Fluid Exchange
Continuous replenishment of hot water in the wet spinning process ensures that the chemical composition and temperature of the treatment bath remain stable over long production shifts. Implementing a counter current trough refresh involves introducing fresh water at the exit end of the spinning trough and drawing contaminated water out from the rove entry side. This movement runs opposite to the path of the advancing flax rove, ensuring that the cleanest water contacts the cleanest fibres.
The rate of this exchange is matched to the throughput speed of the spinning frame.
Dissolution Gradient
Pectins and hemicelluloses dissolved from the flax rove during wetting are steadily moved towards the waste outlet by the directional flow of the fresh water. By avoiding a build up of these sticky compounds, counter current trough refresh prevents the re-deposition of organic residues onto the surface of the rove before it passes to the drawing rollers. This continuous rinse action maintains a low concentration of soluble impurities throughout the active bath.
Yarn quality is preserved because the rove is consistently processed in relatively pure liquid, which minimizes the friction and breakage of the wet fibres.
Thermal Control
Heat distribution within the wetting trough is stabilized by the counter current movement of the supply stream. Freshly heated water enters where the rove exits, maintaining the maximum temperature at the point where the pectins must be most pliable for the drafting rollers. Cold spots are eliminated.
High water flow rates are restricted to maintain thermal efficiency.
