FLAT WALL PANEL AT LEAST SUBSTANTIALLY MADE OF CELLULOSE MATERIAL

PANNEAU MURAL PLAT COMPRENANT AU MOINS EN GRANDE PARTIE UN MATERIAU CELLULOSIQUE

English Abstract

A flat wall panel at least substantially made of cellulose
material, a special feature being the fact that the wall panel
is at least substantially made of layers of paper/cardboard,
each layer at least substantially being made up of a
corrugated sublayer and a flat sublayer provided on one side
thereof, which layers of paper/cardboard are interconnected
via an adhesive applied to the corrugations of the corrugated
sublayers, wherein the wall panel is impregnated, in
particular with a resinous material, and wherein at least one
strengthening layer having a greater elasticity modulus than
the layers of paper/cardboard is provided, which strengthening
layer is connected to a layer of paper/cardboard on one side
of the wall panel via an adhesive.

Claims

7
CLAIMS
1. A flat wall panel at least substantially made of
cellulose material, characterized in that the wall panel
is at least substantially made of layers of
paper/cardboard, each layer at least substantially being
made up of a corrugated sublayer and a flat sublayer
provided on one side thereof, which layers of
paper/cardboard are interconnected via an adhesive
applied to the corrugations of the corrugated sublayers,
wherein the wall panel is impregnated, in particular with
a resinous material, and wherein at least one
strengthening layer having a greater elasticity modulus
than the layers of paper/cardboard is provided, which
strengthening layer is connected to a layer of
paper/cardboard on one side of the wall panel via an
adhesive.
2. A wall panel according to claim 1, wherein two
strengthening layers are provided, which are connected to
a layer of paper/cardboard on either side of the wall
panel via an adhesive.
3. A wall panel according to claim 1 or 2, wherein the
strengthening layer(s) comprise(s) a fibre material.
4. A wall panel according to claim 3, wherein the fibre
material consists of glass fibres, carbon fibres, mineral
fibres and/or synthetic fibres.
5. A wall panel according to any one of the preceding claims
1-4, wherein the strengthening layer(s) comprise(s) a
layer of plastic material.

8
6. A wall panel according to any one of the preceding claims
1-5, wherein the strengthening layer(s) comprise(s) a
layer of rubber.
7. A wall panel according to any one of the preceding claims
1-6, wherein the strengthening layer(s) is (are) made of
a metal.
8. A wall panel according to any one of the preceding claims
1-7, wherein the strengthening layer(s) is (are) made of
wood.
9. A wall panel according to any one of the preceding claims
1-8, wherein the wall panel is at least substantially
made of an even number of layers of paper/cardboard.
10. A wall panel according to claim 9, wherein the wall panel
is mirror symmetrical with respect to a central
longitudinal plane of the wall panel.
11. A method for manufacturing a flat wall panel according to
any one of the preceding claims 1-10, characterized in
that the wall panel is at least substantially made of
layers of paper/cardboard, each layer at least
substantially being made up of a corrugated sublayer and
a flat sublayer provided on one side thereof, which
layers of paper/cardboard are interconnected via an
adhesive applied to the corrugations of the corrugated
sublayers, wherein the wall panel is impregnated, in
particular with a resinous material, and wherein at least
one strengthening layer having a greater elasticity
modulus than the layers of paper/cardboard is provided,
which strengthening layer is connected to a layer of
paper/cardboard on one side of the wall panel via an
adhesive.

Description

CA 02484414 2004-10-08
FLAT WALL PANEL AT LEAST SUBSTANTIALLY MADE OF CELLULOSE
MATERIAL
The invention relates to a flat wall panel at least
substantially made of cellulose material. The invention also
relates to a method for manufacturing said wall panel.
Such a wall panel is known from German patent No. 2 026 768
(Universal Papertech corp.). Said patent describes a building
that is built up of a great many different construction
elements, such as a concrete floor, roof and side wall panels
made of an intermediate layer of corrugated cardboard
sandwiched between two flat outer layers, as well as cramps
and corner elements. In practice, the constructional strength
of the roof and side wall panels appears to be insufficient to
give the building sufficient strength.
The object of the invention is to improve the wall panel that
is known from the aforesaid German patent publication, in the
sense that a wall panel having an optimum constructional
stiffness is provided for use as a construction element of a
building, as a wall panel in, for example, a separation wall,
etc. It is noted that the term wall panel is understood to
include an element for use in a wall, a floor, a ceiling, a
roof, etc.
According to the invention, a wall panel of the kind referred
to in the introduction is characterized in that the wall panel
is at least substantially made of layers of paper/cardboard,
each layer at least substantially being made up of a
corrugated sublayer and a flat sublayer provided on one side
thereof, which layers of paper/cardboard are interconnected
via an adhesive applied to the corrugations of the corrugated
sublayers, wherein the wall panel is impregnated, in
particular with a resinous material, and wherein at least one

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strengthening layer having a greater elasticity modulus than
the layers of paper/cardboard is provided, which strengthening
layer is connected to a layer of paper/cardboard on one side
of the wall panel via an adhesive.
In other words, the whole of various adhered-together layers
of paper/cardboard is connected on at least one flat (outer)
are side thereof to the less elastic strengthening layer.
Experiments have shown that the present construction leads to
an unexpectedly great constructional stiffness of the wall
panel, so that it is possible to subject the wall panel to
large forces without the dimensional stability being affected.
The constructional stiffness is increased even further by
using a strengthening layer having an elasticity modulus
greater than or equal to 50 GPA, in particular greater than or
equal to 100 GPA, more in particular greater than or equal to
150 GPA, more in particular greater than or equal to 200 GPA,
more in particular greater than or equal to 300 GPA, more in
particular greater than or equal to 400 GPA.
In a preferred embodiment of a wall panel according to the
invention, the wall panel comprises two strengthening layers,
which are connected to a layer of paper/cardboard on either
side of the wall panel via an adhesive. Thus a sandwich
construction is obtained, in which the whole of various
adhered-together layers of paper/cardboard is connected to a
less elastic strengthening layer on both flat outer sides. The
result is an even greater constructional stiffness having a
corresponding dimensional stability.
It is noted that impregnating the wall panel with, for
example, a resinous material not only has the advantage of
providing a greater constructional stiffness, but also of
providing protection against external influences, such as
moisture. As a result of said additional stiffness, fewer

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layers of corrugated paper/cardboard are in principle needed
in order to give the flat panel the required stiffness. Said
impregnation preferably takes place by means of vapour
deposition, spraying or otherwise, said vapour deposition or
spraying taking place in a direction parallel to the direction
of the "cell structure" of the corrugated paper/cardboard that
is used. Said impregnation may also be effected with
mechanical means, wherein toothed and/or flat rollers are used
for pressing the impregnating medium into the paper/cardboard.
In another preferred embodiment of a wall panel according to
the invention, the strengthening layer comprise a fibre
material. In particular, the fibre material consists of glass
fibres, carbon fibres, mineral fibres and/or synthetic fibres.
Said synthetic fibres may e.g. be fibres of the type known
under the brand names "Kevlar" or "Twaron".
An another preferred embodiment of a plate-shaped material
according to the invention, the strengthening layer comprises
a layer of a plastic material. The plastic of said layer of
plastic material is preferably selected from the group
consisting of PVC-U, PP, PE, ABS, PVC-C and PVDF. It is noted
that the above abbreviations relate to the following (plastic)
materials.
PVC-U Polyvinyl chloride (without plasticizer)
PP Polypropylene
PE Polyethylene
ABS Acrylonitrile-Butadiene-Styrene
PVC-C Polyvinyl chloride (post-chlorinated)
PVDF Polyvinylydene fluoride
In another preferred embodiment of wall panel according to the
invention, the strengthening layer comprises a layer of
rubber. The rubber of said layer of rubber is preferably

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selected from the group consisting of EPDM or NBR. In another
preferred variant, the strengthening layer is made of a metal,
in particular stainless steel or wood.
In another preferred embodiment of a wall panel according to
the invention, the wall panel is at least substantially made
of an even number of layers of paper/cardboard. In combination
with the strengthening layer, this provides a plate-shaped
material which is hardly deformable, if at all. Preferably,
the wall panel is mirror symmetrical with respect to a central
longitudinal plane of the wall panel so as to increase the
dimension all stability thereof, so that "warping" is
prevented at all times.
25 As already said before, the invention also relates to a method
for manufacturing a wall panel according to the invention,
wherein the wall panel is at least substantially made of
layers of paper/cardboard, each layer at least substantially
being made up of a corrugated sublayer and a flat sublayer
provided on one side thereof, which layers of paper/cardboard
are interconnected via an adhesive applied to the corrugations
of the corrugated sublayers, wherein the wall panel is
impregnated, in particular with a resinous material, and
wherein at least one strengthening layer having a greater
elasticity modulus than the layers of paper/cardboard is
provided, which strengthening layer is connected to a layer of
paper/cardboard on one side of the wall panel via an adhesive.
It is noted that the term paper is usually used for lighter
types of paper; in the case of a heavier quality, the term
cardboard is frequently used. Within the framework of the
invention, the terms paper, cardboard and weight are not
intended to be limitative as regards the type of material to
be used.

CA 02484414 2004-10-08
The aforesaid resinous material with which the wall panel
according to the invention is impregnated, is preferably an
epoxy resin, a polyurethane resin, a polyester resin or a
phenol resin. Fire-resistant and/or fire-retarding agents may
5 be added thereto. Preferably, the resinous material with which
the wall panel according to the invention is impregnated also
functions as an adhesive for adhering two layers of
paper/cardboard together, so that a separate adhesive, such as
a glue, is not required. To that end, sets consisting of a
corrugated sublayer and a flat sublayer provided on one side
thereof, which sublayers are already impregnated with the
resinous material, can be placed on top of each other so as to
be adhered together (after the resinous material has dried).
The invention will now be explained in more detail with
reference to figures illustrated in a drawing of a preferred
variant of the invention, in which Fig. 1 is a schematic,
perspective view of the present wall panel, Fig. 2 is a detail
view of Fig. l, and Fig. 3 is an exploded view of the wall
panel of Fig. 1.
The figure shows a flat wall panel 1 according to the
invention in the form of a "sandwich", in the sense that a
core 2 built up of several layers of corrugated cardboard is
connected on either side to a less elastic strengthening layer
3 of a thin material having an elasticity modulus of about 400
Gpa.
In this case, four layers of corrugated cardboard are
provided, which are each built up of corrugated sublayer 4 and
a flat sublayer 5 glued to one side thereof, using a glue
applied to the corrugations 6 of the corrugated sublayer 4.
The core 2 is impregnated with a resinous material. As already
said before, the strengthening layers 3 are glued to both
sides of the core 2.

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The wall panel 1 is mirror symmetrical with respect to a
central longitudinal plane 7 of the wall panel 1.
It is noted that the invention is not limited to the
embodiment as shown in the figures, but that it also extends
to other variants that fall within the scope of the appended
claims. Thus it will be apparent to those skilled in the art
that the wall panel may exhibit a (slight? curvature, whilst
the wall panel may also comprise a curved longitudinal edge.

Representative Drawing