Structural Displacement
Structural deformation across crystalline domains represents the fundamental physical response of plant bast fibres during liquid-assisted mechanical drawing. In flax spinning mills, cellulose microfibril shear occurs when hydrogen bonds between adjacent glucan chains break under axial tension, allowing longitudinal slipping within the secondary cell wall of the flax fibre. This molecular displacement determines the degree to which individual filaments slide past one another inside wet-spun sliver, directly influencing yarn evenness.
Over-stretching during drawing causes permanent micro-fractures, while under-stretching leaves bundles intact and reduces yarn fineness.
Drafting Mechanics
Drafting roller speed differentials govern the rate at which stress accumulates across the fibre cross-section in wet spinning frames. When warm water softens the pectin matrix binding the elementary fibres, cellulose microfibril shear allows orderly realignment without complete filament severance. Excessive drafting tension forces unravelling at the crystalline interface, generating weak spots along the yarn length.
Mill technicians adjust the draw ratio on wet ring spinning machines between two point four and two point eight to maintain uniform sliver elongation.
Tensile Boundary
Boundary limits for structural displacement depend on moisture content and bath temperature during wet drafting. Unsuitable hydration stops structural sliding and initiates brittle fracture along the middle lamella, increasing short fibre content during carding and combing.
