From Ocean To Fibers: How Chitosan Fibers Are Becoming A New Answer For Sustainable Textiles?

From Chitin to Chitosan

Chitin is a naturally occurring polysaccharide widely found in the exoskeletons of shrimp, crabs, and insects, as well as in the cell walls of certain algae. With an estimated annual biosynthesis of approximately 10 billion tons, chitin is the second most abundant natural organic polymer on Earth, following cellulose.

Chitosan is obtained by deacetylating chitin with concentrated alkali. Chemically, it is known as β-(1→4)-2-amino-2-deoxy-D-glucose. Chitosan appears as a white to light-yellow translucent solid, with a relative molecular weight ranging from several hundred thousand to several million. It is soluble in most dilute acids, including hydrochloric acid, acetic acid, and benzoic acid.

Thanks to its biodegradability, excellent biocompatibility, strong cell affinity, and good fiber-forming ability, chitosan serves as an ideal raw material for functional fiber production.

Production Technology of Chitosan Fibers

Common methods for producing chitosan fibers include wet spinning, dry–wet spinning, and electrospinning. Among these, wet spinning is the most widely used technique in industrial-scale production.

In a typical wet-spinning process, chitosan is first dissolved in a 5% aqueous acetic acid solution. After filtration and degassing, a homogeneous spinning solution with suitable viscosity is obtained. This solution is then pumped through a spinneret using a metering pump. As the fine jets enter a coagulation bath, they solidify into continuous fibers. Subsequent stretching and post-processing steps yield the final chitosan fibers with stable and desirable properties.

Applications of Chitosan Fibers

Medical and Healthcare Applications

Chitosan fibers are widely used in the medical field due to their natural antibacterial properties and excellent biocompatibility. Typical applications include wound dressings, hemostatic materials, wound-healing products, surgical sutures, embolization devices, anti-adhesion barriers, and other medical materials.

Home Textiles and Apparel

Chitosan fibers are often blended with natural fibers such as cotton and linen to produce home textile products, including bed sheets, duvet covers, towels, blankets, and napkins. These textiles are soft, breathable, and comfortable, making them especially suitable for women, children, the elderly, and individuals with sensitive or allergy-prone skin.

Hygiene and Personal Care Products

Chitosan nonwoven fabrics offer antibacterial, deodorizing, anti-inflammatory, anti-itching, moisturizing, and skin-care benefits. As a result, they are widely used in sanitary napkins, diapers, and facial masks, and are increasingly applied in the cosmetics and personal care industries.

Environmental Protection and Adsorption Materials

Chitosan fibers have a high specific surface area and contain both amino and hydroxyl functional groups, enabling them to effectively adsorb and chelate harmful substances such as formaldehyde and heavy metals. They are used in cigarette filters to reduce smoking-related harm, as well as in water purification, air purification, and nuclear contamination treatment.

Derived from abundant marine resources and offering a unique combination of sustainability, functionality, and safety, chitosan fibers represent a promising material for next-generation textiles and advanced functional applications. As production technologies continue to mature and application areas expand, chitosan fiber is expected to play an increasingly important role in both the textile industry and beyond.