Alginate wound dressing is a fibrous nonwoven pad or ribbon made from sodium Alginate through processes of Wet Spinning, Carding, Cutting and Packaging. During the production sodium alginate is converted into calcium alginate through an ion exchange process, then made into nonwovens by carding and needle punching. Calcium alginate is natural polymer materials which is safe and harmless for human.
The raw material
Our raw material is sodium alginate which is sourced from world reputable suppliers. The sodium alginate for our wound dressing is originally processed from brown seaweed.
At our plant, we dissolve sodium alginate n purified water to form a viscose polymer solution. We then extrude the solution into a calcium-ion-rich bath to convert sodium alginate into calcium alginate filaments which is water insoluble. This is normally referred to as the ion exchange process. The calcium alginate filaments are then put through various physical steps to make it stronger and easier for the subsequent processes. Excess water in the filaments is also removed during this process and the filament is crimped and cut into staple length. This entire process is called a wet-spinning production by the industry.
Carding and needle punching process
The alginate fibres are further processed at carding to make the fibres separated and aligned to form a thin web. The web is folded then needle punched to become a nonwoven. The nonwoven is then slit and cut into pad or ribbon with required sizes.
The alginate pad or ribbon is then packed into pouches by an automatic packing line, and then sterilized by gamma irradiation.
The chemistry of alginate
The formulation of calcium alginate
How does Alginate Dressing work?
When the alginate is in contact with wound exudates, calcium ions in the dressing is exchanged with sodium ions from wound fluid turning the calcium alginate into sodium alginate. Sodium alginate becomes gel when in contact with wound exudates which help to maintains a moist wound environment that supports the wound healing process. The gelling nature of the alginate also helps the removal of the dressing without damaging the newly formed tissue.
Features and Benefits
1. High Absorbency：Alginate dressing can absorb large amounts of wound exudates then forms a gel to protect the wounds and encourage wound healing.
2. Wet Strength: Alginate wound dressing can be easily remove in one piece.
3. Gel-forming Property: After absorption of exudates, the exchange of calcium in the dressing and sodium from wound fluid forms a stable gel that can maintain a moist wound healing environment promoting cell re-generations.
4. Pain Reducing: Owing to the protection of gel, peripheral nerves within the wound bed are less likely to be stimulated by external process so there is a potential for pain reduction [Ref 1].
5. Haemostatic Function: The release of calcium ions can cause the aggregation and deformation of erythrocyte and increase the platelet activating to promote clotting. In addition, its special physical characteristics play an important role in the process of Haemostatic [Ref 2].
It has been proven clinically [Ref 3,4] that alginate is indicated for the management of moderately to heavily exuding chronic wounds and acute wounds, and to control minor bleeding in superficial wounds.
[Ref 1] D Bettinger; D Gore; Y Humphries. Evaluation of calcium alginate for skin graft donor sites[J]. J Burn Care Rehabil,1995, Vol.16,59-61.
[Ref 2] Cui F.-Y.;Wang B.; Wei L.; Wang H.-T.; Chen H.; Chu X.-X.; Wang Z.-Z.; Yang L.-H. Haemostatic mechanism of calcium alginate dressing [J]. Chinese Journal of Tissue Engineering Research,2015, Vol.19,.7681-7686.
[Ref 3] Dumville J.C.; Keogh S.J.; Liu Z.; Stubbs N.; Walker R.M.; Fortnam M. Alginate dressings for treating pressure ulcers[J]. Cochrane Database of Systematic Reviews, 2015, Vol.2015, CD011277
[Ref 4] O'Meara S.; Martyn-St James M.; Adderley U.J. Alginate dressings for venous leg ulcers[J]. Cochrane Database of Systematic Reviews, 2015, Vol.2015, CD010182