Biological Extraction
Microbially mediated dissolution of the pectin binder separates the usable bast fibers from the woody core of the flax stem. This biochemical process, known as retting, represents the first processing stage after the flax harvest. Moisture and temperature conditions in the field or in controlled tanks dictate the speed of enzyme activity.
Controlling this stage ensures that the fiber remains strong while becoming easy to separate during scutching.
Process Monitoring
Industrial management of the decomposition phase requires regular assessment of the stem flexibility and color changes to avoid fiber damage. Field supervisors record the moisture levels and temperature during the retting phase in the agricultural tracking log. In Chinese flax processing facilities, the end of this phase is determined by hand-testing the ease of separating the fiber from the stem.
If the process is halted too early, the extraction yields are low and the fiber remains coarse and stiff. If the process continues for too long, microorganisms begin to consume the cellulose, which reduces the strength of the fiber.
Extraction Outcome
Scutching yields and fiber length distribution are direct results of the chemical changes achieved during the decomposition. Proper retting allows the extraction of long line fibers of high grade that are suitable for fine yarn spinning. Overly dry conditions during this phase stop the reaction and produce low yield batches.
Successful extraction relies on balanced environmental moisture.
