Method for recycling of composite material pultruded profiles and box type products

Abstract

The application relates to a composite material pultrusion profile unqualified product recycling method and a box type product. The recycling method comprises the following steps: S1: defect detection and marking: detecting the composite material pultrusion profile unqualified product, marking unusable defect sections and usable sections; S2: cutting and sorting: removing the unusable defect sections, cutting the usable sections according to the design size of the box type product, and cutting out various frame beams of the box type product; S3: splicing and fixing: splicing the frame beams to form a frame of the box type product according to a storage box structure, and fixing. The recycling method realizes the conversion of the composite material pultrusion profile unqualified product into a practical product, and improves the utilization rate of the composite material.

Description

Technical Field

[0001] This invention relates to the field of secondary utilization technology of composite pultruded profiles, specifically to a method for reusing defective composite pultruded profiles and box-shaped products. Background Technology

[0002] For non-structurally fatal defects such as surface flaws, slight dimensional deviations, end damage, and localized glue deficiency that are generated during the production of pultruded square tubes made of composite materials such as glass fiber and carbon fiber, the relevant technologies often adopt recycling and remodeling (crushing and granulation) or direct disposal. However, the remodeling process is complex and costly, and direct disposal will cause serious waste of resin and fiber raw materials, which is not conducive to resource recycling. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] Composite material pultruded square tubes are widely used in new energy, construction, warehousing, and rail transportation due to their high specific strength, corrosion resistance, weather resistance, and high molding efficiency. During production, a certain percentage of defective products may occur due to process errors, raw material defects, and testing standards. Although these defective products may have localized appearance or dimensional defects, they still retain the excellent structural stiffness and mechanical properties of composite materials and are not completely unusable.

[0005] In related technologies, there are significant limitations in the handling and reuse of defective pultruded composite profiles. Crushing and reprocessing requires additional steps such as crushing, heating, and reshaping, increasing energy consumption and processing costs. Furthermore, fiber breakage significantly reduces the mechanical properties of the composite material, resulting in extremely low added value of the recycled material. A few reuse schemes simply cut the defective parts into simple blocks or supports, resulting in limited utilization and low added value.

[0006] In contrast, the self-made storage boxes in related technologies mostly use metal profile welding or solid wood splicing, which have problems such as easy rusting, heavy weight, and complicated processing. Furthermore, they lack standardized and modular designs for defective composite pultruded square tubes, making it impossible to achieve stackable and combinable large-scale applications.

[0007] The present invention aims to at least partially solve one of the technical problems in the related art.

[0008] Therefore, embodiments of the present invention propose a method for reusing defective pultruded composite profiles, comprising the following steps: S1: Defect detection and marking: Inspect non-conforming composite pultruded profiles and mark unusable defective sections and usable sections; S2: Cutting and sorting: Remove unusable defective sections, cut usable sections according to the design dimensions of the box-type product, and cut out the various frame beams of the box-type product; S3: Splicing and fixing: Splice the frame beams according to the storage box structure to form the frame of the box-shaped product, and then fix it.

[0009] Pultruded composite profiles are long and narrow. This invention addresses the shape and material characteristics of defective pultruded composite profiles by reusing them. Compared to related technologies that directly discard defective products or remelt them, this invention applies the defective parts of the pultruded profiles to box-shaped products, where the requirements are lower than in the original application scenario. Usable sections of the defective parts are cut and assembled, transforming them into practical products and improving the utilization rate of composite materials. The cutting and splicing process can be performed using simple equipment, without high temperatures, breakage, or welding. It has a low operating threshold, high processing efficiency, and is suitable for manufacturers to perform in-house processing. Meanwhile, the box-type products, made from substandard materials as the core frame material, inherit the advantages of composite materials such as high specific strength, corrosion resistance, weather resistance, and light weight. The frames are stable, have good load-bearing capacity, and are corrosion-resistant and rust-resistant, making them suitable for special scenarios such as outdoor use and chemical storage. They have a long service life and eliminate the need for additional material purchases. Compared to purchasing similar storage boxes externally, this reduces manufacturing and solid waste treatment costs. Furthermore, the box-type products made from composite pultruded profiles have high structural strength, ensuring safe and reliable use, increasing the added value of waste products, and bringing additional economic benefits to enterprises. In addition, it reduces the emission of solid waste from composite materials, lowers the energy consumption and exhaust emissions from recycling, aligns with industrial policies promoting a circular economy and green production, and helps improve the environmental benefits of enterprises.

[0010] In some embodiments, in S1, the portion of the composite pultruded profile that exhibits at least one of the following conditions—partial breakage, fiber exposure, and strength failure—is marked as an unusable defective segment, while the remaining portion is marked as a usable segment; and / or, the complete segment of the composite pultruded profile that exhibits surface scratches, minor end damage without strength failure, and / or local dimensional deviation is marked as a usable segment, while the remaining portion is marked as an unusable defective segment.

[0011] In some embodiments, in step S2, the cut frame beam is surface treated to remove burrs and resin is applied to areas with scratches or minor damage.

[0012] In some embodiments, the composite pultruded profile is U-shaped.

[0013] In some embodiments, in step S2, the ends of the frame beams are beveled to form splicing surfaces, and in step S3, during splicing, the splicing surfaces of the connected frame beams are joined together.

[0014] In some embodiments, in step S3, resin is used to bond the joint.

[0015] In some embodiments, in step S3, for pultruded profiles containing glass fibers in composite materials, polyurethane adhesive is used for bonding; for pultruded profiles containing carbon fibers in composite materials, epoxy resin adhesive is used for bonding; and / or, in step S3, L-shaped corner brackets are used to connect the two frame beams at the splice, and the L-shaped corner brackets and frame beams are fixed with screws.

[0016] In some embodiments, in step S2, short segments cut from available segments are installed as partitions inside the box-type product.

[0017] In some embodiments, after step S3, step S4 is performed: assembling the panel and / or the door to form a closable enclosure.

[0018] The box-shaped product of this invention is prepared using the aforementioned method for reusing defective pultruded composite profiles. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of the box-type product according to an embodiment of the present invention; Figure label: 100. Box-type products, 1. Frame beams, 2. Panels. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The following describes in detail, with reference to the accompanying drawings, a method for reusing defective pultruded composite profiles and box-shaped products according to embodiments of the present invention.

[0022] The method for reusing defective pultruded composite profiles according to an embodiment of the present invention includes the following steps: S1: Defect detection and marking: Inspect non-conforming composite pultruded profiles and mark unusable defective sections and usable sections; S2: Cutting and sorting: Remove unusable defective sections, cut usable sections according to the design dimensions of the box-type product, and cut out the various frame beams of the box-type product; S3: Splicing and fixing: Splice the frame beams according to the storage box structure to form the frame of the box-shaped product, and then fix it.

[0023] like Figure 1 As shown, the box-shaped product of this embodiment of the invention is prepared using the method of reusing defective pultruded profiles of composite materials according to this embodiment of the invention.

[0024] Pultruded composite profiles are long and narrow. This invention addresses the shape and material characteristics of defective pultruded composite profiles by reusing them. Compared to related technologies that directly discard defective products or remelt them, this invention applies the defective parts of the pultruded profiles to box-shaped products, where the requirements are lower than in the original application scenario. Usable sections of the defective parts are cut and assembled, transforming them into practical products and improving the utilization rate of composite materials. The cutting and splicing process can be performed using simple equipment, without high temperatures, breakage, or welding. It has a low operating threshold, high processing efficiency, and is suitable for manufacturers to perform in-house processing. Meanwhile, the box-type products, made from substandard materials as the core frame material, inherit the advantages of composite materials such as high specific strength, corrosion resistance, weather resistance, and light weight. The frames are stable, have good load-bearing capacity, and are corrosion-resistant and rust-resistant, making them suitable for special scenarios such as outdoor use and chemical storage. They have a long service life and eliminate the need for additional material purchases. Compared to purchasing similar storage boxes externally, this reduces manufacturing and solid waste treatment costs. Furthermore, the box-type products made from composite pultruded profiles have high structural strength, ensuring safe and reliable use, increasing the added value of waste products, and bringing additional economic benefits to enterprises. In addition, it reduces the emission of solid waste from composite materials, lowers the energy consumption and exhaust emissions from recycling, aligns with industrial policies promoting a circular economy and green production, and helps improve the environmental benefits of enterprises.

[0025] In some embodiments, in S1, the portion of the composite pultruded profile that exhibits at least one of the following conditions—partial breakage, fiber exposure, and strength failure—is marked as an unusable defective segment, while the remaining portion is marked as a usable segment; and / or, the complete segment of the composite pultruded profile that exhibits surface scratches, minor end damage without strength failure, and / or local dimensional deviation is marked as a usable segment, while the remaining portion is marked as an unusable defective segment.

[0026] In some specific embodiments, portions of non-conforming composite pultruded profiles exhibiting at least one of the following conditions—localized breakage, exposed fibers, and strength failure—are marked as unusable defective sections, while complete sections of non-conforming composite pultruded profiles exhibiting surface scratches, minor end damage without strength failure, and / or localized dimensional deviations are marked as usable sections.

[0027] The surface features of defective products, such as localized fractures, exposed fibers, surface scratches, minor end damage, and localized dimensional deviations, are easily observed and judged by the human eye. The strength failure section can be tested by simple mechanical testing. For example, if a person can manually break or deform it, it is considered as a strength failure. The judgment method is simple and efficient.

[0028] In some specific embodiments, in step S2, a profile cutting machine (e.g., an abrasive wheel cutter) is used to cut the defective product along the marked areas to remove unusable defective sections. The various frame beams of the box-type product are then precisely cut according to the design dimensions. For example, if the box-type product is a regular rectangular box, frame beams corresponding to its length, width, and height are cut according to the dimensions. For instance, the length frame beam is 660mm, the width frame beam is 450mm, and the vertical (height) frame beam is 750mm. The end faces are kept flat during cutting to ensure subsequent splicing accuracy.

[0029] In some embodiments, in step S2, the cut frame beams undergo surface treatment to remove burrs and apply resin to areas with scratches or minor damage. No high-precision processing is required; basic splicing and appearance requirements are met, making the operation simple.

[0030] After the frame beams are cut, they are grouped together according to their same dimensions and stacked.

[0031] In some embodiments, the composite pultruded profile is U-shaped. That is, the defective composite pultruded profile is U-shaped, and the cut frame beam is a U-shaped square tube, which is the same as the frame structure used in most box-type products in related technologies. This makes it easier to reuse defective products and further reduces the difficulty of remanufacturing box-type products, which is conducive to further improving the reuse rate of U-shaped composite pultruded profiles.

[0032] In some embodiments, in step S2, the ends of the frame beams are beveled to form splicing surfaces, and in step S3, the splicing surfaces of the connected frame beams are joined together. The beveled splicing surfaces facilitate the joining of two frame beams to form a right angle. It should be noted that the end face of the frame beam can be cut into either a beveled or straight surface, depending on the ease of assembly and design considerations. For example, the ends of the longitudinal frame beams are beveled to form 45° splicing surfaces, the ends of the transverse frame beams are beveled to form 45° splicing surfaces, and the two 45° splicing surfaces are joined to form a connecting right angle; the splicing surface of the vertical frame beam is a straight surface.

[0033] In some embodiments, in step S3, resin is used to bond the joint. The resin is applied evenly to the joint surface and then pressed together to achieve chemical bonding. The 45° bevel significantly increases the bonding area, resulting in a connection strength more than 60% higher than that of a right-angle butt joint. The bonding process is simple, the connection is stable, and it does not damage the original material properties of the composite material.

[0034] In some embodiments, in step S3, for pultruded profiles containing glass fibers in the composite material, polyurethane adhesive is used for bonding; for pultruded profiles containing carbon fibers in the composite material, epoxy resin adhesive is used for bonding.

[0035] In some embodiments, in step S3, L-shaped corner brackets are used to connect the two frame beams at the splicing point, and screws are used to fix the L-shaped corner brackets and frame beams. The fixing connection using corner brackets and screws is simple to operate and provides a stable connection.

[0036] Specifically, the L-shaped corner bracket is made of the same material as the frame beam, and can be formed by cutting the available segments in step S2. The use of the same material for the L-shaped corner bracket as the frame beam avoids electrochemical corrosion and helps to further extend the service life of the box-type product.

[0037] The screws are self-tapping screws, which pass through the corner brackets and the side walls of the frame beams for fixation. The screw holes are located in the middle of the side walls of the frame beams, providing better load-bearing capacity. 2-4 screws are placed at each corner to further enhance the corner connection strength, solve the problem of loosening caused by traditional right-angle splicing, and further improve the structural strength and reliability of the box-type product.

[0038] In some specific embodiments, in step S3, resin is first used to bond the joint, and then L-shaped corner brackets are used to connect the two frame beams at the joint. The L-shaped corner brackets and frame beams are then fixed with screws. This can further improve the structural strength and reliability of the box-type product, making it suitable for applications with larger dimensions or multiple stacked boxes.

[0039] In some embodiments, after step S3, step S4 is performed: assembling the panel and / or the door to form a closable enclosure.

[0040] In some specific embodiments, the panel can be made of plastic sheet, fiberglass sheet, plywood, thin aluminum sheet, etc., depending on the usage requirements. For example, if waterproofing is required, choose plastic sheet; if corrosion resistance is required, choose fiberglass sheet; if load-bearing capacity is required, choose thin aluminum sheet.

[0041] For panel fixing: attach the panel to the inside or outside of the frame beam and fix it to the side wall of the frame beam with self-tapping screws; or, pre-set simple slots on the side wall of the frame beam, insert the panel into the slots, and realize quick assembly and disassembly of the panel.

[0042] In embodiments where the panels are fixedly mounted on the frame beam, there can be four panels and two doors; alternatively, there can be five panels and one box body, with the box body opened and closed via the doors. In embodiments where the panels are detachably mounted on the frame beam, there can be six panels, with the box body opened and closed via any one of the detachable panels. Alternatively, a portion of the multiple panels can be fixedly connected to the frame beam, while another portion can be detachably connected, with the box body opened and closed via the detachable panels. Doors can be added according to design requirements to form a complete storage box.

[0043] In embodiments where multiple boxes are stacked, a panel can be installed between the frame beams of two adjacent boxes to separate them.

[0044] In some specific embodiments, positioning bosses are provided at the four corners of the top frame of the storage box, and positioning grooves are provided at the four corners of the bottom frame. When the upper and lower boxes are stacked, the bosses and grooves engage precisely to prevent stacking offset and improve stacking stability.

[0045] In some specific embodiments, holes are drilled in the square tubing of the vertical frame beams on both sides of the storage box to install plastic or composite material handles, thereby facilitating handling. The handle positions are matched to the ergonomic height of the design drawings.

[0046] In some specific embodiments, universal casters are fixed at the four corners of the bottom frame of the storage box to enable the storage box to move and adapt to logistics turnover scenarios.

[0047] In some specific embodiments, in step S2, short material segments cut from the available segments are installed as partitions inside the box-shaped product. Removable partitions are added to the storage space to achieve partitioned storage, reduce the generation of secondary waste, and further improve the utilization rate of composite pultruded profiles.

[0048] In some specific embodiments, plastic latches are installed on the frame on the open side, which, together with the box door or a detachable panel, achieve the sealing and anti-theft of the storage box.

[0049] Therefore, the method for reusing defective pultruded composite profiles and the box-type product of this invention fully utilize the remaining structural properties of defective pultruded U-shaped square tubes, reducing raw material waste and improving resource recycling rates. The splicing and fixing method of the box-type product is adapted to the composite material, avoiding complex processes such as welding. The processing equipment is universal and easy to operate, reducing secondary processing costs. The resulting storage boxes have advantages such as structural stability, good load-bearing capacity, corrosion and weather resistance, standardized dimensions, and stackability, making them suitable for various scenarios such as industrial warehousing, logistics turnover, and civilian storage. This achieves graded utilization of defective pultruded composite profiles, ensuring full utilization of both standard length sections and non-standard short sections, without generating secondary waste. Simultaneously, it reduces solid waste emissions for enterprises, meeting the requirements of green production and circular economy industrial development.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for reusing defective pultruded composite profiles, characterized in that, Includes the following steps: S1: Defect detection and marking: Inspect non-conforming composite pultruded profiles and mark unusable defective sections and usable sections; S2: Cutting and sorting: Remove unusable defective sections, cut usable sections according to the design dimensions of the box-type product, and cut out the various frame beams of the box-type product; S3: Splicing and fixing: Splice the frame beams according to the storage box structure to form the frame of the box-shaped product, and then fix it.

2. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, In S1, the portion of a non-conforming composite pultruded profile exhibiting at least one of the following conditions—local breakage, fiber exposure, and strength failure—is marked as an unusable defective segment, while the remaining portion is marked as a usable segment; and / or, the complete segment of a non-conforming composite pultruded profile exhibiting surface scratches, minor end damage without strength failure, and / or local dimensional deviation is marked as a usable segment, while the remaining portion is marked as an unusable defective segment.

3. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, In step S2, the cut frame beams are surface treated to remove burrs and apply resin to areas with scratches or minor damage.

4. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, The composite pultruded profile is U-shaped.

5. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, In step S2, the ends of the frame beams are beveled to form splicing surfaces. In step S3, during splicing, the splicing surfaces of the connected frame beams are joined together.

6. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, In step S3, resin is used to bond the joints.

7. The method for reusing defective pultruded composite profiles according to claim 6, characterized in that, In step S3, for pultruded profiles containing glass fibers in composite materials, polyurethane adhesive is used for bonding; for pultruded profiles containing carbon fibers in composite materials, epoxy resin adhesive is used for bonding; and / or, in step S3, L-shaped corner brackets are used to connect the two frame beams at the splice, and the L-shaped corner brackets and frame beams are fixed with screws.

8. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, In step S2, short segments cut from the available segments are installed as partitions inside the box-shaped product.

9. The method for reusing defective pultruded composite profiles according to claim 1, characterized in that, After step S3, proceed to step S4: assemble the panel and / or the door to form a closable enclosure.

10. A box-shaped product, characterized in that, The composite pultruded profiles are prepared using the method for reusing defective products as described in any one of claims 1 to 9.

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