Methods, laminates, and formable sheet of cellulosic material

Abstract

The present invention relates to the field of laminate composites, particularly those comprising materials with cellulosic content. More specifically, the invention pertains to a novel, formable sheet of wood veneer or similar cellulosic anisotropic material, deliberately patterned with cuts that enable it to stretch, compress, and / or be curved, and laminate composite elements featuring at least one layer of said novel cellulosic sheet.

Description

[0001] METHODS, LAMINATES, AND FORMABLE SHEET OF CELLULOSIC MATERIAL

[0002] DESCRIPTION

[0003] TECHNICAL FIELD

[0004] Methods for the manufacture of composite laminates and formable sheets of cellulosic material are disclosed.

[0005] In the fields of architecture, construction, transportation, manufacturing of furniture and objects of irregular shapes, among others, the search for lighter elements with structural capacity that enable formability, produced with less materials and lower carbon emissions has become a priority, both for environmental and economic reasons.

[0006] Some composite materials have shown to meet these requirements, especially those that display both special, thin geometries - for example shell configurations - and materials of cellulosic origin.

[0007] The present invention relates to the field of laminate composites, particularly those comprising materials with cellulosic content. More specifically, the invention pertains to a novel, formable sheet of wood veneer or similar cellulosic anisotropic material, deliberately patterned with cuts that enable it to stretch, compress, and / or be curved, and laminate composite elements featuring at least one layer of said novel cellulosic sheet.

[0008] BACKGROUND ART

[0009] Laminate composites are widely used in various industries for their versatility and mechanical properties. These composites typically consist of layers bonded together, each layer contributing specific characteristics to the composite as a whole.

[0010] Carbon fibre or glass fibre reinforced plastics, and aluminium are also widely used for similar purposes. While these materials may be lightweight, they are still far from being economically convenient and environmentally sustainable, as their production processes are costly and generate high CO2 emissions. Wood-based or cellulosic laminate composites offer advantages such as high mechanical performance, low weight, aesthetic appeal, ease of manipulation, lower costs, and lower overall CO2 emissions than traditional composite materials and alloys.

[0011] Usually, the manufacture of curved or double-curved wood or cellulosic laminate composites presents challenges due to the inherent bending resistance of wood-based materials. Achieving desired curvatures often involves the use of chemicals and complex mechanical processes, which can be time-consuming, costly, energy intensive, and consequently not environmentally efficient.

[0012] Patent US9056444B1 presents moulded planar products, such as doors, produced by moulding lignocellulosic and cellulosic composite materials. The doors can be manufactured by compressing and heating a layered mixture of fine wood particles blended with thermo-set moulding resins and coarse wood particles between two moulds, which may contain relief patterns. Although through this process it is possible to obtain products with single and double curves, the process is costly, energy intensive, has high CO2 emissions, and the products obtained by it are relatively heavy and do not display the kind of mechanical performance that construction and transportation industries, among others, require.

[0013] Flexible plywood or plywood-like composites crafted from wood veneer or similar materials are also sought after in many industries. The characteristics of traditional wood-based materials impose significant flexing constraints, impeding small curvature radii. Special plywood-like composites have been developed to enhance their flexibility, for example, patent PL34466B1 discloses a flexible plywood board composed of several layers, characterised in that between each two sheets of veneer with parallel arrangement of their fibres, there is a layer of linen cloth, which makes the plywood easy to bend and not to break. Other formulas for flexible plywood have been developed over the last decades, with different manufacturing techniques and material specifications, but all share the limitation of only allowing for simple curves of large radii.

[0014] Patent WO2023055257A1 discloses a method of manufacturing flexible plywood that comprises gluing a pre-pressed stack of wood veneer in a hot press, and then cutting boards of plywood from said glued stack. The stack is made from veneer having the same grain direction throughout the entire stack with the exception of one or two sheets of veneer that are placed with a perpendicular grain direction, which serve as guard plies for the stack. All the sheets in the stack have the same thickness. The invention makes it possible for this plywood to be used as formwork in the creation of curved, round, and oval structures. As with patent PL34466B1 , the boards obtained by this method allow only for simple curves.

[0015] Cut patterns on sheets of various materials are also known in the art. For example, in the metalworking industry cut patterns are used to enable metal sheet expanding. There are also the techniques of Kirigam i, related to Origami, the Japanese art of folding paper. In Kirigam i, the paper is cut as well as being folded, enabling a three-dimensional design that can stand away from the page. These uses of cut patterns are very different than the cut patterns optimised for anisotropic materials according to the present invention, which are intended to retain as much of the anisotropic wood-based sheet of material’s mechanical properties as possible, in addition to gaining forming capabilities.

[0016] To address the problem of manufacturing environmentally efficient, strong wood-based or cellulosic laminate composite elements of single-curved, doublecurved, synclastic, anticlastic, or free-form shapes - either rigid or flexible - there is a need for formable anisotropic wood-based sheets that upon forming as layers into said formed elements will provide them with mechanical strength.

[0017] The present invention addresses this need by introducing a novel type of wood veneer, and other cellulosic anisotropic sheet for layering, with strategically designed optimised patterns of cuts and / or cut-outs that enable their formation into singlecurved, double-curved, synclastic, anticlastic, or free-form structures - and combinations thereof - with improved formability and manipulability, and optimised structural and mechanical attributes, showcasing low weight and high strength, alongside lower CO2 emissions.

[0018] DISCLOSURE OF INVENTION

[0019] It is an object of the present invention to provide novel lightweight wood-based anisotropic sheets of material that can be used as layers in the forming of specially shaped and mechanically efficient laminate composite elements. It is also an object of the present invention to provide a method for the manufacturing of said lightweight wood-based anisotropic sheets in a way that they are tailored to specific case by case requirements, by providing said sheets with specially designed and optimised patterns of cuts.

[0020] Another object of the present invention is to present a novel type of laminate composite element that comprises a sheet or sheets as described above, which can be specially shaped while also structurally strong.

[0021] In a first aspect, a sheet of cellulosic anisotropic material, preferably a sheet of wood veneer, is provided, the sheet comprising any cut pattern of one or more cuts, whose sizes, shapes, and positions are designed, i.e., optimised, such that they increase the sheet’s formability while optimising its manipulability and structural attributes, according to specific case by case requirements.

[0022] In particular, a sheet of cellulosic anisotropic material is provided, wherein said sheet comprises: a cut pattern of one or more cuts, whose sizes, shapes, and positions are configured to enhance the sheet’s formability without compromising its manipulability and structural integrity, and at least one bridge within the cut pattern, the bridge being an uncut region connected to at least one cut, wherein the sheet of cellulosic anisotropic material comprises fibres and the dimension, position and frequency of the cuts and bridges at least depend on the orientation of said fibres.

[0023] It is noted that the uncut region, i.e. the bridge, can connect the extremities of two cuts or can connect one extremity of one cut to the edge of the sheet of material.

[0024] In one example, the cuts can comprise at least one of longitudinal cuts extending along a direction parallel to the fibres orientation, and transverse cuts extending along a direction orthogonal to the fibres orientation. In other words, the cut pattern can include only longitudinal cuts or only transverse cuts, or a combination thereof. The cuts can also be diagonal cuts, i.e. cuts extending along a direction that is neither parallel nor orthogonal to the fibres orientation. Specifically, the cuts can extend along a direction forming an angle a with the fibres orientation comprised between 0 and 90° or comprised between 90° and 180°. It is noted that the cuts can be linear or can have a curved shape. In case of curved shape, the longitudinal cuts, transverse cuts and diagonal cuts are intended as small portions of the entire curved cut. In this way, a curved cut can have portions extending along a direction parallel to the fibres orientation, portions extending along a direction orthogonal to the fibres orientation and / or portions extending along a direction that is neither parallel nor orthogonal to the fibres orientation, all these portions being connected to each other to form a curved shape.

[0025] The longitudinal cuts allow formability through shear deformation, but don't allow for material stretching in the direction of the fibres. Transverse cuts to the fibre, on the other hand, interrupt the material's structural capacity at that point. Diagonal cuts help to spread the fibre interruption over a longer area, helping to avoid cut overlapping among layers.

[0026] A combination of longitudinal, transverse, and diagonal cuts within a cut pattern allows for continuity in the material, keeping it as a connected unit.

[0027] A predetermined cuts pattern has two effects over the sheet material: a) that the material becomes "breakable" with a controlled and known force through the cuts that are aligned to the fibres and / or close, leaving weak "bridges" that are prone to break under stress, inducing deformation through shear in the direction parallel to the fibre; or b) the sheet of material acquires a degree of "elasticity" (spring-like behaviour) by inducing local out-of-plane torsions and buckling of the sheet in between cuts within the elastic range of the material.

[0028] The longitudinal cuts (parallel to fibres) are optimized so the length of the bridges between cuts are long enough to allow for good stress transfer but short enough to allow for the material's adaptation to the geometry by reducing the sheet's bending strength, allowing for local deformations and controlled failure.

[0029] The transversal cuts interrupt the fibres, creating a point that will attract stresses. This, combined with longitudinal cuts patterns that induce local failure through "bridges" breakage allows for shear deformation of the material while allowing the material to separate in the area of the transversal cut. This separation increases the global stretching of the material in certain areas. The location, shape and frequency of these cuts should be obtained by the analysis of the target shape, the fibre orientation of the material, and the intended mechanical performance of the resulting part, if desired. The optimisation tools used in this process account for the sheets’ material type, thickness, size, shape, mechanical and forming requirements, cutting procedure, anisotropic directionality, and other variables, to produce the most optimal possible cut pattern for each specific case requirements.

[0030] One or more of these sheets is used to produce a laminate composite element or to form part of a laminate composite, which thanks to the cut patterns in the sheet or sheets that allow for them to be formable, can be of mostly any shape, and may be strong and / or flexible, all customised according to how the design of the sheets’ cut patterns was optimised.

[0031] Our invention also consists of the manufacturing methods that enable both the manufacturing of our novel sheet of cellulosic anisotropic material with cut patterns, and the manufacturing of novel laminate composite elements with them.

[0032] The anisotropic wood-based sheets with cut patterns according to the present invention enable the creation of specifically tailored laminate composite elements. The optimised patterns offer the sheets a range of engineered attributes, including thermal expansion / contraction control, vibration and acoustic damping, and more. By leveraging formability, density variations, stretching, compression, and overall sheet manipulation, these patterns provide the sheets with capabilities beyond those inherent to the material itself that they are made of. This way, laminate composite elements can incorporate one or multiple individually optimised sheet layers (or fragments of sheets in the same layer with equal or different fibre orientations), each contributing distinct characteristics to the laminate composite as a whole. In examples, the pattern is a type of pattern selected from the group consisting of regular, irregular, symmetric, asymmetric, periodic, and combinations thereof.

[0033] Examples of application of our invention are building elements for construction and civil engineering, furniture parts, and parts for cars, airplanes, buses, and trains, among many others.

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] A brief description of the figures is provided, which will be followed by a detailed description to explain some preferred embodiments of the invention. It is critical to emphasise that these figures serve only as support for understanding the invention and should not be interpreted as precise representations of the final elements, parts, or components of the invention, nor in terms of actual or proportional scale. It is also most important to note that the invention should not be considered as limited only to what is shown in the figures, since these represent, in an illustrative manner, the important aspects of some of the main embodiments of the invention here presented, and may fail to include other possible embodiments and elements that are common knowledge in the state of the art.

[0036] Figure 1 : Plan view illustration of two sheets of cellulosic anisotropic material displaying respective cut patterns according to the present invention, designed to fit contiguously with each other.

[0037] Figure 2: Frontal grayscale photograph of a laminate composite element comprising a sheet of wood veneer according to the present invention as its top layer, displaying a regular pattern of cuts.

[0038] Figure 3: Plan view illustration of a sheet of cellulosic anisotropic material according to the present invention with a regular pattern design, comprising cuts and cut-outs.

[0039] Figure 4: Plan view illustration of a sheet of wood veneer displaying a cut pattern according to the present invention, and a zoomed-in view to a detail in the pattern.

[0040] Figure 5A: Frontal elevation view of a sheet of cellulosic anisotropic material according to the present invention and a knife in sequence before, during and after producing a cut into the sheet, in this case in an angle perpendicular to the sheet.

[0041] Figure 5B: Frontal elevation view of a sheet of cellulosic anisotropic material according to the present invention and a knife in sequence before, during and after producing a cut into the sheet, in this case in an angle oblique to the sheet.

[0042] Figure 6: Diagram and graph with data regarding the results of tensile tests performed on different sheets according to the present invention.

[0043] Figure 7A: Grayscale photograph of a piece of wood veneer displaying a series of tears after a test of forming it against a double-curved mould of a T shaped connector part, as presented in Figure 7B.

[0044] Figure 7B: Illustration of a double-curved mould of a T shaped connector part.

[0045] Figure 8A: Grayscale photograph of laminate composite element comprising three sheets of wood veneer according to the present invention and displaying a pattern of cuts as shown in Figure 8C, after forming it against the double-curved mould of a T shaped connector part presented in Figure 8B.

[0046] Figure 8B: Illustration of a double-curved mould of a T shaped connector part.

[0047] Figure 8C: Plan view illustration of the sheet of wood veneer displayed in Figure 8A according to the present invention, and its pattern of cuts, before being formed against the mould of Figure 8B.

[0048] Figure 9: Frontal grayscale photograph of a sheet of wood veneer according to the present invention, comprising a pattern of only one cut and one bridge.

[0049] Figure 10: Frontal grayscale photograph of a sheet of wood veneer displaying a cut pattern according to the present invention.

[0050] Figure 11 : Frontal grayscale photograph of a free-form laminate composite element, comprising a top layer displaying contiguous sheets of wood veneer according to the present invention.

[0051] Figure 12: Frontal grayscale photograph of a free-form laminate composite element, comprising a top layer displaying overlapping sheets of wood veneer according to the present invention.

[0052] Figure 13: Diagram of a method for the production of sheets of cellulosic anisotropic material with cut patterns according to the present invention.

[0053] Figure14: Diagram of a method for the production of laminate composite elements comprising sheets of cellulosic anisotropic material with cut patterns according to the present invention.

[0054] DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0055] For a better appreciation of the present invention, we provide the following definitions, which are to be understood as an aid to comprehend particular elements here presented and the terms used to refer to them.

[0056] As used in the present invention description, the term "cut" corresponds to an opening in something, whereas the term "cut-out" corresponds to the space or hole that goes through a thing or material, left after cutting a section out of it, so in the context of the present application the difference between “cut” and “cut-out” is that a cut does not remove material while a cut-out does. It must be noted that some cutting procedures do remove or eliminate material, not as a cut-outs, but as procedural waste, as are the cases, for example, of laser cutting - which burns away some material - and waterjet cutting - which erodes away some material - so the lines these cutting procedures produce may have a narrow width, which may or may not be a deliberate feature in a cut pattern design. This is the case of kerfs. Whereas a cut-out refers to a section that has been removed from a material, typically to create an opening or a specific shape, a kerf is the width of the material that is removed by a cutting tool, such as a saw blade.

[0057] As used in the present invention description, the term "formability" (and “formable”) corresponds to the ability to be flexed, bent, or pressed into different shapes without undesirably breaking or cracking.

[0058] As used in the present invention description, the term "bridge" corresponds to the shortest distance between two cuts within a cut pattern.

[0059] As used in the present invention description, the term "break-fuse" corresponds to a portion or area of the sheet or material that acts as as a safeguard against material breaking or tearing, in a way that when said sheet is tensed or compressed, it will break or tear precisely on the break-fuse, which will absorb the tension, shear, or compression forces, avoiding that it produces a break or tear in other portions or areas of the sheet.

[0060] As used in the present invention description, the term "pattern" corresponds to the design of an arrangement of lines or shapes, from a single line or shape to a plurality of lines and / or shapes.

[0061] As used in the present invention description, the term "contour" corresponds to the outer edges of something, as the outline of its shape.

[0062] As used in the present invention description, the term "contiguous" corresponds to the position of one thing that is next to another thing, whether touching it or not.

[0063] As used in the present invention description, the term “free-form” corresponds to a shape or design that does not exhibit standard forms or structures, and instead normally exhibits combinations of irregular, organic, geometric, undulated, and flowing forms.

[0064] Regarding the lines that depict cuts or cut-outs in the line drawings, they shall not be interpreted as having a specific thickness, nor arbitrary nor proportional to the drawing. Unless specifically stated, all cuts depicted in the line drawings will be assumed to have no determined thickness. Cut patterns according to the present invention are designed and optimised according to specific case by case requirements.

[0065] The cut patterns presented in the Figures are only a few examples among an uncountable collection of possible patterns, and should not be considered as limiting the scope of the present invention, which is not a specific collection of optimised cut patterns; the present invention consists of a sheet of cellulosic anisotropic material, preferably a sheet of wood veneer, that comprises any cut pattern of one or more cuts, whose sizes, shapes, and positions are optimised such that they increase the sheet’s formability while optimising its manipulability and structural attributes, according to specific case by case requirements.

[0066] All cut patterns will include at least one bridge between cuts 10 by default. Some patterns will only define large bridges, while others will define very small ones, which are generally - but not exclusively - more suited for acting as break-fuses. Some patterns will define bridges of varied sizes. In the Figures and their respective descriptions, due to clarity and space constraints, only some bridges will be signalled and described, as will also be the case regarding cuts and cut-outs. In examples, the pattern can comprise areas and / or bridges that are deliberately designed to tear upon stretching or adapting the sheet to a non-flat surface.

[0067] Figure 1 shows a plan view illustration of two sheets 1 of cellulosic anisotropic material, each displaying a pattern of cuts 10 according to the present invention, some of the cuts 10 being straight lines while others are curved irregular lines. Bridges 11 are observable between the ending points of the cuts 10. Arrows 20 show that part of the shape of the sheets’ 1 contours 12 are designed to fit contiguously with each other. In the context of our invention, the contiguous fit of sheets of anisotropic material enables that when providing a layer for a laminate composite we can align or misalign sheets at will, in order to achieve the kind of structural performance required for each element. In examples, the shape of the sheet’s contour 12 is a shape selected from the group consisting of rectangular, polygonal, round, oval, irregular, or free-form.

[0068] Figure 2 is a grayscale photograph of a laminate composite element 2 according to the present invention, comprising a top layer that is a sheet 1 of wood veneer according to the present invention, displaying a regular pattern of straight, double-y shaped cuts 10, covering the whole surface area of the laminate composite element 2. This regular pattern of cuts 10 was used specifically to enable the forming of the sheet 1 to the irregular undulated shape of the laminate composite element 2 without tearing. In examples, wherein the sheet comprises a mesh attached to at least one of its faces. In other examples, the sheet can be pre-impregnated with at least one type of adhesive.

[0069] Figure 3 shows a plan view illustration of a sheet 1 of cellulosic anisotropic material according to the present invention with a regular pattern design, comprising cuts 10 and cut-outs 13. Patterns can be optimised to be customised to the curvature of the element to be formed, adjusting for specific local mechanical strength requirements at different areas of the element.

[0070] Figure 4 is plan view illustration of a sheet 1 of wood veneer displaying a regular pattern of curved cuts 10 according to the present invention, alongside a zoomed-in view 30 to the detail of one of the bridges 11 in the pattern.

[0071] Figure 5A is an elevation view of a sheet 1 of cellulosic anisotropic material according to the present invention and a knife 5 in a left to right sequence of cutting movement signalled by arrows 20 of before, during and after producing a cut 10 into the sheet 1 , in this case in an angle perpendicular to the sheet, i.e. perpendicular to the surface of the sheet 1 .

[0072] Figure 5B is an elevation view of a sheet 1 of cellulosic anisotropic material according to the present invention and a knife 5 in a left to right sequence of cutting movement signalled by arrows 20 of before, during and after producing a cut 10 into the sheet 1 , in this case in an angle oblique to the sheet, i.e. of an oblique angle with regards to the surface of the sheet 1. In examples, the sheet 1 is formable in a way such that part or parts of its surface overlap with another part or other parts of its surface. Oblique cuts allow for very subtle overlapping of small sections of the material’s surface, while both perpendicular and oblique cuts also allow for overlapping of larger segments of the material’s surface.

[0073] In examples, at least one of the cuts 10 in the pattern reaches one of the edges of the sheet 1 .

[0074] Figure 6 is a diagram with a graph informing the results of tensile tests performed on four different sheets of wood veneer. The best performing of them (curves from top to bottom in the graph) had no cuts and was tensed along its fibres (longitudinal). The second best performing of them had cuts made within a large pattern, meaning that the distance between cuts allowed for a minimum fibre length of 9 mm, within said pattern. The third best performing of them had cuts made within a smaller pattern, meaning that the distance between cuts allowed for a minimum fibre length of 3 mm, within said pattern. The worst performing of them had no cuts and was tensed perpendicular to its fibres (transverse).

[0075] It is noted that the density of the pattern is strictly related not only to mechanical performance but also to an increased formability of the sheet 1 . Accordingly, there is a "right point" where formability and performance meet and the software analysis serves for finding that point.

[0076] Figure 7A is grayscale photograph of a piece of wood veneer displaying a series of tears after a test of forming it against a double-curved mould of a T shaped connector part, as presented in Figure 7B.

[0077] Figure 7B is an illustration of the double-curved mould of a T shaped connector part, which the tom piece of wood veneer from Figure 7A was formed onto.

[0078] Figure 8A is a grayscale photograph of a formed laminate composite element 2 according to the present invention, comprising three layers of wood veneer sheet 1 displaying patterns of cuts 10 according to the pattern shown in Figure 8C, after forming them against a double-curved mould of a T shaped connector part as presented in Figure 8B, in order to elaborate the laminate composite element. There are visible signs of stretching along some of the cuts 10 that slightly opened, and breaking of some bridges 11 , enabling the forming of the laminate composite element 2 without much damage. For this type of pattern, digital optimisation tools calculate the position, length, size and / or shape of each cut (10) so that the bridges 11 defined by the pattern either resist or break when faced with a specific curvature or stretching.

[0079] In examples, the sheet 1 is able to stretch such that it occupies a larger surface than its original unstretched surface.

[0080] Figure 8B is an illustration of the double-curved mould of a T shaped connector part, which the sheet of wood veneer from Figure 8A was formed onto.

[0081] Figure 8C is a plan view of an illustration of the sheet 1 of wood veneer displayed in Figure 8A as a grayscale photograph, displaying its regular pattern of cuts 10, before being formed against the mould of Figure 8B.

[0082] Figure 9 is a grayscale photograph of a sheet 1 of wood veneer according to the present invention, comprising a pattern of only one cut 10 and one bridge 11. In this case the cut 10 was made using a procedure that removes material, as it has a perceivable width, forming a gap between its sides.

[0083] Figure 10 is a grayscale photograph of a sheet 1 of wood veneer displaying a regular pattern of cuts 10, bridges 11 , and an irregular contour 12, according to the present invention.

[0084] In a second aspect, a laminate composite element is provided, wherein the element comprises at least one type of adhesive and at least two layers joined by said adhesive, of which at least one layer is a sheet of cellulosic anisotropic material as defined in the first aspect. In examples, in the laminate composite element at least one of the at least one layers of sheet of cellulosic anisotropic material as defined in the first aspect comprises two or more contiguous sheets of cellulosic anisotropic material as defined in the first aspect.

[0085] Figure 11 is a grayscale photograph of a free-form laminate composite element 2, comprising a top layer displaying four contiguous sheets 1 of wood veneer and their respective patterns of cuts 10 and bridges 11 , according to the present invention. The dotted lines 15 demarcate the four contiguous sheets 1 . It is noted that figure 11 shows a laminate composite element 2 comprising four contiguous sheets 1. However, the laminate composite element 2 can comprise any number of sheets 1. In other words, the laminate composite element 2 can comprise a plurality of sheets 1 connected to each other at the demarcation line 15.

[0086] In further examples, in the laminate composite element at least one of the at least one layers of sheet of cellulosic anisotropic material as defined in the first aspect comprises two or more overlapped sheets of cellulosic anisotropic material as defined in in the first aspect.

[0087] Figure 12 is a grayscale photograph of a free-form laminate composite element 2, comprising a top layer displaying a series of overlapping sheets 1 of wood veneer and their respective patterns of cuts 10 and bridges 11 , according to the present invention.

[0088] In some examples, the element comprises at least one adhesive that is flexible.

[0089] In further examples, the element is flexible or rigid.

[0090] In yet other examples, the form of the element is of a type selected from the group consisting of flat, single-curved, double-curved, synclastic, anticlastic, free-form, and combinations thereof. It is noted that the plurality of sheets 1 shown in figure 12 comprise patterns of cuts that are oriented differently from each other. Specifically, the patterns comprise cuts of the same shape and dimension, for example these are longitudinal cuts having a linear shape. However, the cuts 10 (and bridges 11 ) of each single component forming the composite laminate element 2 extend along different orientation. This improves the flexibility of the laminate composite element.

[0091] In a third aspect, a method is provided for manufacturing the sheet of cellulosic anisotropic material according to the first aspect. The method comprises the steps of:

[0092] (a) obtaining a sheet of cellulosic anisotropic material;

[0093] (b) defining the requirements to be met by the sheet of cellulosic anisotropic material once the cut pattern is cut into it;

[0094] (c) generating an optimised cut pattern design according to the requirements defined in step (b); and

[0095] (d) cutting the sheet of cellulosic anisotropic material according to the cut pattern design generated in step (c).

[0096] Figure 13 is a diagram of a method for the production of sheets of cellulosic anisotropic material with cut patterns according to the present invention.

[0097] In examples, step (c) comprises using digital optimisation tools.

[0098] In further examples, step (d) is conducted by a cutting procedure selected from the group consisting of laser cutting, digital cutting, die cutting, waterjet cutting, milling, and combinations thereof.

[0099] In a fourth aspect, a method is provided for manufacturing the laminate composite element according to the second aspect. The method comprises the steps of:

[0100] (a) defining the requirements to be met by the laminate composite element;

[0101] (b) generating the design and structural parameters of the laminate composite element and its constitutive layers, and the material parameters for its constitutive layers and adhesive or adhesives, according to the requirements defined in step (a);

[0102] (c) generating an optimised cut pattern design for each of the at least one sheet of cellulosic anisotropic material as defined in claim 1 comprised in the laminate composite element, according to the design generated in step (b);

[0103] (d) sourcing the materials for the constitutive layers and the adhesive or adhesives, according to the design and parameters generated in step (b);

[0104] (e) obtaining a mould according to the design and parameters generated in step (b);

[0105] (f) cutting each of the at least one sheet of cellulosic anisotropic material as defined in claim 1 according to the cut pattern design or designs generated in step (d);

[0106] (g) providing instructions to at least one machine for the deposition of all the constitutive layers and adhesive or adhesives, according to the design and parameters generated in step (b);

[0107] (h) depositing in the mould all the constitutive layers and adhesive or adhesives, according to the design and parameters generated in step (b);

[0108] (i) pressing the layers with the adhesive or adhesives in the mould; and

[0109] (j) removing the resulting laminate composite element from the mould.

[0110] In one example, the mould comprises at least two parts. In a further example, step (b) comprises using digital optimisation tools.

[0111] Figure 14 is a diagram of a method for the production of laminate composite elements comprising sheets of cellulosic anisotropic material with cut patterns according to the present invention.

Claims

CLAIMS1 . A sheet of cellulosic anisotropic material, comprising: a cut pattern of one or more cuts, whose sizes, shapes, and positions are configured to enhance the sheet’s formability without compromising its manipulability and structural integrity, and at least one bridge within the cut pattern, the bridge being an uncut region connected to at least one cut, wherein the sheet of cellulosic anisotropic material comprises fibres and the dimension, position and frequency of the cuts and bridges at least depend on the orientation of said fibres.

2. The sheet of cellulosic anisotropic material according to claim 1 , wherein the cuts comprises at least one of longitudinal cuts extending along a direction parallel to the fibres orientation, and transverse cuts extending along a direction orthogonal to the fibres orientation.

3. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the pattern is a type of pattern selected from the group consisting of regular, irregular, symmetric, asymmetric, periodic, and combinations thereof.

4. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein at least one of the cuts in the pattern is a cut-out.

5. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the cuts in the sheet may be perpendicular to its surface or of an oblique angle with regards to its surface.

6. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein at least one of the cuts in the pattern reaches one of its edges.

7. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the design of the cut’s sizes, shapes, and positions, is generated by using digital optimisation tools.

8. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is able to stretch such that it occupies a larger surface than its original unstretched surface.

9. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is formable in a way such that part or parts of its surface overlap with another part or other parts of its surface.

10. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is stretchable in two different directions, compressible in two different directions, or both.

11. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is adaptable to a type of surface shape selected from the group consisting of flat, single-curved, double-curved, synclastic, anticlastic, free-form, and combinations thereof.

12. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the pattern deliberately comprises at least one bridge between cuts, designed to function as a break-fuse.

13. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the pattern comprises areas and / or bridges that are deliberately designed to tear upon stretching or adapting the sheet to a non-flat surface.

14. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the shape of its contour is a shape selected from the group consisting of rectangular, polygonal, round, oval, irregular, or free-form.

15. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein all or part of the shape of its contour is designed to fit contiguously with all or part of the shape of the contour of at least one other sheet.

16. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the cellulosic anisotropic material is a wood veneer.

17. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet comprises a mesh attached to at least one of its faces.

18. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is pre-impregnated with at least one type of adhesive.

19. The sheet of cellulosic anisotropic material according to any one of the preceding claims, wherein the sheet is designed to form part of a laminate composite.

20. A laminate composite element, wherein the element comprises at least one type of adhesive and at least two layers joined by said adhesive, of which at least one layer is a sheet of cellulosic anisotropic material as defined in any one of claims 1 to 19.

21. The laminate composite element according to claim 19, wherein at least one of the at least one layers of sheet of cellulosic anisotropic material as defined in any one of claims 1 to 19 comprises two or more contiguous sheets of cellulosic anisotropic material as defined in any one of claims 1 to 19.

22. The laminate composite element according to any one of claims 20 or 21 , wherein at least one of the at least one layers of sheet of cellulosic anisotropic material as defined in any one of claims 1 to 19 comprises two or more overlapped sheets of cellulosic anisotropic material as defined in any one of claims 1 to 19.

23. The laminate composite element according to any one of claims 20 to 22, wherein the element comprises at least one adhesive that is flexible.

24. The laminate composite element according to any one of claims 20 to 23, wherein the element is flexible.

25. The laminate composite element according to any one of claims 20 to 24, wherein the element is rigid.

26. The laminate composite element according to any one of claims 20 to 25, wherein its form is of a type selected from the group consisting of flat, singlecurved, double-curved, synclastic, anticlastic, free-form, and combinations thereof.

27. A method for manufacturing the sheet of cellulosic anisotropic material of claim 1 , comprising the steps of:(a) obtaining a sheet of cellulosic anisotropic material;(b) defining the requirements to be met by the sheet of cellulosic anisotropic material once the cut pattern is cut into it;(c) generating an optimised cut pattern design according to the requirements defined in step (b); and(d) cutting the sheet of cellulosic anisotropic material according to the cut pattern design generated in step (c).

28. The method of claim 27, wherein step (c) comprises using digital optimisation tools.

29. The method of any one of claims 27 or 28, wherein step (d) is conducted by a cutting procedure selected from the group consisting of laser cutting, digital cutting, die cutting, waterjet cutting, milling, and combinations thereof.

30. A method for manufacturing the laminate composite element of claim 20, wherein the method comprises the steps of:(a) defining the requirements to be met by the laminate composite element;(b) generating the design and structural parameters of the laminate composite element and its constitutive layers, and the material parameters for its constitutive layers and adhesive or adhesives, according to the requirements defined in step(a);(c) generating an optimised cut pattern design for each of the at least one sheet of cellulosic anisotropic material as defined in claim 1 comprised in the laminate composite element, according to the design generated in step (b);(d) sourcing the materials for the constitutive layers and the adhesive or adhesives, according to the design and parameters generated in step (b);(e) obtaining a mould according to the design and parameters generated in step(b);(f) cutting each of the at least one sheet of cellulosic anisotropic material as defined in claim 1 according to the cut pattern design or designs generated in step (d);(g) providing instructions to at least one machine for the deposition of all the constitutive layers and adhesive or adhesives, according to the design and parameters generated in step (b);(h) depositing in the mould all the constitutive layers and adhesive or adhesives, according to the design and parameters generated in step (b); (i) pressing the layers with the adhesive or adhesives in the mould; and(j) removing the resulting laminate composite element from the mould.31 . The method of claim 30, wherein the mould comprises at least two parts.

32. The method of any one of claims 30 or 31 , wherein step (b) comprises using digital optimisation tools.

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