Impact of Cellulose Microfibril Angle Dispersion on Hackling Yield
Cellulose microfibril angle dispersion drives transverse cell wall cleavage under pin shear, reducing dressed long line flax yield by up to 16 percentage points.
Tensile Load Distribution
Force Partitioning
Transmission of mechanical force through the complex hierarchy of a flax bundle involves the transfer of stress between individual fibers and the surrounding pectin matrix. Effective tensile load distribution ensures that the entire cross-section of the strand contributes to its overall strength. Proper load sharing prevents a single weak point from causing the immediate collapse of the whole yarn.
Interfacial Shear
Overlap between elementary fibers within the bundle allows the load to move from one cell to another via shear forces in the middle lamella. If the pectins are too brittle or the fibers are too short, the tensile load distribution becomes uneven and leads to slippage. Spinning processes aim to optimize this internal friction to maximize the tenacity of the finished thread.
Wet spinning provides an advantage here by temporarily softening the matrix, allowing the fibers to slide into a more efficient alignment before the yarn dries and the bonds reform.
Structural Failure
Examination of broken yarns often reveals whether the failure was due to fiber rupture or a breakdown in the bonding agent. Irregularities in the thickness of the sliver disrupt the tensile load distribution and create zones where the material is prone to snapping under the high tensions of a loom.