Boric Acid Use in Gypsum
Gypsum is widely used in the construction of walls and ceilings in the construction industry. It is manufactured by calcining gypsum, making a slurry and shaping, setting and cutting the product into boards with a paper backing. The addition of Boric acid to the slurry improves product performance, process efficiency and user convenience.
Boric acid use in the slurry encourages the formation of large, bulky crystals (rather than long, needle-like crystals) which impart rigidity to the finished board as well as a harder outer edge.
The larger crystals created by the addition of Boric acid accelerates the curing time by reducing the drying time. Boric acid also improves the adhesion of the paper backing with a starch adhesive. Boric acid reacts with sodium sulfate in the gypsum to prevent wrinkles in the paper backing as it dries.
A reduction in the weight of each board can be reduced by injecting air into the slurry, boric acid helps prevent potential bond failures between the paper and the gypsum board allowing for up to a 10% weight reduction.