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CN-121424766-B - Composite hollow plate and preparation method thereof

CN121424766BCN 121424766 BCN121424766 BCN 121424766BCN-121424766-B

Abstract

The invention discloses a composite hollow plate and a preparation method thereof, and belongs to the technical field of composite plate preparation. The composite hollow plate comprises an outer plate and an inner plate, a plurality of ripple supporting structures are connected between the outer plate and the inner plate, and a cavity is formed between every two adjacent ripple supporting structures. The wear-resistant reinforcing agent is added into the outer plate material to improve the surface wear resistance, the epoxy-amine dual-core dual-wall microcapsule is introduced into the inner plate material to enhance the crack repairing capability, and the shape memory reinforcing agent is added into the corrugated supporting structure material to endow the material with shape memory characteristics. The invention solves the technical problems of difficult compromise of strength and toughness, short service life, poor buffer performance, insufficient interface bonding strength and the like of the existing composite material hollow plate, and is particularly suitable for application scenes such as steel coil packaging and the like which need repeated use and high reliability.

Inventors

  • HAN XIUMING

Assignees

  • 本溪鹤腾科技发展有限公司

Dates

Publication Date
20260512
Application Date
20251114

Claims (8)

  1. 1. A composite hollow plate is characterized by comprising an outer plate and an inner plate, wherein the thickness of the outer plate is 2-10mm, and the thickness of the inner plate is 2-8mm; the outer plate consists of the following components in parts by weight: 100-160 parts of matrix resin E-51, 20-30 parts of hardener 4, 4-diaminodiphenyl methane, 5-10 parts of wear-resistant reinforcing agent, 8-15 parts of silicon carbide micropowder, 1-3 parts of coupling agent silane coupling agent KH-560 and 50-100 parts of reinforcing fiber chopped glass fiber mat; the inner plate comprises the following components in parts by weight: The matrix resin comprises 100 parts of vinyl ester resin, 70-90 parts of epoxy acrylate, 20-30 parts of a linear polymer network, 3-5 parts of benzoyl peroxide, 0.5-1.5 parts of dimethylaniline, 15-25 parts of a toughening agent, 4-8 parts of maleic anhydride grafted polypropylene, 8-15 parts of an epoxy-amine dual-core dual-wall microcapsule, 3-6 parts of an organic modified montmorillonite, 80-120 parts of a reinforcing fiber and a continuous glass fiber felt, wherein the linear polymer network comprises 3-5 parts of benzoyl peroxide and 0.5-1.5 parts of dimethylaniline; The corrugated supporting structure comprises the following components in parts by weight: The first network resin comprises 100 parts of o-benzene type unsaturated polyester resin, 60-80 parts of second network polyol component, 30-40 parts of castor oil based polyol, 40-60 parts of second network isocyanate component, 60-90 parts of chopped glass fiber, 40-60 parts of glass fiber non-woven fabric, 2-4 parts of cross-linking agent, 3-5 parts of curing system, 0.4-1.0 part of dibutyl tin dilaurate, 5-10 parts of shape memory enhancer, 1-2 parts of foaming agent, 3-5 parts of compound system of sodium bicarbonate and citric acid, 0.5-1.5 parts of foaming stabilizer, 1-3 parts of nucleating agent, 2-4 parts of talcum powder and 0.5-1.5 parts of nano calcium carbonate; The preparation process of the epoxy-amine dual-core dual-wall microcapsule comprises the steps of taking triethylene glycol diglycidyl ether as an inner core repairing agent, taking diethylenetriamine as an outer core curing agent, adopting an interfacial polymerization method to prepare the epoxy-amine dual-core dual-wall microcapsule, wherein the inner wall is a polyurethane-urea resin composite wall material, and the outer wall is a polyurea wall material; dispersing sodium-based montmorillonite in water at 80-90 ℃, adding octadecyl trimethyl ammonium chloride, stirring at 60-70 ℃ for reaction for 2-4 hours, washing until no Cl - ions exist, drying and grinding to obtain the organic modified montmorillonite; the polyurethane prepolymer is castor oil type and has a molecular weight of 1500-2500, the polyether polyol has a molecular weight of 2000-3000, and the polycaprolactone diol has a molecular weight of 800-1200.
  2. 2. A process for the preparation of a hollow panel of composite material according to claim 1, comprising the steps of: S1, preparing an interface enhancement coating, namely respectively preparing an interface enhancement coating A component and a B component, wherein the A component is used for the fiber pretreatment of an outer plate and an inner plate, and the B component is used for the interface enhancement of the surface of a corrugated supporting structure; S2, preparing a three-cavity partition mould, wherein the three-cavity partition mould comprises an outer plate forming cavity, an inner plate forming cavity and a corrugated supporting structure forming cavity, an electrode plate system and a multi-point gate system are arranged on the mould, and a temperature partition control system and a pressure monitoring system are configured; S3, carrying out interface pretreatment, respectively coating the cut chopped glass fiber mats and the continuous glass fiber mats with an interface reinforcing coating A component, and then laying the cut chopped glass fiber mats and the continuous glass fiber mats in a corresponding outer plate forming cavity and an inner plate forming cavity, wherein the coating faces towards the inside of the cavity; s4, respectively preparing an outer plate material, an inner plate material and a corrugated supporting structure material, wherein when the inner plate material is prepared, firstly, organic modified montmorillonite is pre-dispersed in part of epoxy acrylate resin and then mixed with main resin, when the corrugated supporting structure material is prepared, a component A and a component B are respectively prepared, and after vacuum degassing treatment is carried out on the materials, the materials are transferred to a reaction injection machine charging tank; S5, adopting a pulse electric field assisted reaction injection molding process, sequentially injecting an outer plate material, a corrugated support structure material and an inner plate material in three stages, synchronously coating an interface enhancement coating B component on the surface of the corrugated support structure during injection in a second stage, starting to apply a pulse electric field to promote interface bonding and fiber infiltration when the initial viscosity of the resin reaches 0.5-1.0 Pa.s, and controlling the injection interval of each stage to be within 30-90 seconds; and S6, carrying out synchronous solidification and post-treatment, after three-stage injection is finished, controlling the temperature partition to enable each layer of material to finish main solidification reaction within 15-30 minutes and form interface combination, finally cooling and demolding the mold, and carrying out post-solidification treatment on the demolded composite hollow plate.
  3. 3. The preparation process according to claim 2, wherein step S1 comprises: s11, preparing an interface enhancement coating A component, wherein the interface enhancement coating A component comprises, by mass, 70-80 parts of epoxy resin E-44, 15-25 parts of polyurethane prepolymer, 2-3 parts of silane coupling agent KH-550 and 0.5-1.5 parts of nano graphene; S12, when the interface enhancement coating A component is prepared, stirring epoxy resin E-44, polyurethane prepolymer and silane coupling agent KH-550 for 60-90 minutes at 50-70 ℃ to ensure that the components are fully and uniformly mixed, simultaneously pre-dispersing nano graphene in absolute ethyl alcohol and performing ultrasonic treatment for 15-30 minutes, then adding nano graphene dispersion liquid into resin mixed liquid, continuously stirring for 30-60 minutes, standing and degassing for 20-40 minutes to obtain the interface enhancement coating A component; s13, preparing an interface enhancement coating B component, wherein the interface enhancement coating B component comprises, by mass, 60-70 parts of unsaturated polyester resin, 25-35 parts of epoxy acrylate, 2-3 parts of silane coupling agent KH-560 and 0.3-0.8 part of functionalized carbon nano-tubes; And S14, when the interface enhancement coating B component is prepared, stirring unsaturated polyester resin, epoxy acrylate and silane coupling agent KH-560 for 60-90 minutes at 50-70 ℃ to fully and uniformly mix the components, simultaneously pre-dispersing functionalized carbon nano tubes in acetone and carrying out ultrasonic treatment for 15-30 minutes, then adding the carbon nano tube dispersion liquid into the resin mixed liquid, continuously stirring for 30-60 minutes, standing and degassing for 20-40 minutes to obtain the interface enhancement coating B component.
  4. 4. The preparation process according to claim 2, wherein the step S2 comprises: S21, designing and processing a three-cavity partition die main body, dividing the die into three independent forming cavities, wherein an outer plate forming cavity and an inner plate forming cavity are flat plate forming cavities, the corrugated supporting structure forming cavities are designed to be corrugated curved surfaces, sealing partitions are arranged among the forming cavities to prevent different materials from penetrating each other, and a numerical control milling machine or an electric spark machining method is adopted to manufacture the die and ensure the geometric accuracy of the curved surfaces; S22, arranging pouring gates at the wave crest and the wave trough positions of the cavity formed by the corrugated supporting structure, wherein the distance between the pouring gates is 80-120mm, the diameter of the pouring gates is 3-6mm, each pouring gate is provided with a needle valve type nozzle which is controlled to be opened and closed by an electromagnetic valve, 3-5 pouring gates are uniformly arranged in the outer plate forming cavity and the inner plate forming cavity, the diameter of each pouring gate is 4-8mm, an exhaust groove is arranged at the highest point of the die, and the depth of each exhaust groove is 0.02-0.05mm; s23, arranging electrode grooves on the upper surface and the lower surface of the die at a position 5-10mm away from the surface of the forming cavity, embedding electrode plates into the electrode grooves, sealing the electrode grooves by using insulating epoxy resin glue, leading out electrode leads from the side surfaces of the die and connecting the electrode leads to a pulse power supply, wherein an electrode on the upper surface is connected with an anode, and an electrode on the lower surface is connected with a cathode; and S24, installing heating rods and temperature sensors around each forming cavity, setting different target temperatures in the forming cavity subareas of the corrugated supporting structure to realize temperature gradient control, installing pressure sensors in each forming cavity, measuring the range of 0-5MPa, and connecting all the sensors and control equipment to a PLC control system.
  5. 5. The preparation process according to claim 2, wherein step S3 comprises: S31, cutting the fiber reinforcement according to the size of the forming cavity, cutting the chopped glass fiber mat into a size matched with the forming cavity of the outer plate, cutting the continuous glass fiber mat into a size matched with the forming cavity of the inner plate, and checking the integrity of the fiber mat to ensure that no breakage and defect exists; S32, coating an interface enhancement coating A component on the fiber reinforcement by adopting ultrasonic atomization spraying equipment, loading the prepared interface enhancement coating A component into a spraying equipment charging tank, setting ultrasonic frequency to be 1.7-2.4MHz to enable the atomization particle size of the coating to be 5-15 mu m, adjusting the vertical distance between a spray gun and the surface of a fiber mat to be 15-25cm, uniformly coating by adopting a reciprocating spraying path, controlling the thickness of the coating to be 50-150 mu m, and detecting the thickness uniformity of the coating by using a thickness gauge; S33, paving the coated fiber mat in a forming cavity, paving the chopped strand glass fiber mat coated with the interface reinforcing coating A component in an outer plate forming cavity flatly, enabling the coating to face towards the cavity, ensuring that the fiber mat is well attached to the cavity wall and has no bubbles and wrinkles, paving the coated continuous glass fiber mat in an inner plate forming cavity, closing the die and applying pretightening force to seal the die.
  6. 6. The process of claim 4, wherein step S4 comprises: S41, preparing an outer plate material, adding epoxy resin E-51 into a planetary stirrer, stirring at 60-80 ℃ to fully and uniformly mix the resin, pre-soaking nano silicon dioxide and silicon carbide micro powder in a silane coupling agent KH-560 for 30-60 minutes, slowly adding the nano silicon dioxide and the silicon carbide micro powder into the resin, stirring at 70-90 ℃ for 30-50 minutes at a high speed to fully disperse a filler, adding a hardener 4, 4-diaminodiphenylmethane, rapidly stirring for 5-10 minutes, then carrying out vacuum degassing for 15-30 minutes, and adjusting the viscosity to 0.3-0.8 Pa.s to obtain an outer plate reaction mixed solution; S42, preparing an inner plate material, namely firstly ultrasonically dispersing organic modified montmorillonite in epoxy acrylate for 20-40 minutes, adding a dispersing agent, then carrying out high-shear mixing for 10-20 minutes, sequentially adding vinyl ester resin, polyurethane prepolymer, carboxyl-end polybutadiene rubber toughening agent and maleic anhydride grafted polypropylene synergistic auxiliary agent, stirring and mixing each component for 10-15 minutes, slowly adding epoxy-amine dual-core dual-wall microcapsules, stirring at a low speed to uniformly disperse the microcapsules, avoiding damaging the microcapsules by high-speed stirring, adding a benzoyl peroxide initiator and a dimethylaniline accelerator, carrying out rapid stirring for 3-5 minutes, carrying out vacuum degassing for 15-30 minutes, and regulating the viscosity to 0.4-0.9 Pa.s to obtain an inner plate reaction mixed solution; S43, preparing a component A of the corrugated supporting structure material, stirring phthalic unsaturated polyester resin and a divinylbenzene crosslinking agent for 30-50 minutes at 50-70 ℃ to fully mix, sequentially adding an azodicarbonamide foaming agent, a sodium bicarbonate and citric acid composite foaming agent, nano calcium carbonate and talcum powder nucleating agent and a silicone oil foaming stabilizer, stirring and mixing each component for 10-20 minutes, adding chopped glass fibers in batches and stirring at a low speed to uniformly disperse the fibers, adding a cyclohexanone peroxide initiator, stirring rapidly for 3-5 minutes, and adjusting the viscosity to 0.1-0.3 Pa.s to obtain the component A of the corrugated supporting structure material; S44, preparing a corrugated support structure material B component, mixing polyether polyol and castor oil-based polyol according to a mass ratio of 2:1, stirring for 30-50 minutes at 40-60 ℃ to fully and uniformly mix the two polyols, adding a polycaprolactone diol shape memory enhancer, stirring for 20-40 minutes at 50-70 ℃ to fully blend the two polyols, adding a dibutyltin dilaurate catalyst, stirring for 5-10 minutes, weighing a corresponding amount of 4, 4-diphenylmethane diisocyanate, slowly adding the 4, 4-diphenylmethane diisocyanate into a polyol mixed solution, stirring for 10-15 minutes to fully mix the polyol, and adjusting the viscosity to 0.1-0.3 Pa.s to obtain the corrugated support structure material B component; S45, transferring the prepared materials to a reaction injection machine, transferring an outer plate reaction mixed solution to an outer plate material tank, transferring an inner plate reaction mixed solution to an inner plate material tank, respectively transferring a component A and a component B of the corrugated supporting structure material to corresponding tanks, setting the temperatures of the tanks to be 50-60 ℃ of the outer plate material tank, 45-55 ℃ of the inner plate material tank and 40-50 ℃ of the corrugated supporting structure material tank, starting a circulation system to prevent material sedimentation and pregelatinization, and checking the liquid level, the temperature and the circulation pressure of the tanks for later use after being normal.
  7. 7. The preparation process according to claim 2, wherein step S5 comprises: S51, setting pulse electric field parameters and injecting in a first stage, setting the pulse electric field parameters in a PLC control system to have electric field intensity of 0.2-0.8kV/mm, pulse frequency of 50-150Hz and duty ratio of 20-40%, starting an outer plate material gate, setting injection pressure of 0.8-1.2MPa and mold filling speed of 300-500g/S, simultaneously starting a pulse power supply to apply a pulse electric field when the viscosity of an outer plate reaction mixture reaches 0.5-1.0 Pa.s, enabling the outer plate reaction mixture to enter an outer plate molding cavity under the action of injection pressure and the electric field and gradually infiltrate a chopped glass fiber mat, and closing the outer plate material gate when the pressure of the outer plate molding cavity reaches a set value and is stable, thereby completing the injection in the first stage; S52, injecting the second stage, namely immediately starting the injection of the corrugated supporting structure material within 30-90 seconds after the injection of the first stage is finished, respectively pressurizing the component A and the component B to 10-20MPa by a metering pump, conveying the components A and the component B to a high-pressure impact mixing head according to the flow ratio of 1:0.8-1.2, enabling the components A and the components B to flow out immediately after high-speed impact mixing by adopting a hedging structure in the mixing head, setting the injection pressure to 0.5-0.9MPa, and adopting the sequential opening control of a pouring gate to sequentially open the pouring gate from the center to two sides so as to ensure uniform filling; S53, synchronously coating an interface enhancement coating B component in the second stage injection process, spraying the interface enhancement coating B component on the surface of the corrugated support structure while injecting the corrugated support structure material through a preset coating system, controlling the thickness of the coating to be 30-100 mu m, continuously applying a pulse electric field to promote interface combination, and finishing the second stage injection when the pressure of the curved surface forming cavity is stable; S54, injecting the inner plate material immediately within 30-90 seconds after the injection of the third stage is finished, starting an inner plate material gate, setting injection pressure to be 0.7-1.1MPa, filling the mold at a speed of 350-550g/S, enabling the inner plate reaction mixed solution to enter an inner plate molding cavity under the action of injection pressure and an electric field and infiltrating a continuous glass fiber mat, controlling the contact interface temperature of the inner plate material and the corrugated supporting structure material to be 45-55 ℃ to ensure good interface combination, closing the inner plate material gate when the pressure of an inner plate molding cavity is stable, stopping a pulse electric field, and finishing the injection of the third stage; And S55, monitoring the mold filling state and adjusting the curing temperature, collecting pressure and temperature data of each molding cavity in real time through a PLC control system, analyzing a pressure curve to judge the mold filling completion state of each cavity, recording the mold filling completion time of each layer, automatically switching to a curing temperature control mode by the PLC control system after three-stage injection is completed, adjusting the temperature of the molding cavities of the outer plate and the inner plate to 50-60 ℃ to promote the curing of the resin, and maintaining the temperature gradient distribution of the molding cavities formed by the corrugated support structure to realize graded foaming.
  8. 8. The preparation process of claim 2, wherein S6 comprises the steps of synchronous curing, maintaining the temperature stability of each molding cavity, monitoring the temperature change and pressure change in each molding cavity in real time through a PLC control system, performing curing reaction on epoxy resin and hardener in an outer plate material, performing free radical polymerization on vinyl ester resin in an inner plate material under the action of an initiator, simultaneously forming a linear network by polyurethane prepolymer, mixing the vinyl ester resin with main resin to form a semi-interpenetrating network structure, and simultaneously crosslinking unsaturated polyester resin and polyurethane elastomer in a corrugated supporting structure material to form a synchronous interpenetrating network structure, wherein the main curing reaction of each layer of material is completed within 15-30 minutes through temperature partition control, and determining that the curing degree of each layer reaches more than 85 percent through DSC or infrared monitoring; S62, cooling and demolding the mold, closing a heating system by a PLC control system after solidification is completed, starting a cooling system, circulating cooling water through a cooling water pipeline, controlling the cooling rate to be 2-5 ℃ per minute to avoid internal stress generation, sending a demolding signal by the PLC control system when the temperature of the mold is reduced to 40-45 ℃ and is stable for more than 10 minutes, starting a hydraulic system to open the mold, opening the mold at a speed of 10-30mm per minute, and gently taking out the hollow composite material plate from the mold by using a demolding tool; S63, performing post-curing treatment, namely placing the demoulded composite hollow plate in a special post-curing oven, setting the temperature of the oven to be 80-120 ℃, keeping the temperature at 2-5 ℃ per minute, performing the post-curing treatment after the temperature of the oven reaches the set temperature for 2-4 hours to eliminate internal stress and improve the curing degree, closing an oven heating system to naturally cool to below 60 ℃ after the post-curing treatment is finished, and opening an oven door to enable the product to be continuously cooled to room temperature in the oven, wherein the cooling rate is not more than 3 ℃.

Description

Composite hollow plate and preparation method thereof Technical Field The invention relates to the technical field of composite material plate preparation, and provides a composite material hollow plate and a preparation method thereof. Background With the rapid development of the global steel industry and the increasing frequency of international trade, steel coils as important forms of steel products need to be protected by reliable packaging materials during production, storage and transportation. The steel coil packaging material not only needs to bear the huge weight of the steel coil, but also resists various impact, vibration and extrusion loads in the processes of loading, unloading, transporting and long-distance transportation, and meanwhile, has the function of preventing the surface of the steel coil from being scratched and rusted. Conventional steel coil packaging materials mainly comprise wooden trays, metal frames, simple plastic liners and the like, and the materials are either excessively heavy to increase transportation cost, or are easily damaged due to insufficient strength, or cannot provide effective buffer protection. The packaging plate made of the composite material gradually becomes an ideal choice in the field of steel coil packaging by virtue of the excellent performances of high specific strength, high specific modulus, strong designability, corrosion resistance and the like. In use, the packing plate needs to bear the static pressure of the steel coil for a long time, absorb various dynamic shocks in the transportation process, and realize repeated use for a plurality of times so as to reduce the packing cost. However, existing packaging boards still present a number of technical bottlenecks in steel coil packaging applications. Packaging boards in the prior art generally adopt a single thermosetting resin system, and the materials generally show contradiction that the strength and the toughness are difficult to be compatible. When formulation design is focused on improving strength, the increased cross-linking density of the material results in increased brittleness, which is prone to brittle fracture when subjected to impact loads and does not effectively absorb impact energy. When the formulation design focuses on improving toughness, the decrease in cross-linking density of the material results in a decrease in strength and rigidity, and cannot bear the weight load of the steel coil. The inherent contradiction between the strength and the toughness makes it difficult for the existing composite material hollow plate to simultaneously meet the dual requirements of the steel coil package on high bearing capacity and high impact resistance. In addition, the existing panel materials lack effective wear-resistant design, the surfaces are easy to wear under the working condition that the steel coil is repeatedly contacted and rubbed, and fragments generated by wear not only pollute the surface of the steel coil, but also can accelerate the performance degradation of the material. The existing hollow composite material plate can continuously exist and continuously expand under the stress action once damage cracks are generated in the using process, and finally the material is invalid. The steel coil packaging material is inevitably subjected to various mechanical damages in practical use, such as collision during loading and unloading, vibration fatigue during transportation, stress concentration at the edge of the steel coil, and the like, and microcracks can be generated in the material. Although the initial size of the microcracks is small and even invisible to naked eyes, the microcracks can gradually be connected and expanded to form macrocracks under the action of cyclic load, and the bearing capacity and the service life of the material are seriously weakened. The prior art lacks an active repair mechanism for damaged cracks, and once damaged, materials can only be detected and replaced manually, so that maintenance cost and downtime are increased, and resource waste is caused. Especially for the steel coil packaging material which needs to be repeatedly used, the unrepairable accumulated damage severely limits the repeated use times and economy. The supporting structure of the existing packaging plate adopts a linear corrugated or grid configuration, and the regular geometric structure is easy to generate stress concentration at turning positions or crossing points when stressed, so that local premature failure is caused. The material in the stress concentration area firstly reaches yield or fracture, but the material strength of other areas is not fully exerted, so that the material utilization rate is low. The load-displacement curve of a linear support structure in the compression process usually presents an approximately linear characteristic and lacks an obvious energy absorption platform area, which means that the material reaches the maximum bearing capacity u