Abstract:
A suspension ceiling panel that includes enhanced durability, sound absorption and increased fire safety qualities. The panel comprises a body substrate including a plurality of apertures. The body is further adapted to be connected to the ceiling grid members. The outer exposed surface of the body substrate is covered by a non-woven fibrous material. Apertures in the body substrate in combination with the non-woven fibrous material on the lower exposed surface of the panel provides the appearance of a traditional acoustical panel but provides desirable sound absorption and fire resistive qualities.

Description:
BACKGROUND  
       [0001]     This disclosure relates to suspended ceiling systems and more particularly to a novel and improved system using perforated metal ceiling panels that include a non-woven fibrous facing material on the lower exposed surface of the panel creating an aesthetically pleasing and durable with fire safety qualities in a sound absorbing paneled ceiling system.  
         [0002]     By way of background but not limitation, suspended-ceiling systems typically include grid members that provide for oppositely extending ceiling panel support flanges. In these systems, the edges of the ceiling panels are installed by laying them in the panel opening created by the grid members. There are also suspended-ceiling systems that have grid members, which include channels designed to grip the vertically extending edges of metal ceiling panels. These ceiling panels are typically installed by snapping the flanges up into the grid member channel, and are generally referred to as “snap-up ceiling panels.” Typical lay-in grid panels are manufactured from slag wool fiber and/or recycled paper and expanded perlite or fiberglass to create light weight aesthetic ceiling panels. Some of these grid panels do not provide durability or sound absorption qualities that are desired for use in commercial, residential and industrial space.  
         [0003]     In view of the above, it should be appreciated that there is a need for a ceiling panel that provides for increased durabilty and sound absorption. The present disclosure satisfies these and other needs and provides further related advantages.  
       SUMMARY  
       [0004]     The disclosure may be described as a novel and improved suspension ceiling panel that includes enhanced sound deadening qualities and increased durability. In the preferred embodiment the panel comprises a metallic panel substrate including a plurality of apertures of varying sizes. The body is further adapted to be connected to the ceiling grid members. The outer exposed surface of the metallic panel substrate is covered by a non-woven fibrous material that is adhered thereto. The multi-dimensioned apertures formed in the panel substrate in combination with the non-woven fibrous fabric on the lower exposed surface of the panel not only provides the appearance of a traditional acoustical panel but provides desirable sound absorption and resistance to flame spread and smoke generation.  
         [0005]     Other features and advantages of the disclosure will be set forth in part in the description which follows and the accompanying drawings, wherein the embodiments of the disclosure are described and shown, and in part will become apparent upon examination of the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The above mentioned and other features of this disclosure and the manner of obtaining them will become more apparent and the disclosure will be best understood by reference to the following description of embodiments of the disclosure taken in conjunction with the accompanying drawings in which:  
         [0007]      FIG. 1  is a perspective view of one type of ceiling system illustrating fibrous faced ceiling panels;  
         [0008]      FIG. 2  is a sectional view of the ceiling system, taken along lines  2 - 2 , illustrating the fibrous faced ceiling panels connected to a grid system;  
         [0009]      FIG. 3  is a top view of the ceiling panel illustrating the spacing and sizes of the perforations;  
         [0010]      FIG. 4  is a top view of the ceiling panel illustrating an alternate perforation pattern;  
         [0011]      FIG. 5  is a perspective view of a ceiling system illustrating the fibrous faced ceiling panels transitioning from a first elevation to a second elevation;  
         [0012]      FIG. 6  is another perspective view of a ceiling system illustrating the fibrous faced ceiling panels transitioning from a first elevation to a second elevation;  
         [0013]      FIG. 7  is a perspective view of a ceiling system illustrating the transition from the fibrous faced ceiling panels to other types of ceiling panels; and  
         [0014]      FIG. 8  is a perspective view of a ceiling system illustrating curved fibrous faced ceiling panels. 
     
    
     DETAILED DESCRIPTION  
       [0015]     While the present disclosure will be described fully hereinafter with reference to the accompanying drawings, in which a particular embodiment is shown, it is to be understood at the outset that persons skilled in the art may modify the disclosure herein described while still achieving the desired result. Accordingly, the description that follows is to be understood as a broad informative disclosure directed to persons skilled in the appropriate art and not as limitations on the present disclosure.  
         [0016]     As illustrated in the drawings,  FIG. 1  illustrates a portion of an assembled suspension ceiling incorporating snap-up fibrous faced ceiling panels  10  in accordance with the present disclosure. In such a ceiling panel system, grid members  12  are interconnected to form a grid structure  13 . The grid members  12  are arranged to form openings  14  sized to receive the ceiling panels  10 . The grid members  12  are suspended from the building structure by wire hangers  16  or other supporting structures.  
         [0017]     To create the grid structure  13 , a row of parallel evenly spaced grid members  12  are suspended by wire hangers  16 . Each row of the grid members  12  are spaced apart to accommodate the size of the fibrous faced ceiling panels  10 . To accommodate a 2 foot by 2 foot ceiling panel, the grid members  12  would be spaced apart 2 feet on-center. The grid structure  13  also includes a second set of grid members  18  that are perpendicularly oriented in relation to the first set of grid members  12  to create the opening required for hanging the panels  10 .  
         [0018]     The fibrous faced ceiling panels  10  are normally rectangular, usually square in shape, and are preferably made out of metal. The panels  10  are durable in that they are impact resistant, self-supporting do not sag or fracture when perforated. Depending upon the ceiling design used, it may be desirable to shape the panels  10  into a square or curved shape, as shown in  FIG. 8 , but other shapes may be utilized. Other shapes would include transition panels, as shown in  FIGS. 5 and 6 , which allow the transition from a first elevation to a second elevation.  FIG. 7  illustrates a decorative transition panel  55  without the facer material, which can be a low gloss or high gloss, reflective panel. While the preferred material used in fabricating the fibrous faced ceiling panels  10  is metal, other materials may be used including gypsum, wood, wood fiber, plastic and other substrate materials that allows perforation while retaining the basic shape and stiffness of the fibrous faced ceiling panels  10 . Metal and plastic material, such as polycarbonate, are preferred since panels can be molded or stamped to include a desired shape or to form various edge configurations for connection to the grid structure  13 . The fibrous faced ceiling panels  10  include an interior face  20  and an exterior face  22 . The panels  10  may also include a hinge  24  along a first corner  25  of the panel  10  to permit the panel to be pivoted to an open position with respect to the grid system  13 . The panel  10  preferably includes flanges  26  along the edges  58  of the panel  10 . While a flanged edge and a hinged edge are disclosed, other edge configurations may be used to secure the panels  10  to the grid system.  
         [0019]     The fibrous faced ceiling panels  10 , as shown in  FIG. 1 , illustrates the panels  10  connected to the grid structure  13  by use of flanges  26 . It is beneficial to use the hinge  24  to support the ceiling panel  10  when all metal ceiling panels become as large as 4 feet by 4 feet, because the panels become awkward to install and remove due to their relatively large size and weight. Further illustrations of the use of a hinge can be found in U.S. Pat. No. 6,467,228, incorporated herein by reference. When working with a piece of sheet metal with such a large surface, any improper handling may result in damage to the overall finish of the ceiling panel  10 . Also, by using the hinge  24  that spans the length of the ceiling panel  10 , the weight of the panel is evenly distributed across the entire corner  25  of the panel  10 , preventing rippling that would be apparent in the bottom surface  20  of the panel  10 . Furthermore, once the ceiling panel  10  is connected to the grid members  12 , the ceiling panel  10  will automatically be in alignment to allow for easy closure by pivoting the ceiling panel  10  upward and snapping in the flanges  26  into the grid.  
         [0020]      FIG. 2  is a cross section of  FIG. 1  taken along line  2 - 2  looking in the direction of the arrows and shows the grid member  12  and the hinge  24  along an corner  25  of a first ceiling panel  10  and the flanged edge  26  of a second ceiling panel  10 . The grid member in this example  12  is fabricated out of a single piece of die-formed sheet metal. The grid member  12  after fabrication includes a bulb portion  34 , a channel  36  and a double layer bridge portion  38  that connects the bulb portion  34  and the channel  36 . The overall shape of the grid member  12  is to give the member  12  strength to prevent flexing. Typically, apertures (not shown) are placed along the length of the bridge portion  38  so that wire hangers  16  can be threaded through and wrapped around the bulb portion  34 . Once the wire hanger  16 , as shown in  FIG. 1 , which can be in the form of a wire, is threaded through an aperture (not shown) and around the bulb portion  34 , the wire hanger  16  is wrapped around itself several times to prevent it from unraveling.  
         [0021]     The bridge portion  38  typically includes slots (not shown) that allow one grid member  12  to be connected to the second grid member  18  to form the grid structure  13 . The channel  36 , as shown in  FIG. 2  is formed by bending the double layers of the bridge portion  38 , 90 degrees outward, 90 degrees downward and 90 degrees inward to form a boxed channel  36 . Bottom edges  42  are folded over to act as an engagement edge for the flange  26  and a retaining surface for the hinge  24 . The hinge  24  is formed in the ceiling panel  10  by die-forming the hinge  24  90 degrees upward to create an upwardly extending leg  43  and then die-forming the edge 90 degrees inward to create an inward lip  44 . The inward lip  44  of the hinge  24  rests upon the bottom edge  42  in the channel  36  of the grid member  12 . The flange  26 , shown in  FIG. 2 , is formed by die-forming or molding the edge  26  of the ceiling panel  10  upward 90 degrees to form a vertical member  45  and by forming a rib  48 . The ceiling panel  10  is retained to the grid structure  13  by forcing rib  48  past the bottom edge  42 . The rib  48  is properly positioned within the channel  36  when the rib  48  is resting upon the bottom edge  42 . The vertical member  45  biases the rib  48  to prevent the ceiling panel  10  from moving out of position. While use of an edge with a rib  48  is preferred, other grid engagement mechanisms may be used including a lay-in arrangement wherein the edges  26  do not include a flange.  
         [0022]      FIG. 2  also illustrates a fibrous facer material  54  adhered to the exterior face  22  of the panel substrate  11  viewable from the environmental area of a building structure. The environmental area of the building structure is defined as the space within a building used by occupants to work or conduct other activities. It is the inhabitable space within a structure. From the environmental area, the fibrous facer material  54  is substantially exposed and viewable by the occupants below. The interior face  20  of the panel  10  is substantially concealed from the environmental area and is not viewable by the occupants below. The fibrous facer material  54  creates an aesthetically pleasing surface that gives the ceiling a soft appearance as opposed to a painted metallic ceiling panel, which has an undesirable shiny appearance.  
         [0023]      FIG. 3  is a top view of the fibrous faced ceiling panel  10  that illustrates the positioning of apertures  52  of a first diameter and apertures  53  of a second diameter across the panel  10 . The non-woven fibrous facer material  54  on the exterior face  22  of the panel  10  is adapted to cover the entire face  22  of the panel  10  including the apertures  52 ,  53 . When the fibrous facer material  54  is applied to the panel  10 , only the fibrous facer material  54  is visible from below. The panel substrate  11  or the apertures  52 ,  53  are not viewable from below. The sound absorption mechanism of the fibrous faced ceiling panels  10  is a combination of resonant absorber sound attenuation due to the resistance in air flow through the pores of the non-woven fibrous facer material  54  and the perforation of the panel  10 . In order to maximize sound absorption at varying frequencies, three main parameters need to be optimized. This includes the extent of perforation of the panel  10  with apertures  52 , the airflow resistance of the fibrous facer material  54  and the plenum height, i.e. the distance between the structure and the ceiling.  
         [0024]      FIG. 4  illustrates a top view of an alternate aperture arrangement wherein the panel  10  includes apertures  52  of a first diameter apertures  53  of a second diameter and apertures  55  of a third diameter. The combination of the three aperture sizes enhances the resistance of sound waves of varying frequency. The apertures  52  shown in  FIG. 1  are all of a uniform size.  
         [0025]     The extent of the perforation of the panel  10  is partially dependent upon the strength of the selected substrate material and its resistance to mechanical impact and to excessive panel flex. Substrates such as metal and plastic can be extensively perforated, while gypsum board is limited to no more than about 20% of its surface area in order to maintain strength. In order to achieve the proper sound deadening qualities, the substrate is perforated from about 10% to about 35% open area. Optimally, the percentage of the open area of the face  50  of the panel  10  should be about 30% to about 33%.  
         [0026]     Sound is made up of various frequencies. A cymbal for instance would emit a high frequency whereas a base drum would emit a low frequency. The varying amplitude of the frequencies renders it difficult to provide a medium that is sufficient at deadening sound. A particular media may be efficient at capturing low frequency noise but is incapable of capturing high frequency noise. In order to enhance sound absorption at different frequencies the substrate panel  11  is perforated with apertures of different diameters. More specifically, two or three different aperture sizes are preferred. For the panel  10  to achieve the desired sound deadening qualities, the diameter of the apertures in the panel are from about 0.039 inches to about 0.117 inches to achieve the desired sound deadening qualities. Preferably, the perforated pattern is a combination of 15/128 of an inch apertures and 3/32 of an inch apertures. While circular apertures are preferred, oval triangular, polygonal, square or elliptical shaped apertures can also be used. Apertures with large diameters permit the passage of low frequency sounds with large amplitudes whereas apertures with smaller diameters permit the passage of high frequency sounds with smaller amplitudes.  
         [0027]     Spacing between the panels  10  is important in order to gain the maximum benefits from the panels. In order to maximize the sound absorption qualities of the panels, it is sufficient that the gap tolerance between panels is in the range from about zero gap to about ⅜ of an inch and preferably from about a zero gap to a gap of about ¼ of an inch. Spacing between the panels larger than ⅜ of an inch permits excessive sound to be deflected off of the grids  12  and back into the room, reducing the effectiveness of the ceiling system.  
         [0028]     In testing of the panel  10  of the present disclosure smoke development and flame spread by the panel resulted in values substantially lower than industry standards. Limiting smoke development in a building fire is essential in order to increase the ability for occupants in the build to escape without being subjected to smoke inhalation. Typically in a fire, smoke inhalation, and not the fire itself cause death to the occupants.  
         [0029]     The non-woven fibrous facer material  54  is applied to the panel substrate with use of an adhesive. The adhesive utilized to adhere the non-woven fibrous facer material  54  to the ceiling panel  10  is preferably a hot melt adhesive that is substrate compatible. The adhesive must also be compatible with the type of facer material  54  applied to the panel  10 . While hot melt adhesive is preferred, it is foreseeable that other types of adhesives, such as spray, brush or roll-on adhesives may be used. The sound absorption qualities of the panel are also varied by the type and amount of the glue used on the fibrous facer material  54 .  
         [0030]     The panel substrate  11  and fibrous facer material  54  are designed to permit molding or stamping of the panel  10  into desired configurations to create flanges  26 . Transition panels  57 , as shown in  FIGS. 5 and 6  or curved ceiling panels, as shown in  FIG. 8  may also be created by molding or stamping the panel. Transition panels  57  are used to transition from a first ceiling elevation to a second ceiling elevation and can be formed by bending or curving the panels  10 . In order to permit the panel  10  to be formed into the desired configuration, the panel substrate  11  is preferably made from steel, aluminum or polymer. The fibrous facer material  54  used to cover the exterior face  51  of the panel substrate  11  can be of various materials so long as the material does not rip or tear when formed with the panel. Certain materials when tested such as fiberglass tear or crack when the panel  10  is molded to create flanges  26  or other desired shapes. Preferred materials for use as a fibrous face material  54  include polymer mixtures having polyster fibers. Another such usable material is a combination of NYLON6 and Polyethylene. Polymer mixtures of fibrous materials, permit the passage of airflow through the material  54  and allow the panel  10  to be shaped after the fibrous material  54  has been adhered to the panel  10  without tearing the fibrous face material  54 .  
         [0031]     To achieve the desired sound deadening qualities, the panel substrate  11 , in combination with the fibrous facer material  54  should have an airflow resistance from about 900 mks rayls to about 1050 mks rayls. Specific airflow resistance is the product of the airflow resistance of a specimen and its area. This is equivalent to the air pressure difference across the panel  10  divided by the linear velocity of airflow measured outside the panel  10 . The airflow resistance of the fibrous facer material  54  in combination with the perforated panel substrate is critical to the efficiency of the acoustic attenuation process. If the airflow resistance is too high, the material reflects the sound wave as if it were a solid wall. If it is too low, the sound wave freely travels through the material. In either case the sound attenuation is less than optimum. The preferred airflow resistance of the facer material  54  should be about 100 mks rayls to about 600 mks rayls.  
         [0032]     Airflow resistance of a panel  10  is defined as the ratio of the pressure drop across the material to the velocity of the gas passing through it and can be expressed in cgs rayls (dyne/cm 2  per cm/sec). Determination of flow resistivity is the main property in describing the acoustical performance of any porous material. Every fibrous material has specific flow resistance characteristics based on its manufacturing process or inherent nature. In the case of composite materials, such as the present panel  10 , which is a combination of the fibrous facer material  54  and the perforated panel  10 , it is important to understand the individual flow resistance of each component. However, for optimum performance of the resultant panel  10 , it is vital to tune the flow resistance of the entire system fibrous facer material  54  and panel substrate  11  to maximize sound absorption. As previously stated, this optimum airflow resistance is about 900 mgs rayls to about 950 mks rayls.  
         [0033]     In most cases, plenum height  64  behind the panel  10  is limited and therefore the sound absorption performance of the panel  10  is restricted by the short plenum gap, as shown in  FIG. 2 . In order to further enhance the sound absorption of the panel  10  with a short plenum height a second layer of porous insulation material  56  such as glass fiber, mineral fiber, thermoplastic polymeric fiber, thermosetting polymeric fiber, carbonaceous fiber, milkweed fiber, or foam insulation, (with preference to polyolefin microfiber melt blow products) can be applied to the interior face  20  of the panel  10 .  
         [0034]     The panels  10  are designed with four edges  58  that are adapted to be connected to the grid structure  13 . The panels  10  can be connected to the grid structure  13  using various edge configurations. The edges  58  of the panel  10  can include the vertical member  45  and a rib member  48 . This allows the panel to be snapped into the bottom edges  42  of the grid members  12  and  18 . In yet another alternative, the panel  10  does not include edges  25  and simply lays into the openings  14  created by the grid structure  13 .  
         [0035]     While the concepts of the present disclosure have been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only the illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired and protected.  
         [0036]     There are a plurality of advantages that may be inferred from the present disclosure arising from the various features of the apparatus, systems and methods described herein. It will be noted that alternative embodiments of each of the apparatus, systems, and methods of the present disclosure may not include all of the features described yet still benefit from at least some of the inferred advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of an apparatus, system, and method that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the invention as defined by the appended claims.