High strength powder tray

Abstract

The utility model provides a kind of high-strength powder tray, including substantially planar bottom plate and the side wall that is extended upward by the edge of the bottom plate, the powder tray is configured to be laid 11kg of powder in the range of area 1.0m×1.9m When the sag height of the bottom plate does not exceed 8mm;The powder tray has upper surface layer, honeycomb core layer and lower surface layer that are sequentially stacked and are integrated by hot-pressing mode, the honeycomb core layer is formed by a plurality of plastic tubes being arranged in axial direction parallel to the thickness direction of the honeycomb core layer and being fused to each other, the plastic tube includes PP inner tube and POE outer tube;Wherein, the upper surface layer, honeycomb core layer and lower surface layer form bottom plate and side wall under the extrusion of a mould in hot-pressing process, by adopting the plastic tube formed by PP inner tube and POE outer tube Arrangement fusion forms honeycomb core layer, realizes the extreme lightweight of structure, simultaneously, excellent deformation resistance and bearing performance are shown.

Description

Technical Field

[0001] This utility model relates to the field of synthetic board technology, specifically to a high-strength powder tray. Background Technology

[0002] Powder pallets are widely used in the chemical, food, and pharmaceutical industries for the storage, handling, and transportation of powder materials. Traditional powder pallets are typically made of metal, wood, or ordinary plastic. While metal pallets (such as those made of steel or aluminum) offer high strength, they are heavy, expensive, and susceptible to corrosion, hindering lightweight design and long-term use. Wooden pallets are prone to moisture absorption, deformation, or bacterial growth, resulting in a limited lifespan. Ordinary plastic pallets (such as those made through injection molding) may suffer from insufficient material strength, leading to significant deformation when bearing heavy powders, particularly sagging of the base plate, which affects safety and efficiency.

[0003] To overcome the aforementioned drawbacks, composite material pallets have gradually gained application, with honeycomb structures attracting particular attention due to their lightweight and high strength. For example, existing technologies disclose pallet structures using paper honeycomb, aluminum honeycomb, or plastic honeycomb as the core layer. Paper honeycomb core layers are low in cost but have poor moisture resistance and strength, making them prone to damage in humid environments; aluminum honeycomb core layers have high strength but are expensive, complex to process, and prone to interface separation when bonded to the surface layer; plastic honeycomb core layers (such as PP or PE materials) have some corrosion resistance, but typically have a high density, increasing the overall weight of the pallet, and the bonding strength between honeycomb units is insufficient, making them prone to deformation or cracking during hot-pressing.

[0004] For example, Chinese invention patent CN118544642A provides a lightweight rigid honeycomb panel, including a first skin layer, a core layer, and a second skin layer. The first and second skin layers are connected to opposite first and second end faces of the core layer. Both the first and second skin layers include at least two layers of fiberglass tape. The core layer includes multiple tubular structures arranged in a honeycomb pattern. However, its first and second skin layers are composed of fiberglass, which has relatively limited structural strength. Under significant external forces, it is prone to breakage, making it difficult to meet the requirements of some applications with extremely high strength requirements.

[0005] Therefore, there is an urgent need in the field for an improved powder tray that can achieve lightweight and high strength, while improving the bonding strength between the honeycomb core layer and the surface layer through optimized structure and manufacturing process, and ensuring the durability and economy of the tray. Utility Model Content

[0006] The purpose of this invention is to overcome the problems of insufficient strength in existing powder trays and to provide a high-strength powder tray. This tray achieves lightweight, high strength, and durability through optimized structure and manufacturing process.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A high-strength powder tray includes a generally flat base plate and sidewalls extending upward from the edge of the base plate, wherein the sag of the base plate does not exceed 8 mm when the powder tray is configured to lay 11 kg of powder in an area of ​​1.0 m × 1.9 m. The powder tray has an upper surface layer, a honeycomb core layer, and a lower surface layer that are stacked in sequence and bonded together by hot pressing. The honeycomb core layer is formed by multiple plastic tubes arranged axially parallel to the thickness direction of the honeycomb core layer and fused together with each other. The plastic tubes include PP inner tubes and POE outer tubes. The upper surface layer, honeycomb core layer, and lower surface layer are formed into a base plate and sidewalls under the extrusion action of a mold during the hot-pressing composite process.

[0008] Furthermore, the plastic tube includes a PP inner tube and a POE outer tube. The POE outer tube melts during the hot pressing process, bonding and fixing adjacent plastic tubes to form a honeycomb core layer.

[0009] Furthermore, the wall thickness of the POE outer tube is less than 15% of the wall thickness of the plastic tube.

[0010] Furthermore, the density of the honeycomb core layer does not exceed 120 kg / m³.

[0011] Furthermore, the thickness of the base plate is 5 to 10 mm, and the sidewall has an edge portion extending in a horizontal direction, the thickness of which is 2 to 5 mm.

[0012] Furthermore, the inner diameter of the plastic tube is 6-10 mm.

[0013] Furthermore, when the length × width dimensions of the powder tray are configured as 1.1m × 1.95m, its total weight does not exceed 5.5kg.

[0014] Furthermore, at least one of the upper and lower surface layers is bonded to the honeycomb core layer via a connecting layer, the connecting layer comprising: A nonwoven fabric layer is disposed on the side facing the honeycomb core layer, and the end faces of the nonwoven fabric layer and the honeycomb core layer are fused together during hot pressing; and An adhesive layer is inseparably bonded to the side of the nonwoven layer opposite to the honeycomb core layer to be suitable for bonding the upper or lower surface layer. The nonwoven fabric layer is configured to improve the bonding strength between the liquid cooling plate layer and the honeycomb core layer by increasing the interfacial bonding performance between the honeycomb core layer and the adhesive layer.

[0015] Furthermore, the nonwoven fabric layer has a porous structure with a porosity between 30% and 80%; the nonwoven fabric layer is physically integrated with the end face of the honeycomb core layer during the hot pressing process; the overall thickness of the connecting layer is 0.1 mm to 1.0 mm.

[0016] Furthermore, the adhesive layer is attached to the nonwoven fabric to form a coated nonwoven fabric.

[0017] By adopting the above technical solution, this utility model has the following beneficial effects: This invention achieves extreme lightweighting by using a honeycomb core layer formed by fusion welding of plastic tubes consisting of an inner PP tube and an outer POE tube, and controlling the density of the honeycomb core layer to not exceed 120 kg / m³. When the powder tray size is 1.1m × 1.95m, the total weight does not exceed 5.5kg, which is much lighter than traditional metal or solid wood trays. At the same time, this unique honeycomb structure can control the sag of the bottom plate to within 8mm under specific load conditions (11kg of powder laid flat on an area of ​​1.0m × 1.9m), demonstrating excellent resistance to deformation and load-bearing capacity, perfectly resolving the traditional contradiction between lightweighting and high strength.

[0018] By utilizing the melting property of the POE outer tubes during hot pressing, adjacent plastic tubes are fused together to form a highly integral honeycomb core layer. A dedicated connecting layer is placed between the honeycomb core layer and the upper / lower surface layers. This connecting layer includes a non-woven fabric layer and an adhesive layer that are fused and embedded with the end faces of the honeycomb core, creating a physical bond. This design effectively prevents interlayer delamination under long-term use or temperature changes, significantly improving the structural integrity and service life of the pallet.

[0019] This invention achieves a rational material distribution while ensuring the rigidity of key components by precisely controlling the thickness of the base plate (5-10mm) and the thickness of the sidewall edges (2-5mm). In particular, the use of a hot-pressing composite process allows the upper surface layer, honeycomb core layer, and lower surface layer to be molded in a single step into an integral structure including the base plate and sidewalls. This not only simplifies the manufacturing process and reduces production costs but also ensures product consistency and dimensional accuracy. This integrated design and manufacturing approach provides an ideal solution for the large-scale production of high-quality, low-cost powder trays. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only involve some embodiments of this utility model, and are not intended to limit this utility model.

[0021] Figure 1 This is a schematic diagram of the overall structure of the powder tray after processing according to this utility model; Figure 2 This is an exploded view of the powder tray of this utility model before processing; Figure 3 This is an exploded view of the powder tray of this utility model before it is processed; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the honeycomb core layer structure of this utility model; Figure 6 This is a cross-sectional view of the honeycomb core layer of this utility model; Figure 7 This is a schematic diagram of the structure of the powder processing tray of this utility model.

[0022] Explanation of reference numerals in the attached figures: 100 - Powder tray; 101 - Base plate; 102 - Side wall; 103 - Edge; 1-Upper surface layer; 2-Lower surface layer; 3-Honeycomb core layer; 31-Plastic tube; 311-PP inner tube; 312-POE outer tube; 4-Connecting layer; 41-Non-woven fabric layer; 42-Adhesive layer. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] Unless otherwise defined, the technical or scientific terms used in this patent document shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model patent specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or its equivalents, and do not exclude other elements or objects. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

[0028] Example 1: Please see Figures 1 to 7 This embodiment provides a high-strength powder tray 100. For example... Figure 1 As shown, the powder tray 100, after molding, includes a generally flat base plate 101 and a side wall 102 extending upward from the edge of the base plate 101. The top of the side wall 102 has an edge portion 103 extending in a horizontal direction, which enhances the rigidity of the side wall 102 and the stability of the overall structure, facilitating handling and stacking.

[0029] The powder tray 100 is designed with overall dimensions of 1.1m x 1.95m (length x width), and its total weight is controlled to not exceed 5.5kg, achieving significant weight reduction. To ensure its load-bearing capacity, the tray is configured such that when 11kg of powder material is evenly spread within an area of ​​1.0m x 1.9m, the maximum sag at the center of its base plate 101 does not exceed 8mm. This performance indicator is achieved through a unique lamination structure and material selection, which will be detailed later.

[0030] See Figures 2 to 4 The core structure of the powder tray 100 is a sandwich structure, which consists of an upper surface layer 1, a honeycomb core layer 3 and a lower surface layer 2 stacked from top to bottom, and then bonded together into a solid whole by hot pressing.

[0031] The honeycomb core layer 3 is the key to this structure. For example... Figure 5 and Figure 6 As shown, it is formed by tightly arranging multiple plastic tubes 31 along their axial direction (i.e., the length direction of the tubes) parallel to the thickness direction of the honeycomb core layer 3, and fusing them together by hot pressing. Each plastic tube 31 is a composite structure, including a PP (polypropylene) inner tube 311 and a POE (polyolefin elastomer) outer tube 312 wrapped around the PP inner tube 311. The melting point of POE material is significantly lower than that of PP material. During the hot pressing process, the applied heat melts the POE outer tube 312, while the PP inner tube 311 maintains its basic shape and does not melt. The molten POE material flows, fuses, and cools and solidifies between the contact surfaces of adjacent plastic tubes 31, thereby firmly bonding the numerous independent plastic tubes 31 into a single honeycomb core layer 3. This "internal support, external bonding" mechanism ensures both the high strength of the core layer and the integrity of the structure.

[0032] To optimize the bonding effect, the dimensions of the plastic tube 31 were designed in this embodiment. The inner diameter of the plastic tube 31 is preferably 6-10 mm, and 8 mm is used in this embodiment. The wall thickness of the POE outer tube 312 is designed to be less than 15% of the total wall thickness of the plastic tube 31, specifically 10% in this embodiment. Specifically, the total wall thickness of the plastic tube 31 is 3 mm, and the wall thickness of the POE outer tube is 0.3 mm. This design ensures sufficient POE melting during hot pressing to form an effective bond, while avoiding an excessively thick POE layer that adds unnecessary weight or causes relative displacement of the PP inner tube 311. Through this structure, the density of the honeycomb core layer 3 in this embodiment is successfully controlled to no more than 120 kg / m³, specifically 70 kg / m³ in this embodiment, achieving extremely high lightweighting.

[0033] The upper surface layer 1 and lower surface layer 2, serving as the load-bearing surface and protective layer, need to possess good rigidity, wear resistance, and impact resistance. In this embodiment, they are made of fiber-reinforced composite materials, specifically comprising glass fiber and polypropylene (PP) resin. The glass fiber content is controlled between 55% and 65% (by weight), preferably 60%. This ratio ensures high strength while maintaining good processability. The glass fiber is provided in the form of unidirectional tapes (UD tapes), each tape being approximately 0.15 mm to 0.17 mm thick. During installation, at least two layers of unidirectional glass fiber tapes are used, with the fiber directions of adjacent layers perpendicular to each other (e.g., one layer with a fiber direction of 0°, and adjacent layers at 90°). This orthogonal layup structure effectively resists bending stress and impact loads from different directions. Depending on the target load-bearing requirements, the number of layups can be appropriately increased to obtain higher stiffness. The unidirectional glass fiber tape is formed by impregnating and bonding multiple bundles of parallel glass fibers with a small amount of PP resin, followed by drying and shaping.

[0034] like Figure 7 The upper surface layer 1, the honeycomb core layer 3, and the lower surface layer 2 are formed into the final tray shape in one step under the extrusion of a specially designed mold during the hot-pressing composite process, that is, the bottom plate 101 and the side wall 102 (including the edge portion 103) are formed simultaneously. The mold provides the cavity for the final shape of the tray. During the hot pressing process, at a specific temperature (e.g., POE melts and surface resin softens, within the POE melting temperature range of 80°C to 120°C) and pressure, the three layers of material are pressed and shaped within the mold. During this process, not only does the POE outer tube 312 melt and bond to form the honeycomb core layer 3, but also, under the lateral pressure of the mold, some material is extruded to form the sidewall 102. The final thickness of the base plate 101 is controlled within the range of 5–10 mm, and in this embodiment, it is 8 mm. The thickness of the edge portion 103 of the sidewall 102 is controlled within the range of 2–5 mm, and in this embodiment, it is 3 mm. The overall height of the powder tray 100 in this embodiment is 20 mm. This differentiated thickness design, while ensuring the rigidity of the main load-bearing area (base plate), further optimizes the material distribution and reduces the overall weight.

[0035] Based on the above, the interface bonding performance between the honeycomb core layer 3 and the upper surface layer 1 and the lower surface layer 2 was further optimized to further improve the structural integrity and durability of the pallet under long-term cyclic loads or harsh working conditions.

[0036] like Figure 3 and Figure 4 As shown, in this embodiment, both the upper surface layer 1 and the lower surface layer 2 are joined to the honeycomb core layer 3 via a dedicated connecting layer 4. Of course, depending on actual needs, the connecting layer 4 can also be provided on only one side.

[0037] The connecting layer 4 is a composite structure, mainly comprising a non-woven fabric layer 41 and an adhesive layer 42.

[0038] A nonwoven fabric layer 41 is disposed on the side facing the honeycomb core layer 3. Its material is preferably a coated nonwoven fabric. This nonwoven fabric layer 41 has a porous structure, with a porosity preferably between 30% and 80%, and approximately 60% in this embodiment. During the hot-pressing process, the applied heat and pressure cause a portion of the POE material (molten POE) at the top of the honeycomb core layer 3 to embed into the porous structure of the nonwoven fabric layer 41, forming a strong physical interlock (mechanical interlock) upon cooling. This interlocking effect greatly increases the contact area and bonding force between the two.

[0039] The adhesive layer 42 is inseparably bonded to the side of the nonwoven fabric layer 41 facing away from the honeycomb core layer 3. The nonwoven fabric layer 41 is a coated nonwoven fabric, meaning a hot melt adhesive film is coated onto one side of the nonwoven fabric substrate using a coating process; this hot melt adhesive film constitutes the adhesive layer 42. In another embodiment, the adhesive layer 42 is attached to the coating of the coated nonwoven fabric. This adhesive layer 42 melts during hot pressing, effectively wetting and bonding the back side (typically PP material or containing PP) of the upper surface layer 1 or the lower surface layer 2, forming a reliable physical bond. This hot melt adhesive film enables a strong bond between the upper surface layer 1, the lower surface layer, and the honeycomb core layer 3, and the hot melt adhesive can be purchased directly from the market or prepared in-house.

[0040] Therefore, the connecting layer 4 forms a "physical fit" with the end face of the honeycomb core layer 3 through its nonwoven fabric layer 41. The overall thickness of the connecting layer 4 is controlled between 0.1mm and 1.0mm, and in this embodiment it is about 0.5mm. While ensuring excellent bonding strength, it has a negligible impact on the overall thickness and weight of the tray.

[0041] In conjunction with the above embodiments, the manufacturing process of the high-strength powder tray 100 mainly includes the following steps: Prefabricated honeycomb core layer: The composite plastic tube 31 (PP inner tube 311 + POE outer tube 312) is cut to a fixed length according to the tray design thickness, and then arranged closely to form the required area size to form the prefabricated honeycomb core layer 3.

[0042] Prepare the surface layer and the connecting layer: Prepare the pre-formed sheet as the upper surface layer 1 and the lower surface layer 2. If the connecting layer 4 is used, cut the coated nonwoven fabric (with the hot melt adhesive layer) to the appropriate size.

[0043] Assembly: On the lower mold of the hot press mold, place the lower surface layer 2, (optional) lower connecting layer 4, honeycomb core layer 3 preform, (optional) upper connecting layer 4, and upper surface layer 1 in sequence.

[0044] Hot pressing: The upper mold is closed, and a predetermined temperature (to melt the POE and hot melt adhesive) and pressure are applied. During this process: the POE outer tube 312 of the plastic tube 31 melts, causing adjacent tube walls to bond together. The non-woven fabric layer 41 of the connecting layer 4 is fused and embedded with the end face of the honeycomb core layer 3, and its adhesive layer 42 melts and bonds the surface layer. The mold cavity extrudes the entire laminated structure into an integrated tray shape with a base plate 101 and side walls 102.

[0045] Cooling and demolding: After holding the pressure and cooling, open the mold and take out the formed powder tray 100.

[0046] Based on the above detailed description, the high-strength powder tray 100 of this utility model has significant advantages and performance: Achieving a perfect balance between extreme lightweighting and high strength, the unique PP / POE composite plastic tube honeycomb core layer boasts a density as low as 70kg / m³, resulting in a total weight of less than 5.5kg for a 1.1m × 1.95m pallet. Simultaneously, when this structure supports 11kg of powder in a 1.0m × 1.9m area, the base plate sagging is strictly controlled to within 8mm, resolving the traditional contradiction between lightweighting and load-bearing rigidity.

[0047] With superior structural integrity and durability, the honeycomb core layer achieves strong inter-tube bonding through POE melting. By introducing a physical interlocking layer, the interfacial bonding between the core layer and the surface layer is greatly enhanced, effectively preventing interlayer delamination during use and extending service life.

[0048] Optimized structural design and manufacturing efficiency, along with differentiated thickness designs for the base plate and side walls (including edges), achieve rational material distribution and efficient utilization. The use of a hot-pressing mold for one-time molding simplifies production steps, ensures product dimensional accuracy and consistency, and is suitable for large-scale, low-cost manufacturing.

[0049] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A high-strength powder tray, comprising a generally flat base plate and sidewalls extending upward from the edge of the base plate, wherein the sag of the base plate does not exceed 8 mm when the powder tray is configured to lay 11 kg of powder in an area of ​​1.0 m × 1.9 m; characterized in that: The powder tray has an upper surface layer, a honeycomb core layer, and a lower surface layer that are stacked in sequence and bonded together by hot pressing. The honeycomb core layer is formed by multiple plastic tubes arranged axially parallel to the thickness direction of the honeycomb core layer and fused together with each other. The plastic tubes include PP inner tubes and POE outer tubes. The upper surface layer, honeycomb core layer, and lower surface layer are formed into a base plate and sidewalls under the extrusion action of a mold during the hot-pressing composite process.

2. The high-strength powder tray according to claim 1, characterized in that, The plastic tube includes a PP inner tube and a POE outer tube. The POE outer tube melts during the hot pressing process, bonding and fixing adjacent plastic tubes to form a honeycomb core layer.

3. The high-strength powder tray according to claim 2, characterized in that, The wall thickness of the POE outer tube is less than 15% of the wall thickness of the plastic tube.

4. The high-strength powder tray according to claim 1, 2, or 3, characterized in that, The density of the honeycomb core layer does not exceed 120 kg / m³.

5. The high-strength powder tray according to claim 4, characterized in that, The thickness of the base plate is 5 to 10 mm, and the sidewall has an edge portion extending in a horizontal direction, the thickness of which is 2 to 5 mm.

6. The high-strength powder tray according to claim 5, characterized in that, The inner diameter of the plastic tube is 6-10 mm.

7. The high-strength powder tray according to claim 5 or 6, characterized in that, When the length × width dimensions of the powder tray are configured as 1.1m × 1.95m, its total weight does not exceed 5.5kg.

8. The high-strength powder tray according to claim 1, characterized in that, At least one of the upper and lower surface layers is bonded to the honeycomb core layer via a connecting layer, the connecting layer comprising: A nonwoven fabric layer is disposed on the side facing the honeycomb core layer, and the end faces of the nonwoven fabric layer and the honeycomb core layer are fused together during hot pressing; and An adhesive layer is inseparably bonded to the side of the nonwoven layer opposite to the honeycomb core layer to be suitable for bonding the upper or lower surface layer. The nonwoven fabric layer is configured to improve the bonding strength between the liquid cooling plate layer and the honeycomb core layer by increasing the interfacial bonding performance between the honeycomb core layer and the adhesive layer.

9. The high-strength powder tray according to claim 8, characterized in that, The nonwoven fabric layer has a porous structure with a porosity between 30% and 80%; the nonwoven fabric layer is physically integrated with the end face of the honeycomb core layer during the hot pressing process; the overall thickness of the connecting layer is 0.1 mm to 1.0 mm.

10. The high-strength powder tray according to claim 8, characterized in that, The adhesive layer is attached to the nonwoven fabric to form a coated nonwoven fabric.

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