A lattice reinforced foam curved-surface sandwich panel and a production process thereof

Abstract

The present application relates to the technical field of composite sandwich structure, and particularly relates to a lattice reinforced foam curved sandwich panel capable of being recycled as a whole and a production process thereof, which comprises a core material, an upper panel, a lower panel and a lattice reinforced body, the upper panel and the lower panel are respectively arranged on the upper and lower surfaces of the core material, the lattice reinforced body is arranged inside the core material, and the upper panel and the lower panel of the lattice reinforced body are connected. Through vacuum infusion process integrated curing forming, the upper panel, the lattice and the foam core material form a synergistic stress structure, which significantly improves the bending stiffness, interface bonding performance and overall carrying capacity of the structure. The present application adopts a full thermoplastic material system, can realize the overall disassembly, classified recycling and reuse of the structure, fundamentally solves the technical problems that the traditional thermosetting sandwich structure is difficult to recycle and easy to cause environmental pollution, and is suitable for the fields of wind power blades, rail transit, ships and building curved components, and has the dual advantages of high mechanical performance and green sustainability.

Description

Technical Field

[0001] This invention relates to the field of composite sandwich structure technology, specifically to a recyclable lattice-reinforced foam curved sandwich panel and its manufacturing process. Background Technology

[0002] The composite sandwich structures widely used in existing engineering projects mostly use polyurethane (PU) foam or polyvinyl chloride (PVC) foam as the core material, combined with fiber-reinforced thermosetting resin panels. Although this type of sandwich structure has certain specific strength and specific stiffness, it still has the following shortcomings: On the one hand, the core material and panels of traditional sandwich structures are mostly thermosetting materials, which are difficult to disassemble and recycle, and can only be disposed of through landfill or incineration, resulting in resource waste and environmental pollution, which does not meet the requirements of green and low-carbon development; on the other hand, the core material and the panel are only bonded by interface adhesive, which has low bonding strength. Under bending and impact loads, the core material is prone to shear failure and the face-core interface is prone to peeling, resulting in insufficient structural load-bearing capacity and service reliability, making it difficult to adapt to the use requirements of complex curved surface components.

[0003] Currently, there are related technologies for improving composite sandwich structures, such as Chinese invention patent application CN202010161715.0 "Spatial Lattice Web Reinforced Composite Sandwich Structure and Preparation Method", which improves the load-bearing capacity abrupt change and failure mode of the sandwich structure by cutting along the thickness direction of the core material, filling the cut position with fiber cloth and introducing resin. Chinese invention patent application CN202511866036.2 "A PLA Material Curved Sandwich Panel Based on 3D Printing and Its Modeling, Optimization and Protective Application", which improves the curved surface fit, impact resistance and energy absorption performance of the curved sandwich panel through tetrahedral mesh topology core layer and FDM integrated molding process. Chinese invention patent application CN202510440874.7 "A Preparation Method of Reinforced PET Material for Wind Turbine Blades", which improves the tensile, compressive and shear properties of PET sandwich material by drilling through holes and grooves in PET sandwich panels, inserting fiberglass yarn in the holes and fiberglass sheets in the grooves.

[0004] However, the above solutions still have certain shortcomings: the spatial lattice web-reinforced composite sandwich structure mainly focuses on improving the arrangement of the lattice web, the sudden change in load-bearing capacity and the failure mode. It usually still relies on fiber cloth filling and resin curing molding, and fails to solve the problem of integral injection molding of the all-thermoplastic material system in large-size curved sandwich components and the overall recycling after decommissioning; the curved sandwich panels based on 3D printed PLA materials mainly focus on additive manufacturing, structural modeling and small protective equipment applications, and are difficult to be directly applied to the vacuum injection production of large-size curved composite sandwich components such as wind turbine blades, rail transit, and ships; although the reinforced PET material for wind turbine blades improves the mechanical properties of PET sheets through Z-direction yarn threading and transverse and longitudinal grooves, its technical focus is on the reinforcement of PET flat sheets or sheets, and it has not formed a recyclable curved sandwich panel structure and production process that adapts the radial and circumferential lattices to the curved surface contour.

[0005] Therefore, for curved sandwich structures using thermoplastic foam core materials and thermoplastic fiber reinforced panels, how to prefabricate continuous injectable radial and circumferential lattice channels in the curved core material, so that the thermoplastic resin can be fully impregnated between the interfaces of the curved lattice, the panel and the core material, and simultaneously achieve curved bonding, lattice connection, interface reinforcement and recyclability after decommissioning during a single vacuum injection curing process, remains a technical problem that has not yet been effectively solved by existing technologies.

[0006] In view of the above-mentioned defects, the inventors of this invention have finally obtained this invention after a long period of research and practice. Summary of the Invention

[0007] The purpose of this invention is to solve the technical problems of existing composite sandwich structures, such as non-recyclable materials, poor interfacial bonding performance, insufficient bending stiffness, and weak adaptability to curved surfaces, and to provide a recyclable lattice-reinforced foam curved sandwich panel and its production process.

[0008] To achieve the above objectives, this invention discloses a recyclable lattice-reinforced foam curved sandwich panel, comprising a core material, an upper panel, a lower panel, and a lattice reinforcement. The upper panel and the lower panel are respectively disposed on the upper and lower surfaces of the core material, and the lattice reinforcement is disposed inside the core material and connected to the upper and lower panels. The core material is a thermoplastic foam curved core material, and the upper panel, lower panel, and lattice reinforcement are all formed by impregnation and curing with a thermoplastic resin system, so that the core material, upper panel, lower panel, and lattice reinforcement constitute an integrated curved sandwich structure that is recyclable as a whole.

[0009] The core material is an integrally formed continuous curved surface structure. The curved surface shape of the core material is a single circular arc surface. The lattice reinforcement includes radial lattice and circumferential lattice. The radial lattice penetrates the core material along the thickness direction, and the circumferential lattice is distributed radially within the curved surface of the core material.

[0010] The radial lattice includes single-layer, multi-layer vertical, and trapezoidal longitudinal lattices that penetrate along the thickness direction of the core material, forming an arrangement that is orthogonal to and staggered with the single-layer and double-layer circumferential lattice.

[0011] The core material is thermoplastic closed-cell PU foam or PET foam.

[0012] The thermoplastic resin is polymethyl methacrylate or Elium® thermoplastic resin.

[0013] The sandwich panel as a whole can be disassembled by at least one of chemical dissolution, pyrolysis or mechanical separation.

[0014] This invention also discloses a manufacturing process for the above-mentioned recyclable lattice-reinforced foam curved sandwich panel, comprising the following steps:

[0015] S1, Mold processing: Process curved surface molds according to the target curved surface component lines. The mold surface is flat and smooth, and is treated with a release agent.

[0016] S2, Core material pretreatment: The core material is cut into a preset arc-shaped core material by CNC milling;

[0017] S3, wrap the cut core material with alkali-free glass fiber cloth, and use vacuum induction molding process to prepare the internal lattice web, so that the lattice and the core material form an integrated structure;

[0018] S4, Panel laying and stacking assembly: A pre-cut thermoplastic fiberglass cloth is laid at the bottom of the mold as the lower panel. The assembled curved core material is accurately placed on the lower panel according to the positioning requirements. Then, an upper layer of thermoplastic fiberglass cloth is laid on top of the core material. Subsequently, a guide net and a vacuum bag are laid on top of the panel to prepare for vacuum infusion.

[0019] S5, Vacuum Infusion Curing: After the sealing system is evacuated, it is introduced into the thermoplastic resin system. After curing, it is naturally cooled to room temperature and demolded. Excess edges are removed by CNC cutting to obtain a lattice-reinforced PET foam curved sandwich panel that can be recycled as a whole.

[0020] In step S2, a groove 2 mm wide and 3 mm deep is reserved on the side of the curved core material.

[0021] In step S4, the laying tension of both the upper and lower panels is 7 N / m.

[0022] In step S5, the vacuum is drawn to -0.095 MPa, the curing temperature is 22℃, and the curing time is 8 hours.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. This invention differs from sandwich structures that improve load-bearing capacity solely by setting up spatial lattices. It integrates radial lattices, circumferential lattices, curved core materials, and upper and lower panels into a fully thermoplastic resin vacuum infusion system, thus avoiding the problem of non-recyclability of traditional thermosetting resins.

[0025] 2. This invention differs from 3D printed PLA curved sandwich structures by using curved foam core material preforming and vacuum infusion process, making it more suitable for larger components such as wind turbine blades, rail transit, ships and vessels, and building curved components;

[0026] 3. The present invention forms a continuous flow path through lateral grooves and grid channels, enabling thermoplastic resin to simultaneously impregnate the panel fiber cloth and the grid fiber cloth, thus solving the technical difficulties of insufficient impregnation in curved grid areas and unreliable connection at the grid ends.

[0027] 4. This invention forms a continuous thermoplastic resin phase of panel-lattice-core material and an interlaced force transmission path, which improves bending stiffness, shear performance and interface stability, while enabling decommissioned structures to be recycled as a whole or reused in categories through crushing, heating and softening or reprocessing, achieving the effect of both mechanical enhancement and green recycling. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a recyclable lattice-reinforced foam curved sandwich panel according to Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of a recyclable lattice-reinforced foam curved sandwich panel according to Embodiment 2 of the present invention;

[0030] Figure 3 This is a schematic diagram of a recyclable lattice-reinforced foam curved sandwich panel according to Embodiment 3 of the present invention;

[0031] Figure 4 This is a schematic diagram of a recyclable lattice-reinforced foam curved sandwich panel according to Embodiment 4 of the present invention;

[0032] Figure 5 This is a schematic diagram of vacuum introduction for a recyclable lattice-reinforced foam curved sandwich panel according to Embodiment 5 of the present invention.

[0033] The numbers in the image represent:

[0034] 1-Core material; 2-Upper panel; 3-Lower panel; 4-Radial lattice; 5-Circular lattice; 6-Mold; 7-Guide net; 8-Vacuum inlet device. Detailed Implementation

[0035] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment provides a recyclable lattice-reinforced PET foam curved sandwich panel, including a core material, a panel, and a lattice; the core material is an integrally formed curved thermoplastic foam between the upper and lower panels, the panel is an upper and lower thermoplastic fiber reinforced composite material, and the lattice is a three-dimensional orthogonal lattice reinforcement.

[0038] In this embodiment, a curved PET foam core material with a density of 100 kg / m³ is first prepared. 3 Using closed-cell PET foam as raw material, it is CNC milled into a pre-set single-arc curved surface. The specific dimensional parameters of the PET foam core material are: core material thickness 25 mm, width 400 mm, radius of curvature 580 mm, and curvature angle 90°. Then, according to the spacing and number of grids, the curved foam core material is cut into 4 parts along the circumferential direction and 4 parts radially, for a total of 16 grids. The curvature angle of adjacent radial grids is 22.5°, for a total of 3 radial grids. The spacing between adjacent circumferential grids is 100 mm, for a total of 3 circumferential grids. At the same time, a groove is reserved on the side of the foam core material (along the direction of the curved surface extension), with the specific dimensions of the groove being 2 mm wide and 3 mm deep.

[0039] Next, the lattice reinforcement is prepared. First, 16 foam core materials are sprayed with adhesive. Then, a layer of ±45° glass fiber cloth is wrapped around the foam blocks to make the fibers fit tightly with the curved core material. After vacuum injection molding, the internal lattice web will be formed.

[0040] Subsequently, three pre-cut layers of fiber cloth are laid at the bottom of the processed mold, with the layup angle from bottom to top being (0, 90°) / (±45°) / (0, 90°). Then, the wrapped curved core material is placed on the base cloth as required, followed by another three layers of fiber cloth, with the layup angle from bottom to top being (0, 90°) / (±45°) / (0, 90°). A flow guide net is then laid, and the entire structure is formed using a vacuum infusion process. The final panel layup is (0, 90°) / (±45°) / (0, 90°) / (±45°), which allows for optimized fiber orientation based on the direction of stress, thereby improving overall load-bearing efficiency and anti-delamination capabilities.

[0041] The two ends of the lattice are in close contact with the upper and lower thermoplastic fiberglass panels, forming a synergistic force-bearing system of "panel-lattice-core material", which effectively improves the bending stiffness, shear strength and impact resistance of the sandwich panel.

[0042] Example 2

[0043] like Figure 2As shown, this embodiment provides a recyclable lattice-reinforced PET foam curved sandwich panel, which has a structure that is basically the same as that of Embodiment 1. The difference is that the lattice is a single-layer trapezoidal lattice reinforcement, and the structure, materials and connection methods of the remaining core materials and panels are the same as those of Embodiment 1.

[0044] In this embodiment, the single-layer trapezoidal longitudinal lattice reinforcement adopts a single-layer arrangement and is made of high-modulus untwisted roving glass fiber. A certain number of foam blocks are wrapped with a layer of ±45° glass fiber cloth. After vacuum injection molding, an internal trapezoidal lattice web is formed, which adapts to the arc-shaped contour of the curved PET foam core material. Unlike the vertical orthogonal lattice in Embodiment 1, this embodiment uses a diagonal cutting method to form a single-layer trapezoidal radial lattice during the circumferential cutting process. Specifically, four trapezoidal units are set along the arc length of the curved surface to form five circumferential lattices. Adjacent diagonal cuts are arranged alternately, and the angle between the diagonal cuts and the horizontal direction of the core material is 45°, so that a continuous trapezoidal lattice channel is formed between adjacent foam core blocks. At the same time, the curvature angle of adjacent radial lattices is 22.5°, with a total of three radial lattices.

[0045] The single-layer trapezoidal lattice is in close contact with the upper and lower thermoplastic glass fiber panels at both ends, forming a synergistic force-bearing system of "panel-single-layer trapezoidal lattice-core material", which can effectively improve the bending stiffness, shear performance and face-core interface stability of curved sandwich panels.

[0046] Example 3

[0047] like Figure 3 As shown, this embodiment provides a recyclable lattice-reinforced PET foam curved sandwich panel, including a core material, a panel, and a lattice; the core material is an integrally formed curved thermoplastic foam between the upper and lower panels, the panel is an upper and lower thermoplastic fiber reinforced composite material, and the lattice is a double-layer orthogonal lattice reinforcement.

[0048] In this embodiment, a curved PET foam core material with a density of 100 kg / m³ is first prepared. 3 Using closed-cell PET foam as raw material, it is CNC milled into a pre-set single-arc curved surface. The specific dimensional parameters of the PET foam core material are: core material thickness 50 mm, width 400 mm, radius of curvature 580 mm, and curvature angle 90°. Then, according to the spacing and number of grids, the inside of the curved foam core material (along the direction of the curved surface) is first cut into two layers, each with a core material thickness of 25 mm. Then, the curved foam core material is cut into 4 parts along the circumferential direction and 4 parts radially, for a total of 32. The curvature angle of the adjacent radial grids in the upper and lower layers is 22.5°, for a total of 6 radial grids. The spacing between the adjacent circumferential grids in the upper and lower layers is 100 mm, for a total of 6 circumferential grids. At the same time, a groove is reserved on the side of the foam core material (along the direction of the curved surface), with the specific dimensions of the groove being 2 mm wide and 3 mm deep.

[0049] Next, the lattice reinforcement is prepared. First, 32 foam core materials are sprayed with adhesive. Then, a layer of ±45° glass fiber cloth is wrapped around the foam blocks. Two layers of foam profiles are orthogonally stacked in sequence to make the fibers and curved core materials fit tightly together. After vacuum injection molding, the internal lattice web is formed. The upper and lower lattice layers are completely aligned and arranged vertically orthogonally.

[0050] Subsequently, three pre-cut layers of fiber cloth are laid at the bottom of the processed mold, with the layup angle from bottom to top being (0, 90°) / (±45°) / (0, 90°). Then, the first layer of reinforcement and the second layer of lattice reinforcement are laid in sequence, followed by three more layers of fiber cloth, with the fiber layup angle from bottom to top being (0, 90°) / (±45°) / (0, 90°). Finally, a flow guide net is laid, and the overall molding is completed through a vacuum infusion process. After molding, the panel layup is (0, 90°) / (±45°) / (0, 90°) / (±45°), which can optimize the fiber orientation according to the direction of force, thereby improving the overall load-bearing efficiency and anti-delamination ability.

[0051] The double-layer orthogonal lattice is in close contact with the upper and lower thermoplastic glass fiber panels at both ends, forming a synergistic force-bearing system of "panel-double-layer orthogonal lattice-core material", which significantly improves the axial stiffness, ultimate bearing capacity and buckling resistance of the sandwich panel.

[0052] Example 4

[0053] like Figure 4 As shown, this embodiment provides a recyclable lattice-reinforced PET foam curved sandwich panel, which has a structure that is basically the same as that of embodiment 3. The difference is that the lattice is a double-layer staggered lattice reinforcement, and the structure, materials and connection methods of the other core materials and panels are the same as those of embodiment 3.

[0054] In this embodiment, the double-layer staggered lattice reinforcement is arranged in a double-layer form and made of high-modulus untwisted roving fiberglass. A certain number of foam blocks are wrapped with a layer of ±45° fiberglass cloth around the perimeter, and two layers of foam profiles are stacked in a staggered manner. After vacuum infusion molding, an internal lattice web is formed to fit the arc surface profile of the curved PET foam core. At the same time, lattice structures are independently arranged on both the upper and lower layers of the double-layer staggered lattice. Among them, 3 circumferential lattices are arranged on each of the upper and lower layers, and the upper and lower layers of lattices are completely aligned and arranged vertically and orthogonally; 4 radial lattices are arranged on the upper layer and 5 radial lattices are arranged on the lower layer, and the radial lattices and circumferential lattices on both the upper and lower layers are evenly arranged along the width direction of the core; the corresponding curvature angles of adjacent radial lattices on the upper layer and adjacent radial lattices on the lower layer are both 18°, and the spacing between adjacent circumferential lattices on both the upper and lower layers is 100 mm. There are a total of 6 circumferential lattices, which perfectly fit the arc surface of the core; the center line of the circumferential lattice on the upper layer corresponds to the center points of two adjacent circumferential lattices on the lower layer, and a staggered "pin" - shaped arc grid is formed through staggered arrangement to ensure that the overall lattice fully adheres to the core and collaborates in force.

[0055] In this embodiment, the upper and lower ends of the double-layer staggered lattice reinforcement are in close contact with the upper and lower thermoplastic fiber - reinforced composite panels. The two layers of staggered lattices form a mutually constrained force system, which together with the panels and the core constitutes a "panel - double - layer staggered lattice - core" collaborative force system. Compared with the single - layer lattice in Embodiment 1 and Embodiment 2 and the double - layer orthogonal lattice in Embodiment 3, the double - layer staggered lattice reinforcement in this embodiment can significantly improve the ductility of the sandwich panel, avoid brittle failure of the structure, and at the same time enhance the stability of the overall structure and reduce the risk of sudden instability.

[0056] Embodiment 5

[0057] As Figure 5 shown, this example provides a production process for a lattice - reinforced PET foam curved sandwich panel that can be recycled as a whole, including the following steps:

[0058] S1, Mold processing:

[0059] The curved mold is processed according to the linear type of the target curved component. The surface of the mold is flat and smooth, and a mold release agent treatment is carried out to ensure that the contour accuracy of the curved sandwich panel after molding meets the requirements.

[0060] S2, Core pretreatment:

[0061] Select a foam with a density of 100 kg / m 3Closed-cell PET foam blocks were CNC milled into pre-defined curved core materials. The foam core materials were cut into arc shapes according to the required dimensions and quantity of the specimens. A 2 mm wide and 3 mm deep groove was pre-drilled on the side of the foam block to ensure that the resin could smoothly impregnate the lattice structure during vacuum infusion, improving interfacial bonding strength. After completion, the core material underwent drying to remove surface moisture.

[0062] S3, lattice structure:

[0063] The cut curved PET foam core is wrapped with a layer of ±45° alkali-free glass fiber cloth. The internal lattice web is prepared by vacuum induction molding process, so that the lattice and the core material form an integrated structure, which improves the tightness of interface bonding and the efficiency of force transmission.

[0064] S4, Panel Laying and Lamination Assembly:

[0065] A pre-cut thermoplastic fiberglass cloth is laid at the bottom of the wooden mold as the lower panel, with the laying tension controlled at 7 N / m to ensure the panel is wrinkle-free and without displacement. The assembled curved core material is then precisely placed on the lower panel according to the positioning requirements, and an upper layer of thermoplastic fiberglass cloth is laid on top of the core material, also maintaining a tension of 7 N / m. Subsequently, a flow guide net and vacuum bag are laid on top of the panel, ready for vacuum infusion.

[0066] S5, Vacuum Infusion Curing:

[0067] The sealing system was evacuated to -0.095 MPa, then introduced into the thermoplastic resin system and cured at 22°C for 8 hours to ensure a strong interface bond and a dense overall structure.

[0068] S6, Demolding and Post-processing:

[0069] After curing, the material is allowed to cool naturally to room temperature before demolding. Excess edges are removed by CNC cutting to obtain a recyclable lattice-reinforced PET foam curved sandwich panel with a smooth surface and high precision curved contour.

[0070] This invention employs a vacuum infusion integrated curing process, achieving a seamless integration of the panel-lattice-core layer interface. It boasts advantages such as simple process, environmental friendliness, and zero pollution. Furthermore, all components can be recycled and reused as a whole, better meeting the demands of industries such as aerospace and rail transportation for lightweight, environmental protection, and low cost. The overall structural integrity is far superior to traditional step-by-step bonding processes, ensuring long-term service reliability under complex curved surface conditions and dynamic loads.

[0071] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A recyclable lattice-reinforced foam curved sandwich panel, characterized in that, The device includes a core material, an upper panel, a lower panel, and a lattice reinforcement. The upper panel and the lower panel are respectively disposed on the upper and lower surfaces of the core material. The lattice reinforcement is disposed inside the core material and is connected to the upper panel and the lower panel. The core material is a thermoplastic foam curved core material. The upper panel, the lower panel, and the lattice reinforcement are all formed by impregnation and curing with a thermoplastic resin system, so that the core material, the upper panel, the lower panel, and the lattice reinforcement constitute an integrated curved sandwich structure that can be recycled as a whole.

2. The recyclable lattice-reinforced foam curved sandwich panel as described in claim 1, characterized in that, The core material is an integrally formed continuous curved surface structure. The curved surface shape of the core material is a single circular arc surface. The lattice reinforcement includes radial lattice and circumferential lattice. The radial lattice penetrates the core material along the thickness direction, and the circumferential lattice is distributed radially within the curved surface of the core material.

3. The recyclable lattice-reinforced foam curved sandwich panel as described in claim 2, characterized in that, The radial lattice includes single-layer, multi-layer vertical, and trapezoidal longitudinal lattices that penetrate along the thickness direction of the core material, forming an arrangement that is orthogonal to and staggered with the single-layer and double-layer circumferential lattice.

4. The recyclable lattice-reinforced foam curved sandwich panel as described in claim 1, characterized in that, The core material is thermoplastic closed-cell PU foam or PET foam.

5. A recyclable lattice-reinforced foam curved sandwich panel as described in claim 1, characterized in that, The thermoplastic resin is polymethyl methacrylate or Elium® thermoplastic resin.

6. The recyclable lattice-reinforced foam curved sandwich panel as described in claim 1, characterized in that, The sandwich panel as a whole can be disassembled by at least one of chemical dissolution, pyrolysis or mechanical separation.

7. A manufacturing process for a recyclable lattice-reinforced foam curved sandwich panel as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1, Mold processing: Process curved surface molds according to the target curved surface component lines. The mold surface is flat and smooth, and is treated with a release agent. S2, Core material pretreatment: The core material is cut into a preset arc-shaped core material by CNC milling; S3, wrap the cut core material with alkali-free glass fiber cloth, and use vacuum induction molding process to prepare the internal lattice web, so that the lattice and the core material form an integrated structure; S4, Panel laying and stacking assembly: A pre-cut thermoplastic fiberglass cloth is laid at the bottom of the mold as the lower panel. The assembled curved core material is accurately placed on the lower panel according to the positioning requirements. Then, an upper layer of thermoplastic fiberglass cloth is laid on top of the core material. Subsequently, a guide net and a vacuum bag are laid on top of the panel to prepare for vacuum infusion. S5, Vacuum Infusion Curing: After the sealing system is evacuated, it is introduced into the thermoplastic resin system. After curing, it is naturally cooled to room temperature and demolded. Excess edges are removed by CNC cutting to obtain a lattice-reinforced PET foam curved sandwich panel that can be recycled as a whole.

8. The production process of a recyclable lattice-reinforced foam curved sandwich panel as described in claim 7, characterized in that, In step S2, a groove 2 mm wide and 3 mm deep is reserved on the side of the curved core material.

9. The production process of a recyclable lattice-reinforced foam curved sandwich panel as described in claim 7, characterized in that, In step S4, the laying tension of both the upper and lower panels is 7 N / m.

10. The production process of a recyclable lattice-reinforced foam curved sandwich panel as described in claim 7, characterized in that, In step S5, the vacuum is drawn to -0.095 MPa, the curing temperature is 22℃, and the curing time is 8 hours.

Images