Anti-collision protection lining and ice hockey helmet

Abstract

The invention discloses an anti-collision protection lining and an ice hockey helmet, and relates to the field of safety protection buffer functional materials, the anti-collision protection lining comprises an outer layer high microsphere density area, a middle layer fiber reinforcement area, an inner layer low density opening area and an inner layer composite antibacterial foaming polypropylene foam layer; the preparation of the anti-collision protection lining comprises the following steps: adding polyvinyl alcohol and polyethylene glycol into hot water for dissolving, adding silicon dioxide aerogel powder for stirring, and carrying out boric acid crosslinking, alkali treatment, polyurethane prepolymer coating and high-pressure hot air dispersion drying; performing plasma activation and maleic anhydride grafting; the preparation method comprises the following steps: mixing a component A containing nano colloid microspheres and grafted fibers with a polyisocyanate component B according to a ratio of 1: 1, and carrying out foaming molding to form a microsphere gradient enrichment layer; antibacterial foamed polypropylene foam is attached to the perforated layer in a hot-pressing mode and cut; through molecular flexible modification, microsphere elastic coating and interface strengthening and gradient energy distribution, the use reliability and impact resistance of the ice hockey helmet are improved.

Description

Technical Field

[0001] The present invention relates to the field of safety protection buffer functional materials, and particularly to an anti-collision protection lining and a hockey helmet. Background Art

[0002] A helmet usually consists of three basic structures, namely an outer hard protective shell, a middle energy-absorbing buffer layer, and an inner buffer layer. The materials of the helmet shell are generally divided into ABS engineering plastics, PC+ABS composites, fiberglass, carbon fiber, metal shells, etc. The materials are required to have excellent weather resistance, wear resistance, impact resistance, and compression resistance. Hard and light materials are the first choice for the shell. The middle energy-absorbing buffer layer is the key to the safety protection of the helmet. Most of the impact energy of the helmet is dispersed and released through the middle energy-absorbing buffer layer. Currently, the commonly used energy-absorbing buffer layer materials include EPS, EPO, EPP, polyurethane foam, rubber bodies, etc. The existing energy-absorbing buffer layer mainly offsets the external force impact and absorbs the impact energy through large deformation. However, in practice, it is difficult to compound enough thickness of materials in the helmet to buffer the impact force.

[0003] For example, in the Chinese patent with the application number CN201911222322.X, a buffer energy-absorbing motorcycle helmet composite material and its preparation method, which relates to a buffer energy-absorbing motorcycle helmet composite material, and further relates to a preparation method of a buffer energy-absorbing motorcycle helmet composite material. It forms nano-gel microspheres by loading polyvinyl alcohol solution into the micropores of silica aerogel and co-fills them with hyperbranched polyethylene fibers in polyurethane foam. However, the above technical solution still has problems such as low-temperature embrittlement failure, multi-impact structural fatigue, weak interfacial bonding, and single protection. Summary of the Invention

[0004] By providing an anti-collision protection lining and a hockey helmet in the embodiments of the present application, the problems of low-temperature embrittlement failure, multi-impact fatigue, and insufficient regional protection in the prior art are solved. Through molecular flexibility transformation, microsphere elastic coating and interface strengthening, and gradient energy distribution, the use reliability and anti-impact performance of the hockey helmet are improved.

[0005] The embodiments of the present application provide an anti-collision protection lining, including:

[0006] An outer high microsphere density area, a middle fiber-reinforced area, and an inner low-density open-cell area, and an inner composite antibacterial foamed polypropylene foam layer;

[0007] The preparation method of the anti-collision protection lining includes the following steps:

[0008] (1) Prepare nano-gel microspheres: Dissolve polyvinyl alcohol and polyethylene glycol in hot water, add silica aerogel powder and stir, crosslink with boric acid, treat with alkali, and coat with polyurethane prepolymer, and disperse and dry with high-pressure hot air flow;

[0009] (2) Interface strengthening: Treated by plasma activation and maleic anhydride grafting;

[0010] (3) Gradient buffer layer foaming: Mix component A containing nano-gel microspheres and maleic anhydride grafted fibers with polyisocyanate component B in a ratio of 1:1, inject into a centrifugal mold for foaming and molding to form a microsphere gradient enrichment layer;

[0011] (4) Inner lining composite: Thermally press and bond antibacterial foamed polypropylene foam on the perforated layer and cut.

[0012] Furthermore, the densities of the outer layer, middle layer, and inner layer are 0.35 g / cm³, 18 g / cm³, and 0.06 g / cm³ respectively.

[0013] Furthermore, the thickness of the foamed polypropylene foam layer is 3 mm and the density is 0.06 g / cm³.

[0014] Furthermore, in step (1), polyethylene glycol accounts for 10% of the mass of polyvinyl alcohol, and the mass ratio of silica aerogel powder to the glue solution is 1:18.

[0015] Furthermore, in step (1), the dosage of polyurethane prepolymer is 5 - 8% of the mass of the preliminary cross-linking material.

[0016] Furthermore, in step (3), component A includes, by weight: 12 parts of nano-gel microspheres, 4 parts of maleic anhydride grafted hyperbranched polyethylene fibers, 65 parts of polyether polyol, 20 parts of castor oil derivative, 10 parts of epoxy soybean oil acrylate, 1.2 parts of silicone oil L-580, 1.5 parts of dibutyltin dilaurate, 4 parts of cyclopentane, and 1.5 parts of water.

[0017] Furthermore, in step (3), three injection channels are used for partition injection, and the addition amounts of nano-gel microspheres and MAH grafted hyperbranched polyethylene fibers in each area are different. By weight,

[0018] In the front area, 20 parts of nano-gel microspheres and 3 parts of maleic anhydride grafted hyperbranched polyethylene fibers;

[0019] In the side area, 12 parts of nano-gel microspheres and 8 parts of maleic anhydride grafted hyperbranched polyethylene fibers;

[0020] In the top area, 8 parts of nano-gel microspheres and 5 parts of maleic anhydride grafted hyperbranched polyethylene fibers.

[0021] A hockey helmet, comprising:

[0022] The anti-collision protection inner lining as described above;

[0023] Anti-puncture outer shell: Molded by short aramid fibers and high-density polyurethane prepolymer, with a thickness of 0.5 mm;

[0024] The inner lining is bonded to the outer shell through a polyurethane adhesive.

[0025] Furthermore, standardized capsule slots are provided in the forehead core area, the main temporal anti-impact area, and the occipital protection area of the outer shell.

[0026] Furthermore, the capsule slots are detachably connected to functional capsules, including high energy absorption capsules, puncture-resistant capsules, lightweight breathable capsules, and high-frequency rebound capsules.

[0027] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0028] First, through molecular plasticization (PEG-4000 / castor oil to inhibit low-temperature embrittlement), microsphere elastic coating (HDI prepolymer), fiber interface covalent bonding (MAH grafting), and centrifugal gradient foaming (microsphere concentration from 15% to 8% for layered energy absorption), the problems of buffer failure, structural disintegration after multiple impacts, and stress concentration of the ice hockey helmet at -10°C are solved, improving the reliability and anti-impact performance of the ice hockey helmet;

[0029] Second, through multi-injection channel zoning formulation (20% microspheres / 3% fibers on the front, 12% microspheres / 8% fibers on the side, 8% microspheres / 5% fibers on the top) combined with pressure control (±0.1 bar) and centrifugal-vibration process (500 rpm + 50 Hz), a three-dimensional functional gradient structure is constructed to solve the problem of different regional protection requirements of the ice hockey helmet: insufficient energy absorption on the front, weak anti-shear on the side, and redundant weight on the top, achieving an increase in the front energy absorption rate and the side anti-shear strength;

[0030] Third, by setting standardized slots in different areas of the helmet and introducing different functional capsules, the overall protection is disassembled into capsule units of independent functions, and "plug-and-play" type performance customization is achieved through standardized slots, realizing precise strengthening of different areas. Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of the fourth embodiment of the present invention. Detailed Embodiments

[0032] To facilitate the understanding of the present invention, the present application will be described more comprehensively with reference to the relevant drawings; the drawings show preferred embodiments of the present invention, however, the present invention can be implemented in many different forms and is not limited to the embodiments described herein; on the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this invention belongs; the terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] Example 1: An anti-collision protection lining and a preparation method thereof, specifically including the following steps:

[0035] Step 1: Preparation of nano-gel microspheres

[0036] (1) Preparation of glue solution: Polyvinyl alcohol (grade 24-88) and polyethylene glycol (PEG-4000, accounting for 10% of the mass of PVA) are jointly added to hot water at 80 °C (PVA: hot water = 1:25), and stirred until completely dissolved to form a mixed glue solution;

[0037] (2) Aerogel adsorption: Hydrophilic silica aerogel powder (QF600 type, aerogel powder: glue solution = 1:18) is added to the glue solution, and stirred at a high speed of 1000 rpm for 8 min to obtain a semi-dry powder;

[0038] (3) Boric acid cross-linking: Maintain low-speed stirring (90 rpm), slowly add saturated boric acid solution (the dosage is 4% of the mass of the semi-dry powder), and react at 85 °C for 1.5 h to achieve preliminary cross-linking of PVA;

[0039] (4) Alkali treatment and PU coating: Spray saturated sodium hydroxide solution (the dosage is 3% of the mass of the preliminarily cross-linked material) and simultaneously atomize and spray HDI-type polyurethane prepolymer (the dosage is 5-8% of the mass of the preliminarily cross-linked material), and react at 85 °C for 20 min to form a flexible gel microsphere with a double-layer coating;

[0040] (5) Microsphere dispersion: Dispersed and dried by high-pressure hot air flow impact at 120 °C / 1.5 MPa to obtain nano-gel microspheres with a particle size of 80-150 nm;

[0041] Step 2: Interface strengthening treatment of hyperbranched polyethylene fibers

[0042] (1) Plasma activation: Place the hyperbranched polyethylene fibers in an Ar plasma processor (power 50 W, gas pressure 10 Pa) for 30 s to activate the surface;

[0043] (2) MAH grafting: Immerse in a 2 wt% maleic anhydride (MAH)-acetone solution and react at 60 °C for 1 h to complete the grafting of carboxylic acid groups;

[0044] (3)Drying for standby: Dry the fiber at 60 °C, increase the surface oxygen content to 15 at%, and the interfacial bonding strength reaches 12 N / mm.

[0045] Step 3: Foaming and forming of the gradient buffer layer

[0046] (1)Component A: By weight, component A includes 12 parts of nano-gel microspheres, 4 parts of MAH-grafted hyperbranched polyethylene fiber, 65 parts of polyether polyol (molecular weight 3000), 20 parts of castor oil derivative, 10 parts of epoxy soybean oil acrylate, 1.2 parts of silicone oil L-580, 1.5 parts of dibutyltin dilaurate, 4 parts of cyclopentane, and 1.5 parts of water;

[0047] (2)Component B: Polyisocyanate (PM-200 type), weight ratio of A:B is 1:1;

[0048] (3)Centrifugal injection molding and foaming: Inject the A / B components into a centrifugal mold preheated to 40 °C, rotate centrifugally at 500 rpm; High-pressure mixing injection (100 bar), foam and cure in the mold for 20 min to form a microsphere gradient enrichment layer (microsphere concentration on the impact surface is 15%, decreasing inward to 8%);

[0049] (4)After demolding, a three-layer composite inner lining substrate is obtained:

[0050] Outer layer: High ball density area (0.35 g / cm³, anti-impact layer);

[0051] Middle layer: Fiber-reinforced area (0.18 g / cm³, main energy-absorbing layer);

[0052] Inner layer: Low-density open-cell area (0.06 g / cm³, comfort layer);

[0053] Step 4: Inner lining composite processing

[0054] (1)Laminating the foamed polypropylene inner lining: Thermally press and laminate antibacterial foamed polypropylene (EPP) foam (thickness 3 mm, density 0.06 g / cm³) on the inner layer surface of the open-cell area, and the hot melt adhesive temperature is 120 °C;

[0055] Structural processing: Cut it into the curved configuration of the helmet inner lining to obtain an anti-collision protection inner lining.

[0056] The preparation method of a hockey helmet containing the anti-collision protection inner lining, the specific steps are

[0057] Step A: Preparation of the anti-puncture outer shell

[0058] (1)Material mixing: Mix short aramid fibers (10 wt%) with high-density polyurethane prepolymer (density 0.35 g / cm³);

[0059] (2) Compression molding: Inject into the helmet shell mold and compress mold for 10 minutes at 80°C and a pressure of 15 MPa to form a puncture-resistant shell with a thickness of 0.5 mm;

[0060] Step B. Liner-shell integration

[0061] (1) Spray polyurethane adhesive on the inner surface of the puncture-resistant shell;

[0062] (2) Insert the impact-resistant protection liner into the shell, position and apply pressure (pressure 0.5 MPa, time 5 minutes) to bond the outer layer of the liner to the shell.

[0063] Conduct experiments on the technical solutions of this embodiment. The addition amounts of the polyurethane prepolymer are 5% (Experiment 1), 6.5% (Experiment 2), and 8% (Experiment 3) of the mass of the preliminary cross-linked material respectively. No polyurethane prepolymer is added in the comparative example. Perform performance tests on the samples prepared in the comparative example and Experiments 1 to 3;

[0064] 1. Low-temperature impact absorption test (-10°C): Keep the helmet in a constant temperature environment chamber at -10°C for 24 hours, use a 5 kg hemispherical punch to impact the top of the helmet at a speed of 7.5 m / s, record the maximum impact force value (kN), according to: ASTM F1447 standard (the requirement for a hockey helmet is ≤8.0 kN);

[0065] 2. Multi-impact attenuation test (-10°C): Continuously perform 5 impacts (energy 50 J / time) at the same point, calculate the attenuation rate (%) of the peak force between the 5th and the 1st time, according to: CSA Z262.1 standard (the requirement for the attenuation rate is ≤15%);

[0066] 3. Microsphere structural integrity: Take samples of the impacted samples for SEM observation, and count the proportion (%) of the broken microspheres among 200 microspheres, according to: ISO 18516:2019 (evaluation of microsphere structural integrity);

[0067] 4. Interlayer bonding strength test: 90° peel test with a universal testing machine, measure the peel strength (N / mm) between the three-layer structure (high / middle / low density layers), according to: ISO 4587 standard (the requirement is ≥5.0 MPa);

[0068] 5. Lateral shear strength (MPa): Compress the specimen obliquely at 45° until failure, calculate the shear strength τ (MPa), according to: CSA Z262.1 (the requirement is ≥1.8 MPa); The test results are shown in Table 1 below;

[0069] Table 1

[0070] Group Peak force of low-temperature impact (kN) Decay rate of multiple impacts (%) Microsphere impact fracture rate (%) Interlayer bonding strength (MPa) Side shear strength (MPa) Control group 9.2 28 42 2.1 0.3 Experiment 1 7.0 12 18 5.8 1.0 Experiment 2 6.3 7 7 7.2 1.4 Experiment 3 6.5 8 9 6.9 1.2

[0071] The technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0072] By flexibly modifying the molecules and strengthening the interfacial bonding, the energy gradient distribution of the inner lining of the ice hockey helmet is achieved macroscopically, comprehensively improving the overall performance of the ice hockey helmet;

[0073] By introducing the long-chain ether bond of PEG-4000 into the molecular network of polyvinyl alcohol (PVA), the hydrogen bond crystal structure is destroyed, and the glass transition temperature (Tg) of the nanocolloidal microspheres is reduced from 25 °C to -15 °C, endowing them with an elastic recovery ability of 85% at -10 °C; The simultaneously added castor oil derivative penetrates the polyurethane matrix with its long-chain fatty acid ester, inhibiting the low-temperature embrittlement of the hard segment, and jointly ensuring the deformation freedom of the material at low temperature;

[0074] By introducing the HDI polyurethane prepolymer, it in-situ polymerizes on the surface of the microspheres to form an elastic coating layer with a thickness of 0.35 μm. This layer acts through two mechanisms in synergy: First, the dense silicon-oxygen network (Si-O-Si) formed by partial dissolution of silica by alkali solution seals the surface defects; In addition, the polyurethane urea elastomer formed by the reaction of the isocyanate group (-NCO) of the prepolymer with the hydroxyl group of PVA converts the impact stress into elastic deformation energy. At the same time, after the hyperbranched polyethylene fiber is activated by plasma and grafted with maleic anhydride (MAH), the carboxyl group (-COOH) on its surface forms a covalent amide bond (-NHCO-) with the -NCO of the polyurethane matrix, significantly improving the interfacial bonding strength between the fiber and the matrix and avoiding delamination;

[0075] At the macroscopic level, the directional dissipation of impact energy is achieved through the gradient structure design: The centrifugal injection molding process (500 rpm) drives the nano-microspheres to concentrate towards the impact surface, forming an outer-inner three-order density gradient: The outer high-density area (0.35 g / cm³, microsphere concentration 15%) preferentially absorbs 35% of the impact energy through the deformation of the microsphere colloid; The middle fiber-reinforced area (0.18 g / cm³) disperses and conducts the remaining energy through the MAH-bonded fiber network, dissipating 50% of the energy; The inner low-density open-cell area (0.06 g / cm³) buffers the residual stress by foam collapse, avoiding local overload. This structure reduces the peak impact force by 31.5%, and the energy hierarchical dissipation characteristics enable the material to remain structurally intact after 15 impacts of 50 J;

[0076] Through the above improvements, problems such as the energy absorption failure caused by the low-temperature crystallization and hardening of polyvinyl alcohol (PVA)-based nano-microspheres at -10°C in a low-temperature environment and high-frequency impact scenarios, the fragmentation and disintegration of the microsphere structure under multiple impacts, and the delamination and peeling caused by the weak interfacial bonding between the fiber-reinforced network and the matrix are avoided, thus solving the problems of low-temperature embrittlement failure, multiple impact fatigue, and insufficient safety of ice hockey helmets; in the performance test, the impact peak force of the ice hockey helmet at -10°C is 6.3 kN (lower than the safety threshold of 8.0 kN), solving the problem of protective failure in the low-temperature scenario of ice hockey, improving the reliability of use in a low-temperature environment, reducing the microsphere rupture rate to 7%, increasing the interfacial peel strength to 12 N / mm, extending the service life, and enhancing the impact resistance performance.

[0077] Example 2: In the above Example 1, through molecular plasticization (PEG-4000 / castor oil to inhibit low-temperature embrittlement), elastic coating of microspheres (HDI prepolymer), covalent bonding of fiber interfaces (MAH grafting), and centrifugal gradient foaming (layered energy absorption with microsphere concentration from 15% to 8%), the problems of buffer failure, structural disintegration under multiple impacts, and stress concentration of ice hockey helmets at -10°C are solved, improving the reliability of use and impact resistance performance of ice hockey helmets. To further improve their overall performance, further improvements are made on the basis of Example 1.

[0078] Step 3: Forming the gradient buffer layer by foaming

[0079] Set three independent injection runners in the centrifugal mold, corresponding to the front area, side area, and top area respectively; each runner is equipped with a piezoelectric pressure sensor (accuracy ±0.1 bar) and a proportional control valve;

[0080] Among them, the addition amounts of nano-gel microspheres and MAH-grafted hyperbranched polyethylene fibers in each area are different. By weight,

[0081] In the front area, 20 parts of nano-gel microspheres and 3 parts of MAH-grafted hyperbranched polyethylene fibers;

[0082] In the side area, 12 parts of nano-gel microspheres and 8 parts of MAH-grafted hyperbranched polyethylene fibers;

[0083] In the top area, 8 parts of nano-gel microspheres and 5 parts of MAH-grafted hyperbranched polyethylene fibers;

[0084] Inject the component A and component B (PM-200) of the partition into the three runners at a ratio of 1:1 simultaneously;

[0085] (4) After demolding, a three-dimensional functional gradient structure is formed. Normal gradient (from the surface to the inside): microsphere concentration from 15% to 8% (retained by centrifugal effect); transverse gradient (customized by partition): high energy absorption in the front area / shear resistance in the side area / lighter weight in the top area.

[0086] Based on the technical solution of this embodiment, an experiment was conducted on the basis of Experiment 2 of Example 1, as Experiment 4. The difference between Experiment 4 of this embodiment and Experiment 2 of Example 1 is that this embodiment uses multiple injection channels to perform gradient foaming. The performance of the samples prepared in Experiment 4 was tested, and the test results are shown in Table 2 below.

[0087] Table 2

[0088] Group Peak force of low-temperature impact (kN) Decay rate of multiple impacts (%) Microsphere impact fracture rate (%) Interlayer bonding strength (MPa) Side shear strength (MPa) Experiment 4 5.8 6 5 6.9 2.1

[0089] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0090] By combining a multi-injection flow channel zoning formula (20% microspheres / 3% fiber on the front, 12% microspheres / 8% fiber on the sides, and 8% microspheres / 5% fiber on the top) with pressure control (±0.1 bar) and a centrifugal-vibration process (500 rpm + 50 Hz), a three-dimensional functionally graded structure is constructed. This addresses the differentiated protection requirements of ice hockey helmets: insufficient energy absorption on the front, weak shear resistance on the sides, and redundant weight gain on the top, thereby improving both the front energy absorption rate and the side shear strength.

[0091] At the microscopic level, based on the molecular directional functionalization and interface synergy mechanism, the PEG-4000 plasticized PVA molecular chains in the 20% high-concentration microspheres in the front area destroy hydrogen bond crystallization, reducing the glass transition temperature (Tg) to -15°C. During impact, the molecular chains slip significantly, converting kinetic energy into internal friction heat. In the 8% fiber surface area of the side area, MAH grafting forms dense carboxyl groups, which covalently bond with the polyurethane-NCO groups to construct a three-dimensional interlocking network. This allows shear stress to be transmitted along the fiber axis and inhibits crack initiation under 45° oblique impact. In the top area, long-chain fatty acid esters of castor oil derivatives penetrate the polyurethane hard segment. Even with a low microsphere content (8%), it still maintains an elongation at break of 210% at -10°C, ensuring low-temperature toughness after lightweighting.

[0092] At the macro level, a multi-channel dynamic injection-centrifugation synergistic process drives three-dimensional gradient formation: 150 bar high pressure precisely injects high-microsphere slurry into the front area, while 500 rpm centrifugal force concentrates the microspheres toward the impact surface, forming a normal attenuation gradient of 15% to 8%. 100 bar medium pressure evenly disperses high-fiber slurry in the side areas, where the fiber network blocks shear crack propagation. 60 bar low pressure ensures defect-free molding of the low-density foam (0.18 g / cm³) in the top area. Piezoelectric sensors (±0.1 bar) monitor pressure in real time, locking the concentration error in the functional area to ±1% and the gradient slope in the transition zone to ≤3% / mm.

[0093] Through the multi-injection runner partitioned formulation combined with pressure control and centrifugal-vibration process, the energy absorption rate in the front area is 85%, reducing the 50J impact peak force to 5.8kN. The shear strength in the side area is 2.1MPa, which can withstand the maximum swing force of NHL players (2.3MPa). The weight reduction in the top area is 8%, making the total weight only 432g, reducing the neck EMG load of professional players by 18%. The ventilation runner maintains a ventilation volume of 29L / min. The three-dimensional gradient eliminates stress concentration. After 300 impacts, the microsphere rupture rate is only 5%. The deflection angle of the helmet under oblique impact is reduced from 30° to 15°.

[0094] Example 3: In the above Example 2, through the multi-injection runner partitioned formulation combined with pressure control and centrifugal-vibration process, the problem of different protection requirements in different regions of the ice hockey helmet is solved, a three-dimensional functional gradient structure is constructed, and the reliability and impact resistance of the ice hockey helmet are improved. To further improve its overall performance, it is further improved on the basis of Example 2.

[0095] Perform self-healing coating on the surface of the nano-glial microspheres prepared in Step 1;

[0096] The specific self-healing coating is to spray a mixed slurry of 10 parts of dicyclopentadiene (DCPD) microcapsules + 1 part of Grubbs catalyst on the surface of the microspheres in a fluidized bed, with a coating rate of 15wt% and a thickness ≤ 0.2μm;

[0097] After the helmet is prepared, fix the helmet on a servo impact table and apply a 55J impact to the front area (punch Φ30mm, 7m / s); the acoustic emission sensor monitors in real time, and those with a rupture rate > 20% are automatically rejected; the qualified products are left standing for 24h (room temperature) or 4h (60°C) to complete self-healing.

[0098] Experiments are carried out on the technical solution of this embodiment on the basis of Experiment 4 of Example 2. As Experiment 5 of this embodiment, the difference between Experiment 5 of this embodiment and Experiment 4 of Example 2 is that a DCPD microcapsule / Grubbs catalyst coating layer is newly added to the microspheres and the helmet is pre-impacted; the test results are shown in Table 3 below;

[0099] Table 3

[0100] Group Peak force of low-temperature impact (kN) Decay rate of multiple impacts (%) Microsphere impact fracture rate (%) Interlayer bonding strength (MPa) Side shear strength (MPa) Experiment 5 5.3 3 2 8.5 2.3

[0101] The technical solutions in the above embodiments of the present application have at least the following technical effects or advantages:

[0102] By self-healing coating and pre-impact activation of the microspheres, the problem that the rupture rate is high after multiple impacts in the high microsphere area, resulting in a decrease in energy absorption efficiency, is solved, and the protection performance and service life are significantly improved.

[0103] At the micro level, a self-healing trigger-reinforcement closed-loop system is constructed. At the molecular scale, the dicyclopentadiene (DCPD) microcapsules coated on the surface of the microspheres and the Grubbs catalyst form a "dormant repair unit". When a 55J pre-impact triggers the rupture of the microspheres (rupture rate of 15-20%), the released DCPD contacts the catalyst and undergoes ring-opening polymerization to generate a cross-linked polyester network. This network simultaneously achieves: physical filling of cracks, penetrating into micron-sized cracks (5-50μm), with a filling rate ≥90% and interfacial chemical anchoring: the ester bonds of the polyester form a hydrogen bond network with the polyurethane matrix, and the binding energy is increased by 40%; at the microstructural scale, the repair body can blunt the crack tip, reduce the stress concentration coefficient of subsequent impacts, and simultaneously enhance the fiber-matrix node connection;

[0104] At the macro level, the pre-impact process and the three-dimensional gradient structure act synergistically: precise control of the pre-impact, a servo impact machine (±1J) applies a 55J impact to the front area (simulating 120% of the energy in a game), and an acoustic emission sensor captures the rupture characteristic wave of 150-200kHz in real time to ensure a rupture rate of 15-20% (automatically rejected if >20%);

[0105] The gradient function is further strengthened. In the front area, the concentration of the microspheres decreases after repair, but the cross-linked network improves the deformation recovery force, and the energy absorption efficiency is increased by 7%; in the side area, the polyester body enhances the shear-resistant nodes of the fiber network, and the shear strength is increased by 9.5%; in the top area, the lightweight property is not affected (the density remains 0.18g / cm³);

[0106] By triggering the self-healing mechanism through pre-impact (55J impact activates the DCPD polymerization repair), a cross-linked polyester repair network is formed at the micro level, achieving a crack filling rate ≥90% and interfacial binding energy, further improving the protection performance. The peak impact force is 5.3kN, and the attenuation rate after 5 impacts is only 3%; the service life is further enhanced, the rupture rate of the microspheres is significantly reduced, and the self-healing ability endows the helmet with the characteristics of self-healing and performance improvement, and the life is further extended.

[0107] Example 4: In the above Example 3, the self-healing mechanism is triggered through pre-impact to form a self-healing reinforced interface network, significantly improving the multi-impact resistance and structural life, endowing the helmet with the characteristics of damage self-adaptive evolution, solving the problem of rupture failure after multiple impacts in the high microsphere concentration area, improving the reliability and anti-impact performance of the ice hockey helmet, and further improving its overall performance on the basis of Example 3.

[0108] As Figure 1 shown, standardized capsule slots are set in the FZ-1 (frontal core area), LT-1 (temporal main anti-impact area), and OC-1 (occipital protection area) of the helmet, and replaceable functional capsules are introduced;

[0109] The FZ-1 is in the front of the helmet, covering the area from the forehead to above the eyebrow bone;

[0110] The LT-1 is the area from the temples on both sides of the helmet to above the ears;

[0111] The OC-1 is the area at the back of the helmet;

[0112] The capsule body includes a high energy absorption capsule body, a puncture resistant capsule body, a lightweight breathable capsule body and a high frequency rebound capsule body;

[0113] Among them, the high energy absorption capsule body uses shear thickening fluid (STF, dynamic viscosity 10 4 Pa·s) as the core energy dissipation medium, instantaneously hardens upon impact to dissipate kinetic energy, and is internally filled with silica aerogel (porosity 95%) to achieve secondary energy absorption through multi-level pore collapse. It combines a piezoelectric sensor to real-time feedback the impact waveform to the main control system of the helmet, achieving protection with an energy absorption efficiency of 95% and a peak force of 5.8 kN;

[0114] The puncture resistant capsule body uses aramid honeycomb aluminum (density 0.6 g / cm³) as the energy absorption framework, with a silicon carbide coating (hardness 2800 HV) on the surface to resist puncture by sharp objects. An electromagnetic locking device is integrated and instantaneously activated when the gyroscope detects a 45° oblique impact, achieving a puncture resistant energy of 120 J and a penetration depth ≤ 1 mm;

[0115] The lightweight breathable capsule body realizes topological optimization and weight reduction based on 3D printed hollow TPU lattice (porosity 60%), embeds a micro-vortex fan air duct for forced convection heat dissipation, and a graphene heat conduction layer is compounded on the surface layer to quickly conduct heat, achieving a balance of 35% weight reduction and 55% improvement in heat dissipation efficiency;

[0116] The high frequency rebound capsule body uses super elastic TPU foam (rebound rate ≥ 90%) as the core buffer medium. Its molecular chain network instantaneously returns to its original state after impact, and combines with a honeycomb aluminum support layer (density 0.4 g / cm³) for plastic deformation to dissipate residual energy, achieving flexible protection with a peak force ≤ 4 kN under a 30 J impact and having a durability with a cycle life ≥ 5000 times.

[0117] The technical solutions in the embodiments of the present application described above have at least the following technical effects or advantages:

[0118] By setting standardized slots in different areas of the helmet and introducing different functional capsules, the overall protection is disassembled into independent functional units (capsules), and "plug and play" performance customization is achieved through the standardized slots, realizing precise reinforcement in different areas. Among them, a high-energy absorption capsule is adopted in the frontal area (FZ-1 area), and a double-stage energy absorption mechanism of "instantaneous hardening - multi-stage collapse" is constructed by using STF fluid and aerogel; an anti-puncture capsule is adopted in the temporal area (LT-1 area), and an intelligent anti-puncture system of "passive defense - active response" is formed by combining a silicon carbide coating and electromagnetic locking technology; a lightweight / high-frequency rebound capsule is adopted in the occipital area (OC-1 area), and a triple balance of "weight reduction - heat dissipation - rebound" is achieved through topological structure optimization.

[0119] Different capsule types combine with different areas to play an enhanced synergistic role. The high-energy absorption capsule realizes an energy absorption efficiency of up to 95% through the impact hardening of STF fluid and the collapse of aerogel pores, and can resist the impact of an ice hockey at 80 km / h, which is suitable for forward players; the anti-puncture capsule uses the physical barrier of the silicon carbide coating and the shear resistance enhancement of electromagnetic locking to provide an anti-puncture capacity of 120 J, ensuring the near-defense needs of goalkeepers during close defense; the lightweight breathable capsule realizes a 35% weight reduction and a 55% heat dissipation improvement through 3D hollow TPU weight reduction and vortex fan forced heat dissipation technology, which helps full-back players maintain their endurance during long-term competitions; the high-frequency rebound capsule reaches a cycle life of 5000 times by virtue of the instantaneous recovery of super-elastic TPU and the plastic energy dissipation of honeycomb aluminum, significantly reducing the training cost.

[0120] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An anti-collision protection inner lining, characterized in that, Including: An outer layer with a high microsphere density region, a middle layer with a fiber-reinforced region, and an inner layer with a low-density open-cell region, and an inner composite antibacterial foamed polypropylene foam layer; The preparation method of the anti-collision protection lining includes the following steps: (1) Prepare nano-gel microspheres: Dissolve polyvinyl alcohol and polyethylene glycol in hot water, add silica aerogel powder and stir, crosslink with boric acid, treat with alkali, and coat with polyurethane prepolymer, and disperse and dry with high-pressure hot air flow; (2) Interface strengthening: Activate by plasma and perform maleic anhydride grafting treatment; (3) Gradient buffer layer foaming: Mix component A containing nano-gel microspheres and maleic anhydride-grafted fibers with polyisocyanate component B in a ratio of 1:1, inject into a centrifugal mold for foaming and molding to form a microsphere gradient enrichment layer; (4) Lining composite: Thermally press and bond antibacterial foamed polypropylene foam to the open-cell layer and cut.

2. The anti-collision protection inner lining according to claim 1, wherein The densities of the outer layer, middle layer, and inner layer are 0.35 g / cm³, 18 g / cm³, and 0.06 g / cm³ respectively.

3. The anti-collision protection inner lining according to claim 1, characterized in that, The thickness of the foamed polypropylene foam layer is 3 mm and the density is 0.06 g / cm³.

4. The anti-collision protection inner lining according to claim 1, characterized in that, In step (1), polyethylene glycol accounts for 10% of the mass of polyvinyl alcohol, and the mass ratio of silica aerogel powder to the glue solution is 1:

18.

5. The anti-collision protection inner lining according to claim 1, characterized in that, In step (1), the dosage of polyurethane prepolymer is 5-8% of the mass of the preliminary cross-linked material.

6. The anti-collision protection inner lining according to claim 1, characterized in that, In step (3), component A includes, by weight: 12 parts of nano-gel microspheres, 4 parts of maleic anhydride-grafted hyperbranched polyethylene fibers, 65 parts of polyether polyol, 20 parts of castor oil derivative, 10 parts of epoxy soybean oil acrylate, 1.2 parts of silicone oil L-580, 1.5 parts of dibutyltin dilaurate, 4 parts of cyclopentane, and 1.5 parts of water.

7. The anti-collision protection inner lining according to claim 1, characterized in that, In step (3), a three-injection runner is used for partition injection, and the addition amounts of nano-gel microspheres and MAH-grafted hyperbranched polyethylene fibers in each area are different. By weight, In the front area, 20 parts of nano-gel microspheres and 3 parts of maleic anhydride-grafted hyperbranched polyethylene fibers; In the side area, 12 parts of nano-gel microspheres and 8 parts of maleic anhydride-grafted hyperbranched polyethylene fibers; In the top area, 8 parts of nano-gel microspheres and 5 parts of maleic anhydride-grafted hyperbranched polyethylene fibers.

8. A hockey helmet, characterized in that, Including: The anti-collision protection lining according to any one of claims 1-7; An anti-puncture outer shell: Molded by short aramid fibers and high-density polyurethane prepolymer, with a thickness of 0.5 mm; The lining is bonded to the outer shell with polyurethane adhesive.

9. The ice hockey helmet according to claim 8, wherein, Standardized capsule slots are provided in the forehead core area, temporal main anti-area, and occipital protection area of the outer shell.

10. The ice hockey helmet according to claim 9, characterized in that, The capsule slots are detachably connected to functional capsules, including high-energy absorption capsules, anti-puncture capsules, lightweight breathable capsules, and high-frequency rebound capsules.

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