Wet Spinning Trough Softening Physics and Linear Yarn Count Mechanics
Trough water at 70°C hydrolyzes middle lamella pectins to permit inter-fibre slippage, enabling high mechanical drafts down to fine linear yarn counts.
Deionization
Water Purity
Water purification represents the primary step in preparing treatment baths for scouring and bleaching bast fibres to prevent mineral deposits from discolouring the yarn. Through the process of deionization, mineral salts and dissolved ions that would otherwise react with soap or bleaching agents are removed from the water supply. Mill water systems rely on ion-exchange resins to capture calcium and magnesium cations before they can form insoluble precipitates on the flax surface.
This treatment ensures that the processed yarn retains its natural sheen and holds dyes uniformly during subsequent finishing stages. Without this intervention, heavy metal ions like iron would cause catalytic decomposition of hydrogen peroxide during bleaching, which structurally weakens the flax cellulose.
Processing Impact
Dyeing operations in linen spinning mills suffer when uncontrolled divalent metals interfere with anionic dyestuffs. Applying deionization to the wet-processing line prevents the formation of complex metallic aggregates that cause patchiness or streakiness in dyed woven linens. Uniform conductivity in the water supply allows the mill to reproduce shades across multiple yarn packages.
It also minimises the consumption of expensive chelating agents that would otherwise be needed to soften the water.
Treatment Limit
Industrial water systems must balance chemical purity against the operating costs of regenerative ion-exchange beds. While deionization yields water that is free of dissolved minerals, it does not remove organic matter or colloidal silica which can also foul yarn surfaces. Spinners must combine ion exchange with mechanical filtration and carbon beds to protect the yarn from all forms of process contamination.