Note: Descriptions are shown in the official language in which they were submitted.
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Core layer comprising zigzag-shaped wood elements and multilayer composite
comprising the core layer
The present invention relates to a core layer comprising zigzag-shaped wood
elements, which core layer is suitable for producing a multilayer composite or
in a
multilayer composite, preferably for producing a lightweight building board,
and to a
multilayer composite comprising the core layer. The invention further relates
to a
method for producing the core layer and the multilayer composite.
For the production of multilayer composites, it is known to use composite
materials
which have a relatively high mechanical stability in comparison to their
weight.
Multilayer composites of this type are used, for example, in the form of
lightweight
building boards.
CH 254025 relates to a multilayer composite comprising two cover plates and a
core
layer in-between, wherein the core layer comprises at least one layer of
folded
veneer. The veneer is folded at an angle in relation to the grain direction in
the wood.
DE 42 01 201 relates to a wooden semi-finished product or finished product
made of
laminar elements. The laminar elements can be zigzag-shaped. They can be
present
in random distribution together with flat elements.
DE 10 2008 022 806 relates to a lightweight building board having a wavy wood
veneer layer. The waves can be zigzag-shaped.
Common to these multilayer composites is the fact that the core layer
comprises a
loosened structure. When force is applied perpendicular to the surface of the
multilayer composite, the latter has a damping effect, since the core layer
can be at
least partially compressed. A drawback of these loosened core layers lies in
the fact
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that they can have low homogeneity, which is caused by relatively large
cavities in
the core layer. When fastening means, such as, for example, nails, furniture
connectors or screws, are introduced, these can encounter cavities in the
loosened
core layers. This can result in a restricted stability of the fastening means
in the
.. multilayer composite. This can in turn lead to possible impairment of the
stability of
the multilayer composite on a support, for example on a wall, if the said
multilayer
composite is to be fastened to the wall with the aid of nails or screws.
Moreover, the
production of large-format core layers requires correspondingly large veneer
pieces
in high quality.
An object of an aspect of the present invention consists in providing a core
layer and
a multilayer composite containing the core layer, which multilayer composite
has
improved stability with respect to fastening with nails, furniture connectors
or screws
or equivalent fastening means to a support, for example a wall.
This object of an aspect is achieved according to the invention with a core
layer
which is suitable for a multilayer composite comprising at least one cover
layer and
the core layer, wherein the cover layer is arranged such that it at least
partially
covers the core layer and is fixedly connected thereto, and with the
multilayer
.. composite comprising the core layer, wherein the core layer comprises
wooden
elements comprising zigzagging regions.
First aspect of the invention
.. Inventive core layer comprising zigzag-shaped wooden elements
In a first aspect, the invention relates to a core layer which is suitable for
a
multilayer composite comprising at least one cover layer and a core layer,
wherein
the cover layer is arranged such that it at least partially covers the core
layer and is
fixedly connected thereto, wherein the core layer comprises wooden elements
comprising zigzagging laminar regions, wherein a zig region of an element,
together
with an adjoining zag region of the element, form between them a common edge,
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such that the element is zigzag-shaped, and wherein elements are arranged in
the
core layer such that two such edges of two elements, which can be the same or
different from each other, intersect at an angle which is different from zero,
the two
elements being fixedly connected to each other at the point of intersection.
As used in this disclosure, the term "core layer which is suitable for a
multilayer
composite" signifies a core layer which is suitable for producing a multilayer
composite, or which can be present in a multilayer composite.
The term "core layer, as used herein, signifies a layers which comprises a
loosened
structure, i.e. comprises cavities. According to the invention, the core layer
comprises
wooden elements comprising laminar regions. These regions are arranged in the
element in a zigzag shape, wherein a zig region of an element, together with
an
adjoining zag region of the element, form between them a common edge, such
that
the wood element is zigzag-shaped. The term "zigzag-shaped" is used
synonymously
with the term "zigzagged". The zigzag-shaped elements are arranged in the core
layer such that two such edges of two elements intersect at an angle which is
different from zero. At the point of intersection of the edges, the two
elements are
fixedly connected to each other. A suitable connecting means is preferably an
adhesive. Suitable adhesives are known in the prior art.
The term "cover layer", as used herein, signifies a layer of a material which
preferably
serves as support for the core layer. According to the invention, the cover
layer is
arranged such that it at least partially covers the core layer and is fixedly
connected
thereto. The core layer can also be at least partially covered by at least two
cover
layers and can be fixedly connected thereto. Preferably, the core layer is
then located
between the two cover layers. The cover layer can consist of wood or comprise
wood. Other materials, such as sheet metals or plastics, can likewise be used.
The term "at least partially covers", as used herein, includes that the cover
layer can
also fully cover over or cover the core layer.
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The term "multilayer composite", as used herein, signifies a composite of at
least one
core layer and at least one cover layer.
The term "angle which is different from zero", as used herein, includes that
the angle
measures neither 1800 nor 3600
.
The term "element", as used herein, signifies a component part of the core
layer or of
the multilayer composite.
The term "laminar regions", as used herein, includes regions which are
configured in
the form of surfaces. The surfaces can be even or uneven, in this case
preferably
corrugated.
The term "wooden elements comprising zigzagging laminar regions", as used
herein,
includes a laminar wood element, which is formed such that it is present in
zigzag-
shaped configuration, for instance because the lamina is folded about an edge.
Such
a lamina can also be doubly folded, such that a zig region is followed by a
zag
region, which in turn is followed by a zig region. Such a lamina can also be
thrice
folded, such that a zig region is followed by a zag region, which is followed
by a zig
region, which in turn is followed by a zag region; etc. Preferably, edges
which are
formed by zig with zag regions in a wood element are aligned parallel to one
another.
The terms "zig region" and "zag region" are used exchangeably. Both the zig
and the
zag region are laminar.
Hence, the invention, in one embodiment, also relates to a core layer in which
wood
elements comprise repeating units of laminar zig and zag regions which adjoin
one
another, wherein the common edges formed between the regions preferably run
parallel to one another. By such an arrangement of zig with zag regions, the
element
is zigzag-shaped or zigzagged.
The term "edge", as used herein, includes terms like "transition region
between a zig
and the adjoining zag region". This transition region can be an edge which is
sharply
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defined. The term also includes an edge which is configured like a curved
surface. In
this embodiment, the zigzag-shaped wood element can also have a corrugated
course. The term "edge", as used herein, thus includes a sharp edge in the
form of a
line, as well as a wavy or corrugated edge in the form of a curve-shaped plane
or a
curved region between a zig region and a zag region. In this embodiment, the
zigzag
regions have a wave-like structure, i.e. a wave trough is followed by a wave
peak,
and vice versa.
Such edges can be produced by the folding of a laminar wooden element.
Preferably,
the laminar element is in this case configured as a veneer.
Suitable devices for the folding are known from the prior art. Preferably, a
laminar
wood element can be passed through a fast-running pair of profile rollers, as
described in DE 42 01 201. Preferably, the folding takes place substantially
.. transversely to the wood grain direction. In one embodiment, the wood
structure,
which has previously been plasticized by the action of moisture and heat, is
at the
same time kinked, i.e. articulately shaped at the respective folding edge,
preferably
by local compression of the wood fibres, without weakening of the cohesion of
the
wood part. The folding can be performed such that a situation in which the
zigzagging regions in the zigzag-shaped (zigzagged) element are folded back
into
the original position can at least largely be avoided.
In a further embodiment, the edge is produced by cutting. In one embodiment,
wood
is cut for this purpose by means of a suitable knife or a suitable cutter,
which is of
zigzag-shaped profile. Devices and methods are known from the prior art.
In one embodiment, the folding or cutting is performed such that the length of
the
fibres in the resulting wood element is at least twice as long as the
thickness of a zig-
shaped or zag-shaped region. The term "thickness", as used herein, signifies
the
least distance between two surfaces of a zig or zag region. These surfaces are
distanced apart by the thickness of the laminar zig or zag regions.
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In one embodiment, the thickness of the laminar element lies in the range from
0.2
mm to 2 mm.
The height of the zigzag-shaped wood elements lies typically in the range from
0.8
mm to 8 mm. The term "height" is defined as the shortest distance between two
imaginary planes between which the zigzag-shaped wood element can be disposed,
such that the edges which are formed between zig regions and zag regions of
the
zigzag-shaped wood element lie within one of these planes.
In one embodiment, the thickness of the wood element lies in the range from
0.2 mm
to 2 mm and the height of the zigzag-shaped wood element lies in the range
from 0.8
mm to 8 mm.
In one embodiment, the thickness of the zigzag-shaped wood element measures no
more than one-tenth of the thickness of the core layer. This ensures
sufficient
homogeneity of the core layer.
The dimensions of the zigzag-shaped wood elements with respect to width and
length can vary. Preferred ranges are selected from a range from 2 to 20 cm.
The zigzag-shaped or zigzagged elements obtained by cutting or folding can be
further reduced in size, should this be desirable. Suitable cutting devices
are known
from the prior art.
Preferably, the edge or edges formed by the zig and zag region or zig and zag
regions runs or run non-parallel to the preferred direction of the fibres.
In one embodiment, the fibres in two different wood elements have the same
preferred direction.
In a further embodiment, the fibres in two different wood elements have
different
preferred directions.
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In one embodiment, the edge which is formed between a zig region and a zag
region
of the laminar wood element runs non-parallel to the grain direction of the
wood
element.
Preferably, the edge which is formed between a zig region and a zag region of
the
laminar wood element runs perpendicular to the grain direction of the wood
element.
Hence this embodiment of the core layer is also characterized in that one or
more of
the said edges runs or run perpendicular to the preferred direction of the
fibres of the
laminar wood element.
This preferably means also that, in one embodiment, the direction of the
fibres in the
wood element runs in the direction of the mutually adjoining zigzagging
laminar
regions, and perpendicular to the common edges thereof.
The term "perpendicular to the grain direction" signifies that also a
deviation at an
angle of up to 300, for instance, is possible.
In one embodiment, the inventive core layer comprises first laminar wood
elements
having zigzagging regions, and second wood elements having zigzagging regions,
wherein the first and second zigzag-shaped wood elements can be the same or
different from each other. In one embodiment, the first and the second wood
elements differ with respect to their dimensions or the type of wood which is
used. It
is preferred that the wood fibres in the said first and second elements extend
in the
same preferred direction.
In general, more than 50% of the wood elements are present in the core layer
such
that they are fixedly connected to one another, wherein a zig region of an
element,
together with an adjoining zag region of the element, form between them a
common
edge, and wherein elements are arranged in the core layer such that two such
edges
of two different elements interbect at an angle which is different from zero,
the two
elements being fixedly connected to each other at the point of intersection.
The wood
elements are present in the core layer preferably in a random distribution.
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Preferably, more than 60%, or more than 70%, or more than 80%, or more than
90%,
or even 100% of the wood elements are arranged or randomly distributed in the
core
layer such that they are fixedly connected to one another. Preferably, 100% of
the
wood elements are arranged or randomly distributed such that they are fixedly
connected to one another. In this embodiment, the inventive core layer has a
higher
mechanical stability in comparison to a core layer in which not all wood
elements are
fixedly connected to one another.
It is possible for also other regions than the said edges of the laminar wood
elements
comprising zigzag-shaped regions to intersect in the inventive core layer. For
example, zig regions can cross with zig regions of other wood elements such
that not
the edges, but surfaces of the regions intersect or overlap, or the said edges
can
cross or overlap with surfaces of the zig regions.
In one embodiment, the core layer comprises, in addition to the zigzag-shaped
wood
elements, plane elements. The term "plane" includes terms such as "planar" or
"flatly
shaped or flatly configured" or ''planarly configured or planarly shaped".
These plane
elements can be selected from: wood, paper, metal, plastic, and two or more
thereof.
These plane elements can be bonded to the said edges of the laminar wood
elements, which comprise zigzagging regions. If a region of the said zigzag-
shaped
wood elements is bonded to the said plane elements, the inner cohesion of the
core
layer can be further improved.
In one embodiment, the zigzag-shaped wood elements are made of veneer or of
Oriented Strand Board (OSB) chips. In one embodiment, the veneer is provided
in
the form of a leaf or in the form of strips. In one embodiment, the OSB chips
are
provided in the form of flakes comprising elongated and narrow strands.
Second aspect of the invention
Method for producing a core layer comprising zigzag-shaped wooden elements
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According to a second aspect, the invention relates to a method for producing
a
core layer comprising wooden laminar elements which comprise zigzagging
regions,
wherein a zig-shaped region of an element, together with an adjoining zag-
shaped
region of the element, form between them a common edge, such that the element
is
zigzag-shaped or zigzagged. The elements are arranged in the core layer such
that
two such edges of two elements, which can be the same or different from each
other,
intersect at an angle which is different from zero.
In one embodiment, the method comprises at least the steps (i) and (ii):
(i) Presentation of laminar wooden elements comprising zigzagging regions,
wherein a zig-shaped region of an element, together with an adjoining zag-
shaped region of the element, form between them a common edge;
(ii) Arrangement of the elements from step (i) such that two such edges of two
elements intersect at an angle which is different from zero;
(iii) Fixed connection of the edges from step (ii).
Preferably, the fixed connection is realized by means of an adhesive.
In a further embodiment, at the point of intersection of the edges, the two
elements,
which can be the same or different from each other, are fixedly connected to
each
other by plane elements selected from: wood, paper, metal, plastic, and two or
more
thereof, wherein the plane elements are connected to the edges, for their
part, by a
suitable connecting means, such as, preferably, an adhesive.
In one embodiment, the arrangement of the elements can be implemented in step
(ii)
by an alignment of the wood elements, which can be realized either by hand or
mechanically.
The fixed connection in step (iii) can be facilitated by the application of
pressure,
which lies preferably in a range from 0.02 MPa to 1.5 MPa, more preferably in
a
range from 0.01 to 1.0 MPa.
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Each of steps (i) to (iii) can be performed in the presence of a cover layer.
Preferably,
the method is then performed such that the wood elements provided with an
adhesive are presented on the cover layer according to step (i) and are
aligned on
this according to step (ii).
Preferably, this arrangement is then covered and compressed by a further cover
layer. A multilayer composite comprising two cover layers and an intermediate
core
layer is hereupon formed.
Preferably, the core layer according to the first aspect, or produced
according to the
method of the second aspect, is planar.
Third aspect of the invention
Multilayer composite at least comprising a cover layer and a core layer
A third aspect of the invention relates to a multilayer composite at least
comprising a
cover layer and an inventive core layer, wherein the cover layer is arranged
such that
it at least partially covers the core layer and is fixedly connected thereto,
wherein the
core layer is an inventive core layer according to the first aspect of the
invention and
the embodiments described therein, or a core layer is produced according to
the
second aspect and the embodiments described therein.
The cover layer which is used in the inventive multilayer composites can
comprise a
material selected from the group: veneer, woodboard, chipboard, fibreboard,
plywood
board, plastics sheet, plasterboard, sheet metal, fibre cement board, and from
two or
more thereof.
Preferably, the at least one cover layer is plane, i.e. planar.
Preferably, the at least one cover layer comprises a square or rectangular
shape.
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The dimensions of the cover layer are not limited. Preferably, the width and
the
length of the at least one cover layer lie respectively in the range from 0.50
m to 5 m,
further preferably in the range from 1 to 3 m.
A method for producing an inventive multilayer composite has already been
described above in connection with the production of the core layer. The
method then
comprises at least the steps (i) to (iii):
(i) Presentation of laminar wooden elements comprising zigzagging regions,
wherein a zig-shaped region of an element, together with an adjoining zag-
shaped region of the element, form between them a common edge;
(ii) Arrangement of the elements from step (i) such that two such edges of two
elements intersect at an angle which is different from zero;
(iii) Fixed connection of the edges of the elements from step (ii);
wherein in step (ii) the arrangement on a cover layer is realized, and in step
(iii) the
elements are also fixedly connected to the cover layer, preferably by means of
an
adhesive.
If so desired, that side of the core layer which as yet comprises no cover
layer can
then be provided with a cover layer, preferably by bonding to the cover layer.
Fourth aspect of the invention
Compressively deformed core layer and compressively deformed multilayer
composite
A fourth aspect of the invention relates to a core layer and a multilayer
composite
containing the core layer, which are not planar.
In one embodiment, the inventive core layer according to the first aspect or
produced according to the method of the second aspect, and the inventive
multilayer composite according to the third aspect, are subjected to a
compressive
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deformation step, wherein three-dimensional objects can be produced. For this
purpose, the inventive core layer or the inventive multilayer composite can be
deformed in a suitable compression mould. This deformation can be realized
during
the production of the core layer or of the multilayer composite, as well as
following
this.
In one embodiment, only the edges of the core layer or of the multilayer
composite
are deformed, preferably by compression. It is thus possible to seal off the
cavities at
the edges of the core layer or of the multilayer composite. This compressive
deformation can be performed during the joining together of the core layers or
of the
multilayer composite, yet also following the joining together of the core
layers or of
the multilayer composite in a downstream step, for example by thermal
softening of
the adhesive at the edges. This embodiment has the advantage that a sealing of
the
edges, for example by the application of a wood strip, preferably a veneer
strip, can
be omitted.
In the compression, the possibility is obtained to provide the marginal part
of the core
layer or of the multilayer composite with a cambered profile, i.e. a rounded
profile.
This is frequently desirable, for example in high-quality furniture
components.
In a further embodiment, not only the edge region, but additionally, or
separately from
the edge region, also further regions of the core layer or of the multilayer
composite
can be compressively deformed.
A method for producing three-dimensional wooden objects by compressive
deformation is described in DD 271870 and DE 101 24 912.
Accordingly, the invention relates in a fourth aspect to a multilayer
composite, at
least comprising a cover layer and a core layer, wherein the cover layer is
arranged
such that it at least partially covers over the core layer and is fixedly
connected
thereto, wherein the core layer is a core layer according to the first aspect
of the
invention and of the embodiment described therein; or a core layer is produced
according to a method according to the second aspect of the invention and the
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embodiments described therein; or the multilayer composite is a multilayer
composite
according to the third aspect of the invention and the embodiments described
therein; producible according to a method comprising at least step (i):
(i) Compressive deformation of the multilayer composite according to the
third
aspect.
In the same way, it is also possible to deform under pressure only the
inventive core
layer according to the first aspect of the invention and the embodiments
described
therein, or the inventive core layer produced according to the second aspect
of the
invention and the embodiments described therein.
Accordingly, the invention also relates to a core layer which is suitable for
a
multilayer composite comprising at least one cover layer and a core layer,
wherein
the cover layer is arranged such that it at least partially covers the core
layer and is
fixedly connected thereto, wherein the core layer comprises wooden elements
comprising zigzagging laminar regions, wherein a zig region of an element,
together
with an adjoining zag region of the element, form between them a common edge,
such that the element is zigzag-shaped, and wherein elements are arranged in
the
core layer such that two such edges of two elements intersect at an angle
which is
different from zero, the two elements being fixedly connected to each other at
the
point of intersection; producible according to a method comprising at least
step (i):
(i) Compressive deformation of the core layer according to the first aspect of
the
invention and the embodiments described therein; or compressive deformation
of a core layer produced according to a method according to the second aspect
of the invention and the embodiments described therein.
Fifth aspect of the invention
Use of the inventive core layer and of the inventive multilayer composite
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According to a fifth aspect, the invention further relates to the use of the
inventive
multilayer composite or of the inventive core layer.
Preferably, the inventive multilayer composite or the inventive core layer can
be used
in applications which enable high mechanical stress in combination with
relatively low
weight, and/or which call for a high damping capability. In one embodiment,
the
multilayer composite or the core layer is used in furniture production, for
shelving, for
packagings for transport, for use in interior fittings, in doors and gates, in
or as chairs,
as well as in vehicle construction and shipbuilding. For this purpose, the
multilayer
composite or the core layer can be machined by cutting, sawing, filing and/or
drilling
according to known methods.
The inventive core layer and a multilayer composite comprising the inventive
core
layer, for example a lightweight building board, have high compressive
strength and
stress resistance. In this regard, the inventive core layer and the inventive
multilayer
composite produced therefrom are superior to the corresponding core layers or
multilayer composites which are produced from industrial waste from chips and
fibreboards. In addition, dimensional changes in the core layer or the
multilayer
composite under the influence of moisture, in particular dimensional changes
in
terms of the thickness of the core layer or of the multilayer composite, can
be
negligible due to the negligible dimensional changes of the wood elements in
the
grain direction. This applies, in particular, when the grain runs in the
direction of the
at least two mutually adjoining laminar regions and perpendicular to the edges
formed by the mutually adjoining regions. This is a further advantage over
other
known core layers and multilayer composites produced therefrom, such as are
produced, for example, from flat particles or from layers produced with
parallel fibres,
such as plywood or fibreboards, for example.
Without being bound to a theory, it is assumed that the discussed advantages
result
from the structure of the zigzag-shaped wood elements which are used in the
core
layer and the multilayer composite, wherein the said edge does not run
parallel to the
grain direction of the wood element, but preferably perpendicular thereto. The
structure of the wood element is then still supported by the wood fibres, in
particular
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at the said edge. By contrast, wood elements produced from industrial waste
comprise fibres which do not have the same preferred direction, but extend
isotropically in the three spatial directions. The corresponding edges can
then run
parallel to the grain direction. The structure of these wood elements is then
not, or
only to a lesser extent, supported at the said edge in comparison to wood
elements
as are used according to the invention in the core layer and the board
produced
therefrom.
In addition, fastening means such as nails and screws or furniture connectors
find in
the inventive core layer and the inventive multilayer composite a reliable
hold, since
the structure of the core layer, given comparatively low density, comprises
only small
cavities, i.e. has high homogeneity. Stable fastening to a support, for
example to a
wall, can thus be achieved.
In accordance with another aspect, there is provided a core layer, which is
suitable
for a multilayer composite comprising at least one cover layer and a core
layer,
wherein the cover layer is arranged such that it at least partially covers the
core layer
and is fixedly connected thereto, wherein the core layer comprises wooden
zigzag-
shaped elements, comprising zigzagging laminar regions, wherein a zig region
of an
element, together with an adjoining zag region of the zigzag-shaped element,
form
between them a common edge, and wherein zigzag-shaped elements are arranged
in the core layer such that two such edges of two zigzag-shaped elements,
which can
be the same or different from each other, intersect at an angle which is
different from
zero, the two elements being fixedly connected to each other at the point of
intersection; wherein zigzag-shaped wood elements comprise fibres having a
preferred direction, wherein the common edge or the common edges runs or run
non-
parallel to the preferred direction; or wherein the common edge or the common
edges runs or run perpendicular to the preferred direction; and wherein more
than 50
% of the wood elements are present in the core layer such that they are
fixedly
connected to one another, wherein the wood elements are present in the core
layer
in a random distribution; or wherein the wood elements are arranged randomly
in the
core layer and are connected to one another and to the cover layer by an
adhesive,
wherein the wood elements are arranged side by side or one above the other; or
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wherein the wood elements are arranged randomly in the core layer, wherein the
wood elements in the arrangement and subsequent bonding generally have dot-
like
connecting points at the edges which intersect at different angles.
Illustrative embodiments of the invention are represented schematically in the
drawings. They are explained in greater detail below with reference to the
figures of
the drawings.
Fig. la shows a cross section of an embodiment of an inventive multilayer
composite, for example a lightweight building board.
Fig. lb shows a cross section of a preferred embodiment of an inventive
multilayer
composite.
Fig. lc shows a cross section of another preferred embodiment of an inventive
multilayer composite.
Fig. 2a shows a zigzag-shaped element and a plane element of another preferred
embodiment of an inventive multilayer composite or of an inventive core
layer.
Fig. 2b shows a zigzag-shaped element, which is bonded to a planar element.
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Fig. 2c shows a zigzag-shaped element, which is bonded on both sides to a
planar
element.
Fig. 2d shows a plurality of zigzag-shaped wood elements, which are
alternately
bonded to planar elements.
Fig. 3 shows an arrangement of zigzag-shaped wood elements in the inventive
core layer of another preferred embodiment of an inventive multilayer
composite.
Fig. 4 shows an arrangement of zigzag-shaped wood elements of the inventive
core layer and a cover layer of another preferred embodiment of an
inventive multilayer composite.
Fig. 5a shows a cross section of a zigzag-shaped wood element of a core layer
of
another preferred embodiment of an inventive multilayer composite.
Fig. 5b shows a cross section of a zigzag-shaped wood element of a core layer
of
another preferred embodiment of an inventive multilayer composite.
Fig.6a shows the side view of a device used to produce a zigzag-shaped
element,
by folding.
Fig. 6b shows the view in the running direction of a device from Fig. 6a,
which
device is used to produce a zigzag-shaped element.
Fig. 7a shows the production of a zigzag-shaped wood element by cutting, with
a
knife of zigzag-shaped profile, from a wood block.
Fig. 7b shows the obtained wood element from Fig. 7a.
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Fig. 7c shows in zigzag profile the wood element from Fig. 7h, which wood
element
has been obtained by cutting.
Fig. 8a shows the production of zigzag-shaped wood elements by cutting, in
side
view.
Fig. 8b shows the production of zigzag-shaped wood elements from Fig. 8a, in
top
view.
io Fig. 9 shows zigzag-shaped wood elements, which are produced by cutting
with
an appropriately profiled knife.
Fig. la shows a cross section of an embodiment of an inventive multilayer
composite
1. The multilayer composite 1 is designed such that it constitutes a
lightweight
building board. A core layer 3 is covered by the cover layer 2. This is
configured as
wood veneer. The core layer 3 comprises wood elements, which are shaped such
that a wood element comprises two mutually adjoining zigzagging laminar
regions
such that a zig region and the adjoining zag region form between them a common
edge, such that the wood element is zigzag-shaped, wherein elements are
arranged
23 in the core layer such that two such edges of two elements, which can be
the same
or different from each other, intersect at an angle which is different from
zero, the two
elements being fixedly connected to each other at the point of intersection.
The resulting board 1 is relatively light and, due to the veneer cover layer
2, has an
aesthetically pleasing appearance. The mean density of the core layer 3 is
less than
the mean density of the cover layer 2. The wood elements, which can be
produced
from folded pieces of veneer, are arranged randomly within the core layer 3.
They
are connected to one another and to the cover layer 2 by an adhesive. As a
result,
the lightweight building board can withstand shearing forces which act upon
the
layers, irrespective of the direction of the shearing forces in the principal
plane of the
board. This means that the board has a homogeneous lateral stability. The wood
elements are arranged side by side or one above the other. A dense filling of
the core
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layer is thereby enabled, whereby the board acquires a high mechanical
stability, so
that it can be further processed, for example by equipping with nails and
screws or
furniture connectors. This also enables stable fastening to a support, such as
to a
wall, for example.
The wood elements are arranged randomly in the core layer 3, but can also be
arranged regularly, i.e. in a pre-specified manner. For example, the wood
elements
can be arranged regularly in groups, i.e. in domains of sub-units of the core
layer 3,
wherein the wood elements of a first sub-unit have a first preferred direction
and
wood elements of a second sub-unit have a second preferred direction, the
first sub-
unit preferably adjoining the second sub-unit and the first preferred
direction
preferably being different from or, at least, partially equal to the second
preferred
direction. A preferred direction can be defined by the edge of a zigzag-shaped
wood
element, or can be described by a section of the direction of a wood fibre of
a wood
element, or can be described by an edge, for example a section of the long
edge of a
strip-shaped wood element (a strip which is formed such that it is zigzag-
shaped), or
by a connecting line between the edges, formed by the zigzagging regions, of a
zigzag-shaped wood element.
The multilayer composite 1 according to Fig. la comprises only one cover
layer,
namely the cover layer 2. A composite having only a cover layer on one side
has in
comparison to a composite having cover layers on both sides, which cover
layers
surround the core layer in a sandwich-like manner, a reduced stability.
However, it
can serve, for example, as an intermediate product for the production of a
composite
having cover layers on both sides. Such a composite is represented in Fig. 1
b.
Fig. lb shows a cross section of a preferred embodiment of the inventive
multilayer
composite, namely a cross section of the multilayer composite 10 in the form
of a
board. A cover layer 2 and a further cover layer 2' (a base layer) are
provided,
wherein the second cover layer 2' lends additional mechanical stability to the
board.
The visual appearance of the cover layer 2' can be different from that of the
cover
layer 2. Such a composite has substantially higher flexural strength and
flexural
rigidity compared to the composite according to Fig. la.
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Fig. lc shows a cross section of another preferred embodiment of an inventive
multilayer composite, namely the multilayer composite 100 in the form of a
board.
The board comprises a cover layer 2, a cover layer 2' and a cover layer 2"
and, in
addition to the core layer 3, a further core layer 3'. The cover layers 2 and
2' here
surround the core layer 3 in a sandwich-like manner, and the cover layers 2'
and 2"
surround the core layer 3' in a sandwich-like manner. The board 100 thereby
acquires additional mechanical stability compared to the board 10. The zigzag-
shaped wood elements in the core layers 3 and 3' can be arranged randomly or
regularly, i.e. partially regularly (for example in domains) or substantially
fully
regularly. The zigzag-shaped wood elements in the core layer 3 can have a
first
preferred direction and the zigzag-shaped wood elements in the core layer 3'
can
have a second preferred direction, the first preferred direction preferably
being
different from the second preferred direction or, at least, partially equal to
the second
preferred direction.
Fig. 3 shows the arrangement of zigzag-shaped wood elements 30 in the core
layer
3, 3' of a preferred embodiment of an inventive multilayer composite 1, 10,
100. Each
wood element 30 comprises mutually adjoining zig and zag regions 50 and 60,
which
form between them a common edge 70. The arrangement of the zigzag-shaped
wood elements 30 is random. The contact surface 40 between mutually adjoining
wood elements is therefore respectively, a point 40. In the arrangement and
subsequent bonding, the wood elements generally have dot-like connecting
points 40
at the edges 70 which intersect at different angles. These connecting points
press
during moderate compaction, once again by compression, partially one into the
other
and thus enable homogenization of the structure. Depending on the degree of
compaction, a high to medium cavity component remains. This leads to a core
layer
3, 3' of lower resulting density, since an alignment of the wood elements 30
along
their associated preferred directions essentially fails to occur. As a result,
the core
layer is more anisotropic, which implies an anisotropic mechanical
characterization of
the resulting board. The formed structure constitutes a random framework, the
frame
rods of which consist of parallel-grained wood with high load-bearing
capacity. The
compressed, articulated rod connections are, as generally known in frameworks,
not
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weak points, since a framework permits joints. The precondition is sufficient
bonding
of the connecting points to be able to absorb longitudinal forces.
In addition to the high compressive and shearing strength of the finished
lightweight
construction element, resulting from the framework structure, the very small
thickness swelling of the lightweight building board in the event of moisture
variations, due to the virtually negligible swelling of the wood
longitudinally to the
grain direction, should be emphasized. Such a board would thus be superior to
all
other derived timber products made up of flat-lying particles or parallel-
grained
layers, such as chipboards and fibreboards, plywood or coreboards.
In one embodiment, the zigzag-shaped wood elements can be combined with
admixed planar, i.e. planarly configured, elements. Preferably, the zigzag-
shaped
wood elements are bonded to the planar elements. In the bonding,
proportionally
linear connecting points between the zigzag-shaped elements and the planar
elements, and thus an increased transverse tensile strength of the lightweight
building board, are formed.
Fig. 2a shows two component parts of another preferred embodiment of an
inventive
multilayer composite 1, 10, 100 or of an inventive core layer 3, 3'. The core
layer 3, 3'
comprises laminar zigzag-shaped wood elements 30, wherein the wood elements 30
can have a multiplicity of edges 70, which are formed by mutually adjoining
laminar
zig and zag regions 50 and 60, for example five edges 70 as in the wood
element 30
of Fig. 2a. In addition, a planar element 200, designed, for example, as a
veneer, is
present.
Fig. 2b shows that, according to an advantageous variant, a zigzag-shaped
element
is bonded in a first step to a planar element 200 of similar or same format,
so that
a regular and thus very rigid framework structure is formed in the wood
element 30.
30 The planar element 200 can consist of wood veneer, paper, cardboard or
comparable, web-shaped materials. The zigzag-shaped wood element 30 and the
planar element 200 form cavities 300. Upon subsequent compression into a light
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core, this framework of the element formed from the planar element 200 and the
zigzag-shaped element 30 remains fully preserved. Only at the connecting
points of
these framework-shaped elements is a local compaction realized, depending on
the
position. A high cavity component 300 thus remains in the core, which cannot
be
filled by adjacent elements.
This embodiment defines a core layer 3, 3' which is suitable for a multilayer
composite 1, 10, 100 comprising at least one cover layer 2, 2', 2" and a core
layer 3,
3', wherein the cover layer 2, 2', 2" is arranged such that it at least
partially covers
the core layer 3, 3' and is fixedly connected thereto, wherein the core layer
3, 3'
comprises wooden elements 30 comprising zigzagging laminar regions, wherein a
zig region 50 of an element, together with an adjoining zag region 60 of the
element
30, form between them a common edge 70, such that the element 30 is configured
in
a zigzag shape and wherein elements 30 are arranged in the core layer 3, 3'
such
that two such edges 70 of two zigzag-shaped elements 30 intersect at an angle
which is different from zero, the two zigzag-shaped elements 30 being fixedly
connected to each other at the point of intersection; wherein each zigzag-
shaped
wood element 30 is bonded to a planar element 200, such that the zigzag-shaped
element 30 and the planar element 200 form between them one or more cavities
300.
Elements according to Fig. 2b, comprising a zigzag-shaped element 30 and a
planar
element 200, can be present in random distribution in the core layer 3, 3'.
It is also possible, of course, for an element according to Fig. 2b,
comprising a
zigzag-shaped element 30 and a planar element 200, together with further
zigzag-
shaped elements 30, to be present, preferably in random distribution.
This embodiment defines a core layer 3, 3' which is suitable for a multilayer
composite 1, 10, 100 comprising at least one cover layer 2, 2', 2" and a core
layer 3,
3', wherein the cover layer 2, 2', 2" is arranged such that it at least
partially covers
the core layer 3, 3' and is fixedly connected thereto, wherein the core layer
3, 3'
comprises wooden elements 30 comprising zigzagging laminar regions, wherein a
zig region 50 of an element 30, together with an adjoining zag region 60 of
the
element 30, form between them a common edge 70, such that the elements 30 are
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zigzag-shaped, and wherein zigzag-shaped elements 30 are arranged in the core
layer 3, 3' such that two such edges 70 of two zigzag-shaped elements 30
intersect
at an angle which is different from zero, the two zigzag-shaped elements 30
being
fixedly connected to each other at the point of intersection; wherein the core
layer 3,
3' comprises at least one wood element 30, which is bonded to a planar element
200,
such that the zigzag-shaped element 30 and the planar element 200 form between
them one or more cavities 300.
The cavities 300 are formed by the zigzag-shaped regions 50 and 60 in the
zigzag-
.. shaped element 30, together with the planar elements 200.
Fig. 2c shows that a zigzag-shaped wood element 30 can also be glued on both
sides to planar elements 200, with the formation of cavities 300.
This embodiment defines a core layer 3, 3' which is suitable for a multilayer
composite 1, 10, 100 comprising at least one cover layer 2, 2', 2" and a core
layer 3,
3', wherein the cover layer 2, 2', 2" is arranged such that it at least
partially covers
the core layer 3, 3' and is fixedly connected thereto, wherein the core layer
3, 3'
comprises wooden elements 30 comprising zigzagging laminar regions, wherein a
zig region 50 of an element 30, together with an adjoining zag region 60 of
the
element 30, form between them a common edge 70, such that the element 30 is
configured in a zigzag shape, and wherein elements 30 are arranged in the core
layer 3, 3' such that two such edges 70 of two zigzag-shaped elements 30
intersect
at an angle which is different from zero, the two zigzag-shaped elements 30
being
fixedly connected to each other at the point of intersection; wherein the core
layer 3,
3' comprises at least one zigzag-shaped wood element 30, which is bonded to
two
planar elements 200 such that the zigzag-shaped element and the two planar
elements 200 form between them a plurality of cavities 300, wherein the zigzag-
shaped wood element 30 is surrounded in a sandwich-like manner by the two
planar
elements 200.
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Fig. 2d shows that also a plurality of zigzag-shaped wood elements 30 can be
alternately connected to planar elements 200 with the formation of cavities
300,
wherein a planar element 200 separates two zigzag-shaped wood elements 30 from
each other.
This embodiment defines a core layer 3, 3' which is suitable for a multilayer
composite 1, 10, 100 comprising at least one cover layer 2, 2', 2" and a core
layer 3,
3', wherein the cover layer 2, 2', 2" is arranged such that it at least
partially covers
the core layer 3, 3' and is fixedly connected thereto, wherein the core layer
3, 3'
comprises wooden elements 30 comprising zigzagging laminar regions, wherein a
zig region 50 of an element 30, together with an adjoining zag region 60 of
the
element 30, form between them a common edge 70, such that the element 30 is
zigzag-shaped, and wherein zigzag-shaped elements 30 are arranged in the core
layer such that two such edges 70 of two zigzag-shaped elements 30 intersect
at an
angle which is different from zero, the two zigzag-shaped elements 30 being
fixedly
connected to each other at the point of intersection; wherein respectively two
zigzag-
shaped elements 30 are bonded to a planar element 200, such that the zigzag-
shaped elements 30 and the planar element 200 form between them a plurality of
cavities 300, wherein the planar element 200 is surrounded in a sandwich-like
manner by two zigzag-shaped wood elements 30.
Elements according to Fig. 2d, comprising a plurality of zigzag-shaped wood
elements 30 alternately with planar elements 200 with the formation of
cavities 300,
wherein a planar element 200 separates two zigzag-shaped wood elements 30 from
each other, can be present in random distribution in the core layer.
It is possible, of course, for elements according to Fig. 2d, comprising a
plurality of
zigzag-shaped wood elements 30 alternately with planar elements 200 with the
formation of cavities 300, wherein a planar element 200 separates two zigzag-
shaped wood elements 300 from each other, to possibly be present together with
elements 30, preferably in random distribution.
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This embodiment defines a core layer 3, 3' which is suitable for a multilayer
composite 1, 10, 100 comprising at least one cover layer 2, 2', 2" and a core
layer 3,
3', wherein the cover layer 2, 2', 2" is arranged such that it at least
partially covers
the core layer 3, 3' and is fixedly connected thereto, wherein the core layer
3, 3'
comprises wooden elements 30 comprising zigzagging laminar regions, wherein a
zig region 50 of an element 30, together with an adjoining zag region 60 of
the
element 30, form between them a common edge 70, such that the element 30 is
configured in a zigzag shape, and wherein zigzag-shaped elements 30 are
arranged
in the core layer such that two such edges 70 of two zigzag-shaped elements 30
intersect at an angle which is different from zero, the two zigzag-shaped
elements 30
being fixedly connected to each other at the point of intersection; wherein
the core
layer 3, 3' comprises at least one element comprising two zigzag-shaped wood
elements 30, which are bonded to a planar element 200 such that the two zigzag-
shaped elements 30 and the planar element 200 form between them a plurality of
cavities 300, wherein the planar element 200 is surrounded in a sandwich-like
manner by two zigzag-shaped wood elements 30.
In a further embodiment, it is also possible for zigzag-shaped wood elements
30,
together with elements according to Fig. 2b and according to Fig. 2c and
according
to Fig. 2d, to be present in the core layer 3, 3'. Preferably, the elements
are then
arranged or distributed randomly in the core layer.
In a further embodiment, it is also possible for zigzag-shaped wood elements
30,
together with elements according to Fig. 2c and according to Fig. 2d, to be
present in
the core layer 3, 3'. Preferably, the elements are then arranged or
distributed
randomly in the core layer.
In a further embodiment, it is also possible for zigzag-shaped wood elements
30,
together with elements according to Fig. 2b and according to Fig. 2d, to be
present in
the core layer 3, 3'. Preferably, the elements are then arranged or
distributed
randomly in the core layer.
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In a further embodiment, it is also possible for elements according to Fig. 2b
and
according to Fig. 2d to be present in the core layer 3, 3'. Preferably, the
elements are
then arranged or distributed randomly in the core layer.
In a further embodiment, it is also possible for elements according to Fig. 2c
and
according to Fig. 2d to be present in the core layer 3, 3'. Preferably, the
elements are
then arranged or distributed randomly in the core layer.
Zigzag-shaped wood elements, combined with, or without, planar wood elements,
can also be mixed with standard derived timber material elements like wood
chips or
wood fibres to form a light construction core. This glued mixture can be
compressed
into a lightweight derived timber material board, which has further increased
homogeneity. In this context, the applicability of existing technologies, for
example
chipboard production, is particularly advantageous, with the possibility of
boards
having a very much lower bulk density than in standard board production.
Fig. 4 shows the arrangement of zigzag-shaped wood elements 30' of the core
layer
3, 3' on a cover layer 20' of another preferred embodiment of an inventive
multilayer
composite 1, 10, 100. The arrangement of the wood elements is random, which
implies an anisotropic mechanical identification of the resulting board. A
wood
element 30' is a strip-shaped, zigzag-shaped element, which has only one edge
70
between adjacent zig and zag regions 50 and 60. In general terms, a strip-
shaped
element is an element whose length is greater than the width expressed by a
factor
c, wherein c preferably lies between the upper and lower limit according to
{2; 3; 5} <
c < {3; 5; 8; 10; 20}. Of course, the element can also comprise a plurality of
mutually
adjoining zig and zag regions, so that it has a plurality of edges 70.
Fig. 5a shows a cross section of a zigzag-shaped wood element 7 of a core
layer of
another preferred embodiment of an inventive multilayer composite, for example
the
inventive board. The edge portion 7' formed between a zig and a zag region has
a
sharp edge. The wood element 7 has only one edge portion, but can also
comprise a
plurality of edge portions, as indicated by the dotted lines.
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Fig. 5b shows a cross section of a zigzag-shaped wood element 8 of a core
layer of
another preferred embodiment of an inventive multilayer composite. The edge
region
8' does not form a sharp edge, but rather a curved edge in the form of a
curved
plane, which can reach to the height H of the wood element. The wood element 8
comprises only one edge portion, but can comprise a plurality of edge
portions, as
indicated by the dotted lines.
Figs. 6a and 6b show a device with which zigzag-shaped wood elements can be
produced by folding. Fig.6a here shows the side view of the device used for
the
folding, Fig. 6b the view in the running direction.
In this method, veneer, or veneer-like elements, such as OSB chips, having a
production-based wood moisture of at least 30% runs/run into a cutting unit
known
from the prior art, with the wood grain direction running transversely to the
transport
direction. This cutting unit cuts the veneer or the OSB chips into a ribbon or
wood
elements having a width of 10 to 80 mm, according to choice. This ribbon or
these
wood elements make their way into a profiling tool, which, starting from the
middle,
respectively impresses a zigzag profile transversely to the wood grain
direction until
the entire width is profiled. The profiling tool is equipped with a heater,
which heats
the particles after the profiling and dries them to the moisture level
necessary for
further processing. The spring-back of the profiling is thus, at the same
time, confined
to a minimum. Following the profiling and drying, the wood elements pass
through a
roller-type gluing station, in which the folding edges are provided on both
sides with
preferably duroplastic adhesive. The adhesive dries rapidly on the still hot
particles
and is reactivated upon subsequent compression of the particles. After this,
the
splitting of the profiled wood elements parallel to the wood grain direction
into 8 to 80
mm long parts is realized. Marginal portions of correspondingly smaller
lengths are
jointly used, as are part-widths which arise during the splitting of the
veneer.
For the production of a lightweight building board, the adhesive-coated
particles are
scattered onto a prepared cover layer, so that the particles are statistically
distributed
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with respect to direction and position in the areal direction, comparable with
other
particle materials such as chipboard. After the upper cover layer has been put
on, the
board is produced by pressing with moderate compressive force, which leads to
mutual contact of the particle edges. The hardening of the adhesive can be
accelerated by contact warming, high-frequency heating or hot-air heating.
In the production of wooden regular framework elements by the connection of
zigzag-
shaped wood elements and planar, i.e. planarly configured, wood elements, both
types of wood elements, after the profiling, are glued and brought
synchronously
together and bonded.
According to an advantageous variant, the profiling tool is unheated. After
the
profiling, the gluing of the still moist particles with a polyurethane-based
moisture-
hardening adhesive and the gluing together of zigzag-shaped wood elements and
planar wood elements takes place. As a result of this gluing, the zigzag
profile is
fixed. Any spring-back is thus precluded.
After the bonding, the splitting into parts of defined width, and finally the
compression
of the framework particles into a lightweight building board, takes place.
In the processing of still moist particles, an after-drying of the core by
means of
lateral air admission is possible, in order to set the final moisture of the
board.
In a first illustrative embodiment (Example 1), a veneer ribbon 4, which is
0.6 mm
thick, contains a wood moisture content of 30%, is one metre long, measured
transversely to the wood grain direction, and is 50 mm wide in the grain
direction, is
led onto a 40 mm wide, heated roller 5, which is provided with a, in 5 mm
grids,
zigzag-like and firm-gripping profile, and, starting in the middle, is pressed
into the
profile by a heated sliding shoe 6.1, which tracks the centre profile. This is
followed
by the sliding shoes 6.2, 6.3 etc., which respectively press the neighbouring
profile
into the veneer ribbon until the entire width of the veneer ribbon is
profiled. The step-
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by-step profiling, starting from the middle, guarantees a stress-free shaping.
Subsequently, the now ready-profiled veneer ribbon 4.1 is held on the roller 5
by a
likewise heated band 700 and hereupon dried. The profiling in the veneer
ribbon is
thus fixed. There follows a roller-type gluing station 800, in which the
veneer ribbon
4.1 is provided at the profile edges with adhesive. After this, the veneer
ribbon 4.1 is
split in a known cutting station into 20 mm wide, zigzag-shaped wood elements,
for
instance the wood elements 30. These wood elements are compressed into a
wooden lightweight building board of 300 kg/m3 bulk density, which has a high
static
load-bearing capacity.
lo
In a further illustrative embodiment (Example 2), 0.3 mm thick OSB chips
having a
length of 200 mm and a width of 30 mm are led transversely to the transport
direction
in a cutting unit and divided into 40 mm long wood elements. These wood
elements
pass on into a profiling device according to Example 1, the zigzag profile of
which
comprises a 4 mm grid. The further processing corresponds to Example 1. At the
end
of the processing, a slender and homogeneously constructed wooden lightweight
building board having a bulk density of 250 kg/m3 is formed. The particular
advantage
consists in a largely automatable production.
In a further illustrative embodiment (Example 3), a veneer ribbon according to
Example 1, which is profiled in a zigzag shape and is coated with glue, is
brought
together with a planar veneer ribbon of 24 mm width and is bonded thereto.
This
bonded ribbon passes through a pair of gluing rollers in order to provide the
profile
edges or the outer surface of the planar ribbon with adhesive. Following
passage
through a cutting station, particles in the form of a regular framework
according to
Fig. 2b are present. Upon compression, a wooden lightweight building board
having
a bulk density of 180 kg/m' is formed.
Fig. 7a shows the production of a zigzag-shaped wood element by cutting with a
knife 1000 from a wood block 13. According to the invention, the knife 1000
which is
used in the production of rotary cut or sliced veneer or of veneer-like chips,
is of
zigzag-shaped profile.
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Fig. 7b shows the obtained wood element, for example the wood element 30. This
can subsequently be reduced in size, for example in a cutting unit.
Fig. 7c shows a zigzag-shaped wood element 30 of Fig. 7b, wherein the zigzag
profile is dimensioned such that the wood fibres 3000 have at least double the
length
4000 in relation to the thickness 500 and thus enable good transverse tensile
strength and shearing strength. In this variant, the production of profiled
parts in a
single operation, as well as the high constancy of the profiles, is
advantageous. The
wood fibres running obliquely to the profile rods represent a compromise in
terms of
their strength, equally the higher swelling thickness.
Figs. 8a and 8b show in a further illustrative embodiment (Example 4) a device
for
producing zigzag-shaped wood elements by cutting. Fig. 8a shows the side view,
Fig. 8b the top view. On a known veneer slicing machine, a profiled veneer 400
of a
height 11 of 3mm is here sliced off from a 400 mm high wood block 13, by means
of
knife 1000 profiled in a zigzag shape and having a profile grid dimension of 5
mm.
The thickness of the profiled veneer (500 in Fig. 7c) measures 0.5 mm.
Attached to
the profile knife 1000 at 25 mm intervals are scoring knives 12, which cut the
formed
profiled veneer 400 into 25 mm wide and 400 mm long strips. These strips, the
wood
grain direction of which lies transversely to the longitudinal axis, are
comminuted in a
known hammer mill into wood elements having an average width of 16 mm, for
example into wood elements 30. This is followed by the drying, sifting and
gluing in
known drums, whereupon the thus prepared zigzag-shaped wood elements are
spread by means of known spreading machines into a mat and compressed together
with cover layers into a lightweight building board having a bulk density of
350 kg/m3.
In a further illustrative embodiment (Example 5), a knife disc chipper, which
is
standardly used in chipboard technology, is equipped with knives which are
profiled
in a zigzag shape and have a profile grid dimension of 3 mm, wherein the chip
thickness is set at 0.3 mm. The attached scoring knives are spaced 20 mm
apart.
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Roundwood portions, peeler cores and other residual materials are the base
product.
The wood elements produced with this chipper are further processed according
to
Example 4. A particular advantage of this technology is the comparability with
the
highly productive production of chipboards, whereby a very cheap wooden
lightweight building material is formed.
In a further illustrative embodiment (Example 6), a veneer peeling machine is
equipped with a knife according to Example 4. The veneer web, which is
produced
from a peeling block and is appropriately profiled, passes through a veneer
dryer, a
roller-type gluing machine and finally a continuous press, in which a
cardboard web
is pressed on. This web is next split by means of known cutting units into 25
x 25
mm2 large wood elements, which constitute regular frameworks. Following
sifting and
removal of unusable components, these wood elements are provided with adhesive
in a glue-coating drum and then compressed into a wooden lightweight building
board having a bulk density of 200 kg/m'. The usability of low-grade timber
assortments, which are unsuitable for standard veneer production, is here
advantageous.
Fig. 9 shows zigzag-shaped wood elements 30", which are produced by cutting
with
an appropriately profiled knife and which have no constant profile thickness.
These
are distinguished by increased compressive strength. The cutting direction in
the
production of the elements can be executed, with each new cutting stroke, in a
direction offset by up to 90 , wherein the geometry, and thus also the grain-
dictated
stability of the veneer pieces, changes. Given a maximum difference in cutting
.. directions of 90 , the produced "profiled wood element" has a lattice
structure,
irrespective of the cut thickness. Apart from solid wood, derived timber
products, in
particular, which have approximately the same strength characteristics in
different
board directions are suitable as the base material. For this, residual or
waste pieces
of plywood or medium-density fibreboard, for example, can be used.
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Reference symbol list:
1, 10, 100 multilayer composite
2, 2', 2", 20' cover layer
3, 3' core layer
7, 8, 30, 30', 30" zigzag-shaped wood element
50 zig or zag region
60 zag or zig region
7', 8', 70 edge between a zig region and an adjoining zag
region; or
edge between a zag region and an adjoining zig region
40 contact surface or contact point between two
intersecting
edges 7', 8', 70
200 planar element (planarly configured element)
300 cavity which is formed from a zigzag-shaped wood
element 7, 8, 30, 30', 30" by bonding to a planar element
200
4 veneer ribbon
4.1 profiled veneer ribbon
5 roller
6.1, 6.2, 6.3... sliding shoes
700 heated band
800 roller-type gluing station
13 wood block
3000 wood fibres
4000 length of the wood fibres 3000
500 thickness of a zag or zig region 50, 60 of a wood
element
7, 8, 30, 30', 30"
1000 knife of zigzag-shaped profile
400 veneer
11 thickness of the veneer 400
12 scoring knife
length of an edge 7', 8', 70
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height of a zigzag-shaped wood element 7, 8, 30, 30', 30"
