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

2.5.3     THERMAL PROPERTIES
The importance of good thermal insulation in buildings in order to
reduce heating costs cannot be over emphasized. Lightweight building techniques (plasterboard on framework) can supply excellent thermal performance since the construction has a cavity that can be filled with the required amount of insulation. The interior plasterboards protect the insulating material and contribute, together with the vapour barrier, in preventing indoor humidity from getting in, or being trapped in, the insulation material (Fred, 1882).
2.5.4      AESTHETICS AND DESIGN
A richness of forms can be created in plasterboard or stucco. For architects, building with gypsum products allows them to unleash their creativity thus allowing them to answer, even more dramatically, to the demands of their customer while remaining within an affordable budget. In short, Gypsum allows the creation of stunning interiors in any and all styles, from the Classical to the Modern.
2.5.5      SOUND ISOLATION PROPERTIES
Preventing the transfer of unwanted sound to adjoining areas is a key consideration when designing a building, specifically when taking into account the intended activities of occupants in various part of the building. Gypsum board walls and ceiling system effectively help control sound transmission (Miller, 1889).
2.6    MANUFACTURE OF PLASTER FROM GYPSUM
Plaster is one of the oddest known synthetic building material which is manufactured from Gypsum. It is used by the Egyptian at least 4000year ago in the construction of pyramids and the Greek were producing decorative plaster work by 500BC. The chemistry of the conversation of gypsum to plaster was investigated early on by chemist such as Le Chatelier (1850 – 1936) and van’t Hoff (1852 – 1911).
Plaster is made by heating gypsum (CaS04.2H20) powder, thus converting it to calcium sulphate hemihydrate (CaS04.1/2H20). The hemihydrates is also known as Stucco or plaster of Paris – probably so named because of the very large deposit of pure gypsum found beneath Paris.
    In 1888, Augustine sackett used plaster of Paris sandwiched between several layers of paper to produce what would eventually become sackett board, the original gypsum board.
    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 the residential and commercial construction industries.
2.7    PHYSICAL PROPERTIES OF GYPSUM
Gypsum is moderately soluble in water (2.0 – 2.5g/l at 25o c) and in contrast to most other salts, it exhibit retrogate solubility, becoming less soluble at higher temperature when gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, (bassanite, often simply called “Plaster”) and if heated further, to anhydrous calcium sulfate (anhydrite). Gypsum  crystal are found to contain anion water and hydrogen bonding.