Gypsum boards

Gypsum [7778-18-9] Gypsum board Gypsum plaster board Gypsy... 

Fig. 6. Effect of fiber glass on transmission loss of steel stud partition where (—) is 6.35 cm (2S in.) steel stud and 1.27 cm (S in.) gypsum board, and (— -)...

Gypsum board paper is a special three-ply paper manufactured from repulped newspapers. The face paper or cream face has the ply against the core unsized so that the gypsum crystals can grow into it, as this is the principal form of bonding between the core and facers. The middle ply is sized and the outer ply is more heavily sized and treated to control paint absorption. For the completed gypsum board system to work, the joint treatment and paper must absorb paint at the same rate. 

Even when plastics are not a preferred material for the stmctural element of paneling, they are often iacorporated as a surface coatiag or sheet to enhance aesthetics. Some lay-ia ceiling panels for commercial and iastitutional appHcations consist of gypsum board covered with a poly(vinyl chloride) surface sheet to add a textured appearance. Many more are based on gypsum board or mineral wall with a fiber glass or PVC surface. 

C473-87a Physical Testing of Gypsum Board Products ... 

Brenden and Chamberlain (6) measured heat release rate from wall assemblies having fire-retardant-treated studs and gypsum board as interior finish in the FPL fire endurance furnace using three methods (a) the substitution method, by which the amount of fuel required to maintain the ASTM E-119 time-temperature curve for a... 

Interior finish for tests 1 and 2 of each group was plywood finish for tests 3 and 4 was gypsum board. 

Because of the large difference in the behavior of the thin plywood and the gypsum board, the type of interior finish was the dominant factor in the statistical analysis of the total heat release data (Table III). Linear regression of the data sets for 5, 10, and 15 min resulted in squares of the correlation coefficients R = 0.88 to 0.91 with the type of interior finish as the sole variable. For the plywood, the average total heat release was 172, 292, and 425 MJ at 5, 10, and 15 min, respectively. For the gypsum board, the average total heat release was 25, 27, and 29 MJ at 5, 10, and 15 min, respectively. 

A large number of studies have also been done to investigate the lifetime of HC1 in a fire atmosphere [20-24]. These studies have shown that HC1 reacts very rapidly with most common construction surfaces (cement block, ceiling tile, gypsum board, etc.) so that the peak atmospheric concentration found in a fire is much less than would have been predicted from the chlorine content of the burning material. Furthermore, this peak concentration soon decreases and HC1 disappears completely from the atmosphere. 

Figure 7.13 Spread and ignition results for (a) plywood, (b) rigid polyurethane foam, (c) gypsum board and (d) asphalt shingle [18]...

Gypsum, 4 582-601 5 467, 785t 23 576 forms and composition, 4 583t hardness in various scales, 7 3t in Portland cement, 5 467 in Portland cement hydration, 5 477t thermal reduction of, 23 577 thermodynamics and kinetics of formation- decomposition, 4 586-588 Gypsum board, 4 600-601 Gypsum processes, obtaining sulfur from, 23 576-577... 

Formaldehyde Germicide, pressed-wood products, urea-foimaldehyde foam insulation (UFFI), adhesives, paints, plastics, carpeting, gypsum board, ceiling tiles and panels, wood paneling. 083 2A... 

Xylene Solvent, dyes, insecticides, polyester fibres, adhesives, wallpaper, varnish, carpeting, wet-process photocopying, pressed-wood products, gypsum board, water-based adhesives, grease solvents, paints, carpet adhesives. 2.9 3... 

Interior partition walls should be noncombustible construction, such as fabricated of drywall (gypsum board) on metal studs or equivalent. Wood or plywood wall paneling or other combustible construction materials should not be used. The use of wallpaper or other thin wall coverings is acceptable. 

The thermal insulation materials used in the walls, ceilings, and floors of refrigerated storage are usually combustible, such as polyurethane and polystyrene foam, and could present an additional fire hazard. The insulation should be covered with a noncombustible barrier material a V2-in (1.3-cm) thickness of Type-X gypsum board or cement plaster is often used for this purpose. Where the floor is insulated, the floor insulation should be covered with a layer of concrete. 

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