viscosity builder is an alkanolamide (cocoamide DEA in the old days) at the “classic” ratio 4:2:1 anionic: amphoteric: alkanolamide. I’ve found substituting coacoamidopropylamine oxide or lauramidopropylamine oxide for the amide results in good viscosity & foam build but gains better deposition of the polyquaternium/dimethicone (or guar HPTC if you’re one of those people) upon rinsing.
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@ketchito is onto the solution here, in two parts, but let me add some clarification. Cationic emulsions such as yours @Stivtoo require low shear and a long cooling gradient to form lamellar liquid crystal matrices. If the only tool you have is a homogenizer, you will see inconsistent results like you have, and not much to do about it. I would apply the homogenizer for only 5 minutes (@Abdullah is right, 30 minutes unnecessary) at 75C, then begin cooling SLOWLY while mixing with a low shear Lightnin’ mixer at low-moderate speed. Once you get to 40 -45C and thickened you can zap it again with the homogenizer to smooth out even more. @Gordof is correct here: what you see is inversion, your emulsion doesn’t know what it wants to be. Slow cool at low shear and it will be consistent each time.
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There are different ratios of C16:C18 for these. The 30:70 is more generally used but I’ve always preferred the 50:50 material finding the extra cetyl provides easier lamellar liquid crystal formation. Proctor & Gamble figured all this out many years ago when they had the fatty alcohol market homogenized, and P&G still makes and uses a boatload of material every day.
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Agree with @Paprik here @GeorgeBenson : charge density, pKa and ratio is not the main consideration. The mass ratio is however, and the “classic” ratio of anionic: amphoteric is 2:1 based on solids. If you are formulating a conditioning shampoo with cationic polymers, then increase ampho slightly and never use a highly charged anionic (i.e. sulfates, phosphates). Another helpful hint from an Old School formulator (that would be moi): use an amine oxide as builder and your dilution-deposition is even better.
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50C is very high as @Microformulation (Mark) says, @MsCheddar. I’ve been told that 50C temp for accelerated stability arises from an ASTM method used in pharma and unfortunately adapted by personal care formulators. Mark is right, 40C is fine and I usually run at 43C / 65% RH, no higher.
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Upon rinsing the lather from hair, thus the term “dilution-deposition” from the coacervate system.
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@GeorgeBenson the viscosity will peak at pH 6.5 - 7.0, the yield value (suspension factor) will be at maximum in that range too. This is a 30% solution so depending on what surfactants or electrolytes you have in the formula, and final viscosity, start at 4.00% (1.20% solids) and see what happens. It works best to add to water first, then add your surfactants, any alkali you may be using, then adjust pH at end. If you have a high pH surfactant system (decyl glucoside comes to mind) you may drop in later, but that is not advised. Also, like all acrylic rheology modifiers, go easy on the amphoteric surfactants. These are Zwitterions. 10% CAPB (30% soln.) will be fine.