Evaluation of calcium oxalate deposition on different fabrics under different sodium oxalate-based detergent formulations

The builder is an important ingredient in detergents. Sodium oxalate is a good non-phosphate detergent builder, which has good calcium-removing properties and good wash performance in detergents. However, sodium oxalate-based detergent formulations face a tricky problem of “incrustation” on fabrics due to calcium oxalate deposition. If sodium oxalate is used in commercial detergents, then “incrustation” must be solved. In this study, we examined the effect of fabric type, anionic surfactant, polymer, and temperature on incrustation and soil redeposition (“secondary” washing effect) of a sodium oxalate-based detergent. The results showed that both the anionic surfactant and polymer influenced the deposition of calcium oxalate on fabrics. Overall, the amount of calcium oxalate deposition followed the order polyamide < polyester < cotton with the same formulation. Finally, good secondary washing effects (low ash deposition and high whiteness retention) formulations were selected by cumulative washing. The formulation of methyl ester sulfonate (MES)-sodium carboxymethyl cellulose (CMC), MES-polyvinyl pyrrolidone, and alcohol ether sulfate (AES)-CMC had better secondary effects, and the optimal combination of the 12 formulations was AES-CMC.

The structure and properties of wool treated with a reversed-phase microemulsion containing aqueous alkali

In order to limit modification to the surface of wool fibers and decrease pollution caused by conventional chemical treatments using chlorine, a water-in-oil-type reversed-phase microemulsion with decamethylcyclopentasiloxane as the external phase was prepared containing very small amounts of an aqueous solution of alkali. The edges of the wool cuticle scales were modified by the alkali in aqueous solution contained in the reversed-phase microemulsion. The external phase decamethylcyclopentasiloxane can be recycled after application. In this paper, the solubility of water in the reversed-phase microemulsion and its stability were first studied and then it was applied in the treatment of wool. The results showed that surfactant sodium alcohol ether sulfate/NaOH aqueous solution was quite stable. Felting shrinkage of treated wool was reduced and the initial dyeing speed was higher than that for untreated wool. The corroded scales of treated wool were observed by scanning electron microscopy and the bromine Allwörden reaction with bromine water was reduced or eliminated after treatment. This adsorbable organohalogen-free modification should be useful in improving the manufacturing properties of wool, such as hydrophilicity, and as a pretreatment for wool printing.