Contact person
Oleksandr Nechyporchuk
Forskare
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Wet spinning
Wet spinning is a manufacturing process used to produce fibers from polymer solutions by extruding them into a coagulation bath, where the polymer solidifies into fibers. This method is called "wet" spinning because the process involves the use of a liquid coagulation bath.
Purpose
At the Fiber Development unit at RISE, we offer comprehensive research and development services for wet spinning of man-made fibers. We perform trials to develop and optimize wet spinning processes or to produce man-made fibers with certain properties for their testing. The trials can include exploring new polymer solvents, raw materials, and production techniques. By systematically testing and optimizing various parameters such as polymer concentration, wet spinning parameters, coagulation bath compositions etc., we fine-tune fiber properties to suit specific applications.
Method
With our expertise and know-how, we conduct trials at bench- or laboratory-scale, enabling feasibility studies for wet spinning process development and providing data for larger scale trials. Using our pilot-scale equipment and expertise in scaling up wet spinning technologies, we optimize the production processes and deliver larger quantities of fibers and yarns for testing and evaluation.
Bench-scale wet spinning
- Two lines for wet spinning.
- Flexible equipment with possibilities of inline coagulation, stretching and washing in sequential baths, spin finish application, drying and winding of filament yarn.
- A library of spinnerets with different number of holes, hole diameters, L/D etc.
- Dope volumes: from 5 mL to ca. 1 L.
- Capacity: 1–100 g dry fiber per day.
Pilot-scale wet spinning
- Two lines for continuous wet spinning.
- A library of spinnerets and customized spinning head.
- Counter-current washing.
- Inline coagulation, stretching, washing, spin finish application, drying and winding options.
- Spinning of both filament and staple fiber yarns.
- Dope volumes: from 1 L.
- Capacity: up to approximately 50 kg dry fiber per day.
Delivery
Our goal is to deliver tailor-made wet spinning solutions that meet the unique requirements of each customer. Deliverables may include optimized process parameters summarized in a report or actually produced fibers with specific properties.
More about our services in wet spinning
Examples of our wet spinning equipment
Our research topics
We focus on wet spinning of fibers from a variety of raw materials. The aim is to use virgin raw materials or to valorize polymers from textiles for recycling purposes. We work with such polymers as:
- Polysaccharides, such as cellulose and its derivatives, alginate, chitin and chitosan.
- Fibrillar proteins derived from wool and silk (keratin and fibroin).
- Non-fibrillar proteins derived from plants and milk (pea protein isolate, soy protein isolate, zein, casein).
Viscose
Wet spinning technique is largely used for the production of viscose (rayon) fibers. In this method, cellulose dissolution is performed through xanthation with further extrusion through spinnerets into a coagulation bath where cellulose regenerates and solidifies into fibers. These fibers undergo washing, stretching and drying, and are largely used in textile application. We have a viscose pilot plant, where wet spinning of regenerated cellulose fibers can be performed at two different scales.
Novel wet spinning technologies
We work with the development of wet spinning processes for a range of bio-based materials using novel solvent systems, such as Ionic liquids, cold alkali. We have also expertise in air-gap spinning, for example from ionic liquids or NMMO.
Selected publications
- Bengtsson, J., Olsson, C., Hedlund, A., Köhnke, T., & Bialik, E. (2017). Understanding the inhibiting effect of small-molecule hydrogen bond donors on the solubility of cellulose in tetrabutylammonium acetate/DMSO. The Journal of Physical Chemistry B, 121(50), 11241-11248.
- Hedlund, A., Köhnke, T., & Theliander, H. (2017). Diffusion in ionic liquid–cellulose solutions during coagulation in water: mass transport and coagulation rate measurements. Macromolecules, 50(21), 8707-8719.
- Nechyporchuk, O., Håkansson, K. M. O., Gowda.V, K., Lundell, F., Hagström, B., & Köhnke, T. (2019). Continuous Assembly of Cellulose Nanofibrils and Nanocrystals into Strong Macrofibers through Microfluidic Spinning. Advanced Materials Technologies, 4(2), 1800557.
- Nechyporchuk, O., Yang Nilsson, T., Ulmefors, H., & Köhnke, T. (2020). Wet spinning of chitosan fibers: Effect of sodium dodecyl sulfate adsorption and enhanced dope temperature. ACS Applied Polymer Materials, 2(9), 3867-3875.
- Nechyporchuk, O., Ulmefors, H., & Teleman, A. (2021). Silica-rich regenerated cellulose fibers enabled by delayed dissolution of silica nanoparticles in strong alkali using zinc oxide. Carbohydrate polymers, 264, 118032.
Selected patents
- Stigsson, L., Hagström, B., Köhnke, T., Hedlund, A., Bialik, M. (2018). Alkali recycle in cellulose spinning process (US10138578B2).
- Hedlund, A., Köhnke, T. (2021). Process for spinning dissolved cellulose (US11208739B2).
- Olsson, C., Hagström, B., Köhnke T. (2023). System for the production of a spinning dope composition (US11753482B2).
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