U.S. patent application number 11/754406 was filed with the patent office on 2008-12-04 for prefabricated wall panels and a method for manufacturing the same.
Invention is credited to Yitzhak Yogev.
Application Number | 20080295450 11/754406 |
Document ID | / |
Family ID | 40086611 |
Filed Date | 2008-12-04 |
United States Patent
Application |
20080295450 |
Kind Code |
A1 |
Yogev; Yitzhak |
December 4, 2008 |
PREFABRICATED WALL PANELS AND A METHOD FOR MANUFACTURING THE
SAME
Abstract
A multi-layer prefabricated wall panel for modular building and
a method for manufacturing the same. The panel comprises a
load-bearing and vapor barrier core layer; an interior insulating
and utility installation layer bonded to the inner face of the core
layer; an exterior sheet of a first rigid building material bonded
to the interior insulating layer; and an interior sheet of a second
building material bonded to the outer face of said core layer. The
method for manufacturing the wall panel comprises the steps of
forming a stack of the panel layers with adhesive coating between
successive layers and bonding the layers to each other by uniform
compressing forces.
Inventors: |
Yogev; Yitzhak; (Qiryat
Tivon, IL) |
Correspondence
Address: |
SOROKER-AGMON ADVOCATE AND PATENT ATTORNEYS
NOLTON HOUSE, 14 SHENKAR STREET
HERZELIYA PITUACH
46725
IL
|
Family ID: |
40086611 |
Appl. No.: |
11/754406 |
Filed: |
May 29, 2007 |
Current U.S.
Class: |
52/783.1 ;
52/745.19 |
Current CPC
Class: |
E04C 2/26 20130101; E04C
2/384 20130101; E04C 2/521 20130101 |
Class at
Publication: |
52/783.1 ;
52/745.19 |
International
Class: |
E04C 2/36 20060101
E04C002/36 |
Claims
1. A multi-layer prefabricated wall panel, the panel having an
interior and exterior planar surfaces and a thickness defined
therebetween, the panel comprising: a load-bearing and vapor
barrier core layer having an inner face and an opposite outer face;
an interior insulating and utility installation layer bonded to the
inner face of said core layer, the interior insulating and utility
installation layer comprising a plurality of channels extending
from top to bottom thereof for accommodating utility lines; an
exterior sheet of a first rigid building material bonded to said
interior insulating layer; and an interior sheet of a second
building material bonded to the outer face of said core layer.
2. The wall panel of claim 1 wherein the core layer comprises at
least two tubular metal members and one or more interior sandwich
panels extending between said two metal members, the one or more
sandwich panels and the metal members having substantially the same
length and thickness so as to form in combination a solid layer
with two opposite flat faces.
3. The wall panel of claim 2 wherein said one or more sandwich
panels comprise thermal insulating material sandwiched between two
flat metal skins.
4. The wall panel of claims 3 wherein said thermal insulating
material is selected from the group consisting of mineral wool,
polymer foam and timber.
5. The wall panel of claim 1 wherein said insulating and utility
installation layer comprises a plurality of spaced apart elongated
blocks of insulating material.
6. The wall panel of claim 1 wherein said insulating and utility
installation layer comprises a mattress-like body made of
insulating material provided with a plurality of channels extending
the entire length of said mattress-like body having openings at top
and bottom edges of the body.
7. The wall panel of claim 1 wherein said exterior sheet is
selected from the group consisting of a cement board, a timber
board, a metal sheet and a reinforced plastic sheet.
8. The wall panel of claim 1 wherein said interior sheet is
selected from the group consisting of a gypsum board, a cement
board and a timber board.
9. The wall panel of claim 1 wherein said thickness is in the range
of 140 to 260 mm.
10. The wall panel of claim 2 further comprising a top frame member
and a bottom frame member welded to said at least two metal tubular
members for forming a frame around the panel.
11. A method for fabricating a building panel, the method
comprising the steps of: forming a stack of horizontally placed
building layers in a successive manner; coating the upper surface
of each layer with an adhesive before the next layer is placed
thereon; and subjecting said stack to uniform compression
forces.
12. The method of claim 11 wherein said stack comprises a first
sheet of a building material, a core layer, an insulating and
utility installation layer and a second sheet of building
material.
13. The method of claim 11 further comprising the step of
incorporating a frame metal into said stack of building layers.
14. The method of claim 11 wherein said subjecting step is
performed by means of a vacuum manifold.
15. The method of claim 11 wherein said subjecting step is
performed by means of a compression plate.
16. The method of claim 11 wherein said compression forces are in
the range of 0.2 to 0.6 Kg/cm2.
17. A building component comprising at least one prefabricated wall
panel as defined in claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to modular
construction and more specifically to prefabricated wall panels for
use in modular buildings, to a method for fabricating the panels
and to building components including the same.
[0003] 2. Discussion of the Related Art
[0004] Industrialized building methods are becoming more popular
over the last decades in the construction industry for both
domestic and public buildings, Also referred to as large-panel
construction, such methods utilize high degree of factory
prefabrication in order to reduce site work and improve the quality
and speed of construction. The large prefabricated panels are
transported from the factory to the construction site where they
are assembled in a modular manner to form walls, ceiling and/or
floors. Optionally, the panels may be assembled, at least
partially, at the factory site to form larger building components,
where limitation to the size of pre-assembled components is mainly
due to transportation possibilities. In either case, work and
debris at the construction site is reduced significantly as
compared with traditional and/or conventional construction
methods.
[0005] Various prefabricated large panels for modular building are
known in the art, including multi-layer sandwich panels. However,
available building panels and the manufacturing methods for
fabricating such panels still suffer from a number of drawbacks. In
particular, fabrication of known large building panels involves
mechanical fastening for joining the different components and/or
layers of the panel to each other. Thus, not only the assembling of
the panels to form larger building components walls requires manual
work, but in many cases the fabrication of the panel themselves
require manual work which slows down the manufacturing and increase
costs. Furthermore, the panels so produced may suffer from uneven
fastening and consequently from insufficient flatness and from weak
points or seaming lines susceptible to instabilities. Moreover,
many times known prefabricated panels do no provide all the
properties required from building components in terms of stability,
insulation, easiness of utility installation, etc.
[0006] Therefore there still exists a need for improved
prefabricated building panels and for an improved process for
manufacturing the same.
[0007] Accordingly, it is the object of the present invention to
provide a building panel which is fabricated as one solid integral
piece, which is structurally strong and dimensionally stable, which
provides high level of thermal and acoustic insulation and is
moisture and vapor resistant as well as fire resistant.
[0008] A further object of the invention is to provide a building
panel having the above features which allows for easy installation
of utility lines such as electricity wiring and plumbing and which
provides flexibility at the planning and manufacturing stage so
that it can be easily tailored to specific needs and allows for
future changes.
[0009] An additional object of the invention is to provide
prefabricated panels having the above features, which allow for
joining individual panels to each other as well as to floor and
ceiling by welding rather than by mechanical fasteners.
[0010] Yet, a further object of the invention is to provide a
method for fabricating large-size and extra-large-size panels
having the above features, which minimizes manual work at the
fabrication site as well as reduces assembling and finishing work
at the construction site.
[0011] Other advantages of the invention will be apparent from the
following description.
SUMMARY OF THE PRESENT INVENTION
[0012] The present invention provides improved prefabricated wall
panels for modular building and an improved method for fabricating
the same.
[0013] One aspect of the present invention is a multi-layer
prefabricated wall panel having an interior planar surface and an
exterior planar surface. The panel comprises: a load-bearing and
vapor barrier core layer having an inner face and an opposite outer
face; an interior insulating and utility installation layer bonded
to the inner face of the core layer; an exterior sheet of a first
rigid building material bonded to the interior insulating layer;
and an interior sheet of a second building material bonded to the
outer face of the core layer.
[0014] The core layer preferably comprises at least two tubular
metal members and one or more interior sandwich panels extending
between the at least two metal members, wherein the one or more
sandwich panels preferably comprise thermal insulating material,
selected from the group consisting of mineral wool, polymer foam
and timber, sandwiched between two flat metal skins. The wall panel
further comprises a top frame member and a bottom frame member
welded to the least two metal tubular member for forming a frame
around the panel.
[0015] The interior insulating and utility installation layer
comprises a plurality of channels extending from top to bottom
thereof for accommodating utility lines. In accordance with one
embodiment of the invention the interior insulating and utility
installation layer comprises a plurality of spaced apart elongated
blocks of insulating material. In accordance with another
embodiment, the insulating and utility installation layer comprises
a mattress-like body made of insulating material provided with a
plurality of channels extending the entire length of the
mattress-like body and having openings at the top and bottom edges
of the body. The one or more sandwich panels and the metal members
are having substantially the same length and thickness so as to
form in combination a solid layer with two opposite flat faces.
Preferably, the exterior sheet is selected from the group
consisting of a cement board, a timber board, a metal sheet and a
reinforced plastic sheet and the interior sheet is selected from
the group consisting of a gypsum board, a cement board and a timber
board. The thickness of the wall panel, defined as the distance
between interior and exterior planar surfaces of the wall panels is
preferably in the range of 140 to 260 mm.
[0016] A second aspect of the invention is a method for fabricating
a building panel, the method comprising the steps of: forming a
stack of horizontally placed building layers in a successive
manner; coating the upper surface of each layer with an adhesive
before the next layer is placed thereon; and subjecting said stack
to uniform compression forces. The method may further comprise the
step of incorporating a frame metal into said stack of building
layers. The step of subjecting the stack to uniform compression
forces may be performed by means of a vacuum manifold or
alternatively by means of a compression plate. The stack preferably
comprises a first sheet of a building material, a core layer, an
insulating and utility installation layer and a second sheet of
building material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be understood and appreciated
more fully from the following detailed description taken in
conjunction with the drawings in which:
[0018] FIGS. 1 and 2 are a partial isometric view and a partial
frontal view, respectively, of a wall panel according to one
embodiment of the present invention, illustrating the multi-layer
structure of the panel;
[0019] FIG. 3 is a horizontal cut of the wall panel of FIGS. 1 and
2 taken along line 3-3 of FIG. 1;
[0020] FIG. 4 is a vertical cut of the panel of FIGS. 1 and 2 taken
along line 4-4;
[0021] FIG. 5 is an isometric view of the metal frame in accordance
with the embodiment of FIG. 1 showing the upper and lower framing
and the vertical load-bearing metal members;
[0022] FIG. 6A and 6B illustrate two embodiments of the interior
sandwich panels of the core layer;
[0023] FIG. 7 is a vertical cross sectional view of a building
comprising the wall panel of FIG. 1, showing connections of the
wall panel to floor and ceiling and a utility line running through
the inner insulating layer;
[0024] FIG. 8 is a horizontal cut through a wall panel of the
invention in accordance with a second embodiment;
[0025] FIG. 9 is a partial isometric view of the inner insulating
layer in accordance with the second embodiment depicted FIG. 8;
[0026] FIG. 10 is a vertical cross sectional view through a
building comprising of wall panels of FIG. 8;
[0027] FIGS. 11A and 11B are frontal and side cross-sectional
views, respectively, illustrating the formation process of a panel
in accordance with the novel method of the invention;
[0028] FIG. 12A is a frontal view of a wall panel of the invention
comprising pre-designed a window opening;
[0029] FIG. 12B is a horizontal cross section through line B-B of
FIG. 13A.
[0030] FIG. 13A is a horizontal cut through a wall in accordance
with the invention, showing two adjacent panels joined together to
form a wall;
[0031] FIG. 13B is a horizontal cut through a building corner in
accordance with the invention, showing perpendicularly joined
panels.
[0032] It will be realized that the drawings are not drawn to scale
and that the aspect ratio of the elements illustrated, as well as
the dimensional ratios between different elements, are distorted in
order to better demonstrate various features of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] The present invention provides improved wall panels and
improved methods for manufacturing the same. The panels of the
invention comprise multiple layers, each designed to impart the
panel a particular functionality and/or benefit, while the method
of the invention for fabricating the multi-layer panel as one
integral unit with no mechanical fasteners between elements,
further imparts the panel structural stability and enhanced
flatness and smoothness. In accordance with the novel method of the
invention, the different layers of the panel are bonded to each
other under pressure by one compression step rather than being
fastened to each other by mechanical fasteners such as screws and
bolts. Besides enhancing stability and appearance, this allows for
manufacturing extra large panels which significantly reduces the
number of joints and consequently reduces site work and cost as
well as the amount of defects that might be introduced during
joints assembling.
[0034] Referring to the FIGS. 1-4, there is shown a wall panel,
generally designated 10, in accordance with one embodiment of the
invention. Wall 10 comprises a core layer 20, an interior
insulating and utility installation layer 30, an exterior sheet 40
and an interior sheet 50. Layers 20, 30, 40 and 50 are bonded to
each other to form one integral panel having two opposite smooth
planar surfaces defined by the outward faces of sheets 40 and 50.
Panel 10 further comprises a top frame member 64 and a bottom frame
member 62 which together with members 25 of core layer 20 form a
peripheral metal frame 60 that encompasses panel 10 to enhance the
panel structural stability and to allow weld-joining to adjacent
panels as well as to ceiling and floor. Frame 60 is illustrated in
FIG. 5.
[0035] Core layer 20 comprises at least two rectangular, preferably
square, tubular metal members 25 extending about the full length L
of panel 10 and one or more interior sandwich panels 22 extending
between members 25 and in contact therewith to fill the space
therebetween. Members 25 and panels 22 are of the same length and
thickness so as to form a mattress-like layer having two opposite
flat faces, a flat top edge and a flat bottom edge. The outward
sides 26 of members 25 define the side edges of layer 20. Members
25 constitute the main load-bearing construction elements of panel
10 and therefore should be distributed at appropriate intervals.
Thus, depending on the size of panel 10 and on the total
construction requirements, one or more additional members 25 may be
incorporated into layer 20 between panels 22. In practice, frame
members 62 and 64 are welded to members 25 to form structural metal
frame 60, which is incorporated into panel 10 at the manufacturing
process as explained below.
[0036] Interior panels 22 are sandwich panels comprising an
insulating core material 24 sandwiched between opposite skins 26
and 28. Preferably, skins 26 and 28 are metal sheets, preferably
0.2-0.8 mm thick steel sheets. Skins 26 and 28 serve as vapor
barrier between the interior and exterior of panel 10. Insulating
material 24 may be any insulating material and may be in the form
of prefabricated blocks or as a bulk material. Possible materials
for insulator 24 include mineral wool, expanded or extruded polymer
foam or polymer fibers, timber blocks or wood fibers and the like.
Preferably, insulator 24 is mineral wool of 100-140 kg/m.sup.3
density. However, insulator 24 may be selected in accordance to the
thermal and acoustic insulation requirements at the particular
location where the building is to be built. Thus, for rough weather
conditions where thermal insulation is crucial, insulator 24 is
preferably polyurethane or polystyrene foam while under milder
weather conditions insulator 24 is preferably mineral wool, being a
better acoustic insulator. Sandwich panels 22 may be prefabricated
off-the-shelf panels or may be especially fabricated to suit
particular insulation and dimensional requirements. Alternatively,
when insulating material 24 is in the form of blocks, panels 22 may
be formed during the manufacturing process of panel 10. The width
(horizontal dimension) of panels 22 can vary and is mainly
determined by the width of available metal sheets. When layer 20
comprises more than one panel 22, panels 22 are abutted against
each other to form continuous insulating layer between the two
metal skins. FIGS. 6A and 6B illustrate two possible embodiments
for abutting and joining sandwich panels 22 to each other to form a
continuous layer. According to the embodiment illustrated in FIG.
6A, the exterior skins 26 and 28 of panel 22a extend to some extent
26a and 28a, respectively, beyond insulator 24 so that when the
panels are abutted against each other, portion 26a overlap skin 26
of adjacent panel and portion 28a overlap skin 28 of adjacent
panel, in a slate-like manner. According to the embodiment
illustrated in FIG. 6B, additional skins 23 are placed against both
skins 28 and 26 along the seam line between adjacent panels 22b. In
accordance with both embodiments, the continuous overlapping
exterior contact between adjacent panels reinforces layer 20 and
enhances its structural stability. It will be realized that since
the metal skins of panels 22 are only a fraction of a millimeter
thick, the double-skin overlapping areas at the vicinity of seam
lines do not affect the face smoothness of layer 20 to any
significant extent.
[0037] Next to core layer 20 toward the interior face of panel 10,
is insulating and utility installation layer 30. In accordance with
the embodiment illustrated in FIGS. 1-7, the interior insulating
layer 30 comprises a plurality of spaced-apart elongated insulating
blocks 32, preferably of a rectangular cross section, disposed
between core layer 20 and interior sheet 40. Blocks 32 are
preferably made of a water-proof closed-cell polymer foam such as
expanded polystyrene. However, at areas where additional strength
is required, such as for example where cupboards are to be
suspended from the wall, polymer blocks may be replaced by
structured wood blocks in metal profiles for enhancing anchoring
force of cupboard to wall. Elongated blocks 32 of length Li extend
longitudinally between bottom frame member 62 and horizontal beam
67 of top frame member 64. Length Li corresponds to the interior
height of the building. Blocks 32, preferably about 40 to 100 mm
thick and about 100 to 300 mm wide, are equally spaced, leaving
elongated channels 33 therebetween. Channels 33 are of preferably
narrower dimensions than that of blocks 32 so that layer 30
comprises of about 75% solid and about 25% space. Channels 33 allow
for installation of utility lines such as electrical wiring,
plumbing pipes, communication lines etc., as best seen in FIG. 7. A
plurality of openings 65a and 65b provided at bottom frame 62 and
beam 67, respectively, in alignment with channels 33 allow for
threading the utility lines through the frame for connection to
utility hubs installed under floor and/or above ceiling.
[0038] The interior faces of blocks 32, opposite the faces in
contact with panels 22, are covered by interior sheet 50 of length
Li. Interior sheet 50 may be of any building material suitable as
interior wall including a gypsum board, a cement board, a timber
board and the like. Preferably sheet 50 is an off-the-shelf gypsum
board of 9 to 32 mm thickness. It will be appreciated that panel 10
requires no further finishing on the interior side of the building
as it is well known in the art to cover inner surfaces with gypsum
boards. Exterior sheet 40, of length L, bonded on the outward
surface of core layer 20 may be of any durable building material
suitable for withstanding the climate conditions where the building
is to be located, including cement, timber, metal, reinforces
polymer sheets and the like. Preferably, sheet 40 is a cement board
of 7.5 to 20 mm thick. It will be appreciated that although not
necessary, any type of cladding (i.e. siding, stucco, EIFS, brick,
stone) may be applied to the interior and/or exterior faces of the
panel similar to traditional construction methods. The cladding may
be applied at the manufacturing site or may be applied later at the
construction site after the building is erected. It will be
appreciated that the structure of wall 10 is designed such that
there is minimum continuous metal thermal conductive path from one
face of the wall to opposite face. It will be further appreciated
that the interior sandwich panel of the core layer serve as vapor
barrier between inside and outside.
[0039] Referring to FIG. 5, there is illustrated metal frame 60
that encompasses the peripheral edges of layers 20 and 30 of panel
10. Layers 40 and 50 are bonded to the opposite outermost surfaces
of frame 60 as best seen in FIGS. 4 and 7. Frame 60 comprises a
bottom frame member 62, an upper frame member 64 and two vertical
load-bearing members 25. Frame members 62 and 64 extend the full
width of panel 10 and are each having a profile comprising of
vertical and horizontal sections configured to receive the layers
of panel 10 and to allow metal welding to corresponding metal
frames in floor and ceiling. Thus, top member 64 comprises upper
and lower L-shaped profile sections 66 and 67, respectively,
directed at opposite directions and connected by vertical section
61. Similarly, bottom frame member 62 comprises two L-shaped
profile sections 63 and 68 connected by vertical section 69. Core
layer 20 of length L is accommodated between the horizontal
sections of sections 66 and 63 while blocks 32 of layer 30, having
length Li, are inserted between L-shaped sections 67 and 68 and are
positioned between openings 65a and 65b to provide openings into
the channels 33 that are formed between the blocks as best seen in
FIG. 1.
[0040] The overall combined thickness T of panel 10 is preferably
in the range of 120 to 300 mm, where the core layer 20 is about
80-140 mm thick, the interior insulating layer 30 is about 40-100
mm thick, the interior sheet 50 is about 9-32 mm thick and the
exterior sheet is about 7.5 to 20 mm thick. The vertical dimensions
of panel 10, L and Li, correspond to the exterior and interior
heights of the building, respectively, and are determined according
to construction plan. Preferably, L is in the range of 3 to 4 m,
while Li is 20 to 60 cm shorter. The horizontal dimension of panel
10 can be of up to 15 m, meaning that for some buildings, depending
on the building size, a complete wall can be prefabricated as one
integral piece having continuous smooth flat surfaces. It will be
appreciated that the possibility to provide an extra-large
multi-layer wall panel significantly reduces assembling work and
cost. It will be also appreciated that as no mechanical fasteners
are required for joining the multiple layers to each other or for
joining adjacent portions of the same layer in order to form a
larger component, the structural integrity and stability of the
panel as well as surface flatness and smoothness, are significantly
enhanced compared with prior art panels. Furthermore, the unique
multi-later structure of panel 10 provides high level of thermal
and acoustic insulation, vapor barrier properties, easiness of
installation of utility lines and enhanced flexibility in tailoring
the wall panels to fit specific construction requirements.
[0041] Referring to FIG. 7, there is depicted a vertical cut
through a building having walls made of panels 10, showing panel 10
joined to floor 80 and roof 90. As can be seen bottom profile 62 of
panel 10 is welded to foundation frame 82, which also supports the
floor reinforcing beams 84. At its upper end, panel 10 is welded to
reinforcing roof beams 92. A utility line, designated 70, running
through channel 33 of layer 30, may connect to a central utility
line 71 that runs under the flooring 86 through opening 65b in
frame 60 and/or to utility line 72 running above ceiling 96 through
opening 65a. Utility line 70 may be an electrical wiring, a water
or a heating pipe, a communication line such as an optic fiber or a
telephone line, etc. It will be appreciated that panel structure
allows for easy installation of such utility lines to be connected
to central utility hubs under floor or above ceiling, by providing
prefabricated infrastructure channels at a relatively high density.
Layer 30 further facilitates guiding the utility lines and keeping
them separated from each other.
[0042] An alternative embodiment of panel 10, generally designated
110, is illustrated in FIGS. 8-10. In accordance with this
embodiment, the insulating utility-installation layer 30 of panel
10 is replaced by layer 130. Layer 130 comprises a solid body 131
of insulating material provided with a plurality of prefabricated
utility channels 132 that run the full length of body 131 between
top and bottom edges, extending between top openings 135 and bottom
openings (not shown). Layer 130 is preferably made of expanded
polystyrene. Channels 132 are preferably of oval cross section and
are located closer to the inner face of layer 130. The other layers
of panel 110 are similar to layers 20, 40 and 50 described above in
association with FIGS. 1-6. However, in accordance with this
embodiment, upper and lower frame members 164 and 162 are simpler
in shape than frame members 62 and 64 of panel 10 and do not
include openings. Referring to FIG. 10, unlike frame members 62 and
64, frame members 162 and 164 end toward the interior face of the
panel with horizontal sections 161 and 163, respectively, and do
not include a vertical section. Sections 161 and 163 extend up to
openings 135 in layer 130 so as not to cover the openings. It will
be realized that since layer 130 comprises one integral piece,
there is no need to provide further vertical elements in frames 162
and 164. Embodiment 110 has the advantage of reducing panel
assembling time as compared with panel 10 since layer 130 is placed
as one piece instead of placing a plurality of separated blocks.
Layer 130 also has the advantage of continuous and larger contact
surfaces with adjacent layer, thus increasing the panel structural
stability. Furthermore, in accordance with the structure of panel
110, sheet 50 is supported by layer 30 only and is not in contact
with metal frame 60, such that there is no metal continuity between
outer and inner sheets 40 and 50. This prevents any thermal
conductivity between interior and exterior faces and provides
higher level of thermal isolation.
[0043] Turning now to FIGS. 11, the present invention provides a
novel method for fabricating multi-layer building panels by forming
a horizontal stack of the multiple layers with intermediate layers
of adhesive therebetween, and subjecting the stack to pressure,
thereby bonding the layers to each other in a single operation.
Compression may be applied either mechanically by a compression
plate or by means of a vacuum device. In either case, the panels
are uniformly pressurized. FIGS. 11 demonstrate the fabrication
process of a panel in accordance with embodiment 10. It will be
easily realized that the fabrication of a modified panel, such as
panel 110, is performed in a similar manner. In accordance with the
panel fabrication method of the invention, the multiple layers are
orderly placed horizontally on a working table 200 comprising a
horizontal working plate 205 supported on legs 204. The layers are
placed one above the other wherein the yet-free upper surface of
each layer is sprayed to be covered by a layer of adhesive before
the next layer is placed over it. The steel frame, consisting of
the two tubular columns and the top and bottom frame members, is
incorporated into the panel at the appropriate stage in accordance
with the specific structure of the panel in hand. Thus, referring
to FIGS. 11, demonstrating fabrication of panel 10, the first layer
to be placed on working surface 205 is interior sheet 50. The sheet
is sprayed with adhesive layer and frame 60 is placed over its
periphery. Two vertical supporting beams 208 and 210 configured to
conform with the dimensions and with the upper and lower profiles
of the multi-layer panel, are mounted along opposite sides of table
200 to support the panel during fabrication process and to
facilitate alignment of the layers. Beams 208 and 210 are
preferably removably mounted to plate 205 such as to allow the
selection of beams in accordance with the panel in hand. After
frame 60 is appropriately placed over sheet 50, supported on beams
208 and 210, the plurality of insulating blocks 32 are placed over
sheet 50 to form insulating layer 30. Blocks 32 are inserted
between sections 68 and 67 of frame 60 which guide appropriate
placing and help to align the blocks. Next, blocks 32 are sprayed
by adhesive and core layer 20 is placed over layer 30 and over
sections 61 and 69 of frame 60. The upper surface of layer 30 is
then sprayed to be coated by an additional adhesive layer and
exterior sheet 40 is placed over layer 20, peripherally supported
on and in alignment with the outermost surface of frame 60. A
pressure P is then uniformly applied on the multiple layers until
the adhesive is cured for reinforcing bonding between layers,
forming one integral piece. Preferably the pressure applied is in
the range of 0.2 to 0.6 Kg/cm.sup.2. It will be easily realized
that a panel of structure 110 is similarly fabricated with the
exception of mounting frame 160 onto layer 30 after the later is
already placed over sheet 50. It will be also realized that layers
20, 40 and 50, as well as layer 130 in case of embodiment 110, may
consist of one piece or may consist of a number of portions abutted
against each other to form a continuous layer when placed over
table 200. It will be appreciated that the dimensions of such
portions is mainly determined by market availability. The adhesive
used to bond the layers to each other is preferably sprayable
one-component or tow-component polyurethane adhesive such as
polyurethane adhesives distributed by Sika AG.
[0044] As mentioned above, pressure P may be applied by a
compression plate 125 pressed from above, as illustrated in FIG.
11, or alternatively may be applied by means of a vacuum manifold
(not shown) coupled to table 200. In the later case, the vacuum
manifold may be coupled to peripheral channels that circumferences
plate 205 and open inwardly. A flexible air-impermeable cover is
then used for entirely covering the table, including the table
channels and the pre-assembled layers laying on the table, in an
air-tight manner. As the vacuum manifold is activated, the cover is
evacuated to form sub- atmospheric pressure under the cover to
apply uniform pressure on the pre-assembled panel.
[0045] It will be appreciated that the method of the invention
allows for enhanced flexibility in designing a wall panel in terms
of the panel dimensions and the panel specific structure, to be
tailored to specific requirements depending on location of the
building and the location of the specific panel in relation to the
building. It will be further realized that the fact that during
assembling, the layers of the panel are horizontally displayed one
following the other, enhances the easiness by which different
materials may be selected for specific zones within the same panel
in order to optimize the panel functionality. For example, when
knowing in advance where cupboards are to be installed, the
insulator material of interior insulating layer 30 (or 130) at the
known locations may be specifically selected as wood blocks,
instead of the polystyrene foam, for enhancing connection strength
between cupboard and wall. Further, threading of utility lines may
be performed while the panel is still in horizontal position or
even before completion of the assembling process.
[0046] FIG. 13 illustrates a wall panel provided with a
prefabricated opening adapted to receive a window frame. Panel 310
is a composite panel of substantially the same multi-layered
structure as of panel 10 or panel 110 described above. Portions of
core layer 20 and insulating layer 30 (or 130) are cut-out to form
an opening 350. Two vertical metal studs 328 extending the full
length of the panel are added to metal frame 360 for reinforcing
the panel around the opening. It will be realized that the portions
of layers 20 and 30 need not actually being cut out but instead
layers portions of appropriate size may be placed above and below
the opening during fabrication. A window frame 352 is already
incorporated into the panel. In order to protect frame 352 during
transportation, inner and outer sheets 50 and 40 fully cover the
panel when fabricated. After installation of the panels at the
construction site, portions 41 and 51 (shown in broken lines in
FIG. 13B) are cut out to expose the opening and for mounting the
window on window frame 352. It will be easily realized that the
particular size and location of the window opening may varied and
that a door opening may be similarly pre-prepared.
[0047] FIGS. 13A and 13B are horizontal cuts through a wall and a
wall corner, respectively, of a building made of the panels of the
invention, showing the joints between panels. Panels 10a and 110b
and 110b are joined to each other by welding tubular members 25a
and 25b of adjacent panels either in a parallel for forming a
continuous wall or perpendicularly for forming a corner. During
fabrication, core layer 20 at the vicinity of tubular members 25 as
well as members 25 themselves, is left exposed, namely it is not
covered by the other layers, in order to allow accessibility of the
welding device to members 25 during weld-joining. After the panels
are joined, complementary layer pieces 38, 48, and 58 for a
continuous wall joint and pairs 34, 44 and 54 for a corner joint,
are added for covering the joints.
[0048] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described hereinabove. Rather the scope of the present
invention is defined only by the claims which follow.
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