Syndets e shampoos em barra

activeᵢ      = massᵢ × active %ᵢ ÷ 100
actives %    = Σ activeᵢ ÷ total × 100
ratio        = Σ anionic actives ÷ Σ amphoteric actives   # by active, not by weight
water        = Σ(massᵢ × water %ᵢ ÷ 100)

• Active matter is the mass fraction of a raw material that is surfactant, as stated on the supplier’s technical data sheet. Active mass = raw-material mass × active % ÷ 100; the blend’s active matter is the sum of those over the total mass. — The active percentage belongs to a specific grade from a specific supplier. The same chemical is sold at several strengths, so the figure must come from the data sheet for the material actually used.
• Anionic and cationic surfactants carry opposite charges and associate into a neutral complex of low water solubility. Depending on the ratio this precipitates, thickens, or is used deliberately as the coacervate that deposits conditioning polymer on hair. — Whether the interaction is a fault or the point depends on the materials and the ratio. A cationic conditioning surfactant in an anionic shampoo bar reduces foam and can leave the bar grainy; a cationic polymer at low level is how conditioning shampoos work.
• Water carried into the batch by liquid surfactants and other ingredients, from each raw material’s stated water content: water = Σ(massᵢ × waterᵢ % ÷ 100). — A liquid surfactant’s non-active fraction is mostly but not entirely water; salt and preservative make up the rest. Use the data sheet’s water figure where it gives one.