Put the warm water into the bucket, add six sodium phosphate, pur the sodium alginate slowly into warm water u nder continuous stirring , fully stir until the granula disappeared , add water to the total amount of soda and adjust the pH value to 7 ~ 8 and then add the formaldehyde.
Preparing paste without boiling, generally should not exceed 60 degrees, otherwise it will make the viscosity decrease, alginate paste would be hydrolyzed by the action of light, the viscosity decreased rapidly, so the storage must be placed in the darkness. It is stable in the pH value of 6 ~ 11,it can form the gel in the acid and alkali. Heavy metal ions can also cause the gel phenomenon but we can use six partial sodium phosphate to prevent it, the general concentration of the powder and sodium hypochlorite has no effect on it in 20℃.