4d printing humidity-responsive honeycomb cushioning energy-consuming module

Abstract

The present application relates to humidity response protection module technical field, and disclose a kind of 4D printing humidity response type honeycomb buffer energy consumption module, including two ends clamping end, at least one humidity-sensitive honeycomb core unit being set between clamping end, and constraint boundary layer on the upper and lower surfaces of humidity-sensitive honeycomb core unit, also include humidity response state display and carbon fiber electric heating reset unit, humidity-sensitive honeycomb core unit is shaped by 4D printing mode using humidity response material, its honeycomb wall is absorbed when environmental humidity rises Expansion, make honeycomb pore effective size reduce, porosity reduce, and change the compression path of module, structural support strength and buffer energy consumption state, constraint boundary layer uses ordinary non-humidity-sensitive material or low wet expansion material.The 4D printing humidity response type honeycomb buffer energy consumption module can be used for hot and humid transport, storage, cold chain or precision device packaging protection scene, realize adaptive buffering and state visual display with environmental humidity change.

Description

Technical Field

[0001] This invention relates to the field of humidity-responsive protection module technology, specifically a 4D-printed humidity-responsive cellular buffer energy-consuming module. Background Technology

[0002] Honeycomb structures are widely used in packaging protection, transportation, aerospace, electronic equipment protection, and precision instrument cushioning due to their light weight, high specific strength, strong compressibility, and excellent cushioning performance. Traditional honeycomb cushioning structures are typically made of metal, plastic, composite materials, or paper-based materials, and their structural geometry and mechanical response are essentially fixed after manufacturing. During use, traditional honeycomb cores can only passively bear external loads, and their cushioning energy dissipation characteristics are mainly determined by the initial pore size, wall thickness, material modulus, and structural arrangement, making it difficult to actively adjust their configuration according to changes in the external environment. In maritime transport, warehousing, cold chain transportation, and humid environments, humidity changes are a significant environmental factor affecting packaging protection and equipment safety. Traditional cushioning structures typically lack humidity sensing and response capabilities. When ambient humidity increases, condensation occurs, or prolonged exposure to moisture occurs, ordinary honeycomb cushioning cores cannot change their pore structure according to humidity changes, nor can they indicate whether they have experienced a high-humidity environment. Therefore, existing honeycomb cushioning structures suffer from weak environmental adaptability, unobservable service status, and limited functionality. Furthermore, traditional honeycomb cushioning materials, even after exposure to high humidity, condensation, or dampness, typically cannot provide feedback to users regarding changes in their service environment through their structure or appearance. This makes it difficult for users to promptly determine whether the cushioning components need inspection, replacement, or repositioning. Simultaneously, traditional honeycomb cushioning structures generally maintain the same geometric configuration in both normal low-humidity environments and high-humidity, condensation, or dampness-exposed environments; their porosity, compression path, and support strength cannot proactively adjust to humidity changes. When packaging or cushioning components are in high-humidity environments, ordinary materials may also experience moisture absorption and softening, decreased support strength, or instability of the cushioning path, leading to risks such as bottoming out, excessive displacement, or uncontrollable impact peaks.

[0003] Currently, humidity-responsive materials can undergo moisture absorption and expansion, moisture absorption and shrinkage, or morphological changes when environmental humidity changes, providing a possibility for constructing humidity-adaptive honeycomb structures. However, if humidity-sensitive materials are directly fabricated into honeycomb buffer cores, in high-humidity environments, the moisture absorption and expansion of the honeycomb walls not only leads to changes in the honeycomb cell size but may also cause overall warping of the honeycomb core, out-of-plane bulging, edge jamming, node cracking, or changes in assembly gaps, resulting in uncontrollable buffering performance. Therefore, it is urgent to design a honeycomb core structure with boundary constraint structures and moisture expansion release channels, so that the moisture absorption and expansion of humidity-sensitive materials can be transformed into controllable honeycomb cell shrinkage and internal configuration reconstruction. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a 4D-printed humidity-responsive honeycomb buffer energy dissipation module. This module can adapt to humidity-sensitive changes in honeycomb pore size, porosity, and compression deformation path, resulting in different structural support strengths and buffer energy dissipation performance in both low-humidity and high-humidity environments. This adapts to various application scenarios such as conventional transportation, humid storage, maritime transport, cold chain condensation, and protection of precision components. It solves the problems of traditional honeycomb buffer structures failing to actively adjust pore structure according to environmental humidity changes, moisture-sensitive honeycomb cores easily experiencing disordered warping or out-of-plane bulging after absorbing moisture, difficulty in controllably switching buffer energy dissipation states with humidity, invisibility of service status, and difficulty in resetting after humidity response.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: a 4D printed humidity-responsive honeycomb buffer energy-consuming module, comprising a first clamping end, a second clamping end, a humidity-sensitive honeycomb core unit disposed between the first clamping end and the second clamping end, and a constraint boundary layer disposed on the upper surface and the lower surface of the humidity-sensitive honeycomb core unit; The clamping ends are respectively set at both ends of the buffer energy dissipation module for fixing, positioning and installing the humidity-sensitive honeycomb core unit. The clamping ends can be provided with mounting holes, positioning holes, slots, plug slots or limiting structures to facilitate the installation of the buffer energy dissipation module into the packaging box, equipment compartment, transport clamp or protective housing.

[0007] The humidity-sensitive honeycomb core unit is formed by additive manufacturing of humidity-responsive material, using 4D printing. It includes multiple honeycomb holes and honeycomb walls surrounding the honeycomb holes. The honeycomb walls are integrally formed from the same humidity-sensitive material. When the humidity increases, the honeycomb walls absorb moisture and expand, increasing the wall thickness and reducing the effective size of the honeycomb holes. When the humidity decreases, the humidity-sensitive material dehydrates and shrinks, and the honeycomb holes can partially or mainly recover. The linear expansion rate of the humidity-sensitive honeycomb core unit under environmental changes of 30%RH to 90%RH is not less than 1%, preferably 3% to 30%.

[0008] The wall thickness of the honeycomb under high humidity conditions increases by 2%–80% compared to that under low humidity conditions, preferably by 5%–40%. The humidity response expansion rate of the constraint boundary layer is lower than that of the humidity response expansion rate of the humidity-sensitive honeycomb core cell, and the constraint boundary layer is connected to the upper and lower surfaces of the humidity-sensitive honeycomb core cell to limit the warping or out-of-plane deformation of the humidity-sensitive honeycomb core cell in the thickness direction. At least one pair of sides of the moisture-sensitive honeycomb core unit is an open structure, which allows the honeycomb core to have lateral release space when it absorbs moisture and expands, so as to allow the moisture-sensitive honeycomb core unit to release lateral deformation when it absorbs moisture and expands, avoiding excessive internal stress, node cracking, jamming or irreversible deformation caused by complete closed constraint. When the ambient humidity increases, the honeycomb wall absorbs moisture and expands, reducing the effective size of the honeycomb pores, thereby changing the porosity, compression deformation path, structural support strength, and buffer energy dissipation state of the module. Under low humidity conditions, the moisture-sensitive honeycomb core unit has a large equivalent size of honeycomb cells and a high porosity, which enables the module to have a long compression stroke and normal buffering capacity. Under high humidity conditions, the honeycomb wall absorbs moisture and expands, which reduces the equivalent size of the honeycomb cells, decreases the porosity, and increases the honeycomb wall thickness. This causes the honeycomb wall to make contact, buckle, or support earlier during compression, thereby changing the initial compression stiffness, plateau stress, peak compression force, and energy absorption efficiency of the module.

[0009] Preferably, the humidity-sensitive honeycomb core unit is a single integral honeycomb core, or it is formed by splicing, plugging, snapping, or arraying multiple independent honeycomb core units; When the humidity-sensitive honeycomb core unit is composed of multiple independent honeycomb core units, the multiple independent honeycomb core units are arranged in a 2×2 array, a 1×N array, or an M×N array. At least one honeycomb core unit is a detachable structure, using a single honeycomb core or a combination of multiple honeycomb cores. In particular, a 2×2 array of replaceable honeycomb core units can be used. After a certain honeycomb core fails, becomes fatigued, or has a long-term high humidity response, it can be disassembled and replaced individually, improving maintenance convenience. At least one pair of sides of the moisture-sensitive honeycomb core unit remain open, so that the thickness deformation of the moisture-sensitive honeycomb core unit is restricted when it absorbs moisture and expands, while the lateral moisture expansion deformation can be released.

[0010] Preferably, the honeycomb holes of the humidity-sensitive honeycomb core unit are one or a combination of hexagonal holes, circular holes, rhomboid holes, trapezoidal holes, re-entry honeycomb holes, and gradient honeycomb holes; The aperture of the gradient honeycomb pores varies in a gradient along the thickness direction of the honeycomb core; When the humidity-sensitive honeycomb core unit is formed by combining multiple independent honeycomb core units, the different humidity-sensitive honeycomb core units have the same or different pore size, wall thickness, material formulation or printing filling parameters to form a partitioned response structure or gradient buffer structure.

[0011] Preferably, the moisture-sensitive honeycomb core unit is made of at least one of cellulose-based composite material, cross-linked polyvinyl alcohol, cellulose / polyvinyl alcohol composite material, hygroscopic polyamide material or moisture-sensitive resin material.

[0012] Preferably, the humidity-sensitive honeycomb core unit is made of cross-linked polyvinyl alcohol / cellulose composite humidity-sensitive material, comprising the following components in parts by weight: 15-45 parts by weight of polyvinyl alcohol, 1-15 parts by weight of cellulose nanofibers, 2-12 parts by weight of plasticizer, 0.1-5 parts by weight of cross-linking agent, 35-75 parts by weight of water-based photocurable resin matrix, and 0.2-3 parts by weight of photoinitiator.

[0013] Preferably, the upper and lower constraint boundary layers are made of ordinary non-moisture-sensitive materials or low-moisture-expansion materials, and the constraint boundary layers are made of at least one of PA12, PET, PETG, ABS, nylon, epoxy resin, photosensitive resin, carbon fiber reinforced composite material, glass fiber reinforced composite material or metal sheet. The linear expansion rate of the constrained boundary layer material under environmental conditions of 30%RH to 90%RH is lower than the humidity response linear expansion rate of the humidity-sensitive honeycomb core cell material, preferably not higher than 50% of the linear expansion rate of the humidity-sensitive honeycomb core cell material, more preferably not higher than 20%. The upper and lower constrained boundary layers are used to limit the warping and out-of-plane deformation instability of the humidity-sensitive honeycomb core cell in the vertical direction, so that the deformation of the humidity-sensitive honeycomb core cell is mainly manifested as the reduction of honeycomb pores and the reconstruction of internal structure. The humidity-responsive linear expansion rate of the humidity-sensitive honeycomb core cell material is ε core The humidity-response linear expansion rate of the constrained boundary layer material is ε boundary Both satisfy K=ε core / ε boundary And K is greater than 2, and the optimal value is greater than 5.

[0014] Preferably, the equivalent size of the honeycomb cells in the humidity-sensitive honeycomb core unit is reduced by 5%-60% under high humidity conditions compared to low humidity conditions, and more preferably by 10%-40%. The porosity of the humidity-sensitive honeycomb core unit is reduced by 5%-60% under high humidity conditions compared to low humidity conditions, preferably by 10%-40%. The initial compression stiffness, peak compression force, plateau stress, energy absorption per unit volume, specific energy absorption or energy absorption efficiency of the buffer energy dissipation module under high humidity conditions shall not be less than 5% compared with those under low humidity conditions, and preferably the variation range is 10% to 200%.

[0015] Preferably, it also includes a humidity response status display, which is disposed at at least one of the upper surface of the buffer energy consumption module, the outer surface of the first clamping end, the outer surface of the second clamping end, or the side of the buffer energy consumption module. The display can adopt a mechanical displacement display structure or a humidity-sensitive color-changing display structure. In the mechanical displacement display structure, the humidity-sensitive display sheet elongates, warps, or shifts after absorbing moisture, and displays low humidity, medium humidity, or high humidity status by blocking or exposing different color marking areas. The display can also employ a humidity-sensitive color-changing display structure. Humidity-sensitive color-changing agents, humidity-responsive dyes, photonic crystal microstructures, or microcapsule color-changing components can be incorporated into the humidity-sensitive display panel, causing it to display different colors under different humidity conditions. Because the display material is the same as or in the same system as the honeycomb core material, the display's response can more closely reflect the actual humidity expansion state of the honeycomb core, rather than simply displaying the ambient air humidity.

[0016] The humidity response status display includes at least one humidity-sensitive display panel and low humidity status display area, medium humidity status display area and high humidity status display area; The humidity-sensitive display sheet is made of the same or the same humidity-responsive material as the humidity-sensitive honeycomb core unit, and displays the humidity response status of the humidity-sensitive honeycomb core unit through at least one of the following methods: moisture absorption expansion, warping, displacement, obscuring color mark or humidity-sensitive color change. The low humidity display area corresponds to the initial pore state of the humidity-sensitive honeycomb cell, the medium humidity display area corresponds to the pore shrinkage transition state of the humidity-sensitive honeycomb cell, and the high humidity display area corresponds to the high humidity pore reconstruction state of the humidity-sensitive honeycomb cell.

[0017] This invention includes a humidity response status display, and the display uses the same or similar humidity-sensitive material as the honeycomb core, enabling the display to respond synchronously or nearly synchronously with the honeycomb core. The display does not simply detect ambient air humidity, but rather shows the degree of moisture absorption response, pore shrinkage state, or service status of the humidity-sensitive honeycomb core unit. Users can observe whether the module is in a low, medium, or high humidity response state through the display, thereby determining whether the module needs inspection, replacement, or reset.

[0018] Preferably, it also includes a carbon fiber electrothermal reset unit. The carbon fiber electrothermal reset unit is an optional structure and can be disposed within the constraint boundary layer, on the surface of the constraint boundary layer, between the humidity-sensitive honeycomb core unit and the constraint boundary layer, or disposed inside the first clamping end and inside the second clamping end. It is used to generate heat when energized to promote the dehumidification and reset of the humidity-sensitive honeycomb core unit, shorten the structure recovery time, enable the structure to reset faster when the humidity reduction is insufficient or when rapid recovery is required, and improve the reusability of the module. The carbon fiber electrothermal reset unit is one of carbon fiber bundle, carbon fiber cloth, carbon fiber sheet, carbon fiber heating film or carbon fiber composite electrothermal layer, with conductive electrodes at both ends and powered by a low-voltage DC power supply. In the technical solution, the carbon fiber electrothermal reset unit is not used as the main driving source for the pore shrinkage of the humidity-sensitive honeycomb core unit, but is used as an auxiliary dehumidification reset device after the high humidity response. The carbon fiber electrothermal reset unit is spaced apart from the honeycomb core body or arranged along the edge region of the honeycomb core to avoid hindering the humidity-responsive deformation of the honeycomb cells.

[0019] Preferably, the carbon fiber electrothermal reset unit operates at a voltage of 3V to 24V, has a single power-on time of 30 seconds to 20 minutes, and operates at a temperature of 30°C to 80°C. The carbon fiber electrothermal reset unit is connected to a temperature sensor, a thermistor, a temperature limiting element, or a temperature control circuit to prevent the moisture-sensitive honeycomb core unit from softening, rapidly losing water and cracking, or structural damage due to overheating. After the humidity decreases or the moisture is removed by heating and dehumidifying by the carbon fiber electrothermal reset unit, the equivalent size recovery rate of the honeycomb cells is not less than 50%, preferably not less than 70%, and more preferably not less than 80%.

[0020] (III) Beneficial Effects Compared with existing technologies, this invention provides a 4D-printed humidity-responsive honeycomb buffer energy-consuming module, which has the following beneficial effects: 1. The humidity-sensitive honeycomb core unit of this invention is made of 4D-printed humidity-responsive material. When the ambient humidity increases, the honeycomb wall absorbs moisture and expands, reducing the effective size of the honeycomb pores. This causes the porosity, compression path, and buffer energy dissipation state of the module to change with humidity, achieving time-dependent configuration reconstruction driven by ambient humidity. The equivalent size of the honeycomb pores can be reduced by 5%–60%, and the porosity can be reduced by 5%–60%. This porosity change further causes changes in the compression deformation path and mechanical response, enabling the module to switch between a normal buffer support state and a high-humidity enhanced support or high-humidity softened buffer state according to the ambient humidity.

[0021] 2. The present invention sets a low moisture expansion constraint boundary layer on the upper and lower surfaces of the moisture-sensitive honeycomb core, and the humidity response expansion rate of the constraint boundary layer is lower than that of the moisture response expansion rate of the moisture-sensitive honeycomb core material. This restricts the warping and out-of-plane deformation of the honeycomb core in the vertical direction, so that the moisture absorption expansion of the moisture-sensitive material is more manifested as the shrinkage of the honeycomb pores, rather than disordered bulging or overall instability, thereby improving the controllability and stability of the structural response.

[0022] 3. This invention does not completely seal and constrain the humidity-sensitive honeycomb core, but retains open or semi-open moisture expansion release space on at least one pair of sides, so that the humidity-sensitive material can release part of the lateral volume change during the moisture absorption and expansion process, avoiding excessive internal stress, node cracking, jamming or irreversible deformation caused by complete restriction on all sides, thereby improving the stability of humidity cycle response.

[0023] 4. This invention can not only be used as a honeycomb buffer energy dissipation structure, but also undergo configurational changes in humid, hot, damp, or condensing environments, resulting in different compression responses and energy dissipation paths under different humidity conditions. In the reinforced support type embodiment, the honeycomb wall expands after absorbing moisture, increasing the wall thickness, reducing the effective size of the honeycomb pores, and decreasing the porosity. This improves the initial compression stiffness, plateau stress, or peak compression force of the module under high humidity conditions compared to low humidity conditions, making it suitable for scenarios requiring enhanced compression support after moisture absorption, such as humid storage, sea transport, cold chain condensation, or packaging. In the softening buffer type embodiment, by adjusting the plasticizer content, crosslinking density, or water-based UV-curable resin content, the modulus reduction effect of the moisture-sensitive material after moisture absorption is greater than the structural densification effect. This reduces the peak transmission force and extends the buffer compression stroke of the module under high humidity conditions, making it suitable for protecting precision instruments, electronic components, or fragile items. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a 4D-printed humidity-responsive honeycomb buffer energy-consuming module proposed in this invention; Figure 2 This is a schematic diagram of the humidity-sensitive honeycomb core unit in a 4D-printed humidity-responsive honeycomb buffer energy-dissipating module proposed in this invention; Figure 3 This is a schematic diagram illustrating the porosity changes of a humidity-sensitive honeycomb core unit under low and high humidity conditions in an embodiment of the present invention. Figure 4 This is a schematic diagram of the clamping end in an embodiment of the present invention; Figure 5 This is a schematic diagram of the humidity response status display in an embodiment of the present invention; Figure 6 This is a schematic diagram of the carbon fiber electrothermal reset unit in an embodiment of the present invention; Figure 7 This is a schematic diagram of the moisture expansion deformation mechanism of a moisture-sensitive honeycomb core cell under conditions of upper and lower constrained boundary layers and lateral open release.

[0025] In the diagram: 1. First clamping end; 2. Buffer energy dissipation module; 3. Second clamping end; 4. Constraint boundary layer; 5. Carbon fiber electrothermal reset unit; 6. Humidity-sensitive honeycomb core unit; 7. Humidity response status display; 8. Honeycomb core structure in low humidity state; 9. Honeycomb core structure in medium humidity state; 10. Honeycomb core structure in high humidity state; 11. Mounting frame for both clamping ends; 12. Mounting holes for clamping ends; 13. Low humidity state display area; 14. Medium humidity state display area; 15. High humidity state display area; 16. Power supply; 17. Wire; 18. Wet expansion deformation of the honeycomb core under lateral open release conditions in low humidity state; 19. Wet expansion deformation of the honeycomb core under lateral open release conditions in high humidity state. Detailed Implementation

[0026] The technical solutions of 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] Example 1: Basic Humidity-Response Cellular Energy Consumption Buffer Module This embodiment provides a 4D-printed humidity-responsive honeycomb buffer energy dissipation module, including a first clamping end 1 at both ends, a second clamping end 3, at least one humidity-sensitive honeycomb core unit 6, and upper and lower constraint boundary layers 4. In a preferred embodiment, the buffer energy dissipation module 2 further includes a humidity response status display 7.

[0028] The humidity-sensitive honeycomb core unit 6 can be a single integral honeycomb structure or formed by combining multiple independent honeycomb core units. In a preferred embodiment, four humidity-sensitive honeycomb core units 6 are arranged in a 2×2 array between the first clamping end 1 and the second clamping end 3. Each humidity-sensitive honeycomb core unit 6 can be an integral honeycomb structure, consisting of multiple hexagonal honeycomb holes, circular holes, rhombic holes, re-entry honeycomb holes, or gradient honeycomb holes. The humidity-sensitive material can be a cross-linked polyvinyl alcohol (PVA) / cellulose composite material. Its specific components may include polyvinyl alcohol, cellulose nanofibers, plasticizer, crosslinking agent, aqueous photocurable resin matrix, and photoinitiator. The humidity-sensitive material includes: 15-45 parts by weight of polyvinyl alcohol, 1-15 parts by weight of cellulose nanofibers, 2-12 parts by weight of plasticizer, 0.1-5 parts by weight of crosslinking agent, 35-75 parts by weight of aqueous photocurable resin matrix, and 0.2-3 parts by weight of photoinitiator; the humidity-sensitive material may also contain 0-5 parts by weight of rheology modifier, defoamer, or wetting and dispersing agent. Polyvinyl alcohol (PVA) serves as the primary moisture-absorbing and expanding component, providing humidity-responsive deformation. Cellulose nanofibers enhance moisture absorption sensitivity, wet mechanical support, and compressive stability of the honeycomb wall. Plasticizers adjust printability, flexibility, and moisture absorption expansion. Crosslinking agents regulate moisture absorption expansion rate, water resistance, and cyclic recovery performance. A waterborne UV-curable resin matrix improves the forming accuracy, curing strength, and compressive load-bearing capacity of the printed honeycomb wall. Plasticizers can be glycerol, sorbitol, polyethylene glycol, or combinations thereof; crosslinking agents can be borax, boric acid, citric acid, glutaraldehyde, or combinations thereof; and the waterborne UV-curable resin matrix can be waterborne polyurethane acrylate, waterborne acrylate resin, waterborne epoxy acrylate, or combinations thereof. The moisture-sensitive printing material can be further supplemented with deionized water or a water-alcohol mixture to achieve a solid content of 20%–70%, preferably 30%–55%, to meet the printing requirements of extrusion, direct-write, or UV-curable assisted additive manufacturing. After printing, the core undergoes cross-linking, curing, and drying processes to form a moisture-sensitive honeycomb core with moisture absorption and expansion capabilities as well as compression support capabilities.

[0029] The upper and lower constraint boundary layers 4 are made of PA12, PETG, high-strength photosensitive resin, carbon fiber reinforced composite material, or metal sheet, and are respectively bonded, snap-fitted, thermo-pressed, or co-printed onto the upper and lower surfaces of the humidity-sensitive honeycomb core unit. The thickness of the constraint boundary layer 4 can be 0.2mm-10mm, preferably 0.5mm-3mm. The linear expansion rate of the constraint boundary layer 4 material under the same humidity change conditions is lower than that of the humidity-sensitive honeycomb core unit 6, thereby limiting the warping of the honeycomb core in the thickness direction, so that the humidity-sensitive honeycomb core unit 6 preferentially exhibits honeycomb pore reduction and internal wall thickness change after moisture absorption.

[0030] The front and rear sides, or at least a pair of sides, of the moisture-sensitive honeycomb core unit 6 remain open or semi-open, allowing the moisture-sensitive material to release some of its volume change laterally when it absorbs moisture and expands. This reduces internal stress and avoids node cracking, edge jamming, excessive deformation, or irreversible damage caused by complete enclosure. The open or semi-open structure can be achieved through clamping end avoidance, side openings, gap grooves, or local limiting structures.

[0031] When the relative humidity of the environment increases from 30%RH-40%RH to 70%RH-90%RH, the moisture-sensitive honeycomb wall absorbs moisture and expands, increasing the honeycomb wall thickness and decreasing the effective size of the honeycomb cells. The thickness of the moisture-sensitive honeycomb wall increases by 2%-80%, more preferably by 5%-40%. The equivalent size of the honeycomb cells is reduced by 5%–60%, more preferably by 10%–40%; the porosity is reduced by 5%–60%, more preferably by 10%–40%. This change alters the compression path, plateau stress, and energy absorption or energy absorption efficiency per unit volume of the buffer energy dissipation module 2, thereby achieving a humidity-responsive buffer state switching. Specifically, when using a higher content of water-based photocurable resin matrix, a higher content of cellulose nanofibers, or a higher crosslinking density, the humidity-sensitive honeycomb core can form an enhanced support response under high humidity conditions. That is, the structural densification effect caused by pore shrinkage and honeycomb wall thickening is greater than the material's moisture absorption and softening effect, thereby improving the module's initial compression stiffness, plateau stress, or peak compression force.

[0032] When using higher plasticizer content, lower crosslinking density, or lower resin matrix content, the moisture-sensitive honeycomb core can form a softening and buffering response under high humidity conditions. That is, the material's moisture absorption and softening effect is greater than the structural densification effect, thereby reducing the peak impact force and extending the compression buffer stroke.

[0033] In one exemplary embodiment, a single humidity-sensitive honeycomb core unit 6 has dimensions of 30mm × 30mm × 10mm. Under low humidity conditions, the equivalent diameter of the honeycomb cells is 5.0mm, the honeycomb wall thickness is 0.8mm, and the porosity is 72%. Under high humidity conditions, the equivalent diameter of the honeycomb cells is 4.0mm, the honeycomb wall thickness is 1.05mm, and the porosity is 58%. After natural drying or electrothermal reset, the equivalent diameter of the honeycomb cells recovers to 4.6mm, and the porosity recovers to 67%. These parameters are merely examples; actual values ​​can be adjusted based on material formulation, honeycomb cell type, wall thickness, and application scenario. In this example, the buffer energy dissipation module 2 is suitable for routine transportation, normal warehousing, or electronic product packaging cushioning under low humidity conditions. Under high humidity conditions, due to the reduced equivalent diameter of the honeycomb cells, increased wall thickness, and decreased porosity, the compression response of the buffer energy dissipation module 2 changes, and it can be designed as an enhanced support type or a softening cushioning type according to the material formulation. The reinforced support type is suitable for preventing packaging collapse and the protected item from touching the bottom in humid storage, sea transport, or cold chain condensation environments; the softened cushioning type is suitable for protecting precision instruments, electronic components, or fragile items that require reduced impact peak transmission force in high humidity environments.

[0034] Humidity response linear expansion coefficient ε h It can be calculated using the following formula: ε h = (L h - L0) / L0× 100% Where L0 is the length of the material under low humidity conditions, L h The length of the material under high humidity conditions.

[0035] The low humidity condition can be 20%RH-45%RH, preferably 30%RH-40%RH; The high humidity level can be 70%RH to 95%RH, preferably 75%RH to 90%RH.

[0036] The rate of change of the equivalent size of the honeycomb cells, ΔD, can be calculated using the following formula: ΔD = (D0 - D) h ) / D0× 100% Where D0 is the equivalent size of the honeycomb pores under low humidity conditions, D h This refers to the equivalent size of the honeycomb pores under high humidity conditions. In one embodiment, ΔD is 5%–60%, preferably 10%–40%.

[0037] The porosity P of the honeycomb core cross-section can be calculated using the following formula: P = A1 / A0 × 100% Where A1 is the total area of ​​the honeycomb cells, and A0 is the total cross-sectional area of ​​the honeycomb core. The porosity change rate ΔP can be calculated using the following formula: ΔP = (P0 - P)h ) / P0× 100% Where P0 is the porosity under low humidity conditions, P h The porosity is defined as that under high humidity conditions. In one embodiment, ΔP is 5%–60%, preferably 10%–40%.

[0038] The compressive stress σ of the module can be calculated using the following formula: σ = F / A Where F is the compressive load and A is the pressure-bearing area of ​​the module.

[0039] Energy absorbed per unit volume W v It can be obtained by integrating the compressive stress-strain curve:

[0040] Where σ(ε) is the compressive stress-strain curve, ε m The target compressive strain can be 10%–60%.

[0041] Specific energy absorption (SEA) can be calculated using the following formula: SEA = E / m Where E is the total energy absorbed during compression, and m is the mass of the module. The total energy E can be calculated using the following formula:

[0042] Where F(δ) is the load-displacement curve, δ m The target is the compression displacement.

[0043] Cellular hole equivalent size recovery rate R D It can be calculated using the following formula: R D = (D r - D h ) / (D0- D h ) × 100% Where D0 is the initial pore size under low humidity, D h D represents the aperture size after high humidity response. r The aperture is the size after natural drying or electrothermal reset. In one embodiment, R D Not less than 50%, preferably not less than 70%, and even more preferably not less than 80%.

[0044] Initial compressive stiffness K of the module c It can be calculated using the following formula: K c = ΔF / Δδ Where ΔF is the load change during the initial compression stage, and Δδ is the corresponding compression displacement change.

[0045] The rate of change of peak compressive force ΔFp can be calculated using the following formula: ΔF p = (F ph - F p0 ) / F p0 × 100% Among them, F p0 F represents the peak compressive force under low humidity conditions. ph This represents the peak compressive force under high humidity conditions.

[0046] The platform stress change rate Δσp can be calculated using the following formula: Δσp= (σ ph - σ p0 ) / σ p0 × 100% Where, σ p0 For the platform stress under low humidity conditions, σ ph This represents the platform stress under high humidity conditions.

[0047] Rate of change of energy absorption per unit volume ΔW v It can be calculated using the following formula: ΔW v = (W vh - W v0 ) / Wv0 × 100% Among them, W v0 For energy absorption per unit volume under low humidity conditions, W vh This refers to the energy absorbed per unit volume under high humidity conditions.

[0048] Example 2: Module with humidity response status display Based on Embodiment 1, this embodiment further provides a humidity response status display 7, which includes at least one humidity-sensitive display chip and a low humidity status display area 13, a medium humidity status display area 14 and a high humidity status display area 15. A humidity response status display 7 is disposed on the upper surface of the module and may include a display housing, an observation window, a humidity-sensitive display panel, and a multi-level status indicator area. The humidity-sensitive display panel is made of the same or similar material as the humidity-sensitive honeycomb core unit 6, such as the same cross-linked PVA / cellulose composite material as the honeycomb core.

[0049] In a humidity-sensitive color-changing display, the humidity-sensitive display sheet may incorporate a humidity-sensitive color-changing agent, a humidity-responsive dye, a photonic crystal microstructure, or a microcapsule color-changing component, causing the humidity-sensitive display sheet to display different colors under different humidity conditions. Preferably, the low-humidity display area 13 is blue, the medium-humidity display area 14 is purple, and the high-humidity display area 15 is orange.

[0050] In another embodiment, the humidity response status display 7 may also adopt a mechanical displacement display structure, wherein the humidity-sensitive display sheet elongates, warps or shifts after absorbing moisture, and displays the humidity response status of the honeycomb core by blocking or exposing different marking areas.

[0051] The low humidity setting can be set to an ambient relative humidity of less than 40%RH, the medium humidity setting can be set to an ambient relative humidity of 40%RH–70%RH, and the high humidity setting can be set to an ambient relative humidity of greater than 70%RH. The upper humidity threshold can be adjusted according to the humidity-sensitive material formulation, honeycomb wall thickness, display panel thickness, and actual application environment.

[0052] This display does not simply detect ambient air humidity, but rather shows the humidity response level and service status of the honeycomb core. Because the humidity-sensitive display material is the same as or in the same system as the honeycomb core material, its response threshold can match the honeycomb core pore shrinkage threshold, allowing users to determine whether the module is in its initial state, pore shrinkage transition state, or high-humidity pore reconstruction state based on the display status.

[0053] Example 3: Module with carbon fiber electrothermal reset unit Based on Embodiment 1 or Embodiment 2, this embodiment further includes a carbon fiber electrothermal reset unit 5.

[0054] The carbon fiber electrothermal reset unit 5 can be made of carbon fiber heating film, carbon fiber cloth, carbon fiber tow, or carbon fiber composite electrothermal layer. This electrothermal unit is disposed inside the upper constraint boundary layer 4, inside the lower constraint boundary layer 4, or between the humidity-sensitive honeycomb core unit 6 and the constraint boundary layer 4.

[0055] A preferred structure is as follows: A thin carbon fiber heating film is embedded inside the upper constraint boundary layer 4, and copper foil electrodes are placed at both ends of the heating film. The copper foil electrodes are connected to an external low-voltage DC power supply 16 via wires 17. Another carbon fiber heating film can be placed on the lower constraint boundary layer 4 to form a double-sided auxiliary heating structure.

[0056] Another preferred structure is: Carbon fiber bundles are arranged near the upper and lower edges of the humidity-sensitive honeycomb core unit 6. The carbon fiber bundles are arranged in a straight line, serpentine, or grid pattern, and their two ends are connected to the power supply 16 through conductive adhesive or copper foil electrodes. The carbon fiber bundles do not pass directly through the main body area of ​​the honeycomb cells, or are kept at a distance from the main body of the honeycomb cells, so as to avoid affecting the humidity response deformation and compression energy dissipation path of the honeycomb cells.

[0057] Carbon fiber heating parameters The electrical power P of the carbon fiber electrothermal reset unit 5 e It can be calculated using the following formula: Pe = UI Where U is the applied voltage and I is the operating current.

[0058] The heating input energy Q can be calculated using the following formula: Q = P e t = UI t Where t is the energizing time.

[0059] The electrical power and energizing time can be determined based on the volume of the humidity-sensitive honeycomb core, its moisture content, the material's heat resistance temperature, and the target reset speed.

[0060] The carbon fiber electrothermal reset unit 5 can be powered by low-voltage DC, with an operating voltage range of 3V to 24V, preferably 5V to 12V.

[0061] In small-scale prototypes, the following parameters can be used: Operating voltage: 5V; Power-on time: 2 to 5 minutes; Target surface temperature: 35°C to 45°C; Application: Mild dehumidification and repositioning.

[0062] In medium-sized modules, the following parameters can be used: Operating voltage: 12V; Power-on time: 5 to 10 minutes; Target surface temperature: 40℃ to 60℃; Application: To promote faster dehumidification of moisture-sensitive honeycomb cores.

[0063] During the recovery process after exposure to high humidity, intermittent heating can be used: Single power-on: 2 to 3 minutes; Interval stop: 1 to 2 minutes; Number of cycles: 2 to 5; Total heating time: 5 to 20 minutes; The maximum temperature should not exceed 80℃, preferably not exceeding 60℃.

[0064] To prevent moisture-sensitive materials from overheating and softening, rapidly losing water and cracking, or suffering irreversible damage, the carbon fiber electrothermal reset unit 5 is preferably connected to a temperature sensor, thermistor, temperature limit switch, or temperature control circuit. It automatically cuts off power or reduces power when the temperature exceeds a set threshold.

[0065] The main function of the carbon fiber electrothermal reset unit 5 is not to drive the honeycomb core to undergo pore shrinkage or 4D configuration change, but to assist its dehumidification and recovery after high humidity response. Therefore, the present invention still uses the change of ambient humidity as the main triggering factor and carbon fiber heating as an auxiliary reset method. Through this setting, the present invention can be avoided from being misunderstood as a simple electrothermal driven deformation structure.

[0066] Example 4: Replaceable four-core module In this embodiment, the humidity-sensitive honeycomb core unit 6 is configured as four independent replaceable single cores. Each of the two ends, the first clamping end 1 and the second clamping end 3, has a clamping end mounting hole 12. The clamping ends of the four humidity-sensitive honeycomb core units 6 are respectively inserted into the corresponding two-sided clamping end mounting frames 11. The upper and lower constraint boundary layers 4 can form an integral support with the first clamping end 1 and the second clamping end 3, and are installed in the two-sided clamping end mounting frames 11, or they can be connected to each single core separately.

[0067] When a single honeycomb core fails due to prolonged exposure to high humidity, cyclic fatigue, structural damage, or response failure, it can be removed and replaced individually without replacing the entire module. This structure is suitable for scenarios requiring regular maintenance, such as transport cases, instrument protective chambers, and electronic equipment buffer compartments.

[0068] The four honeycomb core units can use the same humidity-sensitive material, or they can use the same material but with different pore sizes, wall thicknesses or printing filling parameters to obtain different buffering performance. In the preferred case, the four humidity-sensitive honeycomb core units 6 use the same humidity-sensitive material to ensure consistent humidity response and ease of manufacturing.

[0069] In another embodiment, different humidity-sensitive honeycomb core cells 6 can employ different pore sizes, wall thicknesses, material formulations, or printing filling parameters to form a zoned response or gradient buffer structure. For example, the humidity-sensitive honeycomb core cells 6 near the outer edge can be configured with higher humidity response sensitivity, while the humidity-sensitive honeycomb core cells 6 near the inner edge can be configured with higher compressive strength, thereby balancing humidity response and load-bearing buffer performance.

[0070] like Figure 3 As shown, the wall thickness and pore size of the moisture-sensitive honeycomb core unit 6 after absorbing water under different humidity conditions can be specifically divided into low humidity state honeycomb core structure 8, medium humidity state honeycomb core structure 9, and high humidity state honeycomb core structure 10. like Figure 7 As shown, the wet expansion deformation under lateral open release conditions is specifically the wet expansion deformation 18 of the honeycomb core under low humidity conditions and the wet expansion deformation 19 of the honeycomb core under high humidity conditions.

[0071] The working principle of this invention is as follows: In a low-humidity environment, the humidity-sensitive honeycomb core unit 6 is in its initial state. At this time, the water content of the honeycomb wall is low, the effective size of the honeycomb cells is large, and the buffer energy dissipation module 2 has initial buffering and support capabilities.

[0072] When ambient humidity increases, the moisture-sensitive honeycomb wall absorbs moisture from the air, causing the material to expand hygroscopically. Because the upper and lower surfaces of the honeycomb core are constrained by a low-hygroscopic boundary layer 4, warping, bulging, and out-of-plane deformation of the honeycomb core in the thickness direction are suppressed. Since at least one pair of sides of the honeycomb core remains open or semi-open, material volume changes can be partially released laterally, thus avoiding excessive internal stress caused by complete enclosure. Simultaneously, as the honeycomb wall thickness increases, the effective size of the honeycomb cells decreases, the module porosity decreases, and the compression deformation path, plateau stress, and energy absorption efficiency per unit volume change.

[0073] During the high humidity response process, the mechanical properties of the humidity-sensitive honeycomb core unit 6 change depending on the relative magnitude of the material's moisture absorption softening effect and structural densification effect. When the structural densification effect, resulting from increased honeycomb wall thickness, decreased porosity, and enhanced wall contact, dominates, the buffer energy dissipation module 2 exhibits a high humidity enhanced support state, with increased initial compressive stiffness, peak compressive force, or plateau stress. This is suitable for scenarios requiring load-bearing capacity and bottom-out prevention under high humidity conditions such as humid storage, maritime transport, and cold chain condensation. When the modulus reduction effect after moisture absorption dominates, the buffer energy dissipation module 2 exhibits a high humidity softening buffer state, with decreased peak transmission force and extended compression stroke. This is suitable for scenarios involving the protection of precision devices and fragile items sensitive to impact peaks.

[0074] The humidity response status display 7 uses the same or similar humidity-sensitive material as the honeycomb core. In the mechanical displacement display method, the humidity-sensitive display sheet elongates, warps, or shifts as the ambient humidity increases, displaying different response states by obscuring or revealing different color-coded areas. In the humidity-sensitive color-changing display method, a humidity-sensitive color-changing component is incorporated into the humidity-sensitive display sheet, causing its color to change according to the humidity response state. Specifically, the low humidity state can be set to an ambient relative humidity of less than 40%RH, the medium humidity state can be set to an ambient relative humidity of 40%RH to 70%RH, and the high humidity state can be set to an ambient relative humidity greater than 70%RH. The low humidity state corresponds to the honeycomb core not absorbing moisture significantly or being in its initial porous state; the medium humidity state corresponds to the honeycomb core beginning to absorb moisture and entering a pore shrinkage transition state; and the high humidity state corresponds to the honeycomb core significantly absorbing moisture and expanding, entering a pore reconstruction state. These humidity ranges can be adjusted according to the humidity-sensitive material formulation, honeycomb wall thickness, display sheet thickness, and the actual application environment.

[0075] When the ambient humidity decreases, the humidity-sensitive honeycomb core unit 6 gradually dehumidifies, the honeycomb wall volume shrinks, and the honeycomb pores can partially or mainly recover. If the natural dehumidification rate is slow, the carbon fiber electrothermal reset unit 5 can be activated. The carbon fiber electrothermal reset unit 5 generates heat after being energized at low voltage, accelerating the release of moisture inside the honeycomb core, thereby promoting structural recovery. In one embodiment, the equivalent size recovery rate of the honeycomb pores is not less than 50%, preferably not less than 70%, and more preferably not less than 80%. As the equivalent size and porosity of the honeycomb pores recover, the initial compressive stiffness, plateau stress, peak compressive force, or energy absorption per unit volume of the buffer energy dissipation module 2 can partially or mainly recover to the low-humidity initial state, thereby realizing the reuse of the humidity-responsive buffer energy dissipation module.

[0076] It should be noted that the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0077] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A 4D-printed humidity-responsive honeycomb buffer energy-dissipating module, characterized in that, It includes a first clamping end, a second clamping end, a humidity-sensitive honeycomb core unit disposed between the first clamping end and the second clamping end, and a constraint boundary layer disposed on the upper surface and the lower surface of the humidity-sensitive honeycomb core unit; The humidity-sensitive honeycomb core unit is formed by additive manufacturing of humidity-responsive material and includes multiple honeycomb holes and honeycomb walls surrounding the honeycomb holes; The humidity response expansion rate of the constraint boundary layer is lower than that of the humidity response expansion rate of the humidity-sensitive honeycomb core cell, and the constraint boundary layer is connected to the upper and lower surfaces of the humidity-sensitive honeycomb core cell to limit the warping or out-of-plane deformation of the humidity-sensitive honeycomb core cell in the thickness direction. At least one pair of sides of the moisture-sensitive honeycomb core unit is an open structure to allow the moisture-sensitive honeycomb core unit to release lateral deformation when it absorbs moisture and expands. When the ambient humidity increases, the honeycomb wall absorbs moisture and expands, reducing the effective size of the honeycomb pores, thereby changing the porosity, compression deformation path, structural support strength, and buffer energy dissipation state of the module.

2. The 4D printing humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: The humidity-sensitive honeycomb core unit is a single integral honeycomb core, or it can be formed by splicing, plugging, snapping, or arraying multiple independent honeycomb core units. When the humidity-sensitive cellular core unit is composed of multiple independent cellular core units, the multiple independent cellular core units are arranged in a 2×2 array, a 1×N array, or an M×N array, wherein at least one cellular core unit is a detachable structure. At least one pair of sides of the moisture-sensitive honeycomb core unit remain open, so that the thickness deformation of the moisture-sensitive honeycomb core unit is restricted when it absorbs moisture and expands, while the lateral moisture expansion deformation can be released.

3. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 2, characterized in that: The honeycomb pores of the humidity-sensitive honeycomb core unit are one or a combination of hexagonal pores, circular pores, rhomboid pores, trapezoidal pores, re-entry honeycomb pores, and gradient honeycomb pores. The aperture of the gradient honeycomb pores varies in a gradient along the thickness direction of the honeycomb core; When the humidity-sensitive honeycomb core unit is formed by combining multiple independent honeycomb core units, the different humidity-sensitive honeycomb core units have the same or different pore size, wall thickness, material formulation or printing filling parameters to form a partitioned response structure or gradient buffer structure.

4. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: The moisture-sensitive honeycomb core unit is made of at least one of cellulose-based composite materials, cross-linked polyvinyl alcohol, cellulose / polyvinyl alcohol composite materials, hygroscopic polyamide materials, or moisture-sensitive resin materials.

5. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 4, characterized in that: The humidity-sensitive honeycomb core unit is made of cross-linked polyvinyl alcohol / cellulose composite humidity-sensitive material, comprising the following components in parts by weight: 15-45 parts by weight of polyvinyl alcohol, 1-15 parts by weight of cellulose nanofibers, 2-12 parts by weight of plasticizer, 0.1-5 parts by weight of cross-linking agent, 35-75 parts by weight of water-based photocurable resin matrix, and 0.2-3 parts by weight of photoinitiator.

6. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: The constrained boundary layer is made of at least one of PA12, PET, PETG, ABS, nylon, epoxy resin, photosensitive resin, carbon fiber reinforced composite material, glass fiber reinforced composite material or metal sheet; The linear expansion rate of the constrained boundary layer material under environmental conditions of 30%RH to 90%RH is lower than the humidity-response linear expansion rate of the humidity-sensitive honeycomb core cell material, and not higher than 20% of the linear expansion rate of the humidity-sensitive honeycomb core cell material. The humidity-responsive linear expansion rate of the humidity-sensitive honeycomb core cell material is ε core The humidity-response linear expansion rate of the constrained boundary layer material is ε boundary The two satisfy K=ε core / ε boundary And K is greater than 2.

7. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: The equivalent size of the honeycomb cells in the humidity-sensitive honeycomb core unit is reduced by 5%-60% under high humidity conditions compared to low humidity conditions; The porosity of the humidity-sensitive honeycomb core unit is reduced by 5%-60% under high humidity conditions compared to low humidity conditions; The initial compression stiffness, peak compression force, plateau stress, energy absorption per unit volume, specific energy absorption, or energy absorption efficiency of the buffer energy dissipation module under high humidity conditions vary by 5%-200% compared to low humidity conditions.

8. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: It also includes a humidity response status display, which is disposed at least at one of the following locations: the upper surface of the buffer energy consumption module, the outer surface of the first clamping end, the outer surface of the second clamping end, or the side of the buffer energy consumption module. The humidity response status display includes at least one humidity-sensitive display panel and low humidity status display area, medium humidity status display area and high humidity status display area; The humidity-sensitive display sheet is made of the same or the same humidity-responsive material as the humidity-sensitive honeycomb core unit, and displays the humidity response status of the humidity-sensitive honeycomb core unit through at least one of the following methods: moisture absorption expansion, warping, displacement, obscuring color mark or humidity-sensitive color change. The low humidity display area corresponds to the initial pore state of the humidity-sensitive honeycomb cell, the medium humidity display area corresponds to the pore shrinkage transition state of the humidity-sensitive honeycomb cell, and the high humidity display area corresponds to the high humidity pore reconstruction state of the humidity-sensitive honeycomb cell.

9. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 1, characterized in that: It also includes a carbon fiber electrothermal reset unit, which is disposed within the constraint boundary layer, on the surface of the constraint boundary layer, between the humidity-sensitive honeycomb core unit and the constraint boundary layer, or disposed inside the first clamping end and inside the second clamping end, for generating heat when energized to promote the dehumidification and reset of the humidity-sensitive honeycomb core unit. The carbon fiber electrothermal reset unit is one of carbon fiber bundle, carbon fiber cloth, carbon fiber sheet, carbon fiber heating film or carbon fiber composite electrothermal layer, with conductive electrodes at both ends and powered by a low-voltage DC power supply. The carbon fiber electrothermal reset unit is spaced apart from the honeycomb core body or arranged along the edge region of the honeycomb core to avoid hindering the humidity-responsive deformation of the honeycomb cells.

10. The 4D printed humidity-responsive honeycomb buffer energy-consuming module according to claim 9, characterized in that: The working voltage of the carbon fiber electrothermal reset unit is 3V to 24V, the single power-on time is 30 seconds to 20 minutes, and the working temperature is controlled between 30℃ and 80℃. The carbon fiber electrothermal reset unit is connected to a temperature sensor, a thermistor, a temperature limiting element, or a temperature control circuit to prevent the moisture-sensitive honeycomb core unit from softening, rapidly losing water and cracking, or structural damage due to overheating. After the humidity decreases or the moisture is removed by heating and dehumidification by the carbon fiber electrothermal reset unit, the equivalent size recovery rate of the honeycomb cells is not less than 50%.

Images