Machinery Configuration
The distance between the feed roller and the drawing roller on a wet-spinning frame determines the control of fibers as they are drafted through the hot water bath. The wet-spinning ratch is set shorter than the dry-spinning ratch because the hot water softens the pectins, allowing the technical fiber bundles to split into shorter elementary fibers. Adjusting this distance is necessary to match the softened fiber length and to prevent yarn drafting defects.
Processing Dynamic
The temperature of the spinning bath must remain constant to ensure uniform softening of the pectin binders. If the wet-spinning ratch is too wide, the fibers are not gripped properly by both rollers, resulting in drafting waves that produce thick and thin spots in the yarn. Conversely, a ratch that is too narrow will cause fiber breakage and high spinning frame end breakages, as the roller speed exceeds the fiber’s elongation capacity.
Setting Specification
Spinning mill manuals specify the correct roller distances for each target yarn count and fiber origin. To maintain the wet-spinning ratch at its optimal setting, technicians check the fiber length distribution of the wet drafted sliver during regular maintenance intervals. When spinning very fine yarn counts, the setting must be carefully calibrated to ensure that the elementary fibers are fully drafted without bundle slippage.
This precise configuration is recorded on the yarn production worksheet and serves to guarantee the yarn’s physical properties meet the export standards. Spinners rely on these records to maintain high weaving efficiency in subsequent processing stages, ensuring the woven linen is free from structural defects.
