Honeycomb core and preparation method and device thereof

Abstract

The invention relates to a honeycomb core and a preparation method and device thereof, the preparation method of the honeycomb core comprises the following steps: a plurality of first embedding strips and a plurality of second embedding strips are provided, the first embedding strips comprise a plurality of first embedding slots, and the second embedding strips comprise a plurality of second embedding slots; the plurality of second embedding and inserting strips are arranged at intervals, and the plurality of first embedding and inserting strips are embedded and inserted into the plurality of second embedding and inserting strips under the action of the first embedding and inserting grooves and the second embedding and inserting grooves, so that the honeycomb core comprising a plurality of honeycomb unit cells which are arranged in an array manner is formed. According to the preparation method of the honeycomb core provided by the embodiment of the invention, the honeycomb core structure can be quickly and efficiently prepared.

Description

Technical Field

[0001] The present invention relates to a honeycomb core, and particularly to an efficient preparation of a polyamide honeycomb core. Background Art

[0002] A honeycomb panel is a panel with a geometric shape similar to a honeycomb structure. A plastic honeycomb panel has characteristics such as light weight, high strength, heat insulation, and sound insulation, and can replace traditional metal plates, cardboard, wooden boards, etc., and is used in fields such as building templates, trucks, refrigerated trucks, logistics vehicle compartments, movable panel houses, yachts, partitions, etc., and has a very wide range of applications.

[0003] A traditional plastic honeycomb composite panel is a honeycomb structure material with PP composite yarn fabric or prepreg tape on the upper and lower surfaces and a honeycomb core made of PP raw materials, which is formed by heating and compounding. The problem with it is that the structural strength of the honeycomb core is very limited, and it is difficult to meet the usage requirements in application scenarios with high mechanical property requirements. Moreover, it is necessary to explore honeycomb core and honeycomb panel products that are more conducive to sustainable development planning and meet the energy conservation, emission reduction, and lightweight design requirements in different fields, such as honeycomb cores or honeycomb panels prepared from bio-based polyamide continuous fiber composites. Bio-based polyamide continuous fiber composites belong to new materials, which have special physical and chemical properties. When preparing honeycomb cores or honeycomb panels, the preparation processes of traditional PP or thermosetting composites cannot be directly applied, and specific methods and equipment still need to be developed, which can not only realize the forming of the honeycomb core structure but also be promoted and used industrially. Summary of the Invention

[0004] To overcome at least one defect of the above-mentioned prior art, in a first aspect, an embodiment of the present invention provides a method for preparing a honeycomb core, including the following steps:

[0005] Providing a plurality of first insertion strips and a plurality of second insertion strips, the first insertion strips including a plurality of first insertion slots, and the second insertion strips including a plurality of second insertion slots;

[0006] Arranging the plurality of second insertion strips at intervals, and inserting the plurality of first insertion strips onto the plurality of second insertion strips through the action of the first insertion slots and the second insertion slots to form a honeycomb core including a plurality of honeycomb unit cells arranged in an array.

[0007] In a second aspect, an embodiment of the present invention provides a honeycomb core, including a plurality of honeycomb unit cells, the honeycomb unit cells including through holes surrounded by a plurality of honeycomb walls, and the cross-sectional shape of the honeycomb unit cells being square.

[0008] In a third aspect, an embodiment of the present invention provides a method for preparing an interlocking honeycomb core panel, which includes disposing a first surface layer and a second surface layer on both sides of a honeycomb core respectively to obtain the interlocking honeycomb core panel; wherein, the honeycomb core is obtained by the above-mentioned preparation method.

[0009] In a fourth aspect, an embodiment of the present invention provides a device for preparing a honeycomb core, which includes a cutting unit and an inserting unit; the cutting unit is used for cutting a composite board to obtain a plurality of first inserting strips and a plurality of second inserting strips, and the inserting unit is used for inserting the plurality of first inserting strips onto the plurality of second inserting strips to form the honeycomb core.

[0010] In a fifth aspect, an embodiment of the present invention provides a preparation system for an interlocking honeycomb core panel, which includes the above-mentioned device for preparing a honeycomb core and a laminating device, wherein the laminating device is used for laminating the honeycomb core with a first surface layer and a second surface layer to obtain the interlocking honeycomb core panel.

[0011] The method for preparing a honeycomb core according to an embodiment of the present invention can quickly and efficiently obtain a honeycomb core structure and is applicable to bio-based polyamide continuous fiber composite materials. Description of the Drawings

[0012] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention. Among them:

[0013] Figure 1 is a top view of a honeycomb core according to an embodiment of the present invention;

[0014] Figure 2 is a top view of a honeycomb unit cell according to an embodiment of the present invention;

[0015] Figure 3 is a schematic structural diagram of a first inserting strip according to an embodiment of the present invention;

[0016] Figure 4 is a top view of a composite board after being cut according to an embodiment of the present invention;

[0017] Figure 5 is a schematic structural diagram of a first inserting strip and a second inserting strip during the inserting process according to an embodiment of the present invention;

[0018] Figure 6 is a schematic structural diagram of a roller for applying glue and pasting a surface layer according to an embodiment of the present invention;

[0019] The descriptions of the reference numerals are as follows:

[0020] 101, honeycomb cell; 110, first insertion bar; 111, first insertion slot; 112, tail of the first insertion slot; 120, second insertion bar; 210, X cutting line; 211, first tool; 220, Y cutting line; 221, second tool; 300, insertion component; 10, liquid glue application roller; 11, skin roller; 12, film roller; 13, hot pressing and cooling curing roller; 14, pressing roller

[0021] a, height of the first insertion bar; b, depth of the first insertion slot; c, side length of the honeycomb cell; d, wall thickness of the first insertion bar Detailed implementation mode

[0022] Typical implementation modes embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different implementation modes, all of which do not depart from the scope of the present invention, and the descriptions therein are for illustrative purposes in nature and not intended to limit the present invention

[0023] Referring to Figures 1 to 5 As shown, an implementation mode of the present invention provides a honeycomb core, including a plurality of honeycomb cells 101, and the honeycomb cells 101 include through holes formed by enclosing with a plurality of honeycomb walls

[0024] In an implementation mode, the shape of the cross-section of the honeycomb cell 101 (or the shape of the cross-section of the through hole) can be circular, elliptical or polygonal; further, the polygon can be a quadrilateral, such as a rectangle or a rhombus; still further, the shape of the cross-section of the honeycomb cell can be square

[0025] In an implementation mode, two adjacent honeycomb cells 101 have a common honeycomb wall

[0026] In an implementation mode, a plurality of honeycomb cells 101 are arranged in an array, such as a quadrilateral array, further can be a rectangular array, and still further can be a square array

[0027] In an implementation mode, the cross-section of the honeycomb cell is quadrilateral, preferably square, that is, a plurality of honeycomb cells 101 are arranged in a square array, and the side length of the honeycomb cell can be 10 - 50 mm, such as 11 mm, 12 mm, 14 mm, 15 mm, 16 mm, 18 mm, 20 mm, 21 mm, 22 mm, 24 mm, 25 mm, 26 mm, 28 mm, 30 mm, 32 mm, 35 mm, 38 mm, 40 mm, 42 mm, 45 mm, 48 mm; the height of the honeycomb cell or the height of the honeycomb core can be 8 - 25 mm, such as 10 mm, 12 mm, 15 mm, 16 mm, 18 mm, 19 mm, 20 mm, 22 mm, 24 mm

[0028] In one embodiment, the density of the honeycomb core can be 0.05 - 0.5 g / cm 3 , and further can be 0.08 - 0.4 g / cm 3 , such as 0.1 g / cm 3 , 0.15 g / cm 3 , 0.18 g / cm 3 , 0.2 g / cm 3 , 0.21 g / cm 3 , 0.25 g / cm 3 , 0.26 g / cm 3 , 0.28 g / cm 3 , 0.3 g / cm 3 , 0.32 g / cm 3 , 0.35 g / cm 3 , 0.38 g / cm 3 , 0.4 g / cm 3 , 0.42 g / cm 3 , 0.45 g / cm 3 .

[0029] In one embodiment, the compressive strength of the honeycomb core can be 5 - 60 MPa, and further can be 30 - 50 MPa, such as 6 MPa, 10 MPa, 13 MPa, 15 MPa, 16 MPa, 18 MPa, 20 MPa, 21 MPa, 25 MPa, 31 MPa, 32 MPa, 35 MPa, 38 MPa, 40 MPa, 42 MPa, 44 MPa, 45 MPa, 46 MPa, 48 MPa.

[0030] In one embodiment, the honeycomb core includes a plurality of honeycomb cells 101 arranged in an array and having a quadrilateral cross-section (such as a rectangle, square), and the whole can be in a lattice shape. The honeycomb core can be formed by inserting and arranging a plurality of first inserting strips 110 arranged substantially along the X direction and a plurality of second inserting strips 120 arranged substantially along the Y direction. The first inserting strips 110 and the second inserting strips 120 form the honeycomb walls of the plurality of honeycomb cells 101, that is, the material of the honeycomb cells 101 is the same as the material of the first inserting strips 110 and / or the second inserting strips 120.

[0031] In one embodiment, the X direction is perpendicular to the Y direction.

[0032] In one embodiment, the length direction of the plurality of first inserting strips 110 is substantially the same as the X direction. For example, the angle between the length direction of the first inserting strips 110 and the X direction can be 0 - 1°, such as 0.05°, 0.1°, 0.2°, 0.3°, 0.5°, 0.8°. Further, the length direction of the first inserting strips 110 is parallel to the X direction.

[0033] In one embodiment, the length direction of the plurality of second insertion strips 120 is substantially the same as the Y direction. For example, the angle between the length direction of the second insertion strip 120 and the Y direction can be 0 to 1°, such as 0.05°, 0.1°, 0.2°, 0.3°, 0.5°, 0.8°. Further, the length direction of the second insertion strip 120 is parallel to the Y direction.

[0034] In one embodiment, the first insertion strip 110 can be exactly the same as the second insertion strip 120, such as the material, shape, size, etc. are all the same.

[0035] In one embodiment, the height of the honeycomb core can be the same as the height (or width) of the first insertion strip 110 and / or the second insertion strip 120.

[0036] In one embodiment, referring to Figure 2 , 3 As shown, both the first insertion strip 110 and the second insertion strip 120 are strip-shaped, for example, they can be rectangular strip-shaped plates; a plurality of first insertion slots 111 are provided on the first insertion strip 110, and a plurality of second insertion slots are provided on the second insertion strip 120. By arranging the first insertion slots 111 and the second insertion slots opposite to each other, and making the tail 112 of the first insertion slot enter the second insertion slot and the tail of the second insertion slot enter the first insertion slot 111, the first insertion strip 110 and the second insertion strip 120 can be inserted together in a cross-shaped (for example, perpendicular to each other) manner. Thus, through the cooperation of the plurality of first insertion slots 111 and the plurality of second insertion slots on the plurality of first insertion strips 110 and the plurality of second insertion strips 120, a honeycomb core with a plurality of honeycomb single cells 101 arranged in an array can be formed.

[0037] In one embodiment, the tail 112 of the first insertion slot refers to the part on the first insertion strip 110 that is connected to the first insertion slot 111 along the height direction (or the part where the first insertion slot 111 does not penetrate the first insertion strip 110 along the depth direction); the tail of the second insertion slot refers to the part on the second insertion strip 120 that is connected to the second insertion slot along the height direction (or the part where the second insertion slot does not penetrate the second insertion strip 120 along the depth direction).

[0038] In one embodiment, the plurality of first insertion slots 111 on the first insertion strip 110 are arranged at equal intervals.

[0039] In one embodiment, the plurality of second insertion slots on the second insertion strip 120 are arranged at equal intervals.

[0040] In one embodiment, the shape and size of the first insertion slot 111 can be the same as those of the second insertion slot.

[0041] In one embodiment, the depth direction of the first insertion slot 111 is parallel to the height a (or width) direction of the first insertion bar, or perpendicular to the length direction of the first insertion bar 110.

[0042] In one embodiment, the width of the first insertion slot 111 (i.e., the dimension parallel to the length direction of the first insertion bar 110) can be adjusted according to the thickness of the second insertion bar 120. The depth b of the first insertion slot can be 1 / 2 of the height a of the first insertion bar.

[0043] In one embodiment, the wall thickness d of the first insertion bar is slightly smaller than the width of the second insertion slot, so that the tail 112 of the first insertion slot can enter the second insertion slot. Correspondingly, the wall thickness of the second insertion bar 120 is slightly smaller than the width of the first insertion slot 111, so that the tail of the second insertion slot can enter the first insertion slot 111.

[0044] In one embodiment, the width of the second insertion slot (i.e., the dimension parallel to the length direction of the second insertion bar 120) can be adjusted according to the thickness of the first insertion bar 110. The depth of the second insertion slot can be 1 / 2 of the width (or height) of the second insertion bar 120.

[0045] In one embodiment, a plurality of first insertion bars 110 and a plurality of second insertion bars 120 form a honeycomb core having a plurality of quadrilateral (e.g., rectangular) honeycomb unit cells 101, wherein the honeycomb unit cell 101 is formed by surrounding partial regions of two parallel first insertion bars 110 and partial regions of two parallel second insertion bars 120. The length of the honeycomb unit cell 101 can be the distance between two adjacent first insertion slots 111 on the first insertion bar 110, and the width of the honeycomb unit cell 101 can be the distance between two adjacent second insertion slots on the second insertion bar 120; alternatively, the length of the honeycomb unit cell 101 can be the distance between two adjacent second insertion slots on the second insertion bar 120, and the width of the honeycomb unit cell 101 can be the distance between two adjacent first insertion slots 111 on the first insertion bar 110; the height of the honeycomb unit cell 101 can be the same as the height of the honeycomb core, or the same as the height of the first insertion bar 110 and / or the second insertion bar 120.

[0046] One embodiment of the present invention provides an interlocking honeycomb core panel, including a first surface layer, a second surface layer, and a honeycomb core sandwiched between the first surface layer and the second surface layer, and the structure of the honeycomb core is as described above.

[0047] In one embodiment, the first surface layer and the second surface layer are perpendicular to the depth direction of the through holes of the honeycomb unit cell 101 and cover the through holes of the honeycomb unit cell 101.

[0048] In one embodiment, the material of the first surface layer and / or the second surface layer is selected from bio-based polyamide continuous glass fiber prepreg tape, bio-based polyamide continuous aramid fiber prepreg tape, bio-based polyamide continuous basalt fiber prepreg tape, bio-based polyamide continuous carbon fiber prepreg tape, or a combination thereof. Further, the continuous fiber content of the prepreg tape can be 30-80 wt%, such as 40 wt%, 50 wt%, 60 wt%, 70 wt%; the density can be 1.5-2.0 g / cm 3 , such as 1.6 g / cm 3 , 1.7 g / cm 3 , 1.8 g / cm 3 , 1.9 g / cm 3 ; the thickness can be 0.5-1.0 mm, such as 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm.

[0049] Referring to Figures 1 to 5 shown, one embodiment of the present invention provides a method for preparing the above honeycomb core, including the following steps:

[0050] Provide a plurality of first insertion strips 110 and a plurality of second insertion strips 120. The first insertion strip 110 includes a plurality of first insertion slots 111, and the second insertion strip 120 includes a plurality of second insertion slots;

[0051] Arrange a plurality of second insertion strips 120 at intervals, and insert a plurality of first insertion strips 110 on the plurality of second insertion strips 120 through the action of the first insertion slots 111 and the second insertion slots, forming a plurality of honeycomb single cells 101 arranged in an array. Among them, the first insertion strip 110 is inserted on the second insertion strip 120 in a cross-cross form.

[0052] In one embodiment, a plurality of first insertion strips 110 are arranged in parallel at equal intervals, and the distance between two adjacent first insertion strips 110 is the same as the distance between two adjacent second insertion slots on the second insertion strip 120.

[0053] In one embodiment, a plurality of second insertion strips 120 are arranged in parallel at equal intervals, and the distance between two adjacent second insertion strips 120 is the same as the distance between two adjacent first insertion slots on the first insertion strip 110.

[0054] In one embodiment, a plurality of second insertion strips 120 arranged in parallel at intervals are disposed along the Y direction, that is, the length direction of the second insertion strips 120 is the same as the Y direction. The first insertion strips 110 disposed along the X direction are placed above the plurality of second insertion strips 120, and each first insertion slot 111 corresponds to a second insertion slot. Then, the first insertion strips 110 are moved downward so that the tails of the second insertion strips 120 enter the first insertion slots 111, and the tails 112 of the first insertion slots enter the second insertion slots, thereby enabling each first insertion strip 110 and each second insertion strip 120 to be inserted together in a cross-cross form. In the same manner as described above, a plurality of first insertion strips 110 are inserted onto the plurality of second insertion strips 120 to form a honeycomb core having a quadrilateral (such as a rectangle) honeycomb unit cell 101.

[0055] In one embodiment, a plurality of first insertion strips 110 and a plurality of second insertion strips 120 can be quickly and efficiently inserted together through an insertion unit.

[0056] In one embodiment, the insertion unit includes a conveying component and an insertion component 300 (or an insertion assembly). The conveying component is used to drive the plurality of second insertion strips 120 to travel along the Y direction, and the insertion component 300 is used to insert the plurality of first insertion strips 110 disposed along the X direction onto the plurality of second insertion strips 120 to form a honeycomb core structure.

[0057] In one embodiment, the traveling speed of the conveying component can be in a multiple relationship with the distance between adjacent second insertion slots (or the first insertion slots 111) or the side length c of the square honeycomb unit cell to ensure the precise alignment of the insertion strips and form an interlocking honeycomb core structure.

[0058] In one embodiment, the plurality of second insertion strips 120 can be disposed in parallel on the conveying component. Under the action of the conveying component, the plurality of second insertion strips 120 can travel along the Y direction, and the length direction of the second insertion strips 120 is also the Y direction; the plurality of first insertion strips 110 are disposed on the insertion component 300. During operation, the plurality of first insertion strips 110 are disposed in a suspended manner. When the plurality of second insertion strips 120 run below the plurality of first insertion strips 110, the insertion component 300 inserts the first insertion strips 110 onto the second insertion strips 120 and releases the first insertion strips 110.

[0059] In one embodiment, the insertion component 300 can be an insertion roller, which is disposed above the conveying component and is used to sequentially insert the plurality of first insertion strips 110 onto the second insertion strips 120 disposed on the conveying component.

[0060] In one embodiment, the conveying component can include a conveyor belt, and the plurality of second insertion strips 120 can be disposed on the conveyor belt.

[0061] A method for preparing a honeycomb core according to an embodiment of the present invention includes the steps of preparing a first insertion strip 110 and a second insertion strip 120.

[0062] In one embodiment, the first insertion strip 110 and / or the second insertion strip 120 are obtained by cutting a composite board. Further, a milling cutter, a saw blade, a water jet, a laser cutting, etc. can be used to cut the composite board.

[0063] In one embodiment, the composite board can be continuously cut along the X and Y directions respectively by a tool, and a plurality of insertion strips can be directly obtained after cutting to improve the cutting efficiency.

[0064] In one embodiment, with reference to Figure 4 As shown, multi-row spaced cuts are made along the X direction on the composite board to form a plurality of X cutting lines 210 extending along the X direction, where "spaced" means that the cutting lines in each row are spaced apart and not continuous together, and the X cutting lines 210 are located inside the composite board; multi-row cuts are made along the Y direction on the composite board to form a plurality of Y cutting lines 220 extending along the Y direction, where each row of Y cutting lines 220 is continuous and penetrates the composite board. After cutting, the cutting in the Y direction divides the composite board into a plurality of insertion strips, and the cutting in the X direction forms insertion slots (first insertion slots or second insertion slots) on the insertion strips.

[0065] In one embodiment, the distance between two adjacent Y cutting lines 220 on the composite board can be the same as the width or height of the insertion strip. Half of the length of each X cutting line 210 can be the same as the depth or height of the insertion slot.

[0066] In one embodiment, the multi-row cuts in the X direction can be made first, and then the multi-row cuts in the Y direction can be made.

[0067] In one embodiment, a first tool 211 can be used to make multi-row cuts in the X direction, and a second tool 221 can be used to make multi-row cuts in the Y direction. The first tool 211 and the second tool 221 can be the same or different.

[0068] In one embodiment, the composite board for preparing the first insertion strip 110 and / or the second insertion strip 120 can be a continuous fiber reinforced polyamide composite board, which contains polyamide and continuous long fibers. The mass percentage of the continuous long fibers is 50-90%, such as 50%, 55%, 60%, 65%, 68%, 69%, 70%, 71%, 72%, 75%, 80%, 85%, 90%.

[0069] In one embodiment, the types of the continuous long fibers include one or a combination of several of carbon fibers, glass fibers, silicon carbide fibers, basalt fibers, natural flax fibers, aramid fibers, metal fibers, and boron fibers.

[0070] In one embodiment, the continuous fiber reinforced polyamide composite plate contains one or a combination of two or more of a polyamide film, a continuous fiber fabric, and a polyamide unidirectional prepreg tape. Among them, the polyamide film contains polyamide; the polyamide unidirectional prepreg tape contains polyamide and continuous long fibers; the continuous fiber fabric is a fiber cloth, a fiber yarn containing continuous long fibers, or a combination thereof.

[0071] In one embodiment, the method for preparing a continuous fiber reinforced polyamide composite plate includes a laminating step and a pressing step; wherein, the laminating step includes: laminating one or two or more of a polyamide film, a continuous fiber fabric, and a polyamide unidirectional prepreg tape to obtain a multi-layer composite structure; the pressing step includes: performing pre-pressing treatment, exhaust treatment, pressure holding treatment, and cooling treatment on the above multi-layer composite structure.

[0072] In one embodiment, the method for preparing a continuous fiber reinforced polyamide composite plate includes a laminating step and a pressing step; wherein, the laminating step includes: laminating using a unidirectional prepreg tape, a fiber cloth and a polyamide film, or a fiber yarn and a polyamide film to obtain a multi-layer composite structure; the pressing step includes: performing pre-pressing treatment, exhaust treatment, pressure holding treatment, and cooling treatment on the above multi-layer composite structure. Among them, the unidirectional prepreg tape contains continuous fibers.

[0073] In one embodiment, the laminating can be performed manually or using an automatic laminating machine.

[0074] In one embodiment, the unidirectional prepreg tape used for laminating is a bio-based polyamide continuous fiber unidirectional prepreg tape, specifically it can be a bio-based polyamide continuous glass fiber unidirectional prepreg tape, a bio-based polyamide continuous aramid fiber unidirectional prepreg tape, a bio-based polyamide continuous basalt fiber unidirectional prepreg tape, a bio-based polyamide continuous carbon fiber unidirectional prepreg tape, or a combination thereof, such as the continuous long fiber reinforced long carbon chain polyamide resin unidirectional prepreg tape disclosed in Chinese Patent Application CN113232384A.

[0075] In one embodiment, the laminating step includes: laminating one or more polyamide films and one or more continuous fiber fabrics to obtain a multi-layer composite structure.

[0076] In another embodiment, the laminating step includes: laminating a plurality of polyamide unidirectional prepreg tapes to obtain a multi-layer composite structure.

[0077] In one embodiment, the continuous fiber content of the unidirectional prepreg tape for laying can be 30 to 70 wt%, such as 40 wt%, 50 wt%, 60 wt%; the density can be 1.5 to 2.0 g / cm 3 , such as 1.6 g / cm 3 , 1.7 g / cm 3 , 1.8 g / cm 3 , 1.9 g / cm 3 ; the thickness can be 1.0 to 2.5 mm, such as 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm.

[0078] In one embodiment, the orientation of the continuous fibers in the continuous fiber fabric intersects at 0 to 90°, preferably 90° or 45°.

[0079] In one embodiment, the continuous fiber fabric can be a plain weave structure or a twill weave structure. For example, it is a biaxial glass fiber fabric, and the orientation of the continuous fibers therein is 0° / 90° or +45° / -45°.

[0080] In some specific embodiments, the continuous fibers in the continuous fiber fabric are selected from glass fibers, carbon fibers, basalt fibers, aramid fibers, natural fibers or combinations thereof.

[0081] In some specific embodiments, the thickness of the continuous fiber fabric is 0.05 to 0.5 mm.

[0082] In some specific embodiments, the thickness of the continuous fiber fabric is 0.1 to 0.4 mm, preferably 0.175 to 0.193 mm.

[0083] In one embodiment, the fiber cloth for laying can be a carbon fiber cloth or a glass fiber cloth. The glass fiber cloth can be, for example, a plain weave glass fiber cloth or a twill weave glass fiber cloth; the thickness of the fiber cloth can be 0.05 to 0.5 mm, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm.

[0084] In one embodiment, the polyamide film for laying can be a bio-based polyamide film.

[0085] In some specific embodiments, the density of the bio-polyamide film is 1.0 to 1.2 g / cm 3 .

[0086] In some specific embodiments, the thickness of the bio-based polyamide film is 0.05 - 0.2 mm, preferably 0.05 - 0.15 mm, such as 0.05 mm, 0.08 mm, 0.1 mm, 0.12 mm. For example, the polyamide 56 resin film disclosed in paragraph

[0007] of patent application CN111763313A.

[0087] In one embodiment, a fiber cloth and a polyamide film are used for laying, and the mass of the fiber cloth accounts for 30 - 70% of the total mass of the fiber cloth and the polyamide film, such as 40%, 50%, 60%.

[0088] In one embodiment, the preparation monomers of the polyamide in the unidirectional prepreg tape or the polyamide film used for laying include a diamine and a diacid. The diamine includes pentamethylenediamine; the diacid includes one or more of aliphatic diacids having 4 - 18 carbon atoms and / or aromatic diacids having 8 - 10 (such as 9) carbon atoms.

[0089] In one embodiment, the molar ratio of the diamine and the diacid used to prepare the polyamide resin can be (1 - 1.05):1, such as 1.01:1, 1.02:1, 1.03:1, 1.04:1.

[0090] In one embodiment, the diamine includes pentamethylenediamine and other diamines. The other diamines can be one or more of aliphatic diamines having 4 - 16 carbon atoms (excluding pentamethylenediamine); further, the other diamines can be one or more of butanediamine, hexanediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine.

[0091] In one embodiment, the aliphatic diacid having 4 - 18 carbon atoms can be one or more of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid.

[0092] In one embodiment, the aromatic diacid can be one, two, or three of terephthalic acid, isophthalic acid, and phthalic acid.

[0093] In one embodiment, the polyamide in the polyamide or polyamide film of the unidirectional prepreg tape for laying is selected from bio-based polyamides PA56, bio-based polyamide PA510, bio-based polyamide PA511, bio-based polyamide PA512, bio-based polyamide PA513, bio-based polyamide PA514, bio-based polyamide PA515, bio-based polyamide PA516, bio-based polyamide PA56 / 5T, bio-based polyamide PA510 / 5T, bio-based polyamide PA511 / 5T, bio-based polyamide PA512 / 5T, bio-based polyamide PA513 / 5T, bio-based polyamide PA514 / 5T, bio-based polyamide PA515 / 5T, bio-based polyamide PA516 / 5T, bio-based polyamide PA56 / 5I, commercially available 6638, 6308, 6300, 6290, 6635, 6631, 6632, 6520, 5000, 3600, 3601, 3100, 3102, 3300, 3500, 2260, 2262, 1273, 1251, 1320, any one or a combination of several of 1520.

[0094] In one embodiment, the bio-based polyamide, such as Some raw materials of the series products are derived from renewable plant resources, which further adds its commercial potential and scientific research value as a matrix resin for composite materials.

[0095] In one embodiment, the multi-layer composite structure obtained after laying includes multiple layers of unidirectional prepreg tapes containing continuous fibers. The directions of the continuous fibers in the multiple layers of prepreg tapes are not the same. For example, the angle between the continuous fibers in the multiple layers of prepreg tapes can be 0°, 45°, or 90°.

[0096] In one embodiment, the continuous fiber reinforced bio-based polyamide unidirectional prepreg tape is laid in a 0° / 90° or ±45° cross-symmetric manner. The 0° / 90° cross-symmetric laying is such as 0 / 90 / 90 / 0, 0 / 90 / 0 / 90 / 90 / 0 / 90 / 0, etc.

[0097] In one embodiment, the multi-layer composite structure obtained after laying includes multiple layers of polyamide films, fiber cloth, and / or fiber yarns. The polyamide film layers are located at both ends of the multi-layer composite structure, that is, the polyamide film layers are the surface layers of the multi-layer composite structure. For example, polyamide film layer / fiber cloth / polyamide film layer, polyamide film layer / fiber yarn / polyamide film layer; the polyamide film layers can also be arranged inside the multi-layer composite structure at the same time, such as polyamide film layer / fiber cloth / polyamide film layer / fiber yarn / polyamide film layer.

[0098] In one embodiment, the laying method of the composite structure including multiple layers of polyamide films and fiber cloth (and / or fiber yarns) can be the same as that of the prepreg tape. The number of laid films can be designed according to the wall thickness of the square honeycomb core (i.e., the thickness of the continuous fiber reinforced bio-based polyamide sheet) and the fiber content.

[0099] In one embodiment, the multi-layer composite structure obtained after laying can be pressed by an intermittent multi-layer press, that is, pre-pressing treatment, exhaust treatment, pressure holding treatment, and cooling treatment are carried out.

[0100] In one embodiment, the process temperature of the pressing plate is 10 - 30°C higher than the resin melting point of the multi-layer composite structure, such as 15°C, 20°C, 25°C.

[0101] In one embodiment, the pressure of the pre-pressing treatment can be 0 - 3 MPa, such as 1 MPa, 2 MPa; the time can be 2 - 6 min, such as 3 min, 4 min, 5 min.

[0102] In one embodiment, the pressure of the exhaust treatment can be 0 - 3 MPa, such as 1 MPa, 2 MPa.

[0103] In one embodiment, the pressure of the pressure holding treatment can be 3 - 10 MPa, such as 4 MPa, 5 MPa, 6 MPa, 8 MPa; the time of the pressure holding treatment can be 3 - 8 min, such as 4 min, 5 min, 6 min, 7 min.

[0104] In one embodiment, the pressure of the cooling treatment can be 2 - 5 MPa, such as 3 MPa, 4 MPa.

[0105] In one embodiment, a belt conveyor or a steel belt conveyor can be used for the continuous pressing plate process.

[0106] In one embodiment, during the cutting of the composite board, the X direction is preferably consistent with the fiber direction on the surface of the board, which is beneficial to improving the compressive strength of the honeycomb core.

[0107] An embodiment of the present invention provides a method for preparing the above-mentioned interlocking honeycomb core panel, including: disposing a first surface layer (or skin) and a second surface layer (or skin) on both sides of the honeycomb core respectively to obtain an interlocking honeycomb core panel. Further, the first surface layer and the second surface layer are both the aforementioned continuous fiber reinforced polyamide composite panels.

[0108] In one embodiment, the thickness of the first surface layer or the thickness of the second surface layer is 0.2 - 5 mm, such as 0.4 mm, 0.45 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, etc.

[0109] In one embodiment, the formed honeycomb core is coated with glue through a glue application roller 10, preferably using liquid glue, and the liquid glue can penetrate into the insertion joints of the two insertion strips of the honeycomb core (i.e., the position where the first insertion slot 111 and the second insertion slot are connected), so as to bond the gaps at the insertion joints and avoid stress concentration at this place when stressed subsequently.

[0110] In one embodiment, a liquid glue or a glue film is disposed on the honeycomb core and / or the surface layer, and further through heating and pressing, and cooling and curing, an interlocking honeycomb core panel is obtained.

[0111] In one embodiment, the liquid glue or glue film material can be at least one of PE-g-MAH, PP-g-MAH, POE-g-MAH, EPDM-g-MAH, ABS-g-MAH, PS-g-MAH, EVA resin, and a hot melt adhesive film such as low melting point polyamide can also be selected.

[0112] In one embodiment, the glue film can be covered between the honeycomb core and the first surface layer or the second surface layer through a glue film roller 12. The first surface layer or the second surface layer is covered on the surface of the glue film through a skin roller 11, and together with the glue film, it is covered on the surface of the honeycomb core through the glue film roller 12 and a pressure roller 14. Further, the distance between the pressure roller 14 and the surface of the honeycomb core can be set according to the height of the honeycomb core. The skin, the glue film and the honeycomb core are heated, pressed, cooled and cured through a hot pressing and cooling curing roller 13 to form an interlocking honeycomb core panel.

[0113] The method for preparing the above-mentioned interlocking honeycomb core panel according to an embodiment of the present invention includes the following steps:

[0114] S1: Laying

[0115] Cross-symmetrically lay one or more of a polyamide film, a continuous fiber fabric, and a polyamide unidirectional prepreg tape to obtain a multi-layer composite structure containing polyamide and continuous long fibers.

[0116] S2: Pressing

[0117] The multi-layer composite structure is subjected to pre-pressing, degassing, pressure-holding, and cooling treatments to obtain a polyamide thermoplastic composite board.

[0118] S3: Cutting

[0119] The polyamide thermoplastic composite board is cut in multiple rows along the X direction and the Y direction respectively. The cutting in the X direction is used to form a plurality of insertion slots, and the cutting in the Y direction is used to divide the composite board into a plurality of first insertion strips 110 and second insertion strips 120 with insertion slots; wherein, the X direction is perpendicular to the Y direction.

[0120] S4: Insertion

[0121] A plurality of first insertion strips 110 are inserted onto a plurality of second insertion strips 120 to form a honeycomb core structure having a plurality of honeycomb unit cells 101.

[0122] S5: Gluing and surface layer pasting

[0123] Liquid glue is coated on the honeycomb core to bond the gaps of the honeycomb core; then, liquid glue or a glue film is provided between the honeycomb core and the first surface layer and between the honeycomb core and the second surface layer, and through pressurization and cooling and curing, an interlocking honeycomb core board is obtained.

[0124] In one embodiment, during the pressurization process in step S5, the temperature of the system can be 0 - 200 °C, such as 20 °C, 25 °C, 50 °C, 80 °C, 100 °C, 120 °C, 150 °C, 180 °C, 190 °C, 195 °C; the pressure of pressurization can be 0.5 - 5 MPa (gauge pressure), such as 0.8 MPa, 1 MPa, 1.2 MPa, 1.5 MPa, 2 MPa, 3 MPa, 4 MPa; the time of pressurization can be 1 - 10 min, such as 2 min, 3 min, 5 min, 6 min, 8 min.

[0125] One embodiment of the present invention provides a preparation device for the above honeycomb core, including a cutting unit and an insertion unit; the cutting unit is used to cut the composite board to obtain the first insertion strip 110 and the second insertion strip 120, and the insertion unit is used to insert a plurality of first insertion strips 110 onto a plurality of second insertion strips 120 to form a honeycomb core structure.

[0126] In one embodiment, the cutting unit includes a tool for cutting the composite board.

[0127] In one embodiment, the structure of the insertion unit is as described above.

[0128] In one embodiment, the preparation device for the honeycomb core further includes a preparation unit for the composite board, which is used to prepare the above composite board by laying and pressing.

[0129] An embodiment of the present invention provides a preparation system for the above interlocking honeycomb core board, including the preparation device for the above honeycomb core and a laminating device, wherein the laminating device is used to laminate the honeycomb core with the first surface layer and the second surface layer to obtain the interlocking honeycomb core board.

[0130] In one embodiment, the laminating device includes an automatic film laminating roller.

[0131] An embodiment of the present invention provides an application of a continuous fiber reinforced bio-based polyamide material in the preparation of an interlocking honeycomb core board, especially in the honeycomb core.

[0132] In one embodiment, the continuous fiber reinforced bio-based polyamide material can be the above-mentioned unidirectional prepreg tape.

[0133] Hereinafter, the preparation of the interlocking honeycomb core board according to an embodiment of the present invention will be further described in conjunction with the drawings and specific examples. Among them, the raw materials and testing methods used in the examples are as follows:

[0134] Raw material

[0135] 1. 2260, E6635 (or also known as 6635), E3300 (or also known as 3300), and the bio-based polyamide PA512 / 5T are all bio-based polyamides (produced by Kaisai Biotech Co., Ltd.), and the unidirectional prepreg tapes containing continuous long glass fibers prepared using the above bio-based polyamides are all purchased from Kaisai Biotech Co., Ltd.

[0136] 2. The EVA resin is EVA 182 purchased from Tuole Chemical Industry.

[0137] Testing method

[0138] 1. Density: Tested with reference to GB / T 1464-2005.

[0139] 2. Compressive strength: Tested with reference to GB / T1453-2022.

[0140] Example 1

[0141] S1: Layup

[0142] Place the commercially available 2260-70% GF-thickness 0.25 mm bio-based polyamide unidirectional prepreg tape (i.e., using 2260 as the matrix resin, containing 70 wt% of continuous long glass fibers, and a thickness of 0.25 mm) is laid up in the 0 / 90 / 0 pattern to obtain a multi-layer composite structure.

[0143] S2: Pressing

[0144] The multi-layer composite structure is pre-pressed under a pressure of 1 MPa, degassed under a pressure of 1 MPa, held at a pressure of 8 MPa for 8 min, and cooled under a pressure of 5 MPa to obtain a polyamide composite board; the thickness of the composite board is 0.75 mm.

[0145] S3: Cutting

[0146] Perform multi-row and intermittent cutting along the X direction inside the polyamide composite board to form a plurality of X cutting lines 210; then, perform multi-row through-cutting on the composite board along the Y direction (perpendicular to the X direction). The cutting in the Y direction divides the composite board into a plurality of insertion strips, and the cutting in the X direction can form a plurality of insertion slots on the insertion strips.

[0147] S4: Insertion

[0148] Take a part of the insertion strips as the first insertion strips 110 and another part of the insertion strips as the second insertion strips 120; insert the first insertion strips 110 onto a plurality of second insertion strips 120 by matching the insertion slots of the first insertion strips 110 with the insertion slots of the second insertion strips 120 to form a honeycomb core structure having a plurality of square honeycomb unit cells 101. The side length of the square of the honeycomb unit cell 101 is 40 mm, and the height of the honeycomb unit cell 101 is 20 mm. The density of the formed honeycomb core is 0.08 g / cm 3 , and the compressive strength is 5.3 MPa.

[0149] S5: Gluing and surface layer pasting

[0150] Coat the honeycomb core with EVA resin to bond the gaps of the honeycomb core; then, set EVA resin between the honeycomb core and the first surface layer and between the honeycomb core and the second surface layer, heat and press at 200 °C and 1 MPa for 1 min, and cool and cure to obtain an interlocking honeycomb core board. Among them, the first surface layer and the second surface layer are the same, and both are skins with a thickness of 0.45 mm obtained by laying the bio-based polyamide unidirectional prepreg of step S1 in a 0 / 90 / 0 layup and pressing. The temperature and pressure during pressing are the same as those in step S2.

[0151] Example 2

[0152] This example uses basically the same process and raw materials as in Example 1 to prepare an interlocking honeycomb core board, with the only differences being: the layup method in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 1 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 21 mm, the height of the honeycomb unit cell 101 is 19 mm, and the density of the honeycomb core is 0.18 g / cm 3 , and the compressive strength is 16.8 MPa.

[0153] Example 3

[0154] This example uses the same process and raw materials as Example 1 to prepare the interlocking honeycomb core board, with the only differences being: the laying pattern in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 1 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 15 mm, and the height of the honeycomb unit cell 101 is 20 mm; the density of the honeycomb core is 0.21 g / cm 3 , and the compressive strength is 20.1 MPa.

[0155] Example 4

[0156] This example uses the same process and raw materials as Example 1 to prepare the interlocking honeycomb core board, with the only differences being: the laying pattern in step S1 is 0 / 90 / 0 / 90 / 90 / 0 / 90 / 0; the thickness of the composite board obtained in step S2 is 2 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 30 mm, and the height of the honeycomb unit cell 101 is 16 mm; the density of the honeycomb core is 0.26 g / cm 3 , and the compressive strength is 35.3 MPa.

[0157] Example 5

[0158] This example uses the same process and raw materials as Example 1 to prepare the interlocking honeycomb core board, with the only differences being: the laying pattern in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 2 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 25 mm, and the height of the honeycomb unit cell 101 is 16 mm; the density of the honeycomb core is 0.32 g / cm 3 , and the compressive strength is 44.2 MPa.

[0159] Example 6

[0160] This example uses the same process and raw materials as Example 1 to prepare the interlocking honeycomb core board, with the only differences being: the laying pattern in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 2 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 15 mm, and the height of the honeycomb unit cell 101 is 20 mm; the density of the honeycomb core is 0.40 g / cm 3 , and the compressive strength is 50 MPa.

[0161] Example 7

[0162] This embodiment uses basically the same process and raw materials as in Embodiment 1 to prepare the interlocking honeycomb core board, with the only differences being: in step S1, a unidirectional prepreg tape of E6635 - 70% GF - 0.25 mm thick (i.e., with E6635 as the matrix resin, containing 70 wt% continuous long glass fibers and a thickness of 0.25 mm) is used, and the layup pattern in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 1 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 21 mm, and the height of the honeycomb unit cell 101 is 19 mm; the density of the honeycomb core is 0.18 g / cm 3 , and the compressive strength is 15.1 MPa.

[0163] Embodiment 8

[0164] This embodiment uses basically the same process and raw materials as in Embodiment 1 to prepare the interlocking honeycomb core board, with the only differences being: in step S1, a unidirectional prepreg tape of E3300 - 70% GF - 0.17 mm thick (i.e., with E3300 as the matrix resin, containing 70 wt% continuous long glass fibers and a thickness of 0.17 mm) is used, and the layup pattern in step S1 is 0 / 90 / 0 / 0 / 90 / 0; the thickness of the composite board obtained in step S2 is 1 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 21 mm, and the height of the honeycomb unit cell 101 is 19 mm; the density of the honeycomb core is 0.18 g / cm 3 , and the compressive strength is 13.2 MPa.

[0165] Embodiment 9

[0166] This embodiment uses basically the same process and raw materials as in Embodiment 1 to prepare the interlocking honeycomb core board, with the only differences being: in step S1, a unidirectional prepreg tape of bio - based polyamide PA512 / 5T - 70% GF - 0.25 mm thick (i.e., with bio - based polyamide PA512 / 5T as the matrix resin, containing 70 wt% continuous long glass fibers and a thickness of 0.25 mm) is used, and the layup pattern in step S1 is 0 / 90 / 90 / 0; the thickness of the composite board obtained in step S2 is 1 mm; the side length of the honeycomb unit cell 101 of the honeycomb core in step S4 is 21 mm, and the height of the honeycomb unit cell 101 is 19 mm; the density of the honeycomb core is 0.18 g / cm 3 , and the compressive strength is 14.5 MPa.

[0167] Embodiment 10

[0168] In this embodiment, an interlocking honeycomb core panel is prepared using substantially the same process and raw materials as in Embodiment 1, with the only differences being that: in step S1, a unidirectional prepreg tape of bio-based polyamide PA512 / 5T - 70% GF - 0.25 mm thick (i.e., with bio-based polyamide PA512 / 5T as the matrix resin, containing 70 wt% continuous long glass fibers and a thickness of 0.25 mm) is used, and the layup method in step S1 is 0 / 90 / 90 / 0; the thickness of the composite panel obtained in step S2 is 1 mm; the side length of the honeycomb unit 101 of the honeycomb core in step S4 is 11 mm, and the height of the honeycomb unit 101 is 10 mm; the density of the honeycomb core is 0.3 g / cm 3 , and the compressive strength is 31.8 MPa.

[0169] Unless otherwise specified, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0170] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make various other substitutions, changes, and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments and is only defined by the claims.

Claims

1. A method for preparing a honeycomb core, comprising the following steps: Providing a plurality of first embedding strips and a plurality of second embedding strips, wherein the first embedding strips include a plurality of first embedding slots, and the second embedding strips include a plurality of second embedding slots; The plurality of second embedded strips are arranged at intervals, and the plurality of first embedded strips are embedded on the plurality of second embedded strips through the first embedded slots and the second embedded slots to form a honeycomb core including a plurality of honeycomb cells arranged in an array.

2. The preparation method according to claim 1, wherein The plurality of second embedded strips are arranged in parallel on the conveying component. Under the action of the conveying component, the plurality of second embedded strips move along the Y direction, and the angle between the length direction of the plurality of second embedded strips and the Y direction is 0-1°; the plurality of first embedded strips are suspended by the embedded component, and the angle between the length direction of the plurality of first embedded strips and the X direction is 0-1°; when the plurality of second embedded strips run to the bottom of the plurality of first embedded strips, the plurality of first embedded strips are embedded onto the plurality of second embedded strips by the embedded component; and / or, The preparation method comprises: continuously cutting the composite board to obtain a plurality of the first embedded strips and the second embedded strips.

3. The preparation method according to claim 2, wherein The continuous cutting comprises: performing multiple rows of cutting at intervals along the X direction inside the surface of the composite plate to form multiple X-cutting lines extending along the X direction, wherein the X-cutting lines do not penetrate the composite plate; and Performing multiple rows of cutting along the Y direction on the surface of the composite plate to form multiple Y-cutting lines extending along the Y direction and penetrating the composite plate; Wherein, each Y-cutting line divides the cut area into two parts, the cutting in the Y direction divides the composite board into a plurality of first embedded strips and / or second embedded strips, and the cutting in the X direction forms a first embedded slot and / or a second embedded slot on the first embedded strip and / or the second embedded strip; and / or, The X direction is perpendicular to the Y direction.

4. The preparation method according to claim 1, comprising a layering step and a plate pressing step; wherein: The layering step comprises: layering one or more of a polyamide film, a continuous fiber fabric, and a polyamide unidirectional prepreg tape to obtain a multilayer composite structure; The plate pressing step includes: performing pre-pressing treatment, exhaust treatment, pressure holding treatment, and cooling treatment on the multi-layer composite structure.

5. A honeycomb core, comprising a plurality of honeycomb cells, wherein the honeycomb cells comprise through holes formed by being surrounded by a plurality of honeycomb walls, and the cross-section of the honeycomb cells is in the shape of a quadrilateral, preferably a square.

6. The honeycomb core according to claim 5, wherein the side length of the square is 10 to 50 mm; and / or, The height of the honeycomb unit cell or the height of the honeycomb core is 8 to 25 mm; and / or, The density of the honeycomb core is 0.05-0.5 g / cm 3 and / or, The compressive strength of the honeycomb core is 5-60 MPa.

7. A method for preparing an interlocking honeycomb core panel, comprising arranging a first surface layer and a second surface layer on both sides of a honeycomb core, respectively, to prepare an interlocking honeycomb core panel; wherein, The honeycomb core is prepared by the preparation method according to any one of claims 1 to 4 or is the honeycomb core according to claim 5 or 6.

8. A honeycomb core preparation device, comprising a cutting unit and an inserting unit; the cutting unit is used to cut a composite board to obtain a plurality of first inserting strips and a plurality of second inserting strips, and the inserting unit is used to insert the plurality of first inserting strips on the plurality of second inserting strips to form the honeycomb core.

9. The preparation device according to claim 8, comprising a preparation unit for preparing the composite board by laying up and pressing boards.

10. A system for preparing an interlocking honeycomb core panel, comprising the honeycomb core preparation device and the bonding device according to claim 8 or 9, wherein: The bonding device is used to bond the honeycomb core to the first surface layer and the second surface layer to obtain an interlocking honeycomb core panel.

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