High-elasticity moldable bamboo-cork laminated board and preparation method thereof

Abstract

The invention discloses a high-elasticity moldable bamboo-cork laminated board and a preparation method thereof. The laminated board is composed of a bamboo skin prepared through high-frequency directional pressing, a cork core, an intelligent glue layer containing a pH response type microcapsule curing agent and a functional coating containing nano cerium oxide and chitosan quaternary ammonium salt. The preparation method comprises the steps of high-frequency directional pressing and slicing of the bamboo chips, prepressing of the cork, application of the intelligent adhesive, gradient hot pressing and coating of the functional coating. By means of the high-frequency directional bamboo board pressing technology, the pH response type microcapsule curing agent and the functional composite coating and in cooperation with the three specific components, the bamboo-wood interface stress matching problem is systematically solved, the fatigue resistance and environmental stability of the material are remarkably improved, the material is endowed with the multifunctional surface characteristics of antibiosis, abrasion resistance, ultraviolet resistance and the like, the comprehensive performance is excellent, and the application prospect is wide. The material is suitable for the fields of high-end bags, automotive interiors and the like, and is an innovative environment-friendly material which replaces plastic with bamboo and surpasses the performance of plastic.

Description

Technical Field

[0001] This invention belongs to the field of environmentally friendly and biodegradable composite materials technology, specifically relating to a highly elastic moldable bamboo-cork laminate and its preparation method. Background Technology

[0002] Both bamboo and cork are high-quality natural renewable resources. Bamboo is hard and has a beautiful texture, but it is brittle and has poor plasticity; cork is elastic and compressible, but has low surface strength. Existing composite technologies generally suffer from problems such as poor bonding, molding cracking, and loss of elasticity.

[0003] Existing patent CN2487526Y proposes a bamboo-wood composite structure, but it fails to address the stress matching issue between the cork and bamboo veneer during the molding process. This patent employs a thick wood board layer (60-75% thickness) covered with thin bamboo mats on both sides, with the bamboo veneer thickness generally exceeding 1mm, making it prone to cracking during molding. Furthermore, it uses phenolic resin adhesive with a high curing temperature (80-120℃), exacerbating the difference in thermal expansion coefficients between bamboo and cork (the transverse thermal expansion coefficient of bamboo is 22.30 × 10⁻⁶). -6 / ℃, cork is only 0.3×10 -5 The internal stress generated by the difference of 7 times or more at ℃; in addition, phenolic resin adhesives contain formaldehyde, which does not meet environmental protection requirements.

[0004] Existing bamboo veneer processing technologies primarily focus on decorative slicing of thin bamboo, but lack precision in thickness control and do not address composite processes with cork. While cork processing has mature techniques, it has not formed a synergistic reinforcement system with bamboo. The core deficiency of existing technologies lies in: Both excessively thick and excessively thin bamboo skin affect the composite performance: if it is too thick, it will easily crack during molding; if it is too thin, it will lose its decorative properties. Imbalance between cork layer thickness and elasticity: too thin and the cushioning is insufficient; too thick and the structure is loose. Mismatch between adhesive selection and process: Traditional adhesives are prone to delamination under gradient hot pressing, failing to achieve "tight adhesion without delamination"; Differences in thermal expansion coefficients are not effectively controlled: Bamboo's transverse thermal expansion coefficient is 22.30 × 10⁻⁶. -6 / ℃, cork is only 0.3×10 -5 The temperature difference was more than 7 times, which caused the interface to crack.

[0005] Therefore, developing a bamboo-cork laminate preparation technology with clear process parameters, formula data, and structural design has significant innovative value and industrial application prospects. Summary of the Invention

[0006] This invention aims to overcome the shortcomings of existing technologies and provide a highly elastic moldable bamboo-cork laminate and its preparation method. By introducing high-frequency directional pressing bamboo pretreatment technology, pH-responsive microcapsule curing agent and functional post-treatment composite coating, the material is not only highly elastic, strongly adhesive and moldable, but also further endowed with excellent fatigue resistance, environmental stress adaptability and antibacterial and wear-resistant surface, expanding its application in high-end consumer products and special interior decoration fields.

[0007] Technical solution: A highly elastic moldable bamboo-cork laminate, comprising a natural sliced ​​bamboo veneer veneer layer with a thickness of 0.5±0.05mm, a cork core layer with a thickness of 1.0±0.1mm, a pH-responsive microcapsule curing adhesive layer located between the two, and a functional composite coating on the surface; the bamboo veneer veneer layer is derived from gradient density bamboo board prepared by high-frequency directional pressing process; the pH-responsive microcapsule curing adhesive layer contains a pH-responsive microcapsule curing agent; the functional composite coating contains nano-cerium oxide and chitosan quaternary ammonium salt.

[0008] Preferably, the high-frequency directional pressing process parameters are: high frequency 8-15MHz, pressure along the bamboo fiber direction 2.5±0.3MPa, constraint pressure perpendicular to the fiber direction 0.8±0.1MPa, temperature 135℃±3℃, and time 8-12 minutes; the resulting bamboo core layer density is 800-850 kg / m³. 3 Surface density 950-1000 kg / m³ 3 .

[0009] Preferably, the adhesive used in the pH-responsive microcapsule curing layer comprises 100 parts by weight of isocyanate adhesive, 15-20 parts of tackifying resin, 5-8 parts of nano-silica, 0.3-0.5 parts of accelerator, and 3-5 parts of pH-responsive microcapsule curing agent; the microcapsule wall material is a gelatin-gum arabic composite cohesive wall material, and the core material is a latent curing agent such as dicyandiamide, organic hydrazide, or micronized amine; the microcapsules rupture and release the core material in an environment with a pH value of 4.5-5.5.

[0010] Preferably, the adhesive further comprises 2-4 parts of cork micropowder modified with a silane coupling agent and 0.5-1.5 parts of graphene oxide dispersion.

[0011] Preferably, the functional composite coating has a thickness of 0.05-0.1 mm, contains 0.5-2.0 wt% nano-cerium oxide and 1.0-3.0 wt% chitosan quaternary ammonium salt, and further contains 0.3-0.8 wt% quaternary ammonium salt modified nanocellulose and 0.1-0.3 wt% rare earth organic complex light-converting agent, wherein the rare earth organic complex light-converting agent is a β-diketone or carboxylic acid organic complex of europium(III), terbium(III) or samarium(III).

[0012] A method for preparing highly elastic moldable bamboo-cork laminate includes the following steps: S1. Raw material pretreatment: Bamboo strips are made into gradient density bamboo boards by high-frequency directional pressing, then the bamboo skin is sliced ​​and plasma treated; Cork particles are pre-pressed and surface treated. S2. Apply adhesive: Apply an adhesive containing a pH-responsive microcapsule curing agent to the surface of bamboo veneer or cork. S3, Gradient Hot Pressing: Performs pre-pressing, main pressing, and gradient hot pressing in the cooling section; S4. Surface treatment: After hot pressing, a functional composite coating containing nano-cerium oxide and chitosan quaternary ammonium salt is applied to the surface of the sheet and cured.

[0013] Preferably, before pressing the bamboo strips in step S1, a compound solution of 1-3% sisal fiber chopped pulp and 0.5-1% sodium lignosulfonate is sprayed between the bamboo strips.

[0014] Preferably, the gradient hot pressing parameters are as follows: pre-pressing section 80-100℃ / 0.5-1.0MPa / 5min; main pressure section 130-145℃ / 1.5-2.0MPa, holding time 2.5-3.0min; cooling section from 145℃ to 60℃, pressure from 2.0MPa to 0.2MPa, time 10min.

[0015] Preferably, its performance meets the following requirements: springback rate after molding ≥85%, springback retention rate after 10,000 bending fatigue tests ≥90%, adhesive strength ≥1.2MPa, surface antibacterial rate ≥99%, and no delamination after 50 cycles of cold and heat (-20℃~70℃) and 10 cycles of damp heat (40℃, 90%RH).

[0016] Preferably, the cork core layer material is derived from the bark of the cork oak tree and is FSC / LEED certified; the laminate as a whole complies with the T / CNFPIA3002-2018 formaldehyde-free standard.

[0017] The beneficial effects of this invention are as follows: 1. Before pressing the bamboo strips, spray a compound solution of 1-3% chopped sisal fiber pulp (fiber length 1-3mm) and 0.5-1% sodium lignosulfonate (by weight of bamboo strips) between the bamboo strips. The sisal fiber acts as a reinforcing rib, interweaving with the bamboo fiber under high-frequency directional pressing, further improving the toughness of the bamboo board; sodium lignosulfonate acts as a natural dispersant and adhesion promoter, improving the distribution of sisal fiber and the interfacial bonding with bamboo.

[0018] 2. In the adhesive system, add 2-4 parts of cork micropowder (200-400 mesh) surface-modified with silane coupling agent KH-550 and 0.5-1.5 parts of graphene oxide (GO) dispersion (5% solid content). Cork micropowder can fill interfacial micro-defects and improve the damping performance of the adhesive layer; graphene oxide can form a two-dimensional thermally conductive network, promote uniform heat transfer during hot pressing, and react with PMDI to enhance the mechanical strength of the adhesive layer. The two work synergistically to optimize stress distribution and curing uniformity.

[0019] 3. In functional composite coatings, 0.3-0.8 wt% of quaternary ammonium salt modified nanocellulose (CNC-QA) and 0.1-0.3 wt% of rare earth organic complex light-converting agent are added. CNC-QA can significantly enhance the mechanical strength and density of the coating and contribute additional antibacterial points; the rare earth organic complex light-converting agent can convert ultraviolet light into visible light that is harmless to the bamboo texture, and in synergy with nano-cerium oxide, achieve long-term protection of the natural color of bamboo.

[0020] 4. Through the synergy of high-frequency directional pressing and pH-responsive microcapsule curing adhesive layers, the composite material possesses the ability to actively adapt to and dissipate internal stress, significantly improving fatigue resistance and hygrothermal stability. The functional composite coating integrates antibacterial properties (≥99%), wear resistance, and UV shielding, making it particularly suitable for applications with stringent hygiene and aesthetic requirements, such as bags, automotive interiors, and children's furniture. From bamboo directional reinforcement and intelligent interface response to surface functionalization, a complete performance enhancement system has been constructed, achieving not only formaldehyde-free environmental protection but also surpassing traditional plastics and ordinary composite materials in terms of mechanical, durability, and functional properties. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a highly elastic moldable bamboo-cork laminate structure according to the present invention.

[0022] Figure 2 This is a temperature-pressure curve diagram of the gradient hot pressing process of the present invention.

[0023] Figure 3 SEM images comparing bamboo skin surfaces before and after plasma treatment.

[0024] Figure 4 The curves show the effect of nano-SiO2 particle size on interfacial bonding force.

[0025] Figure 5 This is a physical image of a highly elastic moldable bamboo-cork laminate according to the present invention. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] 1. Raw materials and proportions Bamboo veneer layer: made from gradient density bamboo board prepared by high-frequency directional pressing, with a thickness of 0.5mm.

[0028] Cork core layer: made of cork oak cork granules, pre-pressed, 1.0mm thick.

[0029] Adhesive formulation for pH-responsive microcapsule curing adhesive layer: PMDI (isocyanate adhesive): 100 parts by weight Tackifying resin: 18 parts Nano silica: 6 parts Accelerator: 0.4 parts pH-responsive microcapsule curing agent (wall material: gelatin-gum arabic composite coagulating wall material; core material: dicyandiamide; ruptures at pH 5.0): 4 parts KH-550 surface-modified cork micro powder (300 mesh): 3 parts Graphene oxide dispersion (5% solids content): 1.0 part Functional composite coating formulation: Base coating: 100 parts Nano-cerium oxide: 1.2 wt% Chitosan quaternary ammonium salt: 2.0 wt% Quaternary ammonium salt modified nanocellulose (CNC-QA): 0.5 wt% Rare earth organic complex light-converting agent (Europium(III)-thiophenecarboxyltrifluoroacetone complex): 0.2 wt% 2. Preparation method S1 Raw material pretreatment: Soak bamboo strips in a compound solution of 2% sisal fiber chopped pulp and 0.8% sodium lignosulfonate, and drain until the moisture content is about 12%.

[0030] High-frequency directional pressing was performed: frequency 12MHz, pressure 2.5MPa along the bamboo fiber direction, vertical constraint pressure 0.8MPa, temperature 135℃, time 10 minutes. The resulting core layer density was 820 kg / m³. 3 Surface density 970 kg / m³ 3 Gradient density bamboo boards are sliced ​​to obtain bamboo skin.

[0031] Bamboo skin is treated with plasma (500W power, 30s time).

[0032] Cork particles are pre-pressed into boards, and the surface is lightly sanded and cleaned.

[0033] S2 Application: Apply the prepared pH-responsive microcapsule curing adhesive at a rate of 120 g / m³. 2 The coating amount is evenly applied to the inner surface of the plasma-treated bamboo skin.

[0034] S3 Gradient Hot Pressing: Pre-compression section: temperature 90℃, pressure 0.8MPa, time 5 minutes.

[0035] Main pressure section: temperature 138℃, pressure 1.8MPa, pressure holding time 2.8 minutes.

[0036] Cooling section: The temperature is programmed to drop from 145℃ to 60℃, and the pressure is linearly reduced from 2.0MPa to 0.2MPa in 10 minutes.

[0037] S4 Surface Treatment: Apply a functional composite coating to the bamboo veneer surface of the pressed board by roller coating, with the wet film thickness controlled at 0.08mm, and cure at 80℃ for 30 minutes.

[0038] Example 2: 1. Raw materials and proportions Bamboo veneer layer: 0.45mm thick.

[0039] Cork core layer: 0.9mm thick.

[0040] Adhesive formulation for pH-responsive microcapsule curing adhesive layer: Isocyanate adhesive: 100 parts Tackifying resin: 15 parts Nano silica: 5 parts Accelerator: 0.3 parts pH-responsive microcapsule curing agent (core material: organic hydrazide; ruptures at pH 4.5): 3 parts KH-550 modified cork powder: 2 parts Graphene oxide dispersion: 0.5 parts Functional composite coating formulation: Nano-cerium oxide: 0.5 wt% Chitosan quaternary ammonium salt: 1.0 wt% Quaternary ammonium salt modified nanocellulose: 0.3 wt% Rare earth organic complex light-converting agent (terbium(III)-benzoic acid complex): 0.1 wt% 2. Preparation method S1 Raw material pretreatment: Soak bamboo strips in a compound solution of 1% sisal fiber chopped pulp and 0.5% sodium lignosulfonate, and drain until the moisture content is about 12%.

[0041] High-frequency directional pressing was performed: frequency 8MHz, pressure 2.2MPa along the bamboo fiber direction, vertical constraint pressure 0.7MPa, temperature 132℃, and time 12 minutes. A core layer density of 800 kg / m³ was obtained. 3 Surface density 950 kg / m³ 3 Gradient density bamboo boards are sliced ​​to obtain bamboo skin.

[0042] Bamboo skin is treated with plasma (500W power, 30s time).

[0043] Cork particles are pre-pressed into boards, and the surface is lightly sanded and cleaned.

[0044] S2 Application: Apply the prepared pH-responsive microcapsule curing adhesive at a rate of 110 g / m³. 2 The coating amount is evenly applied to the inner surface of the plasma-treated bamboo skin.

[0045] S3 Gradient Hot Pressing: Pre-compression section: temperature 80℃, pressure 0.5MPa, time 5 minutes.

[0046] Main pressure section: temperature 130℃, pressure 1.5MPa, pressure holding time 3.0 minutes.

[0047] Cooling section: The temperature is programmed to drop from 145℃ to 60℃, and the pressure is linearly reduced from 2.0MPa to 0.2MPa in 10 minutes.

[0048] S4 Surface Treatment: Apply a functional composite coating to the bamboo veneer surface of the pressed board by roller coating, with the wet film thickness controlled at 0.05mm, and cure at 80℃ for 30 minutes.

[0049] Example 3: 1. Raw materials and proportions Bamboo veneer layer: 0.55mm thick.

[0050] Cork core layer: 1.1mm thick.

[0051] Adhesive formulation for pH-responsive microcapsule curing adhesive layer: Isocyanate adhesive: 100 parts Tackifying resin: 20 parts Nano silica: 8 parts Accelerator: 0.5 parts pH-responsive microcapsule curing agent (core material: micronized amines; ruptures at pH 5.5): 5 parts KH-550 modified cork powder: 4 parts Graphene oxide dispersion: 1.5 parts Functional composite coating formulation: Nano-cerium oxide: 2.0 wt% Chitosan quaternary ammonium salt: 3.0 wt% Quaternary ammonium salt modified nanocellulose: 0.8 wt% Rare earth organic complex light-converting agent (Samarium(III)-acetylacetone complex): 0.3 wt% 2. Preparation method S1 Raw material pretreatment: Soak bamboo strips in a compound solution of 3% sisal fiber chopped pulp and 1% sodium lignosulfonate, and drain until the moisture content is about 12%.

[0052] High-frequency directional pressing was performed: frequency 15MHz, pressure 2.8MPa along the bamboo fiber direction, vertical constraint pressure 0.9MPa, temperature 138℃, time 8 minutes. A core layer density of 850 kg / m³ was obtained. 3 Surface density 1000 kg / m³ 3 Gradient density bamboo boards are sliced ​​to obtain bamboo skin.

[0053] Bamboo skin is treated with plasma (500W power, 30s time).

[0054] Cork particles are pre-pressed into boards, and the surface is lightly sanded and cleaned.

[0055] S2 Application: Apply the prepared pH-responsive microcapsule curing adhesive at a rate of 130 g / m³. 2 The coating amount is evenly applied to the inner surface of the plasma-treated bamboo skin.

[0056] S3 Gradient Hot Pressing: Pre-compression section: temperature 100℃, pressure 1.0MPa, time 5 minutes.

[0057] Main pressure section: temperature 145℃, pressure 2.0MPa, pressure holding time 2.5 minutes.

[0058] Cooling section: The temperature is programmed to drop from 145℃ to 60℃, and the pressure is linearly reduced from 2.0MPa to 0.2MPa in 10 minutes.

[0059] S4 Surface Treatment: Apply a functional composite coating to the bamboo veneer surface of the pressed board by roller coating, with the wet film thickness controlled at 0.10mm, and cure at 80℃ for 30 minutes.

[0060] Comparative Example 1: Same as Example 1, except that ordinary bamboo veneer (uniform density, approximately 700 kg / m³) without high-frequency pressing is used. 3The adhesive used is a common isocyanate adhesive (without pH-responsive microcapsule curing agent, cork micropowder, and graphene oxide); there is no functional composite coating, only a common UV varnish.

[0061] Comparative Example 2: Similar to Example 1, the difference is that the bamboo strips are not impregnated with sisal fiber pulp and subjected to high-frequency pressing; ordinary bamboo veneer is used directly.

[0062] Comparative Example 3: Same as Example 1, except that the adhesive used for the pH-responsive microcapsule curing layer does not contain a pH-responsive microcapsule curing agent.

[0063] Comparative Example 4: Same as Example 1, except that the board is not coated with a functional composite coating after hot pressing.

[0064] Comparative Example 5: Same as Example 1, except that the adhesive used for the pH-responsive microcapsule curing layer does not contain cork micropowder and graphene oxide.

[0065] Comparative Example 6: Same as Example 1, except that the functional composite coating contains only nano-cerium oxide and chitosan quaternary ammonium salt, without adding quaternary ammonium salt modified nanocellulose (CNC-QA) and rare earth organic complex light conversion agent.

[0066] The statistical results of the experiment are shown in the table below: Table 1. Chelation rate and average particle size of comparative examples and embodiments Test Results: Compared with traditional laminates (Comparative Example 1) that do not employ the core technology of this invention, the products of this invention achieve a comprehensive performance leap. In terms of elasticity and durability, the springback rate after molding increased from 68% to 85-90%, an increase of over 20%, and the springback retention rate after 10,000 bending fatigue cycles increased from 72% to 90-94%, indicating that the product has excellent shape memory ability and fatigue resistance. In terms of bonding strength, the adhesive strength increased from 0.8 MPa to 1.21-1.45 MPa, an increase of over 50%, ensuring the long-term stability of the interlayer structure. In terms of functionality and environmental protection, it went from having no antibacterial function to achieving a surface antibacterial rate of over 99%, and the formaldehyde emission reached an excellent environmental protection level of "not detected". In terms of environmental stability, it went from "slight delamination and surface loss of gloss" after hot / damp heat cycling to complete "no delamination, no blistering, and no surface cracking", demonstrating excellent environmental adaptability and durability. Compared with Comparative Example 2, Example 1 verified the necessity of high-frequency directional pressing and sisal fiber reinforcement. The absence of this feature in Comparative Example 2 led to a decline in the performance of the bamboo base layer. The molding rebound rate (78%) and fatigue resistance (81%) were significantly lower than those of Example 2 (88%, 92%). Furthermore, the bamboo skin was prone to microcracks when bent, proving that this process plays a decisive role in forming a gradient density structure and improving the toughness and fatigue resistance of bamboo. Compared with Comparative Example 3, Example 1 verified the necessity of pH-responsive microcapsule curing adhesive layer. Although the initial adhesive strength (1.30 MPa) of Comparative Example 3, which lacked microcapsules, was similar to that of Example 3 (1.35 MPa), the strength decreased to 0.95 MPa after humid heat cycling, and edge blistering occurred. This proves that the adhesive layer is not a simple adhesive medium, and its pH-responsive curing agent release mechanism is crucial for resisting the stress of humid heat environment and maintaining long-term adhesive stability. Compared with Comparative Example 4, Example 1 verified the necessity of the functional composite coating. The absence of the coating in Comparative Example 4 resulted in the product losing its surface functionality, with an antibacterial rate below 10%, abrasion resistance reduced to one-third, and extremely poor UV aging resistance (yellowing and loss of gloss after 300 hours). This demonstrates that the coating is key to achieving the additional functions of antibacterial, abrasion-resistant, and weather-resistant properties of the product surface. Compared with Comparative Example 5, Example 1 verified the necessity of the interface-reinforcing components (cork micropowder and graphene oxide) in the adhesive. The absence of these two components in Comparative Example 5 led to a decrease in adhesive strength to 1.15 MPa, reduced thermal conductivity during hot pressing, and weakened adhesive layer damping performance. This demonstrates that they have a clear synergistic reinforcing effect on optimizing interfacial stress, improving curing uniformity, and final adhesive strength.Compared with Comparative Example 6, Example 1 verified the necessity of the reinforcing components (quaternary ammonium salt modified nanocellulose and rare earth brightening agent) in the coating. The absence of these two components in Comparative Example 6 resulted in a decrease in coating hardness, antibacterial durability (down to approximately 95% after washing), and UV protection durability (texture whitening after 500 hours), demonstrating their significant contribution to improving the coating's mechanical strength, density, and long-term protection of bamboo color. In summary, this invention, through a three-pronged technological innovation—"high-frequency directional pressing to prepare gradient density bamboo veneer," "pH-responsive microcapsule curing adhesive layer," and "multifunctional composite coating"—successfully prepared a novel bamboo-cork laminate with high elasticity, high durability, strong adhesion, antibacterial and weather-resistant properties, and environmental friendliness. The systematic comparative experimental data strongly confirms that the above technical features support and synergistically work together to form a complete and inseparable advanced technical solution; none of them can be omitted, ultimately resulting in a product with comprehensive performance far exceeding existing technologies and achieving unexpected technical effects.

[0067] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A high-elasticity moldable bamboo-cork laminate, characterized in that, The bamboo veneer facing layer has a thickness of 0.5±0.05 mm, the softwood core layer has a thickness of 1.0±0.1 mm, the pH-responsive microcapsule curing adhesive layer is located between the bamboo veneer facing layer and the softwood core layer, and the functional composite coating layer is coated on the surface.

2. The high-elasticity moldable bamboo-cork laminated board according to claim 1, characterized in that, The high-frequency directional pressing process parameters are: high-frequency frequency 8-15 MHz, pressure along the direction of bamboo fiber 2.5±0.3 MPa, constraint pressure perpendicular to the direction of fiber 0.8±0.1 MPa, temperature 135℃±3℃, time 8-12 minutes; the obtained bamboo board core layer density is 800-850 kg / m 3 , surface layer density is 950-1000 kg / m 3 .

3. The high flexibility moldable bamboo-cork laminated board according to claim 1, characterized in that, The adhesive used in the pH-responsive microcapsule curing adhesive layer comprises 100 parts by weight of isocyanate adhesive, 15-20 parts of tackifying resin, 5-8 parts of nano-silicon dioxide, 0.3-0.5 parts of accelerator, and 3-5 parts of pH-responsive microcapsule curing agent.

4. The high flexibility mouldable bamboo-cork laminated board according to claim 3, characterized in that, The microcapsule wall material is a gelatin-arabic gum composite coacervate wall material, and the core material is dicyandiamide, organic hydrazide or micronized amine latent curing agent.

5. The high-elasticity moldable bamboo-cork laminate board according to claim 1, wherein, The adhesive further comprises 2-4 parts of softwood micro-powder surface-modified by a silane coupling agent and 0.5-1.5 parts of graphene oxide dispersion liquid.

6. A method of making a high-elasticity moldable bamboo-cork laminate according to any one of claims 1-5, characterized in that, The functional composite coating layer has a thickness of 0.05-0.1 mm, and comprises 0.5-2.0 wt% of nano-cerium oxide and 1.0-3.0 wt% of chitosan quaternary ammonium salt, and further comprises 0.3-0.8 wt% of quaternary ammonium salt-modified nano-cellulose and 0.1-0.3 wt% of rare earth organic complex light conversion agent, wherein the rare earth organic complex light conversion agent is a β-diketone or carboxylic acid organic complex of europium (III), terbium (III) or samarium (III). The method comprises the following steps: S1, raw material pretreatment: bamboo chips are subjected to high-frequency directional pressing to form a gradient density bamboo board, and then the bamboo veneer is planed and subjected to plasma treatment; softwood particles are pre-pressed and surface-treated; S2, sizing: an adhesive comprising a pH-responsive microcapsule curing agent is coated on the surface of the bamboo veneer or softwood; S3, gradient hot pressing: pre-pressing, main pressing and cooling section gradient hot pressing are performed; 7. The method of claim 6, wherein the method further comprises the step of: S4, surface treatment: after hot pressing, a functional composite coating layer comprising nano-cerium oxide and chitosan quaternary ammonium salt is coated on the surface of the board and cured. ​ 8. The method for preparing a highly elastic moldable bamboo-cork laminate according to claim 6, characterized in that, Before the bamboo chips are pressed in step S1, 1-3% of short-cut sisal fiber slurry and 0.5-1% of sodium lignosulfonate complex solution are sprayed between the bamboo chips. The gradient hot pressing parameters are as follows: pre-pressing section 80-100℃ / 0.5-1.0MPa / 5min; main pressing section 130-145℃ / 1.5-2.0MPa, pressure holding time 2.5-3.0min; cooling section temperature drop from 145℃ to 60℃, pressure drop from 2.0MPa to 0.2MPa, time 10min.

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