Contact person
Oleksandr Nechyporchuk
Forskare
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Air-gap spinning
Air-gap (dry-jet wet) spinning is a method used for man-made fiber production. In this method, a polymer solution is extruded through a spinneret and travels through an air gap before entering the coagulation bath. Air gap allows better polymer orientation prior to its solidification compared to wet spinning, resulting in higher fiber strength.
Purpose
We offer trials at bench- or laboratory-scale, enabling the development of air-gap spinning process. The trials can include exploring new polymer solvents, raw materials, and production techniques.
Method
With our expertise and know-how, we conduct research trials, enabling feasibility studies for air-gap spinning process development.
Bench-scale equipment for air-gap spinning:
- Two lines for air-gap spinning.
- Flexible equipment with possibilities of inline coagulation, stretching and washing, spin finish application, drying and winding.
- A library of spinnerets with different number of holes, hole diameters, L/D etc.
- Dope volumes: from 15 mL to 350 mL.
- Capacity: 1-50 g dry fiber per day.
Delivery
Our goal is to provide air-gap spinning services that serve the specific needs of each customer. Deliverables may include optimized process parameters summarized in a report or actually produced fibers with specific properties. For further details, please feel free to reach out to us.
More about our services in air-gap spinning
Example of our air-gap spinning equipment
Our research topics
In air-gap spinning, we focus on different combinations of bio-based polymers, both from primary and secondary sources. Examples of what we work with include:
- Cellulose -based fibers for application in textiles, both from primary raw materials, such as wood, and secondary sources, such as agricultural waste or recycled textiles.
- Bio-based precursors for carbon fiber production, spun from lignin and cellulose.
Lyocell
Production of Lyocell involves dissolving cellulose pulp in a solvent, N-Methylmorpholine N-oxide or NMMO. Pulp is first mixed with a water mixture of NMMO, then water is evaporated to achieve the monohydrate form of NMMO, resulting in pulp dissolution. Subsequently, air-gap spinning is conducted to produce Lyocell fibers. With our expertise and state-of-the-art equipment, we offer services for the development and optimization of Lyocell fiber spinning process.
Ionic liquids
Ionic liquids, with their unique solvent properties like low volatility and high thermal stability, offer capabilities for dissolving cellulose and other polymers. Resulting dopes can be used for air-gap spinning of fibers with high mechanical properties. Our ongoing research and development efforts aim to optimize the utilization of ionic liquids for fiber spinning, providing sustainable and high-performance fiber products.
Selected publications
- Bengtsson, J., Jedvert, K., Köhnke, T., & Theliander, H. (2019). Identifying breach mechanism during air‐gap spinning of lignin–cellulose ionic‐liquid solutions. Journal of Applied Polymer Science, 136(30), 47800.
- Bengtsson, A., Bengtsson, J., Sedin, M., & Sjöholm, E. (2019). Carbon fibers from lignin-cellulose precursors: effect of stabilization conditions. ACS Sustainable Chemistry & Engineering, 7(9), 8440-8448.
- Bengtsson, J., Jedvert, K., Köhnke, T., & Theliander, H. (2021). The challenge of predicting spinnability: Investigating benefits of adding lignin to cellulose solutions in air‐gap spinning. Journal of Applied Polymer Science, 138(26), 50629.
- Liu, J., Bengtsson, J., Yu, S., Burghammer, M., & Jedvert, K. (2023). Variation in the hierarchical structure of lignin-blended cellulose precursor fibers. International Journal of Biological Macromolecules, 225, 1555-1561.
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