When Wool Meets the Sea: The Science of Alginate Blends

Innovation in natural textiles rarely starts with a completely blank page. Often, it starts with a question, such as – what happens when two materials are brought together?

That’s the thinking that prompted an emerging development worth watching: the blending of Merino wool with alginate fibre, a natural material derived from brown seaweed.

What is Alginate Fibre?

Alginate is already well-established in medical and culinary applications, where it is used in wound dressings and food thickeners. As a textile fibre, it is relatively new.

To produce alginate fibre requires a wet-spinning process. In that process, sodium alginate, extracted from brown seaweed, undergoes an ion-exchange reaction to become calcium alginate. The calcium alginate solution is then pressed through fine nozzles (extruded) into a calcium bath, where it solidifies into stable fibres.

Brown seaweed is notably low-impact. Seaweed cultivation uses no agricultural land, no fresh water, no pesticides. The alginate fibre is biodegradable and compostable.

What Does Alginate Bring to a Wool Blend?

Testing on 100% alginate fibre yarn reveals several noteworthy characteristics that make it an interesting partner for wool:

• Moisture regain of ~20.7%, meaning it feels naturally soft next to the skin
• Antibacterial and antimicrobial behaviour, which can support a “fresh” feeling in base layer type garments
• Inherent flame retardancy – alginate has a natural limiting oxygen index (LOI) of 45%, significantly higher than most other textile fibres (wool’s is 25)
• Moisture absorption and humidity regulation, which means alginate fibres swell gently when exposed to moisture, a characteristic that leads to comfort in clothing
• Antistatic qualities, arising from the moisture absorption capacity. This also supports good drape.

Testing on wool and alginate blends is ongoing.

Why This Combination is so Appealing

Wool and alginate are both natural materials. Wool is protein-based and alginate is polysaccharide-based. They are both biodegradable. Where wool excels at thermoregulation and resilience during use, alginate may offer complementary surface and moisture benefits.

Where Could We See This Blend?

Potential applications range from performance base layers to medical and hygiene textiles where antimicrobial properties are valued, to home textiles like bedding and workwear that requires flame protection.

Where the Science Stands

Wool/alginate is not yet commercial ready. Early stage development work is being done by Südwolle Group, IMPETUS Portugal Têxteis, and Woolmark. Rigorous testing will ensure both performance and environmental credentials. The R&D process is currently working through how the blends behave through dyeing and finishing, and in different fabric constructions. It’s exciting times, and we’ll continue to track developments and report back.

Thanks to Südwolle Group for their input on this post.