Fiber Structure
Single plant cells of flax that are bound together by pectin and hemicellulose represent the fundamental building blocks of the long linen yarn. These elementary ultimates are obtained when the chemical or mechanical processing of flax completely removes the non-cellulosic gum that holds the fiber bundles together. The length and diameter of these individual cells dictate the maximum potential spinning fineness of the yarn.
Separation Mechanism
Releasing these discrete structures from their bundles requires a process of controlled degumming or intensive acid treatment in the laboratory. This release of elementary ultimates allows researchers to measure the primary cell dimensions under a microscope to evaluate the quality of the raw material. During commercial spinning, however, the fiber bundles are only partially split to preserve the strength needed for high-speed production operations.
Dimensional Evaluation
The length of these individual cells averages between twenty and thirty millimeters, with a diameter that remains extremely narrow compared to other bast fibers. Because of these proportions, the dimensions of the elementary ultimates are measured to determine the optimal retting time for a given crop. If the retting is incomplete, the bundles remain too thick, whereas excessive retting degrades the cell walls and reduces the yarn strength.
This microscopic profiling provides an objective baseline that assists spinners in adjusting their draw frame settings to accommodate variations in crop batches.
