High-strength plastic honeycomb core material with internal support and its preparation process

Abstract

The present invention belongs to the technical field of honeycomb core material preparation, and specifically relates to a high-strength plastic honeycomb core material with internal support, and also relates to a preparation process of the above-mentioned honeycomb core material. The honeycomb core material provided by the present invention includes a honeycomb wall and a honeycomb cell surrounded by the honeycomb wall, and is characterized in that each honeycomb cell has a support mechanism made of any one of polyethylene, polypropylene, polyvinyl chloride, polystyrene or modified thermoplastic plastics, and the support mechanism is adapted to the shape of the honeycomb cell, and the height of the support mechanism is less than the height of the honeycomb wall. The present invention, through a specific process, starts from the honeycomb structure design, and establishes a plastic honeycomb core material with internal support, which increases the force stability and reduces the dependence of the lateral compressive resistance on the surface material, making the design of the surface more flexible, and the support material adopts a thermoplastic material consistent with the honeycomb core material, which is more environmentally friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of honeycomb core material preparation, and in particular relates to a high-strength plastic honeycomb core material with internal support, and also relates to a preparation process of the honeycomb core material. Background Art

[0002] Honeycomb core materials are mainly made of paper, plastic, aluminum and other materials, and the structures include hexagonal, circular, diamond and so on. Honeycomb core materials are widely used in packaging, construction, automobile and other industrial fields because of their excellent compression resistance and ultra-light structural characteristics. However, when the honeycomb core material is thicker, it is easy to be unstable under stress, and the lateral compression resistance is slightly weak. Therefore, when the honeycomb core material is used, protective surface layer materials are often added on both sides. However, the increase of surface layer materials often makes the honeycomb material heavier, affecting the flexibility of the application of honeycomb core materials.

[0003] At present, the honeycomb core material is mainly designed by the graphic structure and material of the core material to increase the mechanical properties of the honeycomb core material, such as designing the honeycomb into a hexagon, circle, diamond, etc., and selecting high-strength paper-based, aluminum, plastic-based and other materials.

[0004] CN108481824A discloses a honeycomb core material, the honeycomb cells of which are composed of honeycomb core layers, and each honeycomb core layer includes at least two layers of material. The honeycomb core layers are fixedly connected to each other. The honeycomb core layers are bonded or welded. Each honeycomb core layer is at least two layers. The honeycomb core layer is divided into a main layer and a reinforcement layer, and the center distance between adjacent bonding or welding points on the surface of the reinforcement layer is half of the center distance between adjacent bonding or welding points on the surface of the main layer. The honeycomb cells are hexagonal structures or nearly hexagonal structures. The thickness of the material of the honeycomb core layer is 0.02mm to 0.2mm. The material of the honeycomb core layer of the honeycomb cells is metal foil, paper or plastic.

[0005] Production method of plastic honeycomb panel (201610492628.7) introduces a method for preparing plastic honeycomb core, and designs the honeycomb panel through the graphic structure of the surface layer and the core layer.

[0006] The disadvantage of ordinary or the above-mentioned honeycomb core materials is that when the thickness of the core material is large, such as when H is 20mm, it is easy to become unstable under stress, and the height or aperture needs to be reduced, which limits its scope of use. Secondly, the existing honeycomb core materials have weak lateral compressive performance and are often used in combination with surface materials. The lateral pressure is mainly borne by the surface layer, and the thickness and material of the surface layer are required to be high, which reduces the design flexibility of the surface material and structure. In addition, the different materials of the surface layer and the core layer of the honeycomb composite material often increase the recycling cost, or even make the material unrecyclable.

[0007] Therefore, it is necessary to improve the above-mentioned defects and design a preparation process for a honeycomb core material with enhanced stress resistance and good lateral compression resistance, and a core material obtained by the process. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a honeycomb core material with enhanced force bearing and good lateral compression resistance. The present invention also provides a preparation process of the above honeycomb core material.

[0009] The present invention relates to a preparation process of thermoplastic honeycomb cores such as polypropylene, and is mainly aimed at improving the current honeycomb core material in which the lateral compressive performance is weak, while the compressive performance of the surface layer in the honeycomb composite material is required to be high, which limits the application scope of the honeycomb composite material. The present invention improves the honeycomb structure to establish a honeycomb core material with internal support, light weight, high strength, and easy recycling, which can be widely used in packaging, construction, automobile and other industrial fields.

[0010] The high-strength plastic honeycomb core material with internal support provided by the present invention comprises a honeycomb wall and honeycomb cells surrounded by the honeycomb wall. A three-dimensional support mechanism is provided inside each honeycomb cell. The support mechanism is adapted to (matches) the shape of the honeycomb cell, and the side surface of the support mechanism fits the honeycomb cell.

[0011] The supporting mechanism is a solid structure or a foamed structure;

[0012] The supporting mechanism is a three-dimensional mechanism made of non-foaming material, hard foaming material or flexible foaming material;

[0013] Preferably, the supporting structure is a three-dimensional structure made of any one of polyethylene, polypropylene, polyvinyl chloride, polystyrene or modified thermoplastics thereof.

[0014] The support structure inside each honeycomb cell is the same in shape, size and volume;

[0015] The upper top surfaces of the supporting mechanisms inside each honeycomb cell are on the same horizontal plane;

[0016] The bottom surfaces of the supporting mechanisms inside each honeycomb cell are on the same horizontal plane;

[0017] The upper top surface and the lower bottom surface of the supporting mechanism inside each honeycomb cell are parallel.

[0018] The height of the supporting mechanism is less than the height of the honeycomb wall; preferably, the height of the supporting mechanism is 1 / 10 to 1 / 2 of the height of the honeycomb wall.

[0019] The honeycomb cells are any of hexagonal, rhombus, circular, triangular, rectangular and square.

[0020] A preparation process of a high-strength plastic honeycomb core material with internal support comprises the following steps:

[0021] S1: inject the following materials into the common honeycomb core material: polyvinyl alcohol resin material, and perform end-capping treatment;

[0022] S2: Forming a support mechanism:

[0023] (1) The supporting material is non-foaming type: a resin with a melting temperature of 100 to 120°C is selected, and the resin liquid or resin powder is filled into the honeycomb cells. A solid-filled supporting structure is obtained through a heating, cooling, and curing process;

[0024] (2) Rigid foaming type: Select a hard resin with a foaming temperature of 100-120°C, add a surfactant, a foaming agent, a toughening agent, and a curing agent to the resin liquid, and stir it thoroughly to make it evenly mixed. Then fill it into the honeycomb cells and solidify it through low-temperature foaming or room-temperature foaming technology to obtain a foamed and filled support structure;

[0025] (3) Flexible foaming type: Select a flexible resin with a foaming temperature of 100-120°C, add a surfactant, a foaming agent, a toughening agent, and a curing agent to the flexible resin, and stir them thoroughly to make them evenly mixed. Then fill them into the honeycomb cells, and obtain a foamed and filled support structure through low-temperature foaming or room-temperature foaming and curing.

[0026] S3: Hydrolysis: The honeycomb core material with the supporting structure and the end-capping resin prepared above is placed in an aqueous solution, and hydrolyzed by heating until the polyvinyl alcohol is completely dissolved, thereby obtaining a plastic honeycomb core material with internal support.

[0027] Preferably, in the above process, polyvinyl alcohol powder with a degree of polymerization of 1000-2000 and a degree of alcoholysis of 85-99% is selected as the main raw material in S1, wherein the components of the polyvinyl alcohol powder are: 50-70 parts of polyvinyl alcohol, 0.5-1.5 parts of antioxidant, 2-5 parts of heat stabilizer, 1-2 parts of fluidity regulator, and 0.1-0.5 parts of melt adhesion enhancer, and the above parts are parts by weight.

[0028] Preferably, in the above process, the resin liquid or resin powder in (1) is any one of polyethylene, polyvinyl chloride, polystyrene and polypropylene;

[0029] The resin in (2) is any one of polyethylene, polyvinyl chloride, polystyrene and polypropylene;

[0030] The flexible resin in (3) is any one of ethylene vinyl acetate and polyethylene ether.

[0031] In S3, the hydrolysis is carried out by heating to a temperature of 80 to 100°C.

[0032] The honeycomb wall is any one of thermoplastics or modified thermoplastics such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastics, other polyolefins and copolymers thereof, polysulfone, polyphenylene ether, etc.

[0033] Traditional or common honeycomb core materials are improved from the material or number of layers of the honeycomb wall (such as the literature mentioned in the background technology), but there are few documents that disclose adding a support mechanism inside the honeycomb wall. The present invention achieves the purpose of the present invention by injecting resin, hydrolyzing the polyvinyl alcohol therein, and retaining the support mechanism. This is the biggest innovation of the present invention.

[0034] The beneficial effects of the present invention are as follows: the present invention establishes a plastic honeycomb core material with internal support, i.e., with a support mechanism, through a specific process, starting from the honeycomb structure design, and increases the stability of the honeycomb wall force, reduces the dependence of the lateral compressive performance on the surface layer material, makes the surface layer design more flexible, and the support material adopts a thermoplastic material consistent with the honeycomb core material, reduces the classification of materials during recycling, and is more environmentally friendly. The process of the present invention is environmentally friendly, convenient for industrial production, and conducive to large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the final structure of the honeycomb core material of Example 1;

[0036] Figure 2 This is a schematic diagram of the hydrolysis of polyvinyl alcohol in Example 1;

[0037] Figure 3 for Figure 2 Schematic diagram of the three-dimensional structure;

[0038] In the figure, 1-honeycomb wall, 2-honeycomb cells, 3-support mechanism, 4-polyvinyl alcohol layer. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0040] Example 1

[0041] A high-strength plastic honeycomb core material with internal support includes a honeycomb wall 1 and a honeycomb cell 2 surrounded by the honeycomb wall 1. A support mechanism 3 is provided inside each honeycomb cell 2. The honeycomb cell 2 is hexagonal. The support mechanism 3 is adapted to the shape of the honeycomb cell and is also hexagonal. The support mechanism 3 is a three-dimensional mechanism, which is filled in the honeycomb cell 2 and supports the honeycomb wall 1, so that the honeycomb wall 1 is more stable under stress. The upper top surface and the lower bottom surface of the support mechanism 3 are both planar structures or structures close to a planar surface; the support mechanism 3 is actually composed of a plurality of support units, each of which is relatively independent and is located in each honeycomb cell 2;

[0042] The support mechanism 3 is mainly made of any one of polyethylene, polypropylene, polyvinyl chloride, polystyrene or modified thermoplastics thereof; but is not limited to the above materials;

[0043] The supporting mechanism 3 inside each honeycomb cell 2 has the same shape, size and volume.

[0044] The upper tops of the supporting mechanisms 3 inside each honeycomb cell 2 are on the same horizontal plane.

[0045] The lower bottom of the supporting mechanism 3 inside each honeycomb cell 2 is on the same horizontal plane.

[0046] The center of the supporting mechanism 3 is located on the horizontal plane and the vertical plane where the center of the honeycomb wall 1 is located.

[0047] The supporting mechanism 3 is made of either solid material or foamed material.

[0048] The height of the supporting mechanism 3 is 1 / 10 to 1 / 2 of the height of the honeycomb wall.

[0049] The principle of preparing the honeycomb core material of the present invention is as follows:

[0050] The traditional honeycomb cells 3 are filled with a material capable of supporting the honeycomb wall 1, specifically a polyvinyl alcohol resin material (see S1 in Example 2 for details), and then a specific process is selected according to the type of supporting material, such as non-foaming type, rigid foaming type or flexible resin, generally: heating, cooling, solidification, and then hydrolyzing so that part of the raw material in the material, namely the polyvinyl alcohol layer 4, is completely hydrolyzed and dissolved, and the remaining raw material is solidified into a supporting structure for supporting the honeycomb wall to make it more stable under stress. ( Figure 2 It is only a schematic diagram of the hydrolysis and dissolution of the polyvinyl alcohol layer 4, indicating that it is separated from the supporting structure 3, and does not represent the thickness of the polyvinyl alcohol when it is dissolved).

[0051] Example 2

[0052] The honeycomb core material is obtained by using a conventional preparation process;

[0053] Alternatively, the manufacturing process in ZL201610492628.7 is adopted to prepare a thermoplastic plastic flat plate by extruding a thermoplastic plastic, and the plastic honeycomb core material is prepared through processes such as core strip glue coating, lamination, pressing, cutting, stretching, shaping, dipping, curing, and slicing;

[0054] In the actual preparation process of the present invention, the process is as follows:

[0055] Based on the honeycomb core material prepared by the above traditional process, the following raw materials are filled into the honeycomb cells:

[0056] S1: Polyvinyl alcohol powder with a degree of polymerization of 1500 and a degree of alcoholysis of about 90% is used as the main raw material, wherein the components of the polyvinyl alcohol powder are: 60 parts of polyvinyl alcohol, 1 part of antioxidant, 4 parts of heat stabilizer, 1.5 parts of fluidity regulator, and 0.3 parts of melt bonding enhancer, and end-capping treatment is performed;

[0057] Wherein, the antioxidant is tributyl phosphate; the heat stabilizer is calcium stearate; the fluidity regulator is polyethylene glycol-2000; the melt bonding enhancer is C5 petroleum resin; the antioxidant, heat stabilizer, fluidity regulator and melt bonding enhancer used in the above Examples 4 to 8 are the same as those in this Example, unless otherwise specified;

[0058] S2: proceed as follows:

[0059] Preparation of non-foaming support structure: select non-foaming resin (or non-foaming modified resin) with a melting temperature of about 110°C, fill the resin liquid or resin powder (95%) and curing agent (benzoyl peroxide 5%) into the honeycomb cells, heat to 110°C for cross-linking, and cool to room temperature for curing to obtain a solid filled support structure;

[0060] S3: placing the honeycomb core material with the supporting structure and the fixing layer (capping resin) prepared above in an aqueous solution, heating and hydrolyzing until the polyvinyl alcohol therein is completely dissolved, the heating temperature is 90° C., and obtaining a plastic honeycomb core material with internal support.

[0061] What remains after the hydrolysis of polyvinyl alcohol is the supporting structure.

[0062] Embodiment 4 to Embodiment 8

[0063] The difference from Example 1 is that the weight parts of each raw material in S1 are different, and each raw material is shown in Tables 1 and 2 below:

[0064] Table 1 Amount of each raw material used in Examples 4 to 8

[0065]

[0066] In Example 5: In addition, in S2, a non-foaming material is used: polyethylene;

[0067] In Example 6: In S2, a non-foaming material is used: polyvinyl chloride;

[0068] In Example 7: In S2, a non-foaming material is used: polystyrene;

[0069] In Example 8: In S2, a non-foaming material is used: polypropylene.

[0070] In Examples 9 to 13:

[0071] Example 9: S2 rigid foaming type: Select a rigid resin polyethylene (90%) with a foaming temperature of about 120°C, add a foaming agent (ethoxylated alkyl sodium sulfate, 5%), a toughening agent (acrylate copolymer, 3%), and a curing agent (benzoic acid peroxide, 2%) to the resin liquid, and stir it thoroughly to mix it evenly. Then fill it into the honeycomb cells, foam it at low temperature (90-100°C) or foam it at room temperature to obtain a foamed and filled support layer;

[0072] Embodiment 10: using hard resin polyvinyl chloride with a foaming temperature of about 120°C;

[0073] Embodiment 11: using hard resin polystyrene with a foaming temperature of about 120°C;

[0074] Embodiment 12: Use hard resin polypropylene with a foaming temperature of about 120°C.

[0075] In Examples 10 to 12, the rest is the same as Example 9.

[0076] Table 2 Amounts of each raw material in Example 9

[0077]

[0078] Embodiment 14~15:

[0079] Example 14: S2 Flexible foaming type: Select flexible resin ethylene-vinyl acetate (75%) with a foaming temperature of about 110°C, add a foaming promoter (zinc oxide, 5%), a foaming agent (azodicarbonamide composite foaming agent, 10%), a toughening agent (styrene-isoprene-styrene block copolymer, 5%), and a curing agent (diisopropylbenzene peroxide, 5%) to the resin liquid, and stir well to mix them evenly. Then fill it into the honeycomb lattice structure, and obtain a foamed and filled support layer by low-temperature foaming (<120°C) or room-temperature foaming and curing;

[0080] Embodiment 15: In S2, a flexible resin polyvinyl ether having a foaming temperature of about 110° C. is selected. The rest is the same as in Embodiment 14.

[0081] Table 2 Amounts of each raw material used in Examples 9 to 13

[0082]

[0083] The greatest innovation of the present invention is that a support mechanism is provided inside the traditional honeycomb core material. The patent documents consulted by the inventor are almost all about strengthening or improving the honeycomb wall; and there is no document disclosing the addition of a support mechanism inside the honeycomb core material.

[0084] The inventor selected Examples 1, 9, and 14 to represent support mechanisms made of three different materials, respectively, to test their performances, and the results are as follows:

[0085]

[0086] It can be seen from the data in the above table that the non-foamed material as a supporting mechanism has a higher compression strength and the largest lateral compression strength, and is a relatively ideal material; the other hard foamed materials or flexible foamed materials are less effective than the non-foamed material used in Example 1.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

[0088] The supporting mechanism in the above embodiments 1 to 2 can also be multi-layered, but the inventors have found that one or two layers are more convenient and easy to use in the production process; in addition, the honeycomb cells mentioned in the present invention can also be quadrilateral, circular or other shapes, and such changes also fall within the scope of protection of the present invention.

Claims

1. A process for preparing a high-strength plastic honeycomb core material with internal support, characterized in that: The preparation process comprises the following steps: S1: injecting the following materials into the common honeycomb core material: polyvinyl alcohol resin material, and performing end-capping treatment; the polyvinyl alcohol resin material selects polyvinyl alcohol powder with a polymerization degree of 1000-2000 and a degree of alcoholysis of 85-99% as the main raw material, wherein the polyvinyl alcohol powder comprises: 50-70 parts of polyvinyl alcohol, 0.5-1.5 parts of antioxidant, 2-5 parts of heat stabilizer, 1-2 parts of fluidity regulator, and 0.1-0.5 parts of melt bonding enhancer, and the above parts are parts by weight; S2: Forming a support mechanism: (1) The supporting material is non-foaming type: a resin with a melting temperature of 100 to 120°C is selected, the resin is filled into the honeycomb cells, and a solid-filled supporting structure is obtained through heating, cooling, and curing processes; or, (2) The supporting material is a rigid foaming type: a rigid resin with a foaming temperature of 100 to 120°C is selected, a surfactant, a foaming agent, a toughening agent, and a curing agent are added to the rigid resin, and the mixture is fully stirred to make it uniform, and then the mixture is filled into the honeycomb cells, and solidified by low-temperature foaming or room-temperature foaming technology to obtain a foamed and filled supporting structure; or, (3) The supporting material is a flexible foaming type: a flexible resin with a foaming temperature of 100 to 120°C is selected, a surfactant, a foaming agent, a toughening agent, and a curing agent are added to the flexible resin, and the mixture is fully stirred to make it uniformly mixed, and then the mixture is filled into the honeycomb cells, and the foamed supporting structure is obtained by low-temperature foaming or room-temperature foaming and curing; S3: hydrolysis: placing the honeycomb core material with the supporting mechanism and the end-capping resin prepared above in an aqueous solution, and hydrolyzing it by heating until the polyvinyl alcohol is completely dissolved, thereby obtaining a plastic honeycomb core material with internal support; The high-strength plastic honeycomb core material with internal support includes a honeycomb wall and honeycomb cells surrounded by the honeycomb wall. Each honeycomb cell has a three-dimensional support mechanism inside. The support mechanism is adapted to the shape of the honeycomb cell, and the side of the support mechanism fits the honeycomb cell.

2. The process for preparing the high-strength plastic honeycomb core material with internal support according to claim 1, characterized in that: The support structure inside each honeycomb cell is the same in shape, size and volume; The upper top surfaces of the supporting mechanisms inside each honeycomb cell are on the same horizontal plane; The bottom surfaces of the supporting mechanisms inside each honeycomb cell are on the same horizontal plane; The upper top surface and the lower bottom surface of the supporting mechanism inside each honeycomb cell are parallel.

3. The process for preparing the high-strength plastic honeycomb core material with internal support according to claim 1, characterized in that: The height of the supporting mechanism is less than the height of the honeycomb wall; the height of the supporting mechanism is 1 / 10 to 1 / 2 of the height of the honeycomb wall.

4. The process for preparing the high-strength plastic honeycomb core material with internal support according to any one of claims 1 to 3, characterized in that: The honeycomb cells are any of hexagonal, rhombus, circular, triangular, rectangular and square.

5. The process for preparing the high-strength plastic honeycomb core material with internal support as claimed in claim 1, characterized in that: The resin in (1) is any one of polyethylene, polyvinyl chloride, polystyrene and polypropylene; (2) The hard resin is any one of polyethylene, polyvinyl chloride, polystyrene and polypropylene; The flexible resin in (3) is any one of ethylene vinyl acetate and polyethylene ether.

6. The process for preparing the high-strength plastic honeycomb core material with internal support as claimed in claim 1, characterized in that: In S3, the hydrolysis is carried out by heating to a temperature of 80 to 100°C.

7. The process for preparing the high-strength plastic honeycomb core material with internal support according to claim 1, characterized in that: The honeycomb wall is made of any one of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyoxymethylene, polycarbonate, polyamide, acrylic plastic, polysulfone and polyphenylene ether.

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