Sourcing Dissolving Pulp Feedstocks for Rayon Yarn Production
Dissolving pulp sourcing for rayon yarn relies on alpha cellulose purity specifications, alkali solubility controls, and commercial air dry tonnage audits.
Steeping Lye Recovery
Caustic Reclamation
Industrial recovery loops for steeping lye recovery reclaim sodium hydroxide from the spent liquor used in viscose manufacture. This chemical recycling process reduces the environmental impact and operating cost of regenerated cellulose production. Most modern factories install these systems to capture alkali for reuse in the initial stages of the spinning process.
Purification Step
Spent liquor contains dissolved hemicelluloses and organic impurities that must be removed before the alkali can be reused. Dialysis or membrane filtration separates the pure sodium hydroxide from the larger organic molecules. The recovered stream is then adjusted to the correct concentration for the next batch of cellulose steeping through the addition of fresh caustic or by evaporation.
Resource Management
Efficient recovery reduces the volume of fresh caustic soda required by the factory. It also minimizes the load on the wastewater treatment plant by capturing organic waste as a concentrated byproduct. Mills monitor the purity of the recovered lye to prevent the accumulation of impurities that could discolor the final fibre.
System Performance
Membrane fouling and salt buildup are the primary factors that limit the efficiency of the recovery unit. The process concludes when the purified lye returns to the main storage tanks.