Structural Displacement
Molecular realignment occurs within the non-crystalline regions of the flax fibre bundle during mechanical processing. High levels of amorphous matrix shear happen when the pectin and hemicellulose binders between cellulose fibrils yield under transverse forces. This displacement defines the permanent deformation limit of the primary wall in linen stalks.
Processing Impact
Lateral pressure applied during the scutching and hackling stages forces the non-crystalline components to slide past each other. When a mill subjects raw flax to these intense mechanical loads, amorphous matrix shear determines how much of the internal structure stays intact and how much breaks into short fibres. The degree of movement depends on the moisture content of the fibre at the point of impact because water acts as a plasticizer for the pectin chains.
Precise control over humidity prevents excessive damage to the bundle by modulating the resistance to these internal forces. Fibres that undergo too much internal sliding lose their tensile strength and become brittle during the subsequent spinning process.
Mechanical Limit
Excessive internal sliding reduces the spinning limit of the resulting yarn. If amorphous matrix shear exceeds the bonding strength of the matrix, the fibre bundles split unevenly and create thick or thin places in the sliver. Proper monitoring of this physical change ensures that the flax maintains enough structural integrity to withstand the high tensions of wet spinning.
