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1945 Theatre Catalog, 4th Edition, Page 135 (113)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 135
Page 135

1945 Theatre Catalog, 4th Edition, Page 135


The different fabricated forms of Fiberglas have different properties, but the fibers themselves possess certain properties that are basically responsible for the wide range of services that Fiberglas is able to perform in its many and diverse fabricated forms.

Flexibility is the property of glass fibers that distinguishes them from all other forms of glass. Glass fibers are dexible for just one reason. They are almost incredibly thin in relation to their length. Glass fibers possess the greatest tensile-strength-to-weight ratio of any commercial material either occurring in nature or synthesized by man. A cubic foot of uncompressed glass fibers of the wool-like type used for thermal insulation weighs only one and a half pounds, and is approximately 100 times lighter than a cubic foot of bulk glass.

Glass fibers possess remarkable dimensional and physical stability. Although they may be as fine as gossamer, the fibers are neither more nor less than microscopically thin glass rods. Because they have no cellular inter-structure, they cannot absorb moisture. Their surfaces can be wet, but moisture cannot get into the fibers to cause them to shrink, stretch, swell or rot.

Finally, the fibers are completely incombustible. Light a match to a strand or clump of the glass fibers, and they will not dame up or even smolder. They may melt, and the match dame will leave a black deposit of carbon-but neither a match nor anything else will make the fibers burn, nor will they give off smoke or any noxious fumes.


In meeting the requirements for thermal insulating materials which will stand up under the strains, stresses, vibration, and humidity conditions to which combat ships and bombergand fighter planes are subjected, the Fiberglas corporation and applicators of its materials developed many improvements in products and installation methods.

These are refiected in the post-war uses of Fiberglas in such standard prewar applications as the thermal insulation of water heaters, freight and passenger planes, railroad cars, trucks, buses and merchant ships, factories and other types of industrial and commercial buildings and their equipment.

In a number of war applications, Fiberglas thermal insulation was employed for the control of sound as well as heat. It was installed for this twin purpose in war-production plants. Blankets, composed of down-like glass fibers, were used for both heat and sound insulation in multieniotored bombers. These and other war uses of Fiberglas as an acoustical material have laid the basis for its wide use to control sound, by many industries, including the motion-picture, radio, and television industries.

Properties of Insulation Material

The resilient mass of intricately interlaced glass fibers which is the basis of all forms of Fiberglas thermal and acoustical insulation is composed of fibers



whose diameters depend on the purpose for which the insulation is to be employed. '

The wool-like mass can be installed in the form of bats, rolls, bulk fibers or shredded fibers. The blankets into which the mass can be formed can be faced with paper, fabric, or metal mesh. The sheets and boards into which the mass can be fabricated can be given a variety of surface treatments, including a sanded, smooth finish on one side, a paper or fabric facing on one side, and an overall asphalt coating. They can be given a hard surface by facing them on one or both sides with sheets of plywood or a plastic material.

The low thermal conductivity is due primarily to the millions of air spaces entrapped by the interlaced fibers. These air spaces are poor conductors of heat. In addition, Where the fibers cross and touch each other they have exceedingly small contact points. Heat, therefore, cannot pass readily from one fiber to another.

The same air spaces, and the tremendous surface area presented by the ma5s of fibers, absorb and break up sound waves. When Fiberglas bats, rolls, blankets, sheets, or boards are installed immediately behind a perforated surface of metal, asbestos board, fiber board or similar material, the noise reduction factor is high, the exact figure depending upon the form, thickness, and density of the Fiberglas, the type of finish and the method of installation.

Fiberglas thermal and sound insulating materials are inherently fire-safe. Organic facing materials can be flameproofed. The small amount of lubricant with which the fibers are treated, or the

small amount of thermosetting resin used to give permanence of form, may volatilize at elevated temperatures, but the fibers themselves retain their complete incombustibility, and present a barrier to the spread of fiame.

The immunity to rot and decay possessed by the glass fibers is carried over to Fiberglas insulating materials. In addition, the materials provide no sustenance for insects or vermin of any kind. Properly installed, they do not settle down under shock or vibration, leaving gaps for heat or sound to pass through; rather, unless bonded with a resin, the compressed fibers tend to fluff out, filling any voids.

The amount of moisture picked up by the massed fibers from humid air is infinitesimal-but a fraction of 1 per cent by weight. The rapidity with which the wool-like forms of Fiberglas insulation will dry out after wetting, if drained and vented to the air, is due to the fact that water can wet only the surfaces of the fibers.

Fiberglas thermal and sound insulation is one of the group of mineral wool insulations, including rock wool and slag wool, with which applicators and users have been familiar for a half century. Its application involves no departure from familiar practices. It is light in weight, easy to handle, easy to cut or fit to required shapes or sizes, and holds together well while being applied.


The bat, roll, bulk, and shredded forms of Fiberglas are suitable for use in all temperatures from sub-zero to approximately 1,000 degrees Fahrenheit. Bats and rolls are widely used in water heat ACOUSTICAL BOARD of Fiberglas serves as decoration as well as insulation against heat and sound, as pointed out in this photograph from the Owens-Corning Fiberglas Corporation of the radio operations room in a police headquarters. Because it is impervious to moisture, Fiberglas does not rot nor decay, and it is not attacked by rodents or other vermin. When properly installed, the material does not settle under shock or vibration.

1945 Theatre Catalog, 4th Edition, Page 135