Let’s learn about the hidden characteristics of sodium alginate!


Sodium Alginate is the sodium salt form of alginic acid and gum mainly extracted from the cell walls of brown algae, a gelling polysaccharide extracted from sea kelp with chelating activity.

Physical Description

-Dry Powder. Nearly odourless : white to yellowish fibrous or granular powder

-Cream-colored powder : Filamentous or granular solid or powder

-Solubility : Insoluble in ethanol, chloroform, ether, acidic aqueous solutions below pH 3 and hydroalcoholic solutions greater than 30% wt/wt ; Dissolves in water to form a viscous colloidal solution

Manufacturing process

1. Alginic acid method

Add acid to the extract to form colloidal alginic acid. This is removed by carbon dioxide promoted flotation. The remaining extract contains trace amounts of alginic acid, to which the solution is added in alcohol and solid sodium carbonate is added until the desired pH is reached.

2. Calcium alginate method

In this method, calcium chloride is added to the extract to obtain solid calcium alginate as fiber. The fibrous material can be removed by sieving and excess calcium can be removed with water. Stir it with dilute acid to get alginic acid, which is spiral-pressed into a paste. Add sodium carbonate until the desired pH is reached. Sodium alginate is extruded, dried and ground in granular form.


1. Pharmaceutical Industry

Alginate swells in water, and the pharmaceutical industry uses this property as a disintegrate. It is used in liquid medicines to increase viscosity and solid suspension. It is also used to fix cells and enzymes.

2. Other Industry

Sodium alginate has the ability to thicken in water, making it suitable for textile printing. It is used for the surface sizing of paper. Its oil resistance to paper is also better. Alginates are widely used in the dental industry as impression materials. It is a good chelating agent for extracting radioactive substances from the body.

No matter what industry you are in, if you want to find an expert who understands sodium alginate. Please feel free to contact us APL, Looking forward to providing you with suitable products!

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