China’s ‘Cork-Skin’ Fiber Innovation Turns Mulberry Bark into Green, Antibacterial Textiles
- Ritambhara K
- Aug 10
- 3 min read
In a breakthrough that could reshape the textile industry’s sustainability goals, a team of Chinese researchers has successfully developed high-performance, recyclable yarns from the bark of the invasive paper-mulberry tree—without relying on petrochemicals or traditional spinning techniques. Their method, which combines natural cellulose fibers with cork-derived suberin, promises fabrics that are strong, antibacterial, fully recyclable, and far less polluting than conventional synthetic textiles.
From Invasive Bark to Wearable Fiber
The innovation, detailed in the Journal of Bioresources and Bioproducts, starts with the paper-mulberry tree, a fast-growing species often considered invasive. Its bark is a rich source of cellulose, the structural material found in plant cell walls. Researchers used a mild alkaline delignification process to gently remove lignin—the glue-like substance holding plant fibers together—without damaging the natural alignment of the cellulose bundles.
Once separated, these bundles were dip-coated in suberin, a natural polyester extracted from cork bark waste. This “cork-skin” forms a dense nanolayer over each fiber, which is then cured at 110 °C. The heat triggers esterification, cross-linking the coating to lock in hydrophobicity (water resistance) and antibacterial properties while preserving the flexibility of the fibers.
Strength, Durability, and Hygiene in One
Tests revealed that the new yarns boast a tensile strength of 0.43 GPa and a Young’s modulus of 6.4 GPa—outperforming cotton and matching the mechanical strength of flax. In antibacterial trials, the fibers inhibited more than 90 % of Staphylococcus aureus and Candida albicans growth, while reducing Escherichia coli by 80 %.
These properties make the fibers particularly attractive for applications requiring hygiene and durability, such as sportswear, hospital textiles, and outdoor clothing. Importantly, they retain their structure and function after washing at 60 °C—demonstrated by hand-crocheted swatches that endured multiple wash cycles without degradation.
Green Credentials Backed by Life-Cycle Analysis
Beyond performance, the environmental footprint of these fibers is remarkably low. A life-cycle assessment calculated a global-warming potential of just 0.046 kg CO₂-equivalent per kilogram of yarn—roughly one-tenth that of conventional polyethylene terephthalate (PET) yarns. Most of the emissions come from renewable electricity used in processing, with no petrochemical feedstocks required.
Equally significant is the recyclability of the fabric. The suberin coating can be stripped off using a choline-based ionic liquid, allowing it to be redeposited up to five times without any loss in knitability. This process recovers 95 % of materials, creating a closed-loop production system and drastically reducing textile waste.
Towards Scalable, Pesticide-Free Clothing
The team has already demonstrated the feasibility of creating meter-long yarn swatches by hand, but the next challenge is industrial-scale production. Plans are underway to adapt the coating method to roll-to-roll processing, enabling continuous manufacturing suitable for commercial textile mills. Long-term laundering and wear-resistance tests are also in progress to ensure the fibers meet the demands of everyday use.
Given their renewable origin, antibacterial qualities, recyclability, and low carbon footprint, these cork-skin coated mulberry fibers could soon find their way into garments, upholstery, and technical fabrics—offering a compelling alternative to pesticide-dependent cotton and pollution-heavy synthetics.
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As global fashion and textile industries face mounting pressure to adopt greener materials, innovations like this present a clear path forward one where clothes not only look and feel good but also protect the planet.
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