We have been asked to duplicate a product on the market that uses ALS as the primary surfactant and Disodium Cocoamphodiacetate as the secondary. Total solids in the formula is 11% and it also has HEC and carbomer in the listing, as well as extracts and glycerin.
I admittedly don’t have much experience with ALS as it’s an older surfactant but have worked out some good ratios with the amphoteric for thickening... and even tried other amphoterics with good thickening while it is in process. I have also tried several ratios of HEC and carbomer to provide yield, because no matter what, batch thins down within a couple days, tops. It also happens if I leave carbomer out or reduce HEC to nothing.
Other items are less than 2% total - Glycerin, Propanediol, extracts. I have also tried several preservatives - Spectrastats, PE9010. It also happens if I leave the preservative out just to observe.
I have never had this happen to me, not even with sulfate free formulations.
Is something causing the ALS to thin? Process? Grade of raw materials (30% active ALS)? Anyone familiar working with ALS, I appreciate it!