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1950-51 Theatre Catalog, 9th Edition, Page 141 (121)

1950-51 Theatre Catalog, 9th Edition
1950-51 Theatre Catalog
1950-51 Theatre Catalog, 9th Edition, Page 141
Page 141

1950-51 Theatre Catalog, 9th Edition, Page 141


Table I

SOUND ABSORPTION COEFFICIENTS (Acoustical Materials Assin Data) Wt.

Noise Unit LbsRed. Size Per Test

COEFFICIENTS Thick- Mount ness ing 128 256 512 102420434096C0ef. Tested Silo N0. Ft. %" 1 .04 .20 .63 .91 .82 .82 .65 12"x12" .69 A48-99 %" 7 .21 .50 .91 .99 .86 .80 .80 12"X24" .62 A48-101 1" 1 .11 .33 .80 .96 .82 .76 .75 12"x12" .86 A48-100 1" 7 .23 .57 .90 .98 .88 .84 .85 12"X24" .87 A48-102

Mounting #l-Adhesive Application. Mounting #7eMechanical Application. Oflicial AMA datae1949 Acoustical Materials Association Bulletin, No. XI.

and board are given in Table No. 1. Table No. 2 shows sound absorption coefficients for the perforated tile. Fiberglas acoustical board is identical to one-inch-thick Fiberglas plain acoustical tile, except for size. The board is made in large sizes for installation convenience. Both tile and board are the

Figures 1 and 2 show details of the simple, suspended type construction.

Figures 3, 4, and 5 show mechanical application using the Securitee-Standard System in typical furred constructions.

The Securitee-Limited System, illustrated in Figure 6, substitutes a threequarter inch standard channel for the

lightest-weight mineral-type, fire-safe acoustical materials available. When one inch thick, they weigh less than one pound per square foot, less than threequarters of a pound per square foot when three-quarters of an inch thick.

They will not warp, buckle, expand or contract. When tested at 95 per cent relative humidity, at 120 degrees Fahrenheit, for a period of 96 hours, no measurable change in dimensions occurred. Moisture absorption was less than one per cent by weight. Occasional wetting due to leaks, with subsequent early drying, will have no effect upon the materials other than a possible discoloration of the surface paint.

The fact that the materials combine high thermal-insulating efficiency with high sound-absorbing efficiency may be a major consideration. The ttk" factor of the basic material from which the Fiberglas tile and board are made is 0.24 BTU per inch per hour per square foot per degree Fahrenheit at 75 degrees mean temperature.

Construction Techniques

The combination of incombustibility, light weight and dimensional stability makes Fiberglas tile particularly well adapted to mechanical application systems. Figures 1 to 5 illustrate the

. - b tibl . ' . use of the Securitee-Standard System. non com us a nature low welghl an

special Securitee Box Channel to reduce cost, and is applicable to suspended type construction. Because of the light weight of the Fiberglas tile, a four-foot centering of the channel work is recommended construction. Other mechanical application systems suitable for applying acoustical tile are adaptable to Fiberglas tile.

Typical Installations

Before and during the period of World War II, Fiberglas materials in the forms used for thermal insulation were employed in numerous applications for the control of sound as well as heat. They were installed for acoustical purposes, and in some instances for thermal purposes, also, in the control rooms of Navy ships, in military and naval aircraft, in bomber assembly plants, dynamometer rooms, sound stacks, and motor test stands. They were employed to deaden sound in chambers used for the testing of communications equipment as at Harvard Universityls Electro-Acoustic Laboratories, and at the New York Navy Yard. They are presently used in the Bell Telephone Laboratories test chamber.

APPLYING FIBERGLAS acoustical tiles b the adhesive method is both easy and simple. Because oi its . I dimensional stability. it offers a high safety factor. Illustrated below is a detail through the tile showing the application to the ceiling. with any quality adhesive.


1950-51 Theatre Catalog, 9th Edition, Page 141