US 3149693 A
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Description (OCR text may contain errors)
Sept. 22, 1964 F. c. KELLER ETAL 3,149,693
ACOUSTICAL SURFACES Filed Aug. l, 1960 Eig@ `INVENTORS E C. KELLER 6L l?. HARP/s United States Patent O 3,149,693 ACUSTCAL SURFACllS Fred C. Keller, Thornville, and Ronald R. Harris, Newark, (Ehio, asslgnors to Owens-Corning Fiberglas Corporation, a corporation of Delaware Filed Aug. 1, 1960, Ser. No. 46,564 3 Claims. (Cl. 1811-4-53) This invention relates to improved acoustical surface panels for ceilings and walls and to a method of applying such panels.
The use of acoustical ceiling tiles is becoming more and more widespread, particularly in commercial buildings and also in less formal rooms of residences, such as recreation rooms. Ceiling tiles are produced in units usually measuring one foot square, although larger tiles are not uncommon, and have beveled edges so that the individual tiles are readily discernible after being applied to a ceiling or wall. Because of the overall appearance produced by the installed acoustical tiles, they are seldom used in more formal rooms of houses, such as living rooms, dining rooms, and bedrooms. Larger ceiling boards, which are similar to acoustical tiles but are of rectangular shape, usually measuring 2 x 4 or larger, are also used, frequently supported below a ceiling by metal T-bars which are exposed below the ceiling boards, thereby giving a broken appearance to the overall ceiling similar to that obtained with acoustical tiles. lence, acoustical ceiling boards are generally limited to the same applications for which ceiling tiles are used.
The present invention provides an acoustical surface panel and a method of applying such a panel to a basic wall or ceiling structure. The new panels, when in place, provide a smooth appearance with no joints or seams whatsoever being visible. Hence, the surface product with the new panels looks similar to a textured plastered wall and can be used whenever plastered walls are deemed appropriate which includes practically any room in a commercial building or house, including the more formal rooms such as living rooms, dining, rooms, and bedrooms.
Basically, the new panels consist of fibrous, sound-abn sorbing boards preferably made of glass fibers because of their very high degree of sound absorption. The iibrous boards are stapled or otherwise affixed in abutting relationship to structural members constituting part of the wall or ceiling to which the acoustical panels are to be applied. Sheets of bonded mats of glass bers are then adhered to the exposed faces of the ilbrous boards with the edges of the sheets in abutting relationship and staggered with respect to the abutting joints of the brous boards so that old joints are almost imperceptible. With the sheets of bonded mat in place, an acoustical paint is then applied to the exposed surfaces of the sheets to completely hide all joints and to give the effect of a continuous slightly textured surface. Acoustical panels according to the invention are as effective in .absorbing sound as are conventional acoustical tiles and will not crack as does plaster. Hence, the panels combine most of the advantages of both acoustical tiles and plastered walls without incurring the disadvantages thereof.
lt is, therefore, a principal object of the invention to provide an acoustical panel capable of absorbing a high percentage of sound yet still having a smooth, unbroken appearance, rendering a wall or ceiling made of such panels suitable for use in many environments.
Another object of the invention is to provide a method of applying acoustical panels to a basic wall or ceiling structure, which method produces an unbroken surface, free of any visible joints.
A further object of the invention is to provide a soundabsorbing wall or ceiling structure which has an appearance somewhat similar to plaster but does not have a tendency to crack or spall.
Other objects and advantages of the invention will be apparent from the following detailed description of preferred embodiments thereof, reference being made to the accompanying drawing, in which:
FIG. l is a sectional view in perspective of a ceiling or Wall structure embodying the principles of the invention;
FIG. 2 is a fragmentary, sectional view on an enlarged scale of a portion of an acoustical panel which is a part of the structure of FIG. 1;
FG. 3 is a fragmentary, sectional view on an enlarged scale of a slightly modified panel;
ilGS. 4 8 are fragmentary, ectional edge views of elements of the acoustical panels of FIG. l and showing the steps employed in applying such panels on a wall or ceiling structure;
FIG. 9 is an enlarged view of a portion of a sheet of bonded liber mat employed in the acoustical panel; and
FIG. l0 is a greatly enlarged view of a portion of the mat shown in FIG. 9 with a coating of paint on part of the Inat.
Referring to FIG. 1, a wall or ceiling structure indicated generally at 10 includes structural members 12 and acoustical panels according to the invention which are indicated generally at 14. While the panels 14 make an excellent acoustical ceiling, they are equally effective for walls. ln 'the latter instance, the panels are preferably used only above a height of three or four feet, with more shock-resistant panels used therebelow, because the panels le are subjected to damage when struck too hard, although they are more shock resistant than most conventional acoustical tiles. The structural members 12 are shown as wooden studs but can be numerous other structures such as concrete blocks on steel beams, for example, and where the acoustical panels 14 are applied on old walls, the structural members 12 might constitute a combination of studding, lath, and plaster, plaster board, or plywood, by way of illustration. In the case of concrete blocks, or similar materials into which nails or staples cannot readily be driven, furring strips can be employed, l x 3 boards being suitable for this purpose.
The panels 14 basically include fibrous boards 16, preferably of glass fibers, which are backed with layers 1S of heavy paper adhered thereto. Strips of heavy paper can also be used behind the joints of the boards 16. Sheets Ztl of bonded fiber mat are adhered to the eX- posed faces of the fibrous boards 16 with abutting joints indicated at 22. The joints 22 are staggered relative to joints 24 between adjacent ones of the boards 16. Finally, a coat 26 of acoustical paint covers the exposed side of the bonded mat sheets Ztl. The board joints 24 are hidden by the sheets 20 and the abutting joints 22 of the sheets 20 are barely visible before the paint coat 26 is applied and cannot be seen at all thereafter.
Referring now in more detail to FlG. 2, which shows the nature of the specific elements of the panels 14, the fibrous boards 16 are preferably made in 2 x 4' rectanguiar sections, each having a thickness of approximately Si, although larger and smaller as well as thicker or thinner panels can be used. The boards preferably consist of intertwined glass fibers which are densified and bonded together with a phenolic resin, resulting in an apparent density of the fibers and binder of approximately 9 pounds per cubic foot. Glass liber boards of this nature with apparent densities between approximately seven pounds per cubic foot and approximately twelve pounds per cubic foot have been found to be suitable for the panels 14. Fibrous boards with densities below about seven pounds per cubic foot tend to lack suicient stiffness while boards with densities above approximately twelve pounds per cubic foot are more expensive and heavier, due to the additional materials employed therein, without adding any benefits to the panels 14.
l The layer 18 of paper backing on each of the boards 16 is used to reduce the amount of air liow therethrough. Such air liow tends to occur quite readily when slight pressure variations occur in a room in which the panels 14 are located because the boards 16 are quite porous, and when the air flows through the panels 14 from the exposed side, it deposits air-borne dirt thereon and causes the surfaces to darken or soil over a period of time. While the panels 14 can be repainted without any great loss in sound absorption, the period of thne before soiling becomes apparent can be lengthened by using the paper layer 1S to reduce such air iiow. In a specilic ernbodiment of the panel 14, a 40 pound natural kraft paper is adhered to the rear side of the boards 1t with asphalt applied in an amount of four ounces per square foot.
The bonded glass liber mat 20 basically is made of long, glass filaments 20a (FlGS. 9 and 10) having diameters in the order of 0.00060 inch which are arranged in overlapping swirl patterns. The overlapping filaments are dipped in a phenolic binder consisting essentially of 42 pounds of a 50% solids deionized resole, 35 pounds of an 88% solids bone glue, and enough water to make 80 gallons of the binder. The binder in the bonded mat preferably ranges from to 25% by weight, and, most desirably, from to 21% by weight. The mat 20 has a thickness of approximately 0.015 and weighs approximately 0.012 pound per square foot, depending principally upon the amount of binder employed. It is packaged in rolls which are three feet wide and are of varying lengths, up to 5000 feet. T he mat 2li, as described above, is stiffer than most bonded mats known in the art in order to facilitate its application to the xposed surfaces of the fibrous boards 16 without excessive wrinkling. ness can be achieved by using more binder Zlib (FIG. 10) than is normally used, by using a harder binder, or by using a thicker layer of continuous glass filaments, The binder in the mat 2.0 adheres the overlapping rbers together `at their points of intersection but does not cornpletely lill interstices between the bers so that many gaps are present through the mat.
The mat is adhered to the exposed faces of the fibrous boards 16 with an adhesive Z1( FIG. 2) containing a binder which dries rather quickly, is water resistant, and is somewhat elastic. The adhesive also must not deleteriously affect the binder in the board 16 whether it be phenolic, urea, melamine, mixtures thereof, or other materials. Solutions of polyvinyl acetate in toluene have been found suitable for use in this adhesive, as well as rubber-type cements, for example.
The acoustical paint in the coat 26 can be a Water based latex type, several of which are known in the art. The paint preferably coalesces on the surface of the mat 20 in small individual globules 26a (FlG. 10) which cover only some of the gaps in the mat 20 and leave the surface of the mat quite porous. The globules of paint give a slightly textured appearance to the surface to the panels In some instances, it is preferred to fasten plaster board or the like to the structural members 12 before applying the fibrous boards 16. Accordingly, a plaster board 23 of FIG. 3 can be nailed or otherwise fastened by fasteners 29 to the members 12 with the fibrous boards 16 then applied to the plaster board 28 with acoustical mastic 28a or the like. In this instance, the layer 18 of backing paper is eliminated because its purpose is served by the plaster board.
The acoustical panels 14- are applied to the structural components of a wall or ceiling according to the following technique:
The stiff- The fibrous boards 16 are first fastened in abutting relationship to theA structural members 12 of FIG. 1 or other structural portions of the ceiling or wall, staples 30 (FIG. 4) being preferred when the structural portions are of an appropriate nature, The staples 30 have good holding power and can be applied quickly with numerous types of staple guns now known in the art. The staples are applied so that their transverse portions are hush with the exposed surfaces of the boards 15.
Adhesive 31 is tuen applied to the boards 16 over an area designated 32 (FIG. 5) and one of the sheets 20 is adhered thereto with portions 34- at all four edges thereof extending beyond the adhesive area 32. With one of the sheets 20 in place, a second area 32 (FIG. 6) of adhesive 31 is applied on the fibrous boards 16 and a second of the sheets 2t? is placed thereon with a second of the portions 3d overlapping the portion 34 of the lirst of the sheets 20. Gther edge portions of the sheets Ztl at the upper or lower edges thereof also overlap any adjacent sheets in a similar manner. Parts of the two overlapped portions 34 are then severed, preferably by running a sharp edge through the two portions 34 along a single cutting line represented in FIG. 6 by a line 36. Remaining parts 33 of the overlapped portions 34 are then pulled back, away from the board 16, as shown in FlG. 7, and the severed parts of the portions 34 are discarded. The remaining parts 3S of the overlapping portions 3d can then be held back by means of pins 40 or the like which are inserted through the sheets 2li and into the board 16. An exposed portion t2 of the hoard 16 between the sheets 20 is then covered by adhesive d3, as from a spray 44 of a spray apparatus 46. The pins 40 are removed subsequently and the remaining parts 35 are adhered to the adhesive on the portion 42 of the board 16 in substantially perfect abutting relationship. A smooth surface is thereby effected with the seams or joints of the abutting sheets 20 barely visible.
The coating 26 of acoustical paint is then sprayed on, or otherwise applied to, the exposed surfaces of the sheets 20 of bonded mat, as shown in FIG. 8, to complete the acoustical surface. The acoustical paint globules 26a form a discontinuous layer on the sheets 2), covering some of the gaps therein, but leaving many of the minute gaps exposed, whereby the entire acoustical surface is discontinuous, with openings extending through both the paint coat 26 and the sheets 20 to the fibrous, soundabsorbing boards 16 to enable sound to enter the boards 16. The individual gaps and the paint globules surrounding them are not readily discernible, per se, but give an overall t xtured effect to the wall. The surface of the wall is entirely free of any visible seams or joints and has the appearance of textured plaster. Because the fibrous boards 16 and the mat Ztl are somewhat elastic, the acoustical surface cannot crack as does plaster due to shrinkage, shift in the structural portion of the wall, or the like.
Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art, and it is to be understood that such modiiications can be made without departing from the spirit and scope of the invention, as defined in the accompanying claims.
1. A sound-absorbing wall structure for a wall, ceiling, or the like, and having an appearance similar to that of a textured plastered surface, said wall structure comprising a substantially non-pervious layer substantially preventing flow of air therethrough, a plurality of fibrous boards, adhesive attaching said boards to said layer in abutting, coplanar relationship, said boards having apparent densities between approximately seven pounds per cubic foot and twelve pounds per cubic foot, a plurality of sheets of fibrous mat of long glass filaments bonded together by a binder present in an amount of from l0 to 25%, by weight, a second adhesive adhering said sheets llc.
of fibrous mat to said fibrous boards in substantially coplanar relationship, with joints of said sheets being out of alignment with the joints of said fibrous boards, and a coating of acoustical paint on the exposed surfaces of said sheets, said coating of paint being on said sheets in the form of small globules which leave the surfaces of said sheets porous and provide a textured appearance for said Wall structure.
2. A sound absorbing wall structure for a wall, ceiling, or the like, and having an appearance similar to that of a textured plastered surface, said wall structure comprising a substantially non-pervious layer substantially preventing flow of air therethrough, a plurality of fibrous boards, adhesive attaching said boards to said layer in abutting, coplanar relationship, said boards having apparent densities between approximately seven pounds per cubic foot and twelve pounds per cubic foot, a plurality of sheets of fibrous mat of long glass filaments bonded together by a phenolic binder present in an amount of from 10 to 25%, by Weight, a second adhesive adhering said sheets of fibrous mat to said fibrous boards in substantially coplanar relationship, with joints of said sheets being out of alignment with the joints of said fibrous boards, and a coating of water-based paint on the exposed surfaces of said sheets, said coating being on said sheets in the form of globules which leave the surfaces of said sheets porous and provide a textured appearance for said Wall structure, said coat also hiding the joints of said sheets.
3. A wall structure according to claim 2 wherein sai-d non-pervious layer comprises heavy kraft paper coated with asphalt.
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