Bio-based polyamide cellular board

Abstract

The utility model relates to a bio-based polyamide honeycomb plate which sequentially comprises an upper skin, a first resin bonding layer, a first composite material bonding layer, a honeycomb core, a second composite material bonding layer, a second resin bonding layer and a lower skin from top to bottom, and the honeycomb core is formed by processing a continuous fiber reinforced bio-based polyamide composite material. Therefore, on the basis that the shape of the honeycomb core is maintained and the appearance of the skin is good, the peel strength and the bending property of the honeycomb plate are obviously improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of composite material, specifically relates to a kind of bio-based polyamide honeycomb board. BACKGROUND

[0002] Honeycomb board is the board material with similar honeycomb structure geometry. Plastic honeycomb board has the characteristics of light weight, high strength, heat insulation, sound insulation, etc., which can replace traditional metal plate, paperboard, wood board, etc., and be used in building formwork, truck, refrigerator car and logistics car compartment, mobile house, yacht, partition, etc. field, and is widely applied.

[0003] The traditional plastic honeycomb composite material is made of upper and lower two surfaces of polypropylene fiber composite yarn fabric or prepreg tape, and the core material is made of polypropylene raw material. The honeycomb structure material is formed by heating and compounding. The problem is that the honeycomb core structure has limited strength, and it is difficult to meet the use requirements in application occasions with high mechanical property requirements.

[0004] The continuous fiber reinforced polyamide composite material has excellent bearing performance as a honeycomb core. However, when it is directly hot-melted with the skin to form a sandwich panel, obvious indentation will appear on the surface of the skin, and serious indentation deformation will occur. Moreover, due to the deviation of part of the fibers of the skin, the mechanical properties will be seriously affected, especially the bending stiffness will be greatly reduced. If the gluing and glue spraying process of aluminum honeycomb board is referred to, the contact area between the low-density continuous fiber honeycomb core and the skin is small, and the peel strength is low, which cannot meet the requirements of products such as compartment board and floor.

[0005] Therefore, when the honeycomb core material is a continuous fiber reinforced bio-based polyamide composite material, the technology of applying it to a honeycomb board needs to be improved. CONTENT OF THE UTILITY MODEL

[0006] The utility model aims at providing a bio-based polyamide honeycomb board, which significantly improves the peel strength of the honeycomb board on the basis of maintaining the shape of the honeycomb core and having a good appearance of the skin.

[0007] To achieve the above-mentioned purpose, the utility model provides a bio-based polyamide honeycomb board, which comprises, from top to bottom, an upper skin, a first resin bonding layer, a first composite material bonding layer, a honeycomb core, a second composite material bonding layer, a second resin bonding layer and a lower skin. The honeycomb core is made of continuous fiber reinforced bio-based polyamide composite material.

[0008] In one embodiment, the first composite material bonding layer, the second composite material bonding layer, the upper skin and the lower skin are all made of continuous fiber reinforced bio-based polyamide composite material.

[0009] In an embodiment, the continuous fiber reinforced polyamide composite has a mass percentage of continuous fiber in the honeycomb core, the first composite adhesive layer, the second composite adhesive layer, the upper skin, and the lower skin of 50-90%, for example 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%.

[0010] In an embodiment, the continuous fiber comprises one or more of glass fiber, carbon fiber, basalt fiber, aramid fiber, natural fiber, metal fiber, boron fiber.

[0011] In an embodiment, the continuous fiber reinforced polyamide composite comprises a continuous fiber reinforced polyamide composite panel, for example a laminate selected from a polyamide unidirectional prepreg tape, a polyamide film, and a continuous fiber fabric, a laminate of a polyamide unidirectional prepreg tape and a polyamide film, a laminate of a polyamide unidirectional prepreg tape and a continuous fiber fabric, or a combination laminate thereof. Wherein the polyamide film contains polyamide; the polyamide unidirectional prepreg tape contains polyamide and continuous long fiber; the continuous fiber fabric is a fiber cloth, a fiber yarn, or a combination thereof containing continuous long fiber.

[0012] In an embodiment, a method for preparing a continuous fiber reinforced polyamide composite panel comprises a layering step and a pressing step; wherein the layering step comprises layering one or more of a polyamide film, a continuous fiber fabric, a polyamide unidirectional prepreg tape to obtain a multi-layer composite structure; and the pressing step comprises pre-pressing, degassing, pressure maintaining, and cooling the multi-layer composite structure.

[0013] In an embodiment, a method for preparing a continuous fiber reinforced polyamide composite panel comprises a layering step and a pressing step; wherein the layering step comprises layering 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; and the pressing step comprises pre-pressing, degassing, pressure maintaining, and cooling the multi-layer composite structure. Wherein the unidirectional prepreg tape contains continuous fiber.

[0014] In an embodiment, the layering can be performed manually or using an automatic layering machine.

[0015] In an embodiment, the unidirectional prepreg tape used for layering is a bio-based polyamide continuous fiber unidirectional prepreg tape, specifically 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, for example the continuous long fiber reinforced long carbon chain polyamide resin unidirectional prepreg tape disclosed in Chinese patent application CN113232384A.

[0016] In some embodiments, the bio-based polyamide continuous fiber unidirectional prepreg tape can be prepared by melt impregnation, solution impregnation or powder impregnation.

[0017] In one embodiment, the continuous fiber content of the unidirectional prepreg tape used for performing the lay-up can be 30-80 wt%, for example 40 wt%, 50 wt%, 60 wt%; the density can be 1.5-2.0 g / cm 3 , for example 1.6 g / cm 3 , 1.7 g / cm 3 , 1.8 g / cm 3 , 1.9 g / cm 3 ; the thickness can be 1.0-2.5 mm, for example 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm.

[0018] In one embodiment, the continuous fibers in the continuous fiber fabric are oriented at 0-90°, preferably at 90° and / or 45°. In one embodiment, the continuous fiber fabric comprises one or more of a square fabric, a non-crimp fabric, a three-dimensional fabric. For example, a glass fiber bi-axial fabric, wherein the continuous fibers are oriented at 0° / 90° or +45° / -45°. In some specific embodiments, the continuous fibers in the continuous fiber fabric are selected from glass fibers, carbon fibers or basalt fibers.

[0019] In some specific embodiments, the thickness of the continuous fiber fabric is 0.05-0.5 mm.

[0020] In some specific embodiments, the thickness of the continuous fiber fabric is 0.1-0.4 mm.

[0021] In one embodiment, the fiber cloth used for performing the lay-up can be a carbon fiber cloth or a glass fiber cloth, for example a plain weave glass fiber cloth or a twill weave glass fiber cloth; the thickness of the fiber cloth can be 0.05-0.5 mm, for example 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm.

[0022] In one embodiment, the polyamide film used for performing the lay-up can be a bio-based polyamide film, which can be prepared by coating, film blowing or calendering.

[0023] In some specific embodiments, the density of the bio-based polyamide film is 1.0-1.2 g / cm 3 .

[0024] In some embodiments, the bio-based polyamide film has a thickness of 0.05-0.3 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 CN111763313A.

[0025] In one embodiment, the fiber cloth and the polyamide film are used for the lay-up, and the mass of the fiber cloth accounts for 30-70% of the total mass of the two, such as 40%, 50%, 60%.

[0026] In one embodiment, the polyamide in the unidirectional prepreg or the polyamide film used for the lay-up is selected from bio-based polyamides, and the preparation monomers of the bio-based polyamides include diamines and diacids, the diamines include bio-based pentanediamine and other diamines, the other diamines are one or more of aliphatic diamines with a carbon atom number of 4-16 (not including pentanediamine); the diacids include one or more of aliphatic diacids with a carbon atom number of 4-18 and aromatic diacids with a carbon atom number of 8-10 (for example, 9), and the molar ratio of the diamines and the diacids can be (1-1.05):1, such as 1.01:1, 1.02:1, 1.03:1, 1.04:1.

[0027] In one embodiment, the bio-based polyamide is selected from any one or a combination of several of bio-based polyamide 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, and 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, and bio-based polyamide PA5T / 66.

[0028] In one embodiment, the bio-based polyamide is selected from commercially available E-6638, E-6308, E-6300, E-6290, E-6635, E-6631, E-6632, E-6520, E-5000, E-3600, E-3601, E-3100, E-3102, E-3300, E-3500, E-2260, E-2262, E-1273, E-1251, E-1320.

[0029] The utility model is a brand of semi-biological or full-biological polyamide raw material of Shanghai Kaisai Biotechnology Co., Ltd., E is followed by a number which is the model number of polyamide corresponding to different performance indexes, the main raw material thereof comes from renewable plant raw material, the biological content is 25%-100%, and the product has the characteristics of renewable source, recyclable product, standard performance and competitive cost.

[0030] In an embodiment, the multi-layer composite structure obtained after laying up comprises a plurality of unidirectional prepreg tapes containing continuous fibers, and the directions of the continuous fibers in the plurality of unidirectional prepreg tapes are different, for example, the angles between the continuous fibers in the plurality of unidirectional prepreg tapes can be 0°, 45° or 90°.

[0031] In an embodiment, the continuous fiber reinforced biobased polyamide unidirectional prepreg tape is laid up in a 0° / 90° or ±45° cross-symmetrical manner, for example, 0 / 90 / 90 / 0, 0 / 90 / 0 / 90 / 90 / 0 / 90 / 0, etc.

[0032] In an embodiment, the multi-layer composite structure obtained after laying up comprises a plurality of polyamide film layers, fiber cloth layers and / or fiber yarn layers, and the polyamide film layers are arranged at both ends of the multi-layer composite structure, i.e., the polyamide film layers are 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, for example, polyamide film layer / fiber cloth / polyamide film layer / fiber yarn / polyamide film layer.

[0033] In an embodiment, the laying up manner of the composite structure comprising a plurality of polyamide film layers and fiber cloth layers (and / or fiber yarn layers) can be the same as the laying up manner of the prepreg tape. The number of laid film layers can be designed according to the thickness of the square honeycomb core (i.e., the thickness of the continuous fiber reinforced biobased polyamide plate) and the fiber content.

[0034] In an embodiment, the multi-layer composite structure obtained after laying up can be subjected to plate pressing operation by an intermittent multi-layer press, i.e., pre-pressing treatment, exhaust treatment, pressure maintaining treatment and cooling treatment.

[0035] In an embodiment, the process temperature of plate pressing is 10-30℃ higher than the melting point of the resin of the multi-layer composite structure, for example, 15℃, 20℃ or 25℃.

[0036] In an embodiment, the pressure of the pre-pressing treatment can be 0-3MPa, for example, 1MPa or 2MPa; and the time can be 2-6min, for example, 3min, 4min or 5min.

[0037] In an embodiment, the pressure of the exhaust treatment can be 0-3 MPa, for example 1 MPa, 2 MPa; the number of exhaust times can be 4-8 times, for example 5 times, 6 times, 7 times.

[0038] In an embodiment, the pressure of the pressure maintaining treatment can be 3-10 MPa, for example 4 MPa, 5 MPa, 6 MPa, 8 MPa; the time of the pressure maintaining treatment can be 3-8 min, for example 4 min, 5 min, 6 min, 7 min.

[0039] In an embodiment, the pressure of the cooling treatment can be 2-5 MPa, for example 3 MPa, 4 MPa; the time can be 4-10 min, for example 5 min, 6 min, 7 min, 8 min.

[0040] In an embodiment, the continuous pressing plate process can use a belt machine or a steel belt machine.

[0041] It should be noted that the selection of the upper skin, the lower skin, the first composite adhesive layer, and the second composite adhesive layer material is independent of each other and is not particularly limited, and can be the same as or different from the honeycomb core material. In order to facilitate the control of the first heating and pressing condition and the second heating and pressing condition, it is preferred that the first composite adhesive layer and the second composite adhesive layer are the same material, and the upper skin and the lower skin are the same material.

[0042] In an embodiment, the first resin adhesive layer and the second resin adhesive layer each include one or a combination of several of PA hot melt adhesive, polyurethane adhesive, epoxy adhesive, acrylic resin, polyolefin resin, EVA resin, and modified resin thereof.

[0043] In an embodiment, the thickness d1 of the first composite adhesive layer and the thickness d2 of the second composite adhesive layer are each 0.1-0.3 mm, for example 0.15 mm, 0.2 mm, 0.25 mm, etc.

[0044] In an embodiment, the thickness d3 of the first resin adhesive layer and the thickness d4 of the second resin adhesive layer are each 0.05-1 mm, for example 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, etc.

[0045] In an embodiment, the thickness d5 of the upper skin and the thickness d6 of the lower skin are each 0.2-5 mm, for example 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, etc.

[0046] In an embodiment, the height d7 of the honeycomb core is 5-150 mm, such as 20 mm, 40 mm, 60 mm, 80 mm, 100 mm, 120 mm, 140 mm, etc.

[0047] In an embodiment, the wall thickness of the honeycomb core is 0.2-3 mm, such as 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, etc.

[0048] In an embodiment, the density of the honeycomb core is 60-300 g / cm 3 , such as 100 g / cm 3 , 150 g / cm 3 , 200 g / cm 3 , 250 g / cm 3 , etc.

[0049] In an embodiment, the height of the bio-based polyamide honeycomb panel is no less than (d1+d2+d3+d4+d5+d6+d7-3) mm and no more than (d1+d2+d3+d4+d5+d6+d7-0.5) mm, such as (d1+d2+d3+d4+d5+d6+d7-2.5) mm, (d1+d2+d3+d4+d5+d6+d7-2) mm, (d1+d2+d3+d4+d5+d6+d7-1.5) mm, (d1+d2+d3+d4+d5+d6+d7-1) mm, etc.

[0050] Specifically, the method for preparing the bio-based polyamide honeycomb panel comprises:

[0051] (1) covering the first and second composite material bonding layers on both sides of the honeycomb core, and performing hot melt welding treatment to obtain a first precore panel;

[0052] (2) covering the first and second resin bonding layers on both sides of the first precore panel to obtain a second precore panel;

[0053] (3) covering the upper and lower skins on both sides of the second precore panel, and performing bonding treatment to obtain a honeycomb core.

[0054] In an embodiment, in step (1), the hot melt welding is achieved by performing first heating and pressurizing on the precore panel.

[0055] In an embodiment, in step (1), the temperature of the first heating and pressurizing is 5-100 ℃ higher than the melting point of the honeycomb core material and lower than the decomposition temperature of the honeycomb core material.

[0056] In one embodiment, in step (1), the first heating and pressing is performed for 10-60 seconds, such as 20 seconds, 30 seconds, 40 seconds, 50 seconds, etc.

[0057] In one embodiment, in step (1), the first heating and pressing is performed at a pressure of 0.5-5 MPa, such as 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4.5 MPa, etc.

[0058] It should be noted that the device used for hot melt welding of the honeycomb core and the composite adhesive layer is not particularly limited, and the honeycomb core and the composite adhesive layer can be combined by heating and pressing using a molding machine, a belt machine, a steel belt machine, or an extrusion roller. For example, when a molding machine is used for heating and pressing, the height of the opening of the molding machine is further limited to limit the thickness of the first preformed core board. Thus, by losing the thickness of the honeycomb core, the honeycomb core and the composite adhesive layer are changed from "line-line" bonding to "face-face" bonding, thereby improving the bonding strength.

[0059] In one embodiment, in step (1), the first heating and pressing is performed at a pressure of 0.5-5 MPa, such as 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4.5 MPa, etc.

[0060] In one embodiment, in step (2), the resin adhesive layer can be applied to the surface of the composite adhesive layer by liquid roll coating, glue spraying, or other methods, or can be applied to the surface by film lamination, and the thickness of the film is 0.05-0.3 mm.

[0061] In one embodiment, in step (3), the bonding is achieved by second heating and pressing of the second preformed core board.

[0062] In one embodiment, in step (3), the second heating and pressing is performed at a temperature higher than the melting point temperature of the first resin adhesive layer or the second resin adhesive layer, and lower than the melting point temperature of the lower one of the first composite adhesive layer material, the second composite adhesive layer material, the upper skin material, and the lower skin material by 10-150°C, and further lower than the softening point temperature of the lower one of the first composite adhesive layer material, the second composite adhesive layer material, the upper skin material, and the lower skin material by 5-80°C. When the resin adhesive layer material is a glue that can be cured at room temperature, such as polyurethane, epoxy, or acrylic resin adhesive, the bonding of the composite adhesive layer and the skin can be achieved without heating, i.e. the temperature of the second heating and pressing is 0°C.

[0063] In one embodiment, in step (3), the second heating and pressing is performed for 30-900 seconds, such as 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, 600 seconds, 700 seconds, 800 seconds, etc.

[0064] In one embodiment, in step (3), the second heating and pressing is performed for 30-900 seconds, such as 100 seconds, 200 seconds, 300 seconds, 400 seconds, 500 seconds, 600 seconds, 700 seconds, 800 seconds, etc.

[0065] It should be noted that the device used for bonding the second precored core plate and the skin is not particularly limited, and a molding machine, a belt machine, a steel belt machine or an extrusion roller can be used to heat and press the same to make it composite.

[0066] The beneficial effects of the present application are as follows:

[0067] For a honeycomb core of continuous fiber reinforced polyamide composite material, the present application provides a novel bio-based polyamide honeycomb panel structure. The bio-based polyamide honeycomb panel comprises, from top to bottom, an upper skin, a first resin bonding layer, a first composite material bonding layer, a honeycomb core, a second composite material bonding layer, a second resin bonding layer and a lower skin, i.e. the honeycomb core and the skin are bonded by the composite material bonding layer and the low resin bonding layer. Thus, on the basis of the honeycomb core shape and good appearance of the skin, the peel strength of the honeycomb panel is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0068] Figure 1 The structure of the bio-based polyamide honeycomb panel of the present application is shown.

[0069] Element number explanation:

[0070] 1: upper skin;

[0071] 2: first resin bonding layer;

[0072] 3: first composite material bonding layer;

[0073] 4: honeycomb core;

[0074] 5: second composite material bonding layer;

[0075] 6: second resin bonding layer;

[0076] 7: lower skin. DETAILED DESCRIPTION

[0077] The following embodiments of the present application are illustrated by way of specific examples, and other advantages and effects of the present application can be easily understood by those skilled in the art from the contents disclosed in the specification.

[0078] It should be understood that the terms used herein are for the purpose of describing specific embodiments only and are not intended to be limiting of the present application, and singular forms "a," "an," and "the" are intended to include plural forms, unless the context clearly indicates otherwise. When the terms "comprises" and / or "comprising" are used in this specification, it means that the features, integers, steps, operations, elements, and / or components that follow, but not those that do not, are included in the present application. The terms "upper," "lower," "front," "rear," "left," "right," and similar terms used herein are for illustrative purposes only and are not limiting.

[0079] The ordinal numbers such as "first" and "second" used in the present application are merely identifiers and do not have any other meaning, such as a specific order, etc. Also, for example, the term "first component" does not by itself imply the existence of a "second component," nor does the term "second component" by itself imply the existence of a "first component."

[0080] EVA adhesive film (PET / PA-899) was purchased from Guangzhou Alarod High Polymer Material Co., Ltd., and others were commercially available unless otherwise specified.

[0081] The continuous glass fiber reinforced polyamide PA5T / 66 unidirectional prepreg tape was prepared from a bio-based polyamide PA5T / 66 resin and continuous glass fibers, wherein:

[0082] (1) Bio-based polyamide PA5T / 66 resin: melting point 265℃, relative viscosity 2.4, obtained by copolymerization of bio-based pentanediamine, hexanediamine, adipic acid and terephthalic acid, purchased from Kaisai (Jinxiang) Biomaterials Co., Ltd.;

[0083] (2) The monofilament diameter of the continuous glass fiber is 17μm, and the linear density is 2400Tex, purchased from Taishan Glass Fiber Co., Ltd.;

[0084] (3) The content of continuous glass fiber in the continuous glass fiber reinforced polyamide PA5T / 66 unidirectional prepreg tape is 70wt%, the density is 1.86g / cm 3 , and the thickness is 0.15mm.

[0085] Sample testing method:

[0086] (1) Compression strength was detected according to the test standard GB / T1457-2022 - Drum peel strength test method for sandwich structures.

[0087] (2) The bending stiffness is detected according to the test standard GB / T1456-2021 - Sandwich structures - Determination of flexural behaviour of sandwich panels.

[0088] (3) The compressive strength is detected according to the test standard GB / T1453-2022 - Sandwich structures or cores - Determination of flatwise compressive behaviour of sandwich panels or cores.

[0089] Example 1

[0090] The materials used for the skin, the composite adhesive layer and the honeycomb core are continuous glass fiber reinforced polyamide PA5T / 66 unidirectional prepreg tapes prepared in the preparation example, with a melting point (Tm) of 265℃ and a crystallization temperature (Tc) of 228℃. Among them:

[0091] (1) The continuous glass fiber reinforced polyamide unidirectional prepreg tapes are laid according to 0 / 90 / 0 and pressed to obtain a hexagonal honeycomb core, with a wall thickness of 0.45mm, a side length of 18mm, a height of 21mm and a density of 68g / cm 3 ;

[0092] (2) The continuous glass fiber reinforced polyamide unidirectional prepreg tapes are laid according to 0 / 90 / 0 and pressed to obtain an upper skin and a lower skin, both with a thickness of 0.45mm;

[0093] (3) The first composite adhesive layer and the second composite adhesive layer both have a thickness of 0.15mm;

[0094] (4) The first resin adhesive layer and the second resin adhesive layer are both EVA adhesive films (softening point 102-135℃), with a thickness of 0.1mm.

[0095] The composite adhesive layer and the honeycomb core are limited to a height of 20mm, heated at 290℃ for 30s under a pressure of 1MPa, so as to be hot melt welded. Then the resin adhesive layer and the skin are heated at 200℃ for 1min under a pressure of 1MPa, to form a bio-based polyamide honeycomb panel.

[0096] The obtained bio-based polyamide honeycomb panel (with a total height of 21.1mm) has a good appearance of the skin, a compressive strength of 5.3MPa, a peel strength of 80N.mm / mm and a bending stiffness of 1.36x10 8 N.mm 2 .

[0097] Example 2

[0098] The hexagonal honeycomb core has a side length of 8mm and a density of 150g / cm 3 , and the others are the same as in Example 1.

[0099] The obtained bio-based polyamide honeycomb panel (total height 21.1 mm) had a good appearance of the skin, a compression strength of 14.2 MPa, a peel strength of 120 N.mm / mm, and a bending stiffness of 1.68 x 10 8 N.mm 2 .

[0100] Comparative Example 1

[0101] The same as Example 1, except that the composite adhesive layer was not used, and the honeycomb core and the skin were directly bonded by the resin adhesive layer at 200°C for 1 min under a pressure of 1 MPa to form the bio-based polyamide honeycomb panel.

[0102] The obtained bio-based polyamide honeycomb panel (total height 22.1 mm) had a good appearance of the skin, a compression strength of 5.1 MPa, but a low peel strength of only 5 N.mm / mm, and a bending stiffness of 7.6 x 10 7 N.mm 2 .

[0103] Comparative Example 2

[0104] The same as Example 1, except that the composite adhesive layer and the resin adhesive layer were not used, and the honeycomb core and the skin were directly bonded at 290°C for 30 s under a pressure of 1 MPa to form the bio-based polyamide honeycomb panel.

[0105] The obtained bio-based polyamide honeycomb panel (total height 21.9 mm) had a poor appearance of the skin, with fiber deviation and local depression on the surface, a low bending stiffness of 5.2 x 10 7 N.mm 2 , and a peel strength of 60 N.mm / mm.

[0106] Comparative Example 3

[0107] The same as Example 1, except that the composite adhesive layer and the honeycomb core were not limited in height.

[0108] The obtained bio-based polyamide honeycomb panel (total height 22.4 mm) had a good appearance of the skin, a compression strength of 5.5 MPa, but a low peel strength of only 8 N.mm / mm, and a bending stiffness of 8.1 x 10 7 N.mm 2 .

[0109] Comparative Example 4

[0110] The same as Example 1, except that the composite adhesive layer and the honeycomb core were limited in height to 18 mm to form the bio-based polyamide honeycomb panel.

[0111] The obtained bio-based polyamide honeycomb panel (total height 22.4 mm) has a good appearance of the skin, a compression strength of 13.8 MPa, but a lower peel strength of only 25 N.mm / mm, and a bending stiffness of 1.55 x 10 8 N.mm 2 but the compression strength decreases to 3 MPa.

[0112] Comparative Example 5

[0113] The same as Example 2, except that the composite adhesive layer is not used, and the honeycomb core and the skin are directly bonded by the resin adhesive layer at 210°C for 1 min under a pressure of 1 MPa to form the bio-based polyamide honeycomb panel.

[0114] The obtained bio-based polyamide honeycomb panel (total height 22.4 mm) has a good appearance of the skin, a compression strength of 13.8 MPa, but a lower peel strength of only 25 N.mm / mm, and a bending stiffness of 1.55 x 10 8 N.mm 2 .

[0115] Comparative Example 6

[0116] The same as Example 2, except that the composite adhesive layer and the honeycomb core are limited to a height of 18 mm to form the bio-based polyamide honeycomb panel.

[0117] The obtained bio-based polyamide honeycomb panel (total height 19.1 mm) has a good appearance of the skin, a peel strength of 125 N.mm / mm, and a bending stiffness of 1.44 x 10 8 N.mm 2 but the compression strength decreases to 8.5 MPa.

[0118] Comparative Example 7

[0119] The same as Example 2, except that the composite adhesive layer and the honeycomb core are not limited to a height.

[0120] The obtained bio-based polyamide honeycomb panel (total height 22.4 mm) has a good appearance of the skin, a compression strength of 13.8 MPa, but a lower peel strength of only 25 N.mm / mm, and a bending stiffness of 1.55 x 10 8 N.mm 2 .

[0121] The above examples and comparative examples only illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A bio-based polyamide honeycomb panel, characterized in that, The honeycomb panel comprises, from top to bottom, an upper skin, a first resin bonding layer, a first composite bonding layer, a honeycomb core, a second composite bonding layer, a second resin bonding layer and a lower skin, and the honeycomb core is processed from a continuous fiber reinforced bio-based polyamide composite material.

2. The bio-based polyamide honeycomb panel according to claim 1, characterized in that, The first composite bonding layer, the second composite bonding layer, the upper skin and the lower skin are all processed from a continuous fiber reinforced bio-based polyamide composite material.

3. The bio-based polyamide honeycomb panel according to claim 1 or 2, characterized in that, The bio-based polyamide is one or a combination of 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 and bio-based polyamide PA5T / 66.

4. The bio-based polyamide honeycomb panel according to claim 1, wherein, The material of the first resin bonding layer and the second resin bonding layer comprises one or a combination of PA hot melt adhesive, polyurethane adhesive, epoxy adhesive, acrylic resin, polyolefin resin, EVA resin and modified resin thereof.

5. The bio-based polyamide honeycomb panel according to claim 1, wherein, The thickness d1 of the first composite bonding layer and the thickness d2 of the second composite bonding layer are both 0.1-0.3 mm.

6. The bio-based polyamide honeycomb panel according to claim 1, wherein, The thickness d3 of the first resin bonding layer and the thickness d4 of the second resin bonding layer are both 0.05-1 mm.

7. The bio-based polyamide honeycomb panel according to claim 1, wherein, The thickness d5 of the upper skin and the thickness d6 of the lower skin are both 0.2-5 mm.

8. The bio-based polyamide honeycomb panel according to claim 1, wherein, The height d7 of the honeycomb core is 5-150 mm.

9. The bio-based polyamide honeycomb panel according to claim 1, wherein, The wall thickness of the honeycomb core is 0.2-3 mm.

10. The bio-based polyamide honeycomb panel according to claim 1, wherein, The density of the honeycomb core is 60 to 300 g / cm 3 .

11. The bio-based polyamide honeycomb panel according to any one of claims 5-8, characterized in that, The height of the bio-based polyamide honeycomb panel is not less than (d1+d2+d3+d4+d5+d6+d7-3) mm and not more than (d1+d2+d3+d4+d5+d6+d7-0.5) mm.

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