Method for producing a laminate

Abstract

The invention relates to a method for producing an intermediate sheet, comprising the following steps: a) providing at least a first sheet material impregnated with a first thermosetting resin and a second sheet material impregnated with a second thermosetting resin; and b) pressing the first and second sheet materials together at a temperature of 60 DEG C to 115 DEG C for 40 to 130 minutes such that the first and second thermosetting resins become liquid, and pressing with a first sufficient pressure such that the first and second sheet materials fuse to form an intermediate sheet without completely curing the first and second thermosetting resins, the first thermosetting resin and the second thermosetting resin can flow again when heated.

Description

Technical Field

[0001] The present invention generally relates to a method for producing an interim sheet used in the manufacture of a laminate, and to a method for producing a laminate. The present invention also relates to an interim sheet and a laminate produced by such a method. Background Art

[0002] Laminate flooring is a popular alternative to parquet or hardwood flooring because it is affordable and relatively simple to install. There are generally two methods used to produce laminates for laminate flooring: the High Pressure Lamination (HPL) process and the Direct Pressure Lamination (DPL) process.

[0003] The HPL process involves impregnating kraft paper, decorative paper and overlay paper with a thermosetting resin, usually phenolic resin or melamine resin. The paper is then pressed while being heated. The pressure used can typically be 70 to 85 kg / cm 2 And the temperature used can be generally 130 to 160°C. The pressing duration depends on the temperature, but can generally be 50 to 80 minutes, with a cooling time of 20 to 40 minutes. After about a day, the pressed paper is bonded to a substrate, which is generally a high-density fiberboard (HDF) or a medium-density fiberboard (MDF). The resulting laminate is then stored for about 3 days and then further processed, for example by profiling. The HPL process produces high-quality, durable and high-product life laminates. However, due to the multi-step method, the HPL process is laborious and time-consuming. From raw materials to finished product, the process generally takes 6 to 7 days.

[0004] The DPL process is a simpler process than the HPL process, in which thermosetting resin-impregnated overlay and decorative papers are pressed directly onto a substrate, such as HDF or MDF. The pressing is done at high temperatures and lasts less than a minute. The DPL process is less time-consuming and labor-intensive than the HPL process, so the final product costs less. However, due to the fewer layers of laminate, DPL laminates are less durable and are more susceptible to scratches and dents.

[0005] US2006 / 172118 A1 relates to a back-grooved laminated wood flooring, wherein a high pressure resin impregnated laminated wood veneer panel (WPL) is laminated on a substrate selected from a vinyl chloride (PVC) resin layer, an oriented strand board (OSB), a high density fiberboard (HDF) and a waterproof plywood.

[0006] US2020 / 207118 A1 relates to an inkjet printing method for manufacturing decorative panels. Summary of the invention

[0007] It is an object of the present invention to remedy or alleviate at least one of the disadvantages of the prior art, or at least to provide a useful alternative to the prior art. This object is achieved by the features specified in the following description and in the appended claims.

[0008] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0009] In a first aspect, the present invention relates to a method for producing an intermediate sheet. The method preferably comprises the following steps:

[0010] a) providing at least a first sheet material (sheet material) impregnated with a first thermosetting resin (impregnated with a first thermosetting resin) and a second sheet material impregnated with a second thermosetting resin; and

[0011] b) pressing the first and second sheet materials together, preferably at a temperature of 60°C to 135°C, preferably at 60°C to 115°C, preferably for 40 to 130 minutes, so that the first and second thermosetting resins become liquid, and pressing with a first sufficient pressure so that the first and second sheet materials fuse to form an intermediate sheet without completely curing the first and second thermosetting resins, so that the first and second thermosetting resins can flow again when heated.

[0012] In some preferred embodiments, the method further comprises the step of digitally printing a pattern on the intermediate sheet.

[0013] In some preferred embodiments, in step b), the temperature is 80°C to 115°C, preferably about 90°C. In some preferred embodiments, in step b), the pressing is performed for 60 to 110 minutes, preferably about 85 minutes. In some preferred embodiments, in step b), the first sufficient pressure is 55 to 95 kg / cm 2 , preferably 65 to 85 kg / cm 2 , preferably about 70kg / cm 2 .

[0014] In some preferred embodiments, the first and / or second thermosetting resins each comprise phenol and / or melamine.

[0015] In a second aspect, the present invention relates to an intermediate sheet obtainable by the method according to the first aspect or a (preferred) embodiment thereof.

[0016] In a third aspect, the present invention relates to a method for producing a laminate. The method preferably comprises the step of producing an intermediate sheet according to the first aspect or a (preferred) embodiment thereof. The method preferably further comprises the following steps:

[0017] c) forming a stack, the stack comprising the following layers:

[0018] - substrate board; and

[0019] - the intermediate sheet of step b); and

[0020] d) pressing the stack together, preferably at a temperature of 170 to 230°C, preferably for 10 to 60 seconds, preferably 10 to 45 seconds, so that the first and second thermosetting resins flow again, and pressing with a second sufficient pressure so that the layers bond together to form a laminate.

[0021] In some preferred embodiments, the stack in step c) comprises at least one of the following sheets:

[0022] o a decorative sheet impregnated with a third thermosetting resin;

[0023] o a decorative sheet that is not impregnated with a thermosetting resin and an overlay sheet that is impregnated with a fourth thermosetting resin, the overlay sheet being positioned as an outermost layer adjacent to the decorative sheet in the stack; or

[0024] o A decorative sheet impregnated with a third thermosetting resin and a cover sheet impregnated with a fourth thermosetting resin, the cover sheet being positioned above the decorative sheet in the stack.

[0025] In some preferred embodiments, the first and / or second and / or third and / or fourth thermosetting resins each comprise phenol and / or melamine.

[0026] In some preferred embodiments, in the stack formed in step c), the intermediate sheet is in direct contact with the substrate.

[0027] In some preferred embodiments, in step c), the stack further comprises a bonding sheet positioned between the substrate and the intermediate sheet, wherein the bonding sheet is impregnated with a fifth thermosetting resin, preferably, wherein the fifth thermosetting resin comprises melamine.

[0028] In some preferred embodiments, in step c), the stack further comprises a balancing sheet impregnated with a sixth thermosetting resin, preferably wherein the sixth thermosetting resin comprises melamine.

[0029] In some preferred embodiments, step d) comprises heating an uppermost side of the stack with a first temperature, and heating a lowermost side of the stack with a second temperature different from the first temperature.

[0030] In some preferred embodiments, in step d), the pressing is performed for 15 to 45 seconds, preferably 20 to 35 seconds, preferably about 30 seconds. In some preferred embodiments, in step d), the second sufficient pressure is 40 to 80 kg / cm 2 , preferably 50 to 70 kg / cm 2 , preferably about 60kg / cm 2 .

[0031] In some preferred embodiments, in step d), the stack is pressed with a pressing plate at the uppermost side of the stack.

[0032] In some preferred embodiments, the method comprises the step of perforating at least one of the sheet materials.Preferably, the method comprises the step of perforating the intermediate sheet.

[0033] In a fourth aspect, the present invention relates to a laminate obtained by a method according to the third aspect of the invention and (preferred) embodiments thereof.

[0034] The invention also relates to a laminate comprising a perforated layer, preferably a perforated interim sheet. Preferably, the laminate is obtained by a method according to the third aspect of the invention and (preferred) embodiments thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] An example of a preferred embodiment is described below, which is illustrated in the accompanying drawings, in which:

[0036] Figure 1 A method of producing a laminate according to one embodiment of the present invention is shown.

[0037] Figure 2 An alternative method of producing a laminate according to one embodiment of the invention is shown.

[0038] Figure 3 Another alternative method of producing a laminate according to one embodiment of the present invention is shown.

[0039] Figure 4A and Figure 4B A perforated sheet material that may be used in accordance with one embodiment of the present invention is shown.

[0040] Figure 5A, Figure 5B and Figure 5C A perforated sheet material that may be used in accordance with one embodiment of the present invention is shown.

[0041] The following numbering will be followed in the diagram:

[0042] 10 - Kraft paper; 11 - middle sheet; 12 - adhesive sheet; 13 - decorative sheet; 14 - covering sheet; 15 - substrate; 16 - balancing sheet; 17 - groove paper; 20 - sub-stack; 21 - stack; 30 - laminate; 100 - first pressing step; 101 - cutting / grinding step; 102 - second pressing step.

[0043] Any position indication refers to the position shown in the figure. In the figures, the same or corresponding elements are represented by the same reference numerals. For the sake of clarity, some elements in some figures may not have reference numerals. Those skilled in the art will understand that these figures are only the main figures. The relative proportions of the various elements may also be distorted. DETAILED DESCRIPTION

[0044] In describing the present invention, the terms used should be interpreted in accordance with the following definitions, unless the context dictates otherwise.

[0045] As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise. For example, "a resin" means one resin or more than one resin.

[0046] As used herein, the terms "comprising", "comprises" and "comprised of" are synonymous with "including", "includes" or "containing", "contains", and are inclusive or open-ended and do not exclude additional, unrecited elements, components or method steps. It is understood that

[0047] As used herein, the terms "comprising," "comprises," and "comprised of" include the terms "consisting of," "consists of," and "consists of."

[0048] Numerical ranges recited by endpoints include all integers and, where appropriate, fractions within the range (e.g., when referring to, for example, multiple elements, 1 to 5 may include 1, 2, 3, 4, and when referring to, for example, measured values, 1 to 5 may also include 1.5, 2, 2.75, and 3.80). The description of endpoints also includes the endpoint values ​​themselves (e.g., from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range described herein is intended to include all subranges incorporated therein.

[0049] All references cited in this specification are incorporated herein by reference in their entirety. In particular, the teachings of all references specifically mentioned herein are incorporated by reference.

[0050] Throughout this specification, references to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. Thus, the phrases "in one embodiment" or "in one embodiment" appearing in various places throughout this specification do not necessarily all refer to the same embodiment, but may refer to the same embodiment. Furthermore, as will be apparent to those skilled in the art from this disclosure, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Furthermore, while some embodiments described herein include some features, other features not included in other embodiments, combinations of features from different embodiments are intended to be within the scope of the present invention and to form different embodiments, as will be understood by those skilled in the art.

[0051] The above terms and other terms used in the specification are fully understood by those skilled in the art.

[0052] Preferred statements (features) and embodiments, resins, articles, methods and uses of the invention are described below. Each statement and embodiment of the invention so defined may be combined with any other statement and / or embodiment unless expressly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features or statements indicated as being preferred or advantageous.

[0053] The independent and dependent claims set out particular and preferred features of the invention. Features in the dependent claims may be combined with features of the independent claim or other dependent claims as appropriate.

[0054] The present invention will now be further described. In the following, different aspects of the present invention will be defined in more detail. Unless explicitly stated otherwise, each aspect so defined may be combined with any other one or more aspects. In particular, any feature indicated as being preferred or advantageous may be combined with any other one or more features indicated as being preferred or advantageous.

[0055] In a first aspect, the present invention relates to a method for producing an intermediate sheet. The method preferably comprises the following steps:

[0056] a) providing at least a first sheet material impregnated with a first thermosetting resin and a second sheet material impregnated with a second thermosetting resin; and

[0057] b) pressing the first and second sheet materials together (preferably at a temperature of 60°C to 135°C, preferably at a temperature of 60°C to 115°C, preferably for 40 to 130 minutes) so that the first and second thermosetting resins become liquid, and pressing with a first sufficient pressure so that the first and second sheet materials fuse to form an intermediate sheet without completely curing the first and second thermosetting resins, so that the first and second thermosetting resins can flow again when heated.

[0058] In the pressing step, the first and second thermosetting resins are heated to the point at which they become liquid. The term "liquid" means that the thermosetting resin has sufficient fluidity to flow at least partially from the sheet material in which it was originally impregnated into the replacement sheet material. That is, when at least a portion of the first thermosetting resin has sufficient fluidity so that it can flow into the second sheet material, according to the present disclosure, the first thermosetting resin is in a liquid phase. When at least a portion of the second thermosetting resin has sufficient fluidity so that it can flow into the first sheet material, according to the present disclosure, the second thermosetting resin is in a liquid phase.

[0059] The method according to the first aspect of the invention has the advantage that the first and second thermosetting resins are not completely cured after the sheet material is pressed. That is, at least a portion of the first and second thermosetting resins can flow again when heated. If the intermediate sheet is pressed together with other sheets in the stack at a suitable temperature and within a suitable time period, the first and second thermosetting resins can at least partially flow into the adjacent sheets so that the sheets in the stack can adhere when the stack is pressed.

[0060] The present invention also has the advantage that it is a less complicated process compared to processes involving multiple semi-curing steps.

[0061] Furthermore, the inventors have found that if the temperature during step b) is too high, the layer closest to the heating tends to become too hard due to the heating gradient. According to the present invention, such problems can be avoided by using lower temperatures and longer times. All of this results in a more efficient process that still provides a durable laminate with high quality.

[0062] In a second aspect, the invention relates to an intermediate sheet obtained by a method according to the first aspect of the invention. (Preferred) embodiments of the first aspect are also (preferred) embodiments of the second aspect, and vice versa.

[0063] In a third aspect, the present invention relates to a method for producing a laminate. The method preferably comprises the step of producing an intermediate sheet according to the first aspect or a (preferred) embodiment thereof. The method preferably further comprises the following steps:

[0064] - forming a stack comprising the following layers:

[0065] ○Substrate;

[0066] ○ An intermediate sheet produced according to the first aspect or a (preferred) embodiment thereof;

[0067] as well as

[0068] - pressing the stack together (preferably at a temperature of 170 to 230°C, preferably for 10 to 60 seconds, preferably 10 to 45 seconds, so that the first and second thermosetting resins flow again, and pressing with a second sufficient pressure so that the layers bond together to form a laminate.

[0069] Therefore, the method according to the third aspect preferably comprises the following steps:

[0070] a) providing at least a first sheet material impregnated with a first thermosetting resin and a second sheet material impregnated with a second thermosetting resin; and

[0071] b) pressing the first and second sheet materials together, preferably at a temperature of 60°C to 135°C, preferably at a temperature of 60°C to 115°C, preferably for 40 to 130 minutes, so that the first and second thermosetting resins become liquid, and pressing with a first sufficient pressure so that the first and second sheet materials fuse to form an intermediate sheet without completely curing the first and second thermosetting resins, so that the first and second thermosetting resins can flow again when heated.

[0072] The method according to the third aspect preferably further comprises the following steps:

[0073] c) forming a stack, the stack comprising the following layers:

[0074] -Substrate;

[0075] - the intermediate sheet of step b); and

[0076] d) pressing the stack together, preferably at a temperature of 170 to 230°C, preferably for 10 to 60 seconds, preferably 10 to 45 seconds, so that the first and second thermosetting resins flow again, and pressing with a second sufficient pressure so that the layers bond together to form a laminate.

[0077] In some preferred embodiments, the stack in step c) comprises at least one of the following sheets:

[0078] ○ a decorative sheet impregnated with a third thermosetting resin;

[0079] o a decorative sheet that is not impregnated with a thermosetting resin and a cover sheet that is impregnated with a fourth thermosetting resin, the cover sheet being positioned as the outermost layer adjacent to the decorative sheet in the stack; or

[0080] o A decorative sheet impregnated with a third thermosetting resin and a cover sheet impregnated with a fourth thermosetting resin, the cover sheet being positioned above the decorative sheet in the stack.

[0081] This approach provides an easy way to build thickness early on and then decide on the design in later steps.

[0082] In some preferred embodiments, the stack in step c) includes a decorative sheet impregnated with a third thermosetting resin. In some preferred embodiments, the stack in step c) includes a decorative sheet not impregnated with a thermosetting resin and a cover sheet impregnated with a fourth thermosetting resin, and in the stack, the cover sheet is preferably positioned as the outermost layer adjacent to the decorative sheet. In some preferred embodiments, the stack in step c) includes a decorative sheet impregnated with a third thermosetting resin and a cover sheet impregnated with a fourth thermosetting resin, and in the stack, the cover sheet is preferably positioned above the decorative sheet.

[0083] In the option in which the stack in step c) comprises a decorative sheet not impregnated with a thermosetting resin and a cover sheet impregnated with a fourth thermosetting resin, in the stack the cover sheet is positioned as the outermost layer adjacent to the decorative sheet; obviously, in this option, the decorative sheet not impregnated with a thermosetting resin is adjacent to the cover sheet, as mentioned previously in the same option.

[0084] In the option in which the stack in step c) comprises a decorative sheet impregnated with a third thermosetting resin and a covering sheet impregnated with a fourth thermosetting resin, in the stack the covering sheet is positioned above the decorative sheet; obviously, in this option the covering sheet is positioned above the decorative sheet impregnated with the third thermosetting resin, as mentioned previously in the same option.

[0085] A (preferred) embodiment of the first aspect is also a (preferred) embodiment of the third aspect, and vice versa.

[0086] The method according to the third aspect of the invention may have a number of advantages. First, the intermediate sheet is not fully cured after pressing. The term "not fully cured" means that at least a portion of the first and second thermosetting resins can flow again when heated after cooling after step b). The first and second thermosetting resins can and at least partially flow into adjacent sheets in the stack when heated, so that the sheets in the stack can adhere together when pressed together in step d).

[0087] Due to the second pressing of the intermediate sheet with the substrate, the method according to the present invention can be faster. It usually takes 10 to 60 seconds to press the stack together. Usually, no glue is needed in this process. If glue is used, the process can reduce the amount of glue required. In some instances, glue may not be used in this process. In the case of eliminating the use of glue, there is no need to wait until the glue is dry. In the case of reducing the use of glue, the time required to start further processing steps for the final laminate and wait for the glue to dry is reduced. Further processing steps can be, for example, molding the final laminate. After the final pressing step, the laminate only needs to be cooled, usually to a temperature of 20 to 30° C. Cooling can be performed in a cooler system before further processing. The whole process usually takes up to 4 days, or preferably 1 to 2 days, until the final laminate is completed and can be packaged.

[0088] Secondly, by pressing the first and second sheet materials together in the first step without the decorative sheet and the cover sheet, the pressing capacity (pressing capacity, pressing ability) increases. Usually, when the stack of kraft paper, decorative sheet and cover sheet is pressed together, a press plate usually made of metal is placed between the stack to form a texture on the surface of the final laminate. When only the first and second sheet materials are pressed together, there is no need to produce texture on the surface, so no press plate is needed at this stage. A thin release sheet (release sheet, release sheet) can be placed between each sub-stack in the press so that the intermediate sheet can be easily separated after pressing. The release sheet takes up less space than the press plate, so more sub-stacks can be pressed at the same time. The term "pressing capacity" refers to the number of sub-stack units that can be pressed simultaneously in one pressing. The term stack or sub-stack is used herein to represent the assembly of sheets positioned on top of each other.

[0089] Furthermore, the planning step that determines the final visual appearance of the laminate is postponed until after the intermediate sheet is formed. This is at a later stage compared to a procedure where the kraft paper, the decorative sheet and the cover sheet are pressed together in a single step. The texture of the final laminate can also be determined in the final pressing step by pressing the decorative sheet or the cover sheet with a pressing plate. Thus, the method according to the invention can be more flexible. By using this flexible method, the consumer can obtain his / her desired design more quickly. Less storage space is required and the laminate can reach the consumer in a short period of time.

[0090] The method according to the third aspect of the invention may be a more efficient process whilst still producing a durable laminate of high quality.The intermediate sheet provides thickness to the final laminate which produces a strong laminate which is less susceptible to scratches and dents.

[0091] Furthermore, the method according to the invention can result in reduced tension in the final laminate. If different types of sheets impregnated with different thermosetting resins are pressed together, tension may occur in the intermediate sheet or laminate due to the different water retention capacity of the thermosetting resins. For example, by pressing together two sheets of kraft paper impregnated with the same thermosetting resin, the tension in the intermediate sheet may be smaller, resulting in less bending of the laminate.

[0092] In addition, the two-step pressing process can result in less tension and warping of the final laminate than a process with one-step pressing and one-step gluing because the water is released in two pressing steps instead of one. In the first pressing step, the fibers in the middle sheet can be stabilized with liquid so that much of the movement of the fibers in the middle sheet will be completed before the second pressing step. In addition, the two pressing steps can result in less moisture in the laminate. Less moisture in the laminate will reduce movement in the laminate when it is exposed to low humidity (e.g., during winter).

[0093] In some preferred embodiments, the method according to the third aspect preferably further comprises a step of digitally printing a pattern on the intermediate sheet, preferably before the step of forming the stack.

[0094] The method as described above may have a number of advantages. First, the intermediate sheet is not fully cured after pressing. Therefore, the first and second thermosetting resins may flow again when heated. The first and second thermosetting resins may and at least partially flow into adjacent sheets in the stack when heated, so that the sheets in the stack may adhere together when pressed together in step d).

[0095] Secondly, as mentioned above, the second pressing of the intermediate sheet with the substrate according to the method of the present invention can be faster.

[0096] Furthermore, the method according to the third aspect of the present invention has an increased pressing capacity for the first pressing step.

[0097] The method according to the third aspect of the invention may be a more efficient process whilst still producing a customised decorative durable laminate of high quality.The intermediate sheet provides a thickness to the final laminate which results in a strong laminate which is less susceptible to scratches and dents.

[0098] Furthermore, as explained with respect to the third aspect of the invention, the method according to the third aspect of the invention can result in less tension in the final laminate. For example, by pressing two sheets of kraft paper impregnated with the same thermosetting resin together, the tension in the intermediate sheet can be less, and thus the bending of the intermediate sheet is less. This can facilitate the printing of decorative patterns on the intermediate sheet.

[0099] The method according to the third aspect of the invention may allow custom laminates. The decorative pattern may be selected by the consumer and digitally printed directly on the intermediate sheet. The method according to the third aspect of the invention is efficient and the consumer may obtain his / her custom designed laminate more quickly.

[0100] In a fourth aspect, the present invention relates to a laminate obtained by a method according to the third aspect of the invention. (Preferred) embodiments of the third aspect are also (preferred) embodiments of the fourth aspect, and vice versa.

[0101] The term "substrate" refers to a board suitable for forming a laminate for floors or walls. For example, the substrate may be HDF, MDF or plywood.

[0102] The term "decorative sheet" refers to a cellulose paper having a decorative design such as a simulated wood design or any other design.

[0103] The term "cover sheet" refers to a cellulose paper which may increase the durability of the final laminate and reduce the risk of wear of the final laminate. The cover sheet may be at least partially translucent and / or at least partially transparent. The cover sheet may preferably contain corundum.

[0104] The term "balancing sheet" refers to a layer impregnated with a thermosetting resin and positioned adjacent to the substrate, on the opposite side of the sheet that constitutes the decorative side of the final laminate. The composition of the balancing sheet depends on the layer on the opposite side of the substrate. For example, the balancing sheet may include one or more fluted papers or an intermediate laminate.

[0105] The term "adhesive sheet" refers to a cellulose paper capable of absorbing a thermosetting resin. Alternative words for adhesive sheet may be impregnated paper or suction paper. The purpose of the adhesive sheet is to increase the adhesion between the substrate and the intermediate laminate. The adhesive sheet is preferably impregnated with a thermosetting resin containing melamine.

[0106] The terms "stack" and "sub-stack" are used herein to refer to an assembly of sheets positioned on top of each other.

[0107] The term "thermosetting resin" refers to a soft solid or viscous liquid of a polymer that hardens when heated. Heating the thermosetting resin causes the polymer chains in the thermosetting resin to crosslink, which causes the thermosetting resin to cure.

[0108] The term "liquid" means that the first thermosetting resin has sufficient fluidity to at least partially flow from the sheet material in which it was originally impregnated into the replacement sheet material. That is, when at least a portion of the first thermosetting resin has sufficient fluidity so that it can flow into the second sheet material, the first thermosetting resin according to the present disclosure is in a liquid phase. When at least a portion of the second thermosetting resin has sufficient fluidity so that it can flow into the first sheet material, the second thermosetting resin according to the present disclosure is in a liquid phase.

[0109] The term "not fully cured" means that after the first pressing step, at least a portion of the first and second thermosetting resins can flow again when heated. If the intermediate sheet is pressed together with other sheets in the stack at a suitable temperature and for a suitable period of time, the first and second thermosetting resins can at least partially flow into adjacent sheets so that the stack can adhere together when pressed together.

[0110] As used herein, the term "tensile force" refers to the tendency of an intermediate sheet or laminate to flex when exposed to changes in temperature and / or humidity.

[0111] In some embodiments, the step of providing at least a first sheet material impregnated with a first thermosetting resin comprises the steps of:

[0112] a11) providing at least a first impregnable sheet material; and

[0113] a12) impregnating the first impregnable sheet material with a first thermosetting resin.

[0114] The first impregnable sheet material may be kraft paper.The first impregnable sheet material may be fluted paper.

[0115] In some embodiments, the step of providing a second sheet material impregnated with a second thermosetting resin comprises the steps of:

[0116] a21) providing at least a second impregnable sheet material; and

[0117] a22) impregnating the second impregnable sheet material with a second thermosetting resin.

[0118] The second impregnable sheet material may be kraft paper.The second impregnable sheet material may be fluted paper.

[0119] In some preferred embodiments, in step b), the temperature is 60°C to 135°C, preferably 60°C to 115°C, preferably 80°C to 115°C, preferably about 90°C. These temperatures have been found to provide the best results. Too low a temperature will not adequately laminate the product (may result in delamination) and may result in bubbles. Too high a temperature will over cure the product and result in delamination in the final step.

[0120] In some preferred embodiments, in step b), pressing can be carried out for 40 to 130 minutes, preferably 60 to 110 minutes, preferably about 85 minutes. It has been found that these times provide the best results. Pressing time that is too short will not fully laminate the product (may cause delamination). Pressing time that is too long will cause the product to be over-cured and cause delamination in the last step.

[0121] In some preferred embodiments, in step b), the first sufficient pressure may be 55 to 95 kg / cm 2 , preferably 65 to 85 kg / cm 2 , preferably about 70kg / cm 2 These pressures have been found to provide the best results. Using pressures outside of these ranges may result in cracking or delamination.

[0122] One of the first sheet and the second sheet can be a white sheet to improve the aesthetics of the final digital printed laminate. In other examples, another color can be selected.

[0123] In some embodiments, the first sheet material comprises paper. The first sheet material may be kraft paper. The first sheet material may be fluted paper.

[0124] In some embodiments, the first sheet material comprises paper. The second sheet material may be kraft paper. The second sheet material may be fluted paper. These materials are environmentally friendly and low in cost. The present invention also includes the use of other materials for the first and / or second sheet. The use of other materials may change the settings in both temperature and pressing time, but still within the preferred range described herein.

[0125] The term "first sheet material" preferably refers to kraft paper or fluted paper. The term "second sheet material" preferably refers to kraft paper or fluted paper.

[0126] The term "kraft paper" refers to a high-strength paper produced from kraft pulp. Kraft paper may be bleached or unbleached. The paper weight of kraft paper may preferably be 60 to 300 g / m 2 The kraft paper may be recycled kraft paper. The term "fluted paper" refers to cellulose paper that is capable of absorbing thermosetting resins. Alternative terms for fluted paper may be impregnated paper or blotter paper.

[0127] The method according to the first aspect of the invention can be used, for example, to press two sheets of kraft paper together. The resulting intermediate sheet can then be used together with, for example, a substrate, a decorative sheet and a cover sheet to form a stack of sheets. The stack can be pressed together to form a laminate.

[0128] When two sheets of kraft paper that have been impregnated with the same thermosetting resin are pressed together, the resulting intermediate sheet can have less tension. That is, the intermediate sheet can be less prone to bending. Due to the flat structure of the resulting intermediate sheet, the intermediate sheet can be more easily used for printing than an intermediate sheet that is bent after the pressing step. This can result in better decorative quality of the final laminated product.

[0129] The first thermosetting resin may include phenol. The first thermosetting resin may include melamine. The first thermosetting resin may include phenol and melamine. The second thermosetting resin may include phenol. The second thermosetting resin may include melamine. The second thermosetting resin may include phenol and melamine. The first and / or second thermosetting resins may include any other suitable thermosetting resins.

[0130] The third thermosetting resin may include phenol. The third thermosetting resin may include melamine. The third thermosetting resin may include phenol and melamine. The fourth thermosetting resin may include phenol. The fourth thermosetting resin may include melamine. The fourth thermosetting resin may include phenol and melamine. The first and / or second and / or third and / or fourth thermosetting resins each include any other suitable thermosetting resin.

[0131] Preferably, the first sheet material is kraft paper and the second sheet material is kraft paper. Preferably, the first and second sheet materials are impregnated with a phenolic thermosetting resin. Preferably, the decorative sheet and the cover sheet are impregnated with a thermosetting resin comprising melamine. If a phenolic thermosetting resin is used, it is advantageous to impregnate the decorative sheet and the cover sheet with a thermosetting resin that does not contain phenol, due to miscolouring of the sheets when cured.

[0132] If both the cover sheet and the intermediate sheet are impregnated with a thermosetting resin containing melamine (e.g. a mixture of 30% melamine and 70% phenol), the decorative sheet positioned between the two impregnated sheets does not have to be impregnated with the thermosetting resin prior to step d). During step d), the thermosetting resin from the cover sheet and the intermediate sheet may at least partially flow into each side of the decorative sheet so that the three sheets may adhere together when the two thermosetting resins cure. The advantage of not impregnating the decorative sheets before pressing the stack together is that it saves time and reduces the use of thermosetting resin.

[0133] In some embodiments, the decorative sheet is impregnated with a third thermosetting resin. In some embodiments, the decorative sheet is not impregnated with a thermosetting resin and the cover sheet is impregnated with a fourth thermosetting resin, preferably the cover sheet being positioned as the outermost layer adjacent to the decorative sheet in the stack.

[0134] In some embodiments, the decorative sheet is impregnated with a third thermosetting resin and the cover sheet is impregnated with a fourth thermosetting resin, preferably the cover sheet being positioned above the decorative sheet in the stack.

[0135] In some preferred embodiments, the method may further include the step of digitally printing a pattern on the intermediate sheet.

[0136] In some preferred embodiments, in the stack formed in step c), the intermediate sheet is in direct contact with the substrate.

[0137] In step c), the stack may further include a cover sheet positioned as an outermost layer adjacent to the middle sheet, wherein the cover sheet is impregnated with a third thermosetting resin. The cover sheet may be a cellulose paper, which may be added to the stack to improve the durability of the final laminate and reduce the risk of wear.

[0138] In some preferred embodiments, in step c), the stack further comprises a bonding sheet positioned between the substrate and the intermediate sheet, wherein the bonding sheet is impregnated with a fifth thermosetting resin. If the first or second thermosetting resin does not contain melamine, it is advantageous to add a bonding sheet impregnated with melamine between the substrate and the intermediate sheet to increase the adhesion between the layers in the stack. The pressing step of d) is typically less than one minute, and melamine is highly reactive and will cure during this step.

[0139] The fifth thermosetting resin may include melamine. The fifth thermosetting resin may include phenol and melamine. The fifth thermosetting resin may include any other suitable thermosetting resin.

[0140] In some preferred embodiments, in step c), the stack further comprises a balancing sheet impregnated with a sixth thermosetting resin. The balancing sheet can reduce tension in the laminate and can reduce the risk of shrinkage or bending of the laminate.

[0141] The sixth thermosetting resin may include melamine. The sixth thermosetting resin may include phenol and melamine. The sixth thermosetting resin may include any other suitable thermosetting resin.

[0142] In some preferred embodiments, step d) includes heating the uppermost side of the stack with a first temperature, and heating the lowermost side of the stack with a second temperature different from the first temperature. The lowermost side of the stack may be a side formed by a substrate or a balancing sheet, and the uppermost side may be a side formed by a decorative sheet or a covering sheet. During pressing, the temperature of the lowermost side may be higher than the uppermost side. The temperature difference may reduce the tension in the laminate, and may reduce the risk of shrinkage or bending of the laminate. The pressing temperature is preferably 170 to 230°C. It is preferred to use different temperatures at the top of the stack and the bottom of the stack, about 210°C on the lower side, and about 200°C on the upper side. The inventors have found that these temperatures provide optimal temperatures to avoid delamination, debonding and / or cracking of the final laminate. Working outside the preferred temperature range also increases the possibility of uneven dimensional stability.

[0143] In step d), pressing can last for 10 to 60 seconds, preferably 10 to 45 seconds, preferably 15 to 45 seconds, preferably 20 to 35 seconds, preferably about 30 seconds. The inventors have found that these temperatures provide the best pressing time to avoid delamination, debonding and / or cracking of the final laminate. Lower pressing times can increase volume and increase yield, but the risk is debonding. On the other hand, longer pressing times reduce yield and can lead to excessive pressure on the substrate (HDF), making it too thin. The scope of the present invention provides the right balance between yield and quality. Working outside the preferred time range will also increase the possibility of uneven dimensional stability.

[0144] In some embodiments, step d) is performed at a lower pressing temperature for a longer pressing time, such as at a pressing temperature of up to 170° C. but for a time of at least 60 seconds. For example, step d) can be performed at a pressing temperature of up to 150° C. but for a time of at least 5 minutes; for example, at a pressing temperature of up to 130° C. but for a time of at least 20 minutes; for example, at a pressing temperature of up to 115° C. but for a time of at least 60 minutes.

[0145] In step d), the second sufficient pressure may be 40 to 80 kg / cm 2 , preferably 50 to 70 kg / cm 2 , preferably about 60kg / cm 2 The inventors have discovered that these pressures provide the optimum pressure to avoid delamination and / or cracking of the laminate.

[0146] In step d), the stack may be pressed with a press plate on the uppermost side of the stack. The press plate forms structures on the surface of the laminate, so that the laminate can be customized according to the preferences of the consumer. These structures can improve the visual appearance of the laminate on the decorative side of the laminate.

[0147] The present invention also relates to the use of an intermediate sheet obtained as described herein for obtaining a laminate, preferably a laminate as described herein.

[0148] In some embodiments, at least one sheet material is perforated. This has the advantage that trapped gas can be evaporated. The perforations can be random or organized. The perforations can be all over the sheet, up to the edge. In some embodiments, the first sheet material is perforated. In some embodiments, the second sheet material is perforated. In some embodiments, the first sheet material and / or the second sheet material are perforated. In some preferred embodiments, the resulting intermediate sheet is perforated. In some embodiments, the decorative sheet is perforated. In some embodiments, the cover sheet material is perforated. In some embodiments, the method includes the step of perforating at least one sheet material. In some embodiments, the method includes the step of perforating the first sheet material and / or the second sheet material. In some embodiments, the method includes the step of perforating the intermediate sheet.

[0149] The present invention also relates to a perforated sheet, preferably a perforated intermediate sheet.Preferably, the perforated intermediate sheet is obtained by the process as described herein.

[0150] The invention also relates to a laminate comprising a perforated layer, preferably a perforated sheet, preferably a perforated intermediate sheet.Preferably, the laminate is obtained by the process as described herein.

[0151] The invention also relates to a method as described herein, comprising the step of perforating at least one sheet material. In some embodiments, the method comprises the step of perforating the intermediate sheet material.

[0152] In some embodiments, the average distance between perforations is at least 1.0 mm to at most 15.0 mm, preferably at least 1.0 mm to at most 10.0 mm, preferably at least 2.0 mm to at most 8.0 mm, preferably at least 4.0 mm to at most 7.0 mm, preferably about 6.0 mm.

[0153] In some embodiments, the perforations are per cm 2 At least 1 perforation, preferably per cm 2 At least 2 perforations, preferably per cm 2 At least 3 perforations, preferably per cm 2 At least 4 perforations are present.

[0154] In some embodiments, the perforations have an average diameter of at least 0.02 mm to at most 3.00 mm, preferably at least 0.05 mm to at most 2.00 mm, preferably at least 0.10 mm to at most 1.00 mm.

[0155] In some embodiments, Figure 5A The length L defined in the range is at least 1250 to at most 6000 mm. In some embodiments, as Figure 5A The width W defined in the range is at least 600 to at most 2500 mm. In some embodiments, as Figure 5A The distance parameter A defined in the range is at least 0 to at most 200 mm. In some embodiments, as Figure 5A The distance parameter B defined in the range is at least 16 to at most 300 mm. In some embodiments, Figure 5A and Figure 5C The parameter C defined in the range is at least 0.05 to at most 2 mm. In some embodiments, as Figure 5B The distance parameter Dx defined in the range is at least 0.05 to at most 20 mm. In some embodiments, as Figure 5B The distance parameter Dy defined in ranges from at least 0.05 to at most 20 mm.

[0156] Example

[0157] The following examples are only used to illustrate the present invention and should not be construed as limiting its scope in any way. Although the present invention is only shown in some forms thereof, it should be apparent to those skilled in the art that the present invention is not limited thereto, but can be easily changed and modified without departing from the scope of the present invention.

[0158] Figure 1 A method for producing a laminate 30 according to one embodiment of the present invention is shown. First and second sheet materials, here shown as two sheets of kraft paper 10, are each impregnated with a thermosetting resin containing phenol and stacked on top of each other to form a sub-stack 20. The first pressing step 100 includes the step of pressing the sub-stacks 20 together. The pressure is about 70 kg / cm 2 , and the temperature in the press is 80 to 115° C. The sub-stack 20 is pressed for 60 to 110 minutes. A plurality of sub-stacks 20 may be pressed simultaneously with release sheets between the sub-stacks 20 .

[0159] The first pressing step 100 produces an incompletely cured intermediate sheet 11. Therefore, when the stack is pressed in a subsequent pressing step, the intermediate sheet 11 may adhere to the other sheets in the stack.

[0160] After the intermediate sheet 11 is sufficiently cooled to, for example, room temperature or 20 to 30° C., preferably about 25° C., inside or outside the press or in a cooler system, the intermediate sheet 11 is cut into desired sizes and ground in step 101. Grinding can improve the adhesion of the layers in the subsequent assembly steps and allow the thermosetting resin and melamine to better penetrate into the laminate.

[0161] Then, the stack 21 is assembled. Four layers may be stacked on top of a substrate 15 (e.g., an HDF board) in the following order: an intermediate sheet 11, a decorative sheet 13, and a cover sheet 14. An adhesive sheet 12 may be optionally incorporated into the stack 21. The decorative sheet 13 and the cover sheet 14 may be impregnated with a thermosetting resin containing melamine. In an embodiment including an optional adhesive sheet 12, the decorative sheet 13 and the cover sheet 14 may be impregnated with a thermosetting resin containing melamine. A balancing sheet 16 impregnated with a thermosetting resin containing melamine is positioned below the substrate 15 to reduce tension in the final laminate 30.

[0162] The second pressing step 102 includes pressing the stack 21 together. The stack 21 can be pressed with at least 40 kg / cm 2 , preferably 40 to 80 kg / cm2, or 50 to 70 kg / cm 2 , or most preferably 60kg / cm 2 The pressure is pressed for 10 to 60 seconds, preferably 10 to 45 seconds, or 15 to 45 seconds, or 20 to 35 seconds, or preferably about 30 seconds. The pressing temperature is 170 to 230°C. Different temperatures are used for the top of the stack 21 and the bottom of the stack 21, for example, the bottom of the stack 21 is 170 to 200°C, and the top of the stack is 170 to 220°C. Using different temperatures at the bottom and top of the stack can reduce the tension of the resulting laminate 30. The top of the stack 21 has more fibers and melamine, which requires more heat to cure. Therefore, the higher temperature at the top of the stack 21 can be beneficial in forming a flat laminate.

[0163] The second pressing step 102 produces the laminate 30. After the laminate 30 is sufficiently cooled, for example to room temperature or 20 to 30°C, the laminate 30 may be further processed.

[0164] Figure 2 An alternative exemplary method is shown in . In this embodiment, the sub-stack 20-1 is formed of a first sheet material (in this case, the sheet material is kraft paper 10 impregnated with a thermosetting resin containing phenol) and a second sheet material (in this case, the sheet material is fluted paper 17 impregnated with a thermosetting resin containing melamine). Figure 2 In the embodiment, the fluted paper 17 is positioned above the kraft paper 10, but may equally be positioned below the kraft paper 10.

[0165] Then, the sub-stack 20-1 is pressed using the first pressing step 100 as described above. The first pressing step 100 produces an intermediate sheet 11-1, which is cut and ground in step 101. The stack 21-1 is then assembled. Three layers are stacked on top of a substrate 15 (e.g., an HDF board) in the following order: an intermediate sheet 11-1, a decorative sheet 13, and a cover sheet 14. Since the intermediate sheet 11-1 is not fully cured in the first pressing step 100 and the groove paper 17 contains melamine, the adhesive sheet 12 is omitted. The cover sheet 14 is impregnated with a thermosetting resin containing melamine. The decorative sheet 13 is positioned between two melamine-impregnated sheets (intermediate sheet 11-1 and cover sheet 14), so the decorative sheet 13 may not be impregnated with a thermosetting resin. A balancing sheet 16 impregnated with a thermosetting resin including melamine or phenolic resin or a combination thereof is positioned below the substrate 15 to reduce tension in the final laminate 30 .

[0166] The stack 21-1 is then pressed, as described above, in a second pressing step 102. This results in a laminate 30 which, after sufficient cooling, can be further processed.

[0167] Figure 3 An alternative exemplary method is shown. In this embodiment, the sub-stack 20-2 is formed by a first sheet material (in this embodiment, the sheet material is kraft paper 10 impregnated with a thermosetting resin containing phenol) and a second and third sheet material (in this embodiment, the sheet material is two fluted papers 17 impregnated with a thermosetting resin containing melamine). The two fluted papers 17 are positioned on both sides of the kraft paper 10.

[0168] The sub-stack 20-2 is then pressed using the first pressing step 100 as described above. The first pressing step 100 produces an intermediate sheet 11-2, which is cut and ground in step 101. The stack 21-2 is then assembled. Three layers are stacked on top of the substrate 15 in the following order: a bonding sheet 12, an intermediate sheet 11-2, and a decorative sheet 13. The bonding sheet 12 and the decorative sheet 13 are impregnated with a thermosetting resin containing melamine. Since the intermediate sheet 11-2 is not fully cured in the first pressing step 100 and the groove paper 17 contains melamine, the bonding sheet 12 is omitted. A balancing sheet 16 impregnated with a thermosetting resin containing melamine or a phenolic resin or a combination thereof is positioned below the substrate 15 to reduce tension in the final laminate 30.

[0169] The stack 21-2 is then pressed in a second pressing step 102 as described above. This results in a laminate 30 which, after sufficient cooling, can be further processed.

[0170] The parameters for the two pressing steps 100 and 102 may be different from the above-described embodiments. Pressing time, temperature and pressure are interdependent, so for example if the temperature in the pressing step increases, the time can be reduced, etc. The higher pressure in the pressing step can also result in a reduction in the pressing time required for sufficient adhesion between the sheets in the sub-stack or stack. Other factors such as the number and type of layers in the sub-stack 20, 20-1, 20-2 and the stack 21, 21-1, 21-2 can also affect the pressing parameters. For example, in the second pressing step 102, the pressure can be up to 95 kg / cm 2 , which depends on the pressing time, temperature, and the number and type of layers in the stack. The type of thermosetting resin can also affect the pressing parameters of pressing steps 100 and 102, such as temperature and time. Phenolic thermosetting resins generally require more time to react than melamine thermosetting resins.

[0171] Exemplary Embodiments

[0172] Laminates are produced through the following process:

[0173] - Two sheets of 158g / m2 impregnated with 36w% phenolic resin 2 The moisture content of the recycled kraft paper is 6.8%.

[0174] - Press two sheets of kraft paper together using the following parameters: temperature 115°C, pressure 75kg / cm 2 , the pressing time was 68 minutes, and the cooling time in the press was 37 minutes.

[0175] - The intermediate sheet obtained was cooled to room temperature and ground.

[0176] - forming a stack comprising the following layers in the specified order: balancing sheets, including two 60 g / m 2 A sheet impregnated with 60w% melamine resin; a HDF substrate; an adhesive sheet impregnated with melamine; an intermediate sheet; a decorative sheet impregnated with 60w% melamine resin; and a cover sheet comprising 50g / m 2 of corundum and impregnated with 70w% melamine resin.

[0177] - The stack was pressed together using the following parameters: temperature of the cover sheet side was 200°C, temperature of the balance sheet side was 210°C, pressure was 45 kg / cm 2 , and for a duration of 30 seconds to produce an exemplary laminate.

[0178] Four tests were conducted to compare the produced exemplary laminates with conventional DPL and HPL boards. The moisture content in the laminates was measured using European standard EN 322. Drop test, abrasion test and scratch test were performed according to European standard EN 13329.

[0179] The test results can be seen in Table 1 below.

[0180]

[0181]

[0182] Table 1

[0183] Moisture, drop, abrasion and scratch test results for three different laminates

[0184] From the results, it can be seen that the exemplary laminate performs similarly to the HPL board in the moisture test and the drop test. The drop test shows that the HPL board and the exemplary laminate have higher durability.

[0185] In addition, the exemplary laminate performed better than the DPL board in the wear test, and the exemplary laminate showed higher wear resistance compared to the DPL board. The higher wear resistance can be due to the intermediate sheet below the decorative sheet and the cover sheet, as well as the high heat and short pressing time during the second pressing step. The presence of the intermediate sheet can prevent the corundum in the cover sheet from penetrating far into the underlaying sheet during the second pressing step. Therefore, the corundum can be closer to the top surface of the laminate, resulting in better wear resistance.

[0186] The scratch test also shows that the exemplary laminate has better results than both the DPL board and the HPL board. Therefore, the exemplary board can be more durable than both conventional laminates.

[0187] It should be noted that the above embodiments illustrate rather than limit the present invention, and that those skilled in the art will be able to design a variety of alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those described in the claims. The article "a" or "an" before an element does not exclude the presence of a plurality of such elements.

[0188] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0189] perforation

[0190] Figure 4A and Figure 4B A perforated sheet material that can be used according to one embodiment of the invention is shown. In this example, the middle sheet 11 is perforated, but it can be any other sheet material. Figure 4B Only a portion of the layer is shown, not the actual edge of the layer.

[0191] FIG. 5A to FIG. 5C A perforated intermediate sheet (11) according to one embodiment of the invention is shown, showing various parameters. Figure 5B and Figure 5C Shows Figure 5A An enlarged view of a portion of the perforated intermediate sheet (11) is shown in FIG.

Claims

1. A method for producing an intermediate sheet (11), the method comprising the following steps: a) providing at least a first sheet material impregnated with a first thermosetting resin and a second sheet material impregnated with a second thermosetting resin; as well as b) pressing the first sheet material and the second sheet material together at a temperature of 60°C to 115°C for 40 to 130 minutes so that the first thermosetting resin and the second thermosetting resin become liquid, and pressing with a first sufficient pressure so that the first sheet material and the second sheet material fuse to form an intermediate sheet without completely curing the first thermosetting resin and the second thermosetting resin, so that the first thermosetting resin and the second thermosetting resin can flow again when heated.

2. The method according to claim 1, further comprising the step of digitally printing a pattern on the intermediate sheet (11).

3. A method according to any one of the preceding claims, wherein: In step b), the temperature is 80°C to 115°C, preferably about 90°C; and / or wherein, in step b), the pressing is performed for 60 to 110 minutes, preferably about 85 minutes; and / or wherein, in step b), the first sufficient pressure is 55 to 95 kg / cm 2 , preferably 65 to 85 kg / cm 2 , preferably about 70kg / cm 2 .

4. A method according to any one of the preceding claims, wherein: The first thermosetting resin and / or the second thermosetting resin each contain phenol and / or melamine.

5. An intermediate sheet (11) obtainable by the method according to any one of the preceding claims.

6. A method for producing a laminate (30), comprising the step of producing an intermediate sheet (11) according to the method of any one of claims 1 to 4, and further comprising the steps of: c) forming a stack (21), wherein the stack (21) comprises the following layers: -Substrate(15); and - said intermediate sheet (11) of step b); and d) pressing the stack together at a temperature of 170 to 230°C for 10 to 60 seconds to allow the first thermosetting resin and the second thermosetting resin to flow again, and pressing with a second sufficient pressure so that the layers bond together to form a laminate (30).

7. The method according to claim 6, wherein: The stack (21) in step c) comprises at least one of the following sheets: o a decorative sheet (13) impregnated with a third thermosetting resin; o a decorative sheet (13) not impregnated with a thermosetting resin and a cover sheet (14) impregnated with a fourth thermosetting resin, wherein in the stack (21), the cover sheet (14) is positioned as an outermost layer adjacent to the decorative sheet (13); or o A decorative sheet (13) impregnated with a third thermosetting resin and a cover sheet (14) impregnated with a fourth thermosetting resin, wherein in the stack (21), the cover sheet (14) is positioned above the decorative sheet (13).

8. The method according to any one of claims 6 or 7, wherein: The first thermosetting resin and / or the second thermosetting resin and / or the third thermosetting resin and / or the fourth thermosetting resin each contain phenol and / or melamine.

9. The method according to any one of claims 6 to 8, wherein: In the stack (21) formed in step c), the intermediate sheet (11) is in direct contact with the substrate (15).

10. The method according to any one of claims 6 to 9, wherein: In step c), the stack (21) further comprises an adhesive sheet (12) positioned between the substrate (15) and the intermediate sheet (11), wherein the adhesive sheet (12) is impregnated with a fifth thermosetting resin, preferably, wherein the fifth thermosetting resin comprises melamine.

11. The method according to any one of claims 6 to 10, wherein: In step c), the stack (21) further comprises a balancing sheet (16) impregnated with a sixth thermosetting resin, preferably, wherein the sixth thermosetting resin comprises melamine.

12. The method according to any one of claims 6 to 11, wherein: Step d) comprises heating the uppermost side of the stack (21) with a first temperature, and heating the lowermost side of the stack (21) with a second temperature different from the first temperature.

13. The method according to any one of claims 6 to 12, wherein: In step d), the pressing is performed for 15 to 45 seconds, preferably 20 to 35 seconds, preferably about 30 seconds; and / or wherein, in step d), the second sufficient pressure is 40 to 80 kg / cm 2 , preferably 50 to 70 kg / cm 2 , preferably about 60kg / cm 2 .

14. The method according to any one of claims 6 to 13, wherein: In step d), the stack (21) is pressed at the uppermost side of the stack (21) using a pressing plate.

15. Method according to any one of claims 1 to 14, comprising the step of perforating at least one of the sheet materials, preferably the intermediate sheet (11).

16. A laminate (30) comprising a perforated layer, preferably a perforated intermediate sheet (11).

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