How is it made? « Costa Building

By: Costa Building Supplies Ltd  09-12-2011

How is it made? « Costa Building

Natural gypsum is a mineral and is extracted by quarrying or mining veins of ore that occur near the earth’s surface. Synthetic gypsum is a by-product primarily from the desulfurization of flue gases in fossil-fueled power plants. Both natural and synthetic gypsum are calcium sulfate (CaSO4 • 2H20). They have the same general chemical composition.
Prior to the 1980s, virtually all the gypsum used to manufacture gypsum board and
gypsum plaster was natural gypsum. While the technology to create synthetic gypsum was developed in Europe in the 1930s and scattered references to its existence are found in industry records prior to World War II, the wholesale use of synthetic gypsum to manufacture gypsum board did not occur in the U.S. until the 1980s.
One hundred pounds of gypsum contains approximately 21 pounds (or 10 quarts) of chemically combined water. To initiate the manufacturing process, natural gypsum rock or synthetic gypsum is crushed to a powder. The powder is heated to about 350 degrees F, driving off three fourths of the chemically combined water in a process called “calcining.” The calcined gypsum (or hemihydrate) is then used as the base for gypsum plaster, gypsum board, and other gypsum products.
To produce gypsum board, the calcined gypsum is mixed with water and additives
to form a slurry that is fed between continuous layers of paper on a board machine. The paper edges of the board are machine- wrapped as the face and back paper become chemically and mechanically bonded to the gypsum core.
As the board moves down a conveyor line, the calcium sulfate recrystallizes or rehydrates, reverting to its original rock state. The board is then cut to length and conveyed through dryers to remove any free moisture.
Subsequent to drying, board is inspected and trimmed to its final length. Individual boards are placed face-to-face in pairs to form a two-sheet “book.” The cut ends of the book are bound together with end bundling tape and the board is then prepared for storage or shipping.

Contact Costa Building Supplies Ltd

Email - none provided

Print this page

Other products and services from Costa Building Supplies Ltd


Drywall/Gypsum & Finishing Products « Costa Building

Over one-third of the material used to manufacture gypsum board is recycled from other industrial processes and the facing material on paper-faced gypsum products is 100% recycled paper. A variation of the basic drywall is greenboard, which is designed to be more moisture-resistant, and up until recently was the preferred backer for ceramic tile in bathrooms.


History Of Gypsum Board « Costa Building

Gypsum board met this need and, conse- quently, became the preferred building material for military housing construction.In the 1920s, several companies joined the gypsum board industry, including CertainTeed Products Company and the National Gypsum Company.


Preferred Finishing Products « Costa Building

DUST CONTROL® Drywall Compound goes on the wall as well or better than other leading drywall compounds, with the added value that when sanding most of the dust falls straight to the floor and doesn't float around in the air. CGC All Purpose Lite Drywall Compound is a ready-mixed, high performance easy-to-use compound that provides superior working qualities and good open time to ensure the smoothest joints possible.


What Is Gypsum Board? « Costa Building

Modern manufacturing permits specialized additives and sheet materials to be placed in boards to provide increased impact resistance and sound attenuation qualities.Gypsum board is the premier building material for wall, ceiling, and partition systems in residential, institutional, and commercial structures.