Flax Cell Wall Microfibril Alignment Determination Methods
X-ray scattering and polarized Raman spectroscopy determine flax microfibril angles to project spinning performance and yarn tenacity.
Degree of Crystallinity
Molecular Order
Chemical polymer organization defines the relative proportion of highly ordered crystalline regions compared to disorganized amorphous regions within flax fiber cellulose. A higher degree of crystallinity provides the fiber with its high tensile strength and resistance to chemical dissolution during boiling off and bleaching. This parameter directly governs how the fiber behaves under tension in the spinning zone.
Because crystalline regions are densely packed, they limit water penetration during wet spinning and demand longer exposure times or higher temperatures to soften the natural pectins. The tight hydrogen bonding in these crystalline lattices prevents the slipping of polymer chains, which is why flax exhibits such low elongation at break.
Performance Consequence
Fibers with highly aligned molecular structures undergo less stretching during wet drafting operations. If the degree of crystallinity is exceptionally high, the fiber bundles resist dye molecule penetration, which leads to lighter or less uniform shades after dyeing. Conversely, lower molecular order enables rapid dye absorption but yields weaker yarn that is susceptible to drafting defects and pilling.
Adjusting the spinning tension and draft ratio becomes necessary when processing fibers of varying molecular structural alignments.
Laboratory Measurement
Spectroscopic and diffraction techniques analyze the crystalline proportion by measuring the scattering of energy through raw fiber samples. Xray diffraction offers the most precise assessment by recording the intensity of diffraction peaks from the cellulose lattices. Spinners rely on these measurements to predict yarn quality and to calibrate bleach concentrations.
This prevents the chemical degradation of the noncrystalline fiber parts while securing uniform fiber preparation.