Patent Application
20130316125
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 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.
One object of the present invention is to provide 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 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.
According to 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, 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.
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.
According to a third aspect, 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.
According to a fourth aspect, the invention relates to a core layer and a multilayer composite containing the core layer, which are not planar.
According to a fifth aspect, the invention further relates to the use of the inventive multilayer composite or of the inventive core layer.
a shows a cross section of an embodiment of an inventive multilayer composite, for example a lightweight building board.
b shows a cross section of a preferred embodiment of an inventive multilayer composite.
c shows a cross section of another preferred embodiment of an inventive multilayer composite.
a shows a zigzag-shaped element and a plane element of another preferred embodiment of an inventive multilayer composite or of an inventive core layer.
b shows a zigzag-shaped element, which is bonded to a planar element.
c shows a zigzag-shaped element, which is bonded on both sides to a planar element.
d shows a plurality of zigzag-shaped wood elements, which are alternately bonded to planar elements.
a shows a cross section of a zigzag-shaped wood element of a core layer of another preferred embodiment of an inventive multilayer composite.
b shows a cross section of a zigzag-shaped wood element of a core layer of another preferred embodiment of an inventive multilayer composite.
a shows the side view of a device used to produce a zigzag-shaped element, by folding.
b shows the view in the running direction of a device from
a shows the production of a zigzag-shaped wood element by cutting, with a knife of zigzag-shaped profile, from a wood block.
b shows the obtained wood element from
c shows in zigzag profile the wood element from
a shows the production of zigzag-shaped wood elements by cutting, in side view.
b shows the production of zigzag-shaped wood elements from
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, 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 layer 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.
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 180° nor 360°.
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 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.
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.
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 exemplary 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 exemplary 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 30°, 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 intersect 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.
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 exemplary 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 exemplary 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.
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 exemplary embodiment, the method comprises at least the steps (i) and (ii), while in other exemplary embodiments, the method comprises steps (i), (ii), and (iii): (i) providing 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) arranging the elements from step (i) such that two such edges of two elements intersect at an angle which is different from zero; and (iii) fixedly connecting the edges from step (ii). Preferably, fixedly connecting the edges from step (ii) is accomplished 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 carried out 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.
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).
In one exemplary embodiment, this arrangement is then covered and compressed by a further cover layer. Accordingly, a multilayer composite comprising two cover layers and an intermediate core layer is formed.
In certain exemplary embodiments, the core layer according to the first aspect, or produced according to the method of the second aspect, is planar.
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. In certain exemplary embodiments, the at least one cover layer is plane, i.e. planar. In certain exemplary embodiments, the at least one cover layer comprises a square or rectangular shape. The dimensions of the cover layer are not limited. In one exemplary embodiment, the width and the length of the at least one cover layer lie respectively in the range from 0.50 m to 5 m. In another exemplary embodiment, the width and length of the at least one cover layer lie respectively in the range from 1 m 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):
In one exemplary embodiment, 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.
A fourth aspect of the invention relates to a core layer and a multilayer composite containing the core layer, which are not planar.
In certain exemplary embodiments, the inventive core layer according to the first aspect or produced according to the method of the second aspect, or the inventive multilayer composite according to the third aspect, may be subjected to a compressive 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 performed during or subsequent to the production of the core layer or the production of the multilayer composite.
In one exemplary 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 step, 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 another exemplary embodiment, not only the edge region, but additionally, or separately from the edge region, 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, which are incorporated by reference herein.
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 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):
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):
According to a fifth aspect, the invention further relates to the use of the inventive multilayer composite or of the inventive core layer.
In certain exemplary embodiments, 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 certain exemplary embodiments, 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 any of these purposes, 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 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.
Turning now to the figures,
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 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
b 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
c 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.
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 exemplary 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.
a 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
b shows that, according to an advantageous variant, a zigzag-shaped element 30 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. 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 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
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 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.
c 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.
d 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
It is possible, of course, for elements according to
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
In a further embodiment, it is also possible for zigzag-shaped wood elements 30, together with elements according to
In a further embodiment, it is also possible for zigzag-shaped wood elements 30, together with elements according to
In a further embodiment, it is also possible for elements according to
In a further embodiment, it is also possible for elements according to
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.
a 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.
b 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.
a and 6b show a device with which zigzag-shaped wood elements can be produced by folding.
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 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-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.
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
a 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.
b shows the obtained wood element, for example the wood element 30. This can subsequently be reduced in size, for example in a cutting unit.
c shows a zigzag-shaped wood element 30 of
a and 8b show in a further illustrative embodiment (Example 4) a device for producing zigzag-shaped wood elements by cutting.
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. 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 25×25 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/m3. The usability of low-grade timber assortments, which are unsuitable for standard veneer production, is here advantageous.
While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative structures and processes, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
| Number | Date | Country | Kind |
|---|---|---|---|
| 12003427.7 | May 2012 | EP | regional |
This application claims priority to and any other benefit of U.S. Provisional Patent Application Ser. No. 61/642,538, filed on May 4, 2012, and also claims priority to and any other benefit of European Patent Application Number 12003427.7, filed on May 4, 2012, the entire contents of which are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61642538 | May 2012 | US |
