Mechanical Gripping
Steel cylinders featuring parallel longitudinal ridges along their surface provide the necessary friction to draw flax slivers through the spinning frame. These fluted rollers clamp the slippery bast fibres against a rubber or synthetic top roller, preventing slippage during the drafting process. Because flax has a high tensile strength and is processed wet in linen mills, the rollers must exert uniform pressure across the entire nip line.
The grooved profile increases the contact surface area and guides the wet fibres along the path without damage. This structured surface prevents any uncontrolled drafting that would result in thin spots or yarn breaks, which improves the tensile properties of the spun yarn. In wet spinning, the metal composition of the rollers must resist corrosion from hot water and chemical additives used to soften the flax pectin.
Roving Control
Spinning operations rely on these rollers to maintain the velocity ratio between successive zones. When fluted rollers are kept clean, they distribute the drafting forces evenly across the roving. If the grooves become packed with pectin residue, the gripping action degrades, leading to draft faults.
Operators must clear the grooves regularly to avoid uneven yarn counts.
Surface Wear
Mill maintenance routines must address groove wear to ensure the longevity of the drafting system. Over time, the high pressure and abrasive action of flax fibres wear down the ridges, causing them to lose grip. Correcting this wear prevents tension fluctuations that cause structural defects in the final woven linen fabric.
