Calculating Mechanical Splay Angles and Harness Friction Coefficients in High Speed Looms
Optimize harness splay angles under 12 degrees and use ceramic mail eyes to reduce dynamic friction below 0.15 for maximum loom speed and efficiency.
Reed Width Geometry
Weaving Width
Mechanical adjustments in the loom determine the width of the warp yarn as it passes through the reed. The reed width geometry governs the spacing of the warp yarns before the weft yarn is inserted, establishing the starting width of the raw fabric. Fabric shrinks during the loom operation and subsequent finishing, so this initial width must be larger than the target width of the finished linen cloth.
Shrinkage Calculation
Fabric manufacturers calculate the required reed width based on the yarn count, fabric density, and the contraction that occurs when the fabric is tensioned and washed. Because flax fibres do not stretch easily, the relaxation of the yarn after it is removed from the loom tension results in a predictable width contraction. Furthermore, wet finishing, scouring, and bleaching cause additional shrinkage as the flax fibres swell and adjust their positions within the fabric structure.
To achieve a finished fabric width of one hundred and forty centimetres, a mill might set the warp yarns to a width of one hundred and fifty-two centimetres in the reed.
Fabric Correction
Textile engineers use these geometrical calculations to select the correct reed count and dent spacing for each fabric quality. An incorrect warp density can cause high yarn friction in the reed dents, leading to yarn abrasion and warp breakages. By optimizing the reed width and dent layout, the mill minimizes warp damage and ensures the finished fabric has a uniform density from selvedge to selvedge.