Surfactant Group
Chemical reaction products resulting from the addition of ethylene oxide to long-chain fatty alcohols serve as non-ionic surface active agents. Industry practitioners use ethoxylated fatty alcohols as emulsifiers, wetting agents, detergents, and dispersants throughout the scouring and dyeing stages. The balance between the hydrophobic carbon chain and the hydrophilic ethylene oxide chain determines the specific application.
Wetting Mechanism
Rapid displacement of air from the interstices of a fabric roll allows for uniform penetration of the dye liquor. These ethoxylated fatty alcohols reduce the surface tension of water, facilitating the movement of chemicals into the core of natural fibres. Low-foaming variants are necessary for high-turbulence jet dyeing machines to prevent foam-related mechanical issues.
The efficiency of the wetting process directly affects the levelness of the final shade.
Removal Performance
Effective detergency relies on the ability of these molecules to lift oils, waxes, and spinning lubricants from the yarn. Once the impurities are emulsified, the surfactant keeps them suspended in the wash bath to prevent redeposition. This cleaning action is verified by measuring the residual oil content after the scouring cycle.
Proper rinsing ensures that no surfactant residue remains to interfere with subsequent water-repellent treatments.
Regulatory Status
Compliance with environmental standards like REACH requires monitoring the biodegradation of these surfactants. While ethoxylated fatty alcohols are more biodegradable than older alkylphenol ethoxylates, specific limits still apply to their discharge. Mills must select ethoxylation levels that meet both performance needs and local effluent toxicity requirements.
Monitoring ensures that the surfactants do not harm aquatic life after leaving the treatment plant.
