Development of dopes for wet and air-gap spinning

An essential step in solution spinning is the development of spinning dopes (polymer solutions) with optimal properties. Precise control over dope properties is essential for ensuring proper extrusion and coagulation, thereby laying the foundation for a well-functioning solution spinning process for man-made fiber production.

This service is also relevant in: Circular transition, Production and manufacturing, Chemical products and processes

Service details

Service: Development of dopes for wet and air-gap spinning
Price: Price on tender

Axel Martinsson

Forskare

+46 10 228 41 06 Read more about Axel

Purpose

Spinning dope is a homogeneous solution made from a polymer dissolved in a solvent. The polymer can originate not only from virgin raw materials but also from polymer fractions for example to be extracted during textile recycling. The composition of spinning dope, molecular weight of the polymer, polymer concentration, dope temperature etc. can be tuned to allow polymer dissolution while limiting its degradation and providing reasonable dope properties, such as viscosity and storage stability. Getting right dope properties is crucial for enabling correct extrusion of filaments through spinneret capillaries into the coagulation bath, especially when multifilament spinning is required. There are also great opportunities to add functionality to the wet-spun fibers through targeted dope formulations.

Method

We develop spinning dopes suitable for multifilament solution spinning. Our capabilities include:

Equipment for polymer dissolution in different scales, including reactors, kneaders and high-shear mixers.
Filtration in various scales.
Deaeration.

We characterize dopes using methods such as:

Filterability.
Rheology.
Microscopy.
Particle analysis.
Polymer dissolution state and solvent-polymer interactions using SAXS/ WAXS.

Delivery

Please contact us for more information for the delivery time and price.

Other relevant services

Related

Solution spinning of man-made fibers

Within our expertise in solution spinning, both wet and air-gap (dry-jet wet) spinning, we develop man-made fibers from polymers that are either non-thermoplastic or sensitive to temperature. This method is particularly useful for the production of fibers from bio-based raw materials.

Biobased materials / Service

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.

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.

Development of filament and staple fibers

Man-made fibers produced using solution spinning are collected and processed as filament or staple fibers depending on the desired application. RISE has equipment and knowledge to develop these two types of fibers that can be further converted into yarns and threads.

Education offer

Training course on wet spinning (solution spinning) of man-made fibers

This course will provide you with essential knowledge of the fundamentals of wet spinning technology used in man-made fiber production. We cover both traditional wet and air-gap (dry-jet wet) spinning, guiding you through the entire process from polymer dissolution to ready yarn, focusing on key considerations that arise during process upscaling.