Preparation method of refrigerator magnetically-attractable panel, refrigerator magnetically-attractable panel and refrigerator door

Abstract

The invention relates to the technical field of refrigerator panels, in particular to a preparation method of a refrigerator magnetically-attracted panel, the refrigerator magnetically-attracted panel and a refrigerator door. The preparation method comprises the following steps: mixing the polyvinyl chloride resin and the magnetic filler to obtain a magnetic polyvinyl chloride composite material; a polyvinyl chloride material is conveyed to a lower-layer runner of the co-extrusion die head through a first extrusion mechanism, and a magnetic polyvinyl chloride composite material is conveyed to an upper-layer runner of the co-extrusion die head through a second extrusion mechanism; the two materials are compounded at an outlet of a co-extrusion die head and then extruded, an initial plate blank with a bottom layer and a surface layer is obtained, the bottom layer is made of a polyvinyl chloride material, and the surface layer is made of a magnetic polyvinyl chloride composite material; cooling and shaping the initial plate blank to obtain a composite plate; and forming and processing the composite board to obtain the refrigerator magnetically-attractable panel. The panel is high in magnetic attraction force, wide in design freedom degree, stable in structure and capable of directly replacing a traditional glass panel.

Description

Technical Field

[0001] This application relates to the field of refrigerator panel technology, and in particular to a method for preparing a magnetically attachable refrigerator panel, the magnetically attachable refrigerator panel, and a refrigerator door. Background Technology

[0002] The refrigerator panel is a core component in modern home appliances, serving both as a storage space enclosure and an aesthetic element. Its materials and functionality directly impact user experience and product market competitiveness. With increasing user demand for personalized decoration and convenient magnetic closures, refrigerator panels with magnetic closures have become an important development direction for the industry.

[0003] To achieve the magnetic attraction function of non-metallic panels, existing technologies mainly adopt two approaches: one is to coat a magnetic ink layer on the surface of a glass substrate using a high-temperature casting process, and then set a pattern layer inside the magnetic layer; the other is to use a stone-plastic substrate layer and a prefabricated stone-plastic magnetic board to form a composite substrate through a lamination method, and then add a protective layer and a pattern layer on the outside of the composite substrate.

[0004] However, existing technologies all have obvious limitations: the magnetic ink layer has insufficient magnetic attraction due to the limited coating thickness, making it difficult to meet the load-bearing requirements of users hanging items, and the dark magnetic material restricts the realization of light colors and complex patterns; although the laminated structure of stone-plastic substrate and magnetic board provides basic magnetic attraction function, the interlayer bonding force is weak and it is easy to delaminate, the poor uniformity of magnetic powder distribution affects the magnetic stability, and the color of the prefabricated magnetic board also limits the freedom of appearance design. Summary of the Invention

[0005] This application provides a method for preparing a magnetically attachable refrigerator panel, a magnetically attachable refrigerator panel, and a refrigerator door, in order to solve the technical problems of insufficient magnetic attraction due to the thin magnetic layer of existing refrigerator panels and low freedom of appearance design due to the limitation of dark magnetic materials.

[0006] To achieve the above objectives, on the one hand, this application provides a method for preparing a magnetically attachable refrigerator panel, comprising: mixing polyvinyl chloride (PVC) resin and magnetic filler to obtain a magnetic polyvinyl chloride composite material;

[0007] The polyvinyl chloride material is fed into the lower flow channel of the co-extrusion die through the first extrusion mechanism;

[0008] The magnetic polyvinyl chloride composite material is conveyed to the upper flow channel of the co-extrusion die through the second extrusion mechanism;

[0009] At the exit of the co-extrusion die, polyvinyl chloride material and magnetic polyvinyl chloride composite material are combined and extruded to obtain an initial slab; the initial slab has a bottom layer and a top layer, the bottom layer is composed of polyvinyl chloride material and the top layer is composed of magnetic polyvinyl chloride composite material;

[0010] The initial slab is cooled and shaped to obtain the composite board.

[0011] The composite board is processed to obtain a refrigerator magnetic panel.

[0012] Preferably, mixing polyvinyl chloride resin and magnetic filler to obtain magnetic polyvinyl chloride composite material specifically includes: mixing heat stabilizer, lubricant, plasticizer, polyvinyl chloride resin and magnetic filler to obtain magnetic polyvinyl chloride composite material.

[0013] Preferably, the magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts of polyvinyl chloride resin, 40-60 parts of plasticizer, 3-5 parts of heat stabilizer, 150-250 parts of magnetic filler and 0.5-1.5 parts of lubricant.

[0014] Preferably, the thickness of the composite board is 2.0-4.0 mm.

[0015] Preferably, the thickness of the bottom layer accounts for 65-95% of the total thickness of the composite board.

[0016] Preferably, conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism specifically includes: mixing polyvinyl chloride resin, calcium carbonate filler, plasticizer and heat stabilizer to obtain polyvinyl chloride material, and conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism.

[0017] Preferably, the processing of the composite board includes:

[0018] A decorative film is attached to the surface of the composite board, with the decorative pattern side of the film facing the composite board.

[0019] Preferably, the processing of the composite board further includes:

[0020] The composite board with the decorative film is cooled and shaped to obtain a preliminary decorative panel.

[0021] The pre-formed decorative panel is mechanically processed to obtain a magnetically attached refrigerator panel.

[0022] Secondly, this application provides a magnetically attachable refrigerator panel, which is prepared by the method for preparing a magnetically attachable refrigerator panel as described in any one of the first aspects.

[0023] Thirdly, this application provides a refrigerator door, including: a magnetically attachable refrigerator panel, a refrigerator door liner, and a refrigerator door frame, as described in the second aspect;

[0024] The refrigerator door frame is spliced ​​and installed with the refrigerator door lining on one side, and a gap is formed between the refrigerator door lining and the refrigerator door frame. The gap is filled with elastic filler.

[0025] The refrigerator's magnetic panel can be attached to the other side of the refrigerator door frame.

[0026] As can be seen from the above technical solutions, this application provides a method for preparing a magnetically attachable refrigerator panel, a magnetically attachable refrigerator panel, and a refrigerator door. The preparation method includes: mixing polyvinyl chloride resin and magnetic filler to obtain a magnetic polyvinyl chloride composite material; conveying the polyvinyl chloride material to the lower flow channel of a co-extrusion die through a first extrusion mechanism; conveying the magnetic polyvinyl chloride composite material to the upper flow channel of the co-extrusion die through a second extrusion mechanism; extruding the polyvinyl chloride material and the magnetic polyvinyl chloride composite material together at the exit of the co-extrusion die to obtain an initial blank with a bottom layer and a surface layer, wherein the bottom layer is composed of polyvinyl chloride material and the surface layer is composed of magnetic polyvinyl chloride composite material; cooling and shaping the initial blank to obtain a composite board; and molding the composite board to obtain a magnetically attachable refrigerator panel. This application achieves integrated manufacturing of the magnetically attachable functional layer and the structural support layer through the separate conveying and co-extrusion composite molding of polyvinyl chloride material and magnetic polyvinyl chloride composite material, enabling the panel to have both strong magnetic attraction and high structural stability, while providing greater freedom in appearance design. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating the method for preparing a magnetically attached refrigerator panel according to an embodiment of this application;

[0029] Figure 2 This is a schematic diagram of the magnetically attached panel structure of a refrigerator provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the refrigerator door structure provided in an embodiment of this application.

[0031] Illustration:

[0032] Among them, 1. Refrigerator magnetic panel; 11. Bottom layer; 12. Surface layer; 13. Decorative film; 2. Refrigerator door lining; 3. Refrigerator door frame. Detailed Implementation

[0033] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application.

[0034] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0035] The terms "first," "second," "third," etc., are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms can be used interchangeably where appropriate.

[0036] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0037] In the field of refrigerator manufacturing technology, based on user demand for magnetic adsorption functionality, magnetic refrigerator panels are key components used to enhance the user experience and provide convenient decorative hanging solutions. They are widely used in refrigeration equipment such as household refrigerators and commercial freezers, and have specific requirements for the panel's magnetic strength, design freedom, and structural stability. Refrigerator panels typically include core components such as a structural base layer, a functional layer, and a decorative layer. Among these, the magnetic functional layer is crucial for ensuring the panel's reliable magnetic adsorption capability and enabling the stable hanging of magnetic items.

[0038] From a technical perspective, the magnetic functional layer must maintain a uniform distribution of magnetic powder within the panel structure. This is to ensure uniform magnetic attraction through a stable distribution of magnetic lines of force, guaranteeing that magnetic items are fully attracted to the panel surface and preventing slippage and suspension failure due to insufficient magnetic force. The distribution of magnetic filler within the functional layer directly affects the panel's magnetic performance and user experience; uneven distribution can lead to weak magnetic areas or magnetic failure.

[0039] In existing solutions for magnetically attached panels, the common approach is to coat the glass panel surface with magnetic ink. However, when magnetic ink is applied to the glass substrate, the limited coating thickness prevents the magnetic filler from forming a sufficient magnetic layer, resulting in weak magnetic areas or uneven magnetic force on the panel surface. This magnetic distribution prevents the panel from providing stable magnetic attraction, leading to insufficient load-bearing capacity for suspended items and even causing magnetic items to fall off due to insufficient magnetic force.

[0040] To address the issues of insufficient magnetic force and design limitations in implementing magnetic attraction on non-metallic refrigerator panels, such as... Figure 1 As shown, some embodiments of this application provide a method for preparing a magnetically attached panel for a refrigerator, including:

[0041] S101. Mix polyvinyl chloride resin with magnetic filler to obtain magnetic polyvinyl chloride composite material.

[0042] Polyvinyl chloride (PVC) resin is the main raw material forming the matrix of the composite material, and it can form a continuous phase after heating and plasticizing. Magnetic fillers are functional components that impart magnetism to the material, and their particles are uniformly dispersed in the PVC resin matrix. Magnetic fillers include magnetic metal oxides, such as one or more of strontium ferrite magnetic powder and neodymium iron boron magnetic powder, and the particle size range of the magnetic fillers is controlled within 300-500 mesh.

[0043] Specifically, a predetermined ratio of polyvinyl chloride (PVC) resin and magnetic filler are added to a high-speed mixer. Under mechanical stirring, the magnetic filler particles are uniformly dispersed in the PVC resin matrix. The particle size of the selected strontium ferrite or neodymium iron boron magnetic powder is controlled within the range of 300-500 mesh. This particle size specification is beneficial for achieving uniform dispersion in the PVC resin matrix. Through the mechanical stirring action of the high-speed mixer, the magnetic filler and PVC resin are thoroughly mixed, resulting in a magnetic PVC composite material with uniformly distributed components.

[0044] S102. The polyvinyl chloride material is conveyed to the lower flow channel of the co-extrusion die through the first extrusion mechanism.

[0045] Polyvinyl chloride (PVC) is the base material used to form the support structure of the refrigerator panel. The first extrusion unit and the second extrusion unit are two independent processing units of the same extrusion equipment; the first extrusion unit processes PVC, and the second extrusion unit processes magnetic PVC composite material. The extrusion equipment includes, but is not limited to, twin-screw extruders and single-screw extruders; any extrusion equipment capable of melting and plasticizing the material and stably conveying it to the co-extrusion die is applicable. The co-extrusion die has mutually isolated lower and upper flow channels. The lower flow channel guides the molten PVC material, and the upper flow channel guides the molten magnetic PVC composite material.

[0046] Specifically, the first extrusion unit transforms the polyvinyl chloride (PVC) material into a molten state through a heating system and screw shearing action. The first extrusion unit achieves material plasticization through zoned temperature control; for example, zone one at 160°C achieves initial plasticization; zone two at 165°C ensures complete melting; zone three at 170°C guarantees melt homogeneity; and the die temperature at 175°C maintains melt fluidity. The first extrusion unit stably delivers the uniformly plasticized PVC melt to the lower flow channel of the co-extrusion die.

[0047] S103. The magnetic polyvinyl chloride composite material is conveyed to the upper flow channel of the co-extrusion die through the second extrusion mechanism.

[0048] The second extrusion unit is an independent operating unit of the extrusion equipment used to process magnetic polyvinyl chloride composite materials. The upper flow channel of the co-extrusion die is an independent channel for guiding the melt of the magnetic polyvinyl chloride composite material.

[0049] Specifically, the second extrusion unit transforms the magnetic PVC composite material into a molten state through a heating system and screw shearing action. The second extrusion unit is configured with zoned extrusion temperatures; for example, zone one is 160°C to avoid damage to the magnetic filler properties and achieve initial plasticization of the material; zone two is 165°C to ensure complete melting of the magnetic composite material; zone three is 170°C to ensure uniform distribution of magnetic powder in the melt; and the die temperature is 175°C to maintain the flowability of the composite melt. The second extrusion unit stably delivers the uniformly plasticized magnetic PVC composite material melt to the upper flow channel of the co-extrusion die.

[0050] S104. At the exit of the co-extrusion die, the polyvinyl chloride material and the magnetic polyvinyl chloride composite material are combined and extruded to obtain the initial slab.

[0051] The co-extrusion die exit is the area where the two melt layers are combined. The initial slab is an unshaped sheet with a preliminary layered structure.

[0052] Specifically, at the co-extrusion die exit, the molten PVC material from the lower flow channel merges and bonds with the molten magnetic PVC composite material from the upper flow channel, forming an initial slab with a bottom layer and a surface layer structure. The bottom layer of the initial slab is composed of PVC material, and the surface layer of the initial slab is composed of magnetic PVC composite material.

[0053] S105. Cool and shape the initial slab to obtain the composite board.

[0054] Cooling and shaping is the process of transforming a material from a molten state to a solid state. Composite panels are layered structural panels with stable dimensions.

[0055] Specifically, the initial slab enters a cooling and shaping device, for example, by passing through a set of temperature-controlled cooling rollers or cooling air ducts, controlling the cooling conditions to reduce the temperature of the composite board to 40-60℃ to ensure its full curing and dimensional stability. After cooling and shaping, the composite board retains its complete layered structure. The bottom layer of the composite board is made of polyvinyl chloride material and provides mechanical support, while the surface layer is made of magnetic polyvinyl chloride composite material and provides magnetic attraction.

[0056] S106. Process the composite board to obtain a refrigerator magnetic panel.

[0057] Processing is the manufacturing process that realizes the final shape of the product, including cutting the composite board into shape, machining holes, and applying a film to the surface.

[0058] Specifically, the composite board is precisely cut to its outline according to the design requirements of the refrigerator panel. Mounting holes are then machined into the composite board according to the installation structure requirements. Finally, a film is applied to the surface of the composite board according to the appearance design requirements. The processed composite board becomes a magnetically attachable refrigerator panel that can be directly assembled.

[0059] As can be seen from the above technical solution, this embodiment achieves the integrated molding of the structural layer and the functional layer through a co-extrusion process. The bottom layer formed by polyvinyl chloride (PVC) material provides the panel with the necessary structural strength and dimensional stability. The surface layer formed by magnetic PVC composite material provides the panel with uniformly distributed magnetic attraction. This embodiment ensures the strong interlayer bonding by laminating PVC material and magnetic PVC composite material in a molten state. The refrigerator panel prepared by this method solves the problems of weak magnetic force and design limitations of magnetic glass panels, maintaining the texture of non-metallic materials while possessing reliable magnetic attraction function.

[0060] In some embodiments, mixing polyvinyl chloride resin with magnetic filler to obtain a magnetic polyvinyl chloride composite material specifically includes: mixing a heat stabilizer, a lubricant, a plasticizer, polyvinyl chloride resin and magnetic filler to obtain a magnetic polyvinyl chloride composite material.

[0061] Heat stabilizers are additives that prevent the thermal degradation of polyvinyl chloride (PVC) resin during processing. Heat stabilizers include, but are not limited to, calcium-zinc composite stabilizers or organotin stabilizers. Lubricants are additives that reduce frictional resistance between materials and equipment. Lubricants include, but are not limited to, polyethylene wax or oxidized polyethylene wax. Plasticizers are components that improve the processing flowability and flexibility of PVC resin. Plasticizers include, but are not limited to, diisononyl phthalate or dioctyl phthalate.

[0062] Specifically, in the preparation of magnetic polyvinyl chloride (PVC) composite materials, a predetermined proportion of heat stabilizer is first added to a high-speed mixer. During mixing, the heat stabilizer is uniformly distributed in the PVC resin, preventing molecular chain breakage due to heat during subsequent extrusion processing. Next, a predetermined proportion of lubricant is added to the high-speed mixer. During mixing, the lubricant coats the surface of the material particles, reducing the coefficient of friction between the material and the metal surface of the processing equipment. Then, a predetermined proportion of plasticizer is added to the high-speed mixer. The plasticizer molecules intercalate between the PVC resin molecular chains, increasing the distance between the chains and improving the melt flowability of the composite material. Next, a predetermined proportion of PVC resin is added to the high-speed mixer. As a matrix material, the PVC resin forms a continuous phase after heating and plasticizing, coating the other components. Finally, a predetermined proportion of magnetic filler is added to the high-speed mixer. As a functional component, the magnetic filler particles are uniformly dispersed in the PVC resin matrix under mechanical stirring.

[0063] In some embodiments, the magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts of polyvinyl chloride resin, 40-60 parts of plasticizer, 3-5 parts of heat stabilizer, 150-250 parts of magnetic filler, and 0.5-1.5 parts of lubricant.

[0064] 100 parts of polyvinyl chloride (PVC) resin serve as a baseline, providing the basic structural framework and mechanical properties for the entire magnetic PVC composite system. 40-60 parts of plasticizer, within this ratio range, effectively reduce the intermolecular forces between PVC resin molecules, ensuring suitable melt flow at processing temperatures for the magnetic PVC composite, while simultaneously guaranteeing that the molded magnetic PVC composite maintains the necessary mechanical strength.

[0065] A heat stabilizer dosage of 3-5 parts can effectively inhibit the decomposition reaction of polyvinyl chloride resin under high-temperature processing conditions, preventing color changes and performance degradation of magnetic polyvinyl chloride composites due to thermal degradation, and ensuring the stability of the production process and the uniformity of the quality of magnetic polyvinyl chloride composites. A magnetic filler dosage range of 150-250 parts ensures that the magnetic polyvinyl chloride composite has sufficient magnetic properties to meet the magnetic attraction requirements of the refrigerator's magnetic panel, while avoiding the deterioration of the processing fluidity of the magnetic polyvinyl chloride composite and the decrease in the interlayer bonding strength between the magnetic polyvinyl chloride composite and the polyvinyl chloride material due to excessive addition of magnetic filler.

[0066] With 0.5-1.5 parts of lubricant in this ratio, a complete lubricating film can be formed on the surface of magnetic PVC composite particles, effectively reducing the frictional resistance between the magnetic PVC composite and the metal surface of the processing equipment, improving the material conveying and surface quality of the magnetic PVC composite during the extrusion process, and avoiding the weakening of the interlayer bonding force between the magnetic PVC composite and PVC material that may be caused by excessive use of lubricant.

[0067] Furthermore, to verify the technical effectiveness of the magnetic polyvinyl chloride composite material of this application in solving the synergistic problems of magnetic attraction, processability, and interlayer bonding, multiple sets of comparative experiments were conducted to test the magnetic properties, processing flow stability, and composite structure reliability. The preparation of all experimental samples strictly followed the limitations of the embodiments of this application, and the experimental data and results directly support the effectiveness and superiority of the technical solution of this application.

[0068] Example 1

[0069] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 40 parts by weight of plasticizer, 3 parts by weight of heat stabilizer, 150 parts by weight of magnetic filler and 0.5 parts by weight of lubricant.

[0070] Example 2

[0071] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 50 parts by weight of plasticizer, 4 parts by weight of heat stabilizer, 200 parts by weight of magnetic filler and 1.0 part by weight of lubricant.

[0072] Example 3

[0073] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 60 parts by weight of plasticizer, 5 parts by weight of heat stabilizer, 250 parts by weight of magnetic filler and 1.5 parts by weight of lubricant.

[0074] For comparison, a comparative formulation exceeding the scope of protection claimed in this application was designed.

[0075] Comparative Example 1:

[0076] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 50 parts by weight of plasticizer, 4 parts by weight of heat stabilizer, 100 parts by weight of magnetic filler and 1.0 part by weight of lubricant.

[0077] Comparative Example 2:

[0078] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 50 parts by weight of plasticizer, 4 parts by weight of heat stabilizer, 300 parts by weight of magnetic filler and 1.0 part by weight of lubricant.

[0079] Comparative Example 3:

[0080] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 30 parts by weight of plasticizer, 4 parts by weight of heat stabilizer, 200 parts by weight of magnetic filler and 1.0 part by weight of lubricant.

[0081] Comparative Example 4:

[0082] The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts by weight of polyvinyl chloride resin, 80 parts by weight of plasticizer, 4 parts by weight of heat stabilizer, 200 parts by weight of magnetic filler and 1.0 part by weight of lubricant.

[0083] The magnetic polyvinyl chloride composite material of the above embodiments and comparative examples was compounded with polyvinyl chloride material through a co-extrusion die to prepare a refrigerator magnetic panel, and its performance was tested.

[0084] The test results are shown in the table below:

[0085]

[0086] The experimental data above show that Embodiments 1, 2, and 3 within the scope of this application achieve a balance between magnetic attraction, processing flowability, and interlayer bonding force. The magnetic attraction is higher than 4.5N, the melt flow rate is in the range of 7-13g / 10min, the interlayer bonding force is higher than 14N / cm, and the surface quality is good.

[0087] Comparative Example 1 shows that the magnetic attraction force is less than 3.0N, which cannot meet the requirements of the magnetic attraction function.

[0088] Comparative Example 2 had a melt flow rate of less than 5.0 g / 10 min, an interlayer bonding force of less than 10.0 N / cm, and surface cracks.

[0089] Comparative Example 3 showed a melt flow rate of less than 5.0 g / 10 min, and flow lines appeared during the extrusion process.

[0090] Comparative Example 4 showed a melt flow rate higher than 20.0 g / 10 min, an interlayer bonding force lower than 10.0 N / cm, and surface bubbles.

[0091] Based on the above technical solutions and experimental data, it is evident that, using 100 parts by weight of PVC resin as a base, the combination of 40-60 parts by weight of plasticizer, 3-5 parts by weight of heat stabilizer, 150-250 parts by weight of magnetic filler, and 0.5-1.5 parts by weight of lubricant can achieve synergy among magnetic properties, processability, and interlayer bonding strength in magnetic PVC composites. The ratio of 150-250 parts by weight of magnetic filler to 40-60 parts by weight of plasticizer is crucial for achieving synergy between magnetic attraction and co-extrusion processability. Exceeding this range will lead to failure of the magnetic attraction function, processing difficulties, or a decrease in interlayer bonding strength.

[0092] In some embodiments, the thickness of the composite board is 2.0-4.0 mm.

[0093] When the composite panel thickness reaches 2.0mm, the PVC material at the bottom layer provides the basic structural rigidity required for the refrigerator panel to resist pressure and impacts during daily use. When the composite panel thickness increases to 4.0mm, the bending resistance of the refrigerator panel is enhanced, sufficient to meet the support requirements of large-sized doors. Simultaneously, within the 2.0-4.0mm range, the magnetic PVC composite material on the surface of the composite panel maintains a thickness sufficient to meet the requirements of magnetic attraction, ensuring ample space for the magnetic filler to achieve uniform distribution, thereby generating a stable and reliable magnetic force.

[0094] In some embodiments, the thickness of the bottom layer of the composite board accounts for 65-95% of the total thickness of the composite board.

[0095] This thickness ratio ensures that the bottom layer of PVC material has sufficient thickness to provide stable structural support and prevent deformation of the refrigerator's magnetic panel; at the same time, it reserves the necessary thickness space for the surface magnetic PVC composite material to achieve the magnetic function, thus balancing the structural reliability and magnetic performance of the refrigerator's magnetic panel.

[0096] In some embodiments, conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism specifically includes: mixing polyvinyl chloride resin, calcium carbonate filler, plasticizer and heat stabilizer to obtain polyvinyl chloride material, and conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism.

[0097] Polyvinyl chloride (PVC) resin is the basic polymer constituting PVC materials. Calcium carbonate filler includes, but is not limited to, heavy calcium carbonate or light calcium carbonate. Plasticizers include, but are not limited to, diisononyl phthalate or dioctyl phthalate. Heat stabilizers include, but are not limited to, calcium-zinc composite stabilizers or organotin stabilizers.

[0098] The addition of calcium carbonate filler effectively improves the rigidity of PVC material while optimizing raw material costs. The addition of plasticizers ensures stable flowability of the PVC material at processing temperatures, effectively preventing melt fracture that may occur during extrusion. The addition of heat stabilizers inhibits the degradation reaction of PVC resin under high-temperature processing conditions, ensuring product quality stability. Through the synergistic effect of these components, the PVC melt achieves suitable viscosity characteristics, enabling smooth flow in the lower runner. When the PVC melt and the magnetic PVC composite melt in the upper runner converge at the co-extrusion die exit, a strong interlayer bonding interface is formed. The resulting composite board exhibits excellent rigidity and strength characteristics, providing a reliable structural support foundation for the magnetically attached refrigerator panel.

[0099] In some embodiments, processing the composite board includes attaching a decorative film to the surface of the composite board, with the decorative pattern side of the decorative film facing the composite board.

[0100] The decorative film comprises a substrate layer and a decorative pattern layer. The substrate layer is made of transparent polyvinyl chloride film or transparent polyethylene terephthalate (PET) film, and the decorative pattern layer is printed on the back of the substrate layer using screen printing technology.

[0101] In the specific application process, the decorative pattern side of the decorative film is placed facing the surface of the composite board, and the decorative film is bonded to the surface of the composite board through a hot-pressing process. The hot-pressing temperature is controlled at 150-170℃, and the hot-pressing pressure is maintained at 0.5-0.7MPa. After application, the substrate layer of the decorative film is on the outermost side, and the decorative pattern layer is located between the substrate layer and the composite board.

[0102] Traditional magnetic panels use a method of directly printing patterns onto the magnetic layer surface. Since the magnetic filler itself is mostly dark, this results in reduced color saturation and insufficient vibrancy of the printed patterns. Furthermore, directly printed patterns lack a protective layer, making them susceptible to scratches and wear during use.

[0103] In this embodiment, the decorative pattern layer of the decorative film effectively blocks the color of the dark magnetic filler in the surface of the composite board by completely covering the surface of the composite board. The high-opacity ink used in the decorative pattern layer ensures that the pattern color is not affected by the color of the underlying material. The outermost transparent substrate layer provides reliable physical protection for the decorative pattern layer, preventing the pattern from being scratched or worn. The combination of the decorative pattern layer and the substrate layer of the decorative film solves the problem of dull patterns caused by dark magnetic fillers in traditional magnetic panels, achieving a unity of magnetic attraction function and vibrant appearance.

[0104] In some embodiments, processing the composite board further includes: cooling and shaping the composite board with the decorative film attached to obtain a pre-formed decorative panel; and machining the pre-formed decorative panel to obtain a refrigerator magnetic panel.

[0105] The cooling and shaping process involves reducing the temperature of the laminated material to room temperature after application. Machining is the process of shaping the decorative panel according to the refrigerator door installation requirements.

[0106] Specifically, the composite board with the decorative film attached is first transported to the cooling station. The cooling and shaping process uses forced air cooling or water cooling to uniformly lower the temperature of the composite board from the hot-pressing temperature (150-170℃) to room temperature. During the cooling process, the interface between the decorative film and the composite board gradually stabilizes, and the substrate layer of the decorative film forms a strong bond with the surface of the composite board.

[0107] After cooling and shaping, a preliminary decorative panel is obtained. The preliminary decorative panel then enters the machining process. Machining includes cutting the outline of the preliminary decorative panel and machining the mounting holes. The outline cutting is performed using CNC cutting equipment to trim the edges of the preliminary decorative panel according to the refrigerator door design dimensions. The mounting hole machining process involves machining hinge and handle mounting holes on the preliminary decorative panel according to the refrigerator door's installation structure requirements.

[0108] This embodiment stabilizes the bonding between the decorative film and the composite board through a cooling and shaping process, and achieves the final forming of the refrigerator's magnetically attachable panel through machining. The combination of cooling and shaping and machining ensures that the refrigerator's magnetically attachable panel has both an aesthetically pleasing appearance and the correct installation dimensions. The resulting refrigerator's magnetically attachable panel can be directly used in the assembly of the refrigerator door, achieving a complete integration of magnetic functionality and aesthetic decoration.

[0109] This application provides a refrigerator with a magnetically attached panel; see [link / reference]. Figure 2 The magnetically attachable refrigerator panel is prepared by the method described in the above embodiments.

[0110] The magnetically attachable refrigerator panel 1 enhances the practicality and aesthetics of the refrigerator door. In practical use, the magnetically attachable refrigerator panel 1 not only maintains the structural functions of traditional panels but also exhibits significant advantages in magnetic adsorption and decorative appearance. Compared to traditional glass panels, the magnetically attachable refrigerator panel 1 prepared using the above-described method provides reliable structural support with its bottom layer 11 made of polyvinyl chloride material, and its surface layer 12 made of magnetic polyvinyl chloride composite material ensures a significant enhancement in magnetic attraction. Simultaneously, the substrate layer of the decorative film 13 provides reliable protection for the decorative pattern layer, ensuring the long-lasting vibrancy of the pattern. The bottom layer 11, surface layer 12, and decorative film 13 provide users with a more convenient magnetic user experience and a more aesthetically pleasing visual experience.

[0111] This application provides a refrigerator door, see [link]. Figure 3 The refrigerator includes: the magnetically attached refrigerator panel 1, the refrigerator door liner 2, and the refrigerator door frame 3 provided in the above embodiments.

[0112] One side of the refrigerator door frame 3 is spliced ​​and installed with the refrigerator door liner 2, forming a gap between the refrigerator door liner 2 and the refrigerator door frame 3. The gap between the refrigerator door liner 2 and the refrigerator door frame 3 is filled with elastic filler, which is used to maintain the internal shape of the refrigerator door and support the insulation layer. The refrigerator magnetic panel 1 is attached and installed on the other side of the refrigerator door frame.

[0113] The surface layer 12 of the refrigerator's magnetic panel 1 provides magnetic attraction, and the decorative film 13 provides decorative effect. The refrigerator door liner 2 forms the internal support structure of the door, and the refrigerator door frame 3 forms the frame of the refrigerator door. An elastic filler forms a sealing and shock-absorbing layer between the refrigerator door liner 2 and the refrigerator door frame 3.

[0114] The refrigerator door structure in this embodiment achieves a complete integration of magnetic attraction function and refrigerator door structure. The refrigerator magnetic panel 1 serves as both a decorative surface and a magnetic surface, satisfying users' dual needs for the aesthetics and practicality of the refrigerator door.

[0115] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A method for preparing a magnetically attachable panel for a refrigerator, characterized in that, include: Polyvinyl chloride resin and magnetic filler are mixed to obtain magnetic polyvinyl chloride composite material; The polyvinyl chloride material is fed into the lower flow channel of the co-extrusion die through the first extrusion mechanism; The magnetic polyvinyl chloride composite material is conveyed to the upper flow channel of the co-extrusion die through the second extrusion mechanism; At the exit of the co-extrusion die, the polyvinyl chloride material and the magnetic polyvinyl chloride composite material are compounded and extruded to obtain an initial slab; the initial slab has a bottom layer and a top layer, the bottom layer is composed of the polyvinyl chloride material, and the top layer is composed of the magnetic polyvinyl chloride composite material; The initial slab is cooled and shaped to obtain a composite board. The composite board is processed to obtain the refrigerator's magnetically attached panel.

2. The method for preparing a magnetically attached refrigerator panel according to claim 1, characterized in that, The process of mixing polyvinyl chloride resin and magnetic filler to obtain magnetic polyvinyl chloride composite material specifically includes: mixing heat stabilizer, lubricant, plasticizer, polyvinyl chloride resin and magnetic filler to obtain magnetic polyvinyl chloride composite material.

3. The method for preparing a magnetically attached refrigerator panel according to claim 2, characterized in that, The magnetic polyvinyl chloride composite material is composed of the following components in parts by weight: 100 parts polyvinyl chloride resin, 40-60 parts plasticizer, 3-5 parts heat stabilizer, 150-250 parts magnetic filler, and 0.5-1.5 parts lubricant.

4. The method for preparing a magnetically attached refrigerator panel according to claim 1, characterized in that, The thickness of the composite board is 2.0-4.0 mm.

5. The method for preparing a magnetically attached refrigerator panel according to claim 1, characterized in that, The thickness of the bottom layer accounts for 65-95% of the total thickness of the composite board.

6. The method for preparing a magnetically attached refrigerator panel according to claim 1, characterized in that, The process of conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism specifically includes: mixing the polyvinyl chloride resin, calcium carbonate filler, plasticizer and heat stabilizer to obtain the polyvinyl chloride material, and conveying the polyvinyl chloride material to the lower flow channel of the co-extrusion die through the first extrusion mechanism.

7. The method for preparing a magnetically attached refrigerator panel according to claim 1, characterized in that, Processing the composite board includes: A decorative film is attached to the surface of the composite board, with the decorative pattern side of the decorative film facing the composite board.

8. The method for preparing a magnetically attached refrigerator panel according to claim 7, characterized in that, The processing of the composite board also includes: The composite board with the decorative film attached is cooled and shaped to obtain a pre-formed decorative panel. The pre-formed decorative panel is machined to obtain the refrigerator's magnetically attached panel.

9. A magnetically attachable panel for a refrigerator, characterized in that, The refrigerator magnetic panel is prepared by any one of claims 1 to 8.

10. A refrigerator door, characterized in that, include: The refrigerator magnetic panel, refrigerator door liner, and refrigerator door frame as described in claim 9; One side of the refrigerator door frame is spliced ​​and installed with the refrigerator door lining, and a gap is formed between the refrigerator door lining and the refrigerator door frame, which is filled with elastic filler. The refrigerator's magnetically attachable panel is fitted onto the other side of the refrigerator door frame.

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