U.S. patent application number 13/371886 was filed with the patent office on 2013-08-15 for ceiling panels made from corrugated cardboard.
This patent application is currently assigned to USG INTERIORS, LLC. The applicant listed for this patent is Mark Englert, Qing Claire Yu. Invention is credited to Mark Englert, Qing Claire Yu.
Application Number | 20130206501 13/371886 |
Document ID | / |
Family ID | 47748788 |
Filed Date | 2013-08-15 |
United States Patent
Application |
20130206501 |
Kind Code |
A1 |
Yu; Qing Claire ; et
al. |
August 15, 2013 |
CEILING PANELS MADE FROM CORRUGATED CARDBOARD
Abstract
An acoustical ceiling panel comprising a flat core and an
acoustically transparent face sheet adhesively attached to one of
two oppositely facing major sides of the core, the core comprising
a multitude of layers of corrugated fiberboard laminated together,
the corrugated fiberboard layers each having a corrugated medium
adhesively attached to a flat liner board, the corrugated medium
forming regularly spaced flutes of curvilinear cross-section, the
flutes of the layers of fiberboard being arranged in parallel
directions extending perpendicularly to the major faces of the
core.
Inventors: |
Yu; Qing Claire;
(Libertyville, IL) ; Englert; Mark; (Libertyville,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yu; Qing Claire
Englert; Mark |
Libertyville
Libertyville |
IL
IL |
US
US |
|
|
Assignee: |
USG INTERIORS, LLC
Chicago
IL
|
Family ID: |
47748788 |
Appl. No.: |
13/371886 |
Filed: |
February 13, 2012 |
Current U.S.
Class: |
181/290 |
Current CPC
Class: |
E04B 9/001 20130101;
E04B 9/045 20130101 |
Class at
Publication: |
181/290 |
International
Class: |
E04B 1/82 20060101
E04B001/82 |
Claims
1. An acoustical ceiling panel comprising a flat core and an
acoustically transparent face sheet adhesively attached to one of
two oppositely facing major sides of the core, the core comprising
a multitude of layers of corrugated fiberboard laminated together,
the corrugated fiberboard layers each having a corrugated medium
adhesively attached to a flat liner board, the corrugated medium
forming regularly spaced flutes of curvilinear cross-section,
sidewalls of the flutes being perpendicular to the face sheet, the
flutes of the layers of fiberboard being arranged in parallel
directions extending perpendicularly to the major faces of the
core, the core having major face dimensions of 2 foot by 2 foot or
2 foot by 4 foot and a nominal thickness of about 1 inch, the face
sheet being a non-woven scrim painted to achieve an air flow
resistance that allows the panel to exhibit an NRC of about
0.7.
2. An acoustical ceiling panel as set forth in claim 1, wherein the
side of the core opposite the side covered by the face sheet is
covered by a backing sheet adhesively attached to the core for
improving CAC.
3. (canceled)
4. An acoustical ceiling panel as set forth in claim 1, wherein the
individual laminations of corrugated fiberboard are all single
sided.
5. (canceled)
6. An acoustical ceiling panel as set forth in claim 1, wherein the
flutes are selected from one or more of A, B, C and E flutes
described in ASTM Standard D4727.
7. An acoustical ceiling panel as set forth in claim 1, wherein the
flutes have a size between 30 per foot with a height of 0.2210
inches and 98 per foot with a height of 0.0445 inches.
Description
BACKGROUND OF THE INVENTION
[0001] The invention relates to building products and, in
particular, to acoustical ceiling tile.
PRIOR ART
[0002] Suspended ceilings customarily comprise a suspended metal
grid and panels or tiles closing the spaces between the grid
elements. Normally, the panels are constructed with selected
materials and/or surface treatments to absorb sound. The ability of
a panel to absorb sound is conventionally reported as its Noise
Reduction Coefficient or NRC. NRC can range between 0 (no
absorption) and 1 (full absorption) with a rating of 0.5, meaning
it absorbs 50% of the sound energy striking it, being required to
qualify a panel as "acoustical". In the industry, panels rated at
0.7 are considered to have good acoustical performance. A need
exists for acoustical tiles that achieve excellent NRC values and
especially have the ability to absorb sound at target frequencies,
have a high post consumer recycle content, resist sagging over
time, are relatively light in weight, and are relatively
inexpensive to produce.
SUMMARY OF THE INVENTION
[0003] The invention provides a ceiling panel with high level
acoustical absorption properties using a core made of ordinary
corrugated fiberboard, sometimes called cardboard. The core
construction consists of numerous narrow strips of corrugated
fiberboard laminated together. The corrugated board is cut
perpendicular to the corrugations or flutes so that the flute
openings lie in front and back planes of the panel core
corresponding to the geometry of the finished panel. The front of
the panel is covered with a suitable sheet of acoustically
transparent material with proper air flow resistance and the back
of the panel is optionally closed with another sheet, preferably
with acoustical isolating properties.
[0004] In addition to high acoustical performance, the panel of the
invention has the potential to be economically produced, light in
weight, and have a high post-consumer recycle content. Corrugated
fiberboard is typically produced on high speed machines with
relatively low energy consumption and with high recycled paper
content. Because the inventive panel is largely air space, it is
relatively light in weight.
[0005] The disclosed vertical orientation of a flat liner board
component of the corrugated fiberboard in the finished panel makes
the panel sag resistant and capable of spanning large grid modules.
The inventive panel can be produced directly from reclaimed
corrugated fiberboard since there is no criticality in the
uniformity of the flute size, flute alignment, and/or number of
walls of the corrugated fiberboard used in a particular panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of an acoustical panel made in
accordance with the present invention;
[0007] FIG. 2 is a fragmentary schematic showing of one manner of
assembling a core of the inventive panel; and
[0008] FIG. 3 is a perspective view of a three-dimensional block
from which the inventive panels are cut in an alternative manner of
producing a core of the inventive panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] FIG. 1 illustrates an example of an acoustical ceiling panel
10 of the invention; the panel is a nominal 2 foot by 2 foot unit
and can have a nominal thickness of 1 inch. Dimensions discussed
herein will be understood to include industry metric equivalents.
The panel 10 includes a corrugated fiberboard core 11, a face sheet
12, and a backing sheet 13. The core 11 is made by assembling
numerous corrugated fiberboard layers 15 side-to-side such that the
combined total thickness of the layers is equal to the length of an
edge of the panel 10.
[0010] As shown in FIG. 2, each layer 15 can comprise a corrugated
medium 16 and a single flat liner board 17, the combination of
these elements sometimes being referred to as a single-sided or
single face corrugated board. The paper compositions and
fabrication of corrugated fiberboard is well known to the relevant
industry. The corrugated medium 16 is a paper, typically, in the
United States having a weight of 0.026 lbs./square foot. The paper
is heated, moistened and formed into a fluted pattern on geared
wheels. Typically, the fluted or corrugated medium 16 is joined to
the flat liner board 17 with a starch-based adhesive to form the
single face board comprising the layer 15. As is typical, the liner
board stock can have the same weight as the paper of the medium 16.
The flutes or corrugations of the medium 16 are essentially
entirely curvilinear in cross-section and resemble a sine wave. The
size of the flutes, designated 19, is ordinarily stated by the
number of flutes in a foot length of the corrugated fiberboard.
ASTM Standard D4727 sets out the following flute sizes, applicable
to single face, as well as singlewall, doublewall and triplewall
corrugated fiberboard (referred to below).
TABLE-US-00001 Flute Flute Flutes/ft Flutes/m Height (in.) Height
(mm) A-Flute 30 to 39 98 to 128 0.1575 to 0.2210 4.00 to 5.61
B-Flute 45 to 53 147 to 174 0.0787 to 0.1102 2.00 to 2.80 C-Flute
35 to 45 115 to 148 0.1300 to 0.1575 3.30 to 4.00 E-Flute 70 to 98
229 to 321 0.0445 to 0.0550 1.13 to 1.40
[0011] Tests have indicated good acoustical properties, with an NRC
in the order of 0.70, can be obtained with all of these standard
flute sizes. Moreover, the panel construction, such as the panel
thickness, can be selected to absorb sound at targeted
frequencies.
[0012] By way of example, the thickness of the corrugated
fiberboard core can be, as mentioned above, nominally 1 inch. FIG.
2 schematically illustrates one method of manufacturing the core
11. Single face stock or board 15, i.e. having only one flat liner
board 17 and one corrugated medium 16, is slit into 1 inch wide
strips. The length of the strips can be equal to one of the nominal
planar dimensions of the finished panel 10. The strips are stacked
on each other with their longitudinal slit edges in registration.
Glue or adhesive is applied to a side of a strip at the interface
between adjacent strips. The stack height is built up until it
reaches the nominal planar dimension of the finished panel
perpendicular to that represented by the length of the laminated
strips.
[0013] FIG. 3 illustrates another method of forming the core 11.
Flat rectangular sheets 21 of corrugated fiberboard having at least
one planar dimension equal to a nominal planar dimension of the
finished panel 10 are stacked to a height equal to the other
nominal planar dimension of the panel. The sheets are permanently
attached to one another with glue or adhesive at their interfaces.
The result is a block 22, which in the illustration of FIG. 3 is a
cube. The block 22 is sliced with a saw along a plane denoted by
lines X-X and Y-Y spaced nominally 1 inch from a side of the block
to form a core. Successive cores 11 are formed by more cuts, each
spaced a distance of 1 inch from the preceding cut.
[0014] The flutes 19 of the core 11 extend perpendicularly to its
major planar faces. The face sheet 12 is an acoustically
transparent medium or film, optionally painted with proper air flow
resistance that can serve as the appearance side visible to an
observer in a room in which the panel 10 is installed. The face
sheet 12 is adhered to the core 11 with a suitable adhesive. The
face sheet 12 can be coated with a paint of a type used on the face
of conventional ceiling tiles to improve its appearance and/or
light reflectance and to obtain overall air flow resistance in a
proper range. An example of a suitable face sheet 12 is a non-woven
fabric such as fiberglass scrim with a caliper of 0.02 inch, basis
weight of 125 g/m.sup.2, and specific air flow resistance of 45.6
Pa.s/m coated with a paint. The choice of face sheet 12 with proper
air flow resistance was found to be important to the overall
acoustical performance of the inventive panel; if the air flow
resistance is too low or too high, the acoustical performance is
impaired.
[0015] The side of the core 11 opposite the facing sheet 12 is
preferably covered with the backing sheet 13 which can be a kraft
paper laminated with a metal foil as used in some commercially
available ceiling tile products. Other non-foiled paper can be used
for the backing sheet 13. The backing sheet 13 can be used to
obtain a good CAC (Ceiling Attenuation Class) value. A suitable
adhesive is used to attach the backing sheet 13 to the core 11.
[0016] The single face board 15 illustrated most clearly in FIG. 2
is the most efficient corrugated fiberboard style from a material
usage standpoint. As shown in FIG. 2, the flat liner board 17 of
one board 15 can serve as a liner board of an adjacent single face
board when it is adhesively attached thereto. From an acoustical
standpoint, singlewall, doublewall and triplewall corrugated
fiberboard work satisfactorily and can be used in place of the
illustrated single face board 15. It is contemplated that where
there is a reliable source of used quality corrugated fiberboard
stock is available, the core 11 can be made by reclaiming this used
material and converting it directly into a core. Since the standard
flute ranges are comparable in acoustical performance in a core
construction, it is possible to produce a core with mixed flute
sizes and without layer to layer flute registration. This flute
size and registration free compatibility can make use of reclaimed
corrugated fiberboard stock in the manufacture of the inventive
panel 10 more practical.
[0017] It should be evident that this disclosure is by way of
example and that various changes may be made by adding, modifying
or eliminating details without departing from the fair scope of the
teaching contained in this disclosure. The invention is therefore
not limited to particular details of this disclosure except to the
extent that the following claims are necessarily so limited.
* * * * *