Design And Production Of Ceiling Board Using Plaster Of Paris (pop) Gypsum Material

CHAPTER TWO
2.0    LITERATURE REVIEW
    In 1888, Augustine Sackett used plaster of Paris sandwiched between several layer to produce what would eventually become Sackett board, the original gypsum board. The  modern gypsum board known as “Sackett board” a composite material that was made of layer of thin plaster placed between four piles of wool felt paper. Sackett board was patented in 1894. In this regards Augustine Sackett is generally considered to be the grandfather of gypsum board manufacturing industry.
    Prior to 1894, gypsum had been used for thousand of years as a building material and as an architectural detailing element. The first use in building construction appears to have occurred in 3700 B.C when  the  Egyptian used gypsum blocks and plaster applied over a woven straw lath in the building of pyramid of cheops. As a testimony to the strength and durability of gypsum, some of this construction is still intact and viewable including walls decorated with murals composed of tinted plaster.
In the late 1700s, the French chemist Lavoisier analysed the chemical make up of gypsum. His work and subsequent research by a group of his comtemporary chemists coupled with the discovery and mining of huge reserves of gypsum near Paris led to the whole sale use of “plaster of Paris” as a building material. Plaster of Paris is a raw gypsum that is chemically altered by heat to remove much of the water contained in the gypsum molecule and then hydrated to make it  useable as a plastering material.
    An American man make used of plaster of Paris manufactured from gypsum combined with fibre to produce a ceiling board with durable strength (Miller, 1930).
    By the 1950s, many innovations in gypsum board technology has been developed including the listing of many fire resistance rated design rounded edges, specialized nails, curved partitions, studless partitions, sound control systems, lightweight gypsum lath, plaster and gypsum board system that fueled a boom period for the use of gypsum products in both residential and commercial construction industries.
    In 1955, an estimated fifty percent of new homes were built using gypsum wall board and P.O.P ceiling board as ceiling finishing. Lightweight gypsum board systems permitted the use of lightweight steels in steels framed buildings which enabled the widespread growth of high rise residential and commercial construction during 1960s and 1970s.
2.1    HISTORY OF GYPSUM
   The word  Gypsum  is  derived  from  the  Greek  word puuoc,(gypsos), “chalk” or “plaster”. Because the quarries of the Montmartre district of Paris have long furnished burnt gypsum (calcined gypsum) used for various purposes, this dehydrated gypsum become known as Plaster of Paris. Upon addition of water, after a few tens minute plaster of Paris becomes regular gypsum (dehydrate) again, causing the material to harden or set in ways that are useful for casting and construction.
    Gypsum was known in old English as spaerstan, “spearstone” referring to its crystalline projections. (thus the word spar in mineralogy is by way of comparison to gypsum, referring to any non ore mineral or crystal that forms in spearlike projections). Gypsum may act as a source of sulfur for plant growth which was discovered by J.M. Mayer and in the early 19th century, it was regarded as an almost miraculous fertilizer.
2.2    OLD USE OF GYPSUM IN CONSTRUCTION
Gypsum is a rock like mineral commonly found in the earth’s crust, extracted, processed and used by Man in construction or decoration in the form of plaster and alabaster since 9000 B.C. Plaster was discovered in Catal-Huyuk in Asia in an underground fresco, and in Israel.
Gypsum floor screeds were found from 7000 B.C. During the time of the Pharaohs, Gypsum was used as mortar in the construction of the Cheops Pyramid (3000 B.C.). In the Middle Ages and the Renaissance, decorations and artistic creations were made of plaster. Since then, the range of construction-related uses have continued to multiply.
Gypsum can indeed also :-
•    Be added to some bread and dough mixes as a calcium source and baking aid.
•    Be used  as a filter and fire retardant in plastic product.
•    Be used in Portland cement and special cement product for set and expansion control.
•    Be a source of calcium and sulphate sulphur for plant growth.
•    Be used as a modeling material for tooth restorations.
•    Be an ingredient in many patching compound.
•    Be used with glass to fabricate large, lightweight architectural decoration.
•    Be used as a mould material to fabricate custom body part for trucks and automobiles.
•    Be an aid in juice and extraction of some fruits and vegetables.