retting

Retting is a processing stage in textile production used to separate bast fibers from the woody stalks of plants such as flax, hemp, jute, and ramie. It targets the pectins and other binding substances that hold the fibers to the core, loosening the structure so the fibers can be extracted for spinning. Different retting methods are used depending on the material, climate, and context. Water retting involves submerging harvested stems in stagnant water to promote microbial action that degrades pectin. Dew retting, or field retting, relies on natural weather and moisture in the field. Chemical retting uses alkaline or acid chemicals to dissolve binding materials, and enzyme retting employs specific enzymes, such as pectinases, to accelerate the breakdown. Modern practice may combine methods or use enzyme-assisted retting to reduce odor and environmental impact.

After retting, the fibers are washed to remove soluble compounds, then dried and subjected to mechanical processing such as scutching and hackling to separate fibrils and align fibers for spinning. The retting quality influences fiber fineness, length, strength, and luster; under-retted fibers can be difficult to separate and over-retted fibers may lose strength.

Environmental considerations are significant, as retting effluent can contribute to water pollution from high organic load and odors. Sustainable approaches emphasize controlled retting in closed systems, wastewater treatment, or shifts to enzyme or mechanical alternatives to reduce environmental impact.