Antibacterial anti-static turnover tray and preparation process

Abstract

The invention discloses an antibacterial and anti-static turnover tray which is formed by compounding a base layer, an antibacterial and anti-static functional layer and a surface protective coating, each layer is composed of the following materials in parts by mass; the base layer material is prepared from 80 to 100 parts of modified high-density polyethylene; the antibacterial and antistatic functional layer is prepared from the following materials in parts by weight: 30-40 parts of polystyrene-butadiene-styrene block copolymer, 10-15 parts of silver-loaded zeolite antibacterial agent, 5-8 parts of polythiophene conductive polymer, 5-8 parts of compatibilizer and 1-2 parts of calcium stearate lubricant; the surface protection coating material is prepared from 20 to 30 parts of waterborne polyurethane emulsion. The formula is improved, and the silver-loaded zeolite antibacterial agent and the polythiophene conductive polymer are introduced, so that the turnover tray is good in durability and has antibacterial and antistatic functions.

Description

Technical Field

[0001] The invention belongs to the technical field of turnover pallet production, and in particular relates to an antibacterial and antistatic turnover pallet. Background Art

[0002] Turnover pallets are a type of equipment widely used in the fields of logistics, transportation and warehousing. They are mainly used for supporting and protecting goods during loading and unloading, handling, storage and transportation. They can effectively improve logistics efficiency, reduce the risk of cargo damage, and play a key role in the modern logistics system.

[0003] In traditional logistics scenarios, most of the turnover pallets currently in widespread use have relatively simple functions and generally lack antibacterial and antistatic properties. In industries with strict hygiene and safety requirements, such as food, medicine, and electronics, turnover pallets lacking antibacterial properties can easily become a breeding ground for bacteria. During the storage and circulation of goods, the surface of the pallets is easily contaminated with dust, moisture, and various microorganisms. Under suitable temperature and humidity conditions, bacteria will rapidly multiply and attach to the goods, which can not only cause food spoilage and drug contamination, affecting product quality and safety, but also shorten the shelf life of the goods, resulting in significant economic losses for the company.

[0004] The dangers of static electricity in the production and transportation of electronic components, precision instruments, and other equipment cannot be underestimated. Ordinary turnover pallets lack anti-static properties, and during the handling and stacking of goods, frequent friction between pallets and pallets easily generates static electricity. When static electricity accumulates to a certain level, it can discharge. For static-sensitive electronic components, even a weak static discharge can cause breakdown of critical components such as chips and circuits, leading to product damage, performance degradation, or even complete failure. This can severely impact production efficiency and quality, increasing production costs and the rate of defective products. Summary of the Invention

[0005] The purpose of the present invention is to propose an antibacterial and antistatic turnover pallet in order to solve the problem that the existing turnover pallet does not have the antibacterial and antistatic functions and has poor applicability.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: an antibacterial and antistatic turnover tray, which is composed of a base layer, an antibacterial and antistatic functional layer and a surface protective coating; the material composition and mass parts of each layer are as follows;

[0007] The base material: 80-100 parts of modified high-density polyethylene;

[0008] The antibacterial and antistatic functional layer material comprises: 30-40 parts of polystyrene-butadiene-styrene block copolymer, 10-15 parts of silver-loaded zeolite antibacterial agent, 5-8 parts of polythiophene conductive polymer, 5-8 parts of compatibilizer and 1-2 parts of calcium stearate lubricant;

[0009] The surface protective coating material: 20-30 parts of aqueous polyurethane emulsion.

[0010] As a further description of the above technical solution:

[0011] The thickness of the base layer is 3-5 mm, the thickness of the antibacterial and antistatic functional layer is 1-2 mm, and the thickness of the surface protection coating is 0.1-0.2 mm.

[0012] As a further description of the above technical solution:

[0013] The edge of the tray is provided with a 20-30 mm surrounding edge, and the inner side of the surrounding edge is provided with anti-slip protrusions arranged in a honeycomb shape, and the height of the anti-slip protrusions is 3-5 mm.

[0014] As a further description of the above technical solution:

[0015] A plurality of radially distributed reinforcing ribs are provided at the bottom of the tray, and the reinforcing ribs are integrally formed with the tray.

[0016] As a further description of the above technical solution:

[0017] The compatibilizer is ethylene-vinyl acetate copolymer.

[0018] As a further description of the above technical solution:

[0019] The present invention also provides an antibacterial and antistatic turnover tray, comprising the following steps:

[0020] S1: Add the modified high-density polyethylene raw material to a twin-screw extruder, set the temperature of each zone of the extruder to: 160-170°C for zone 1, 170-180°C for zone 2, 180-190°C for zone 3, 190-200°C for zone 4, and the die temperature to 195-205°C. The extruded melt is water-cooled, shaped, pulled, and cut to obtain a base sheet;

[0021] S2: adding the polystyrene-butadiene-styrene block copolymer into a high-speed mixer and preheating at 80-90° C. for 10-15 minutes;

[0022] S3: adding the silver-loaded zeolite antibacterial agent surface-modified with sodium lauryl sulfate, the polythiophene conductive polymer, the compatibilizer, and the calcium stearate lubricant in sequence, and mixing at a speed of 100-120 r / min for 20-30 min to fully disperse the components;

[0023] S4: adding the mixed material to a twin-screw extruder, setting the temperature of each zone of the extruder to: 150-160°C for zone 1, 160-170°C for zone 2, 170-180°C for zone 3, 180-190°C for zone 4, the die temperature to 185-195°C, the screw speed to 80-100 r / min, and extruding the melt through water cooling, shaping, pulling, and cutting to obtain an antibacterial and antistatic functional layer sheet;

[0024] S5: adding the aqueous polyurethane emulsion to the coating machine trough, adjusting the gap between the coating rollers of the coating machine to control the coating thickness to 0.1-0.2 mm, passing the antibacterial and antistatic functional layer sheet through the coating machine to evenly coat the aqueous polyurethane emulsion on its surface; sending the coated sheet into an infrared drying oven and drying it at 80-90° C. for 15-20 minutes to solidify the coating;

[0025] S6: stacking the base sheet, the antibacterial and antistatic functional layer sheet, and the functional layer sheet coated with the protective coating in sequence, and placing them into a hot pressing mold to tightly laminate the three layers of sheet material together;

[0026] S7: After the hot pressing is completed, cooling water at 15-20°C is introduced into the cooling water channel of the hot pressing mold and cooled for 10-15 minutes to quickly set the tray;

[0027] S8: Trim and polish the formed pallet to remove edge burrs and surface defects, and conduct quality inspection, including appearance inspection, dimension measurement, antibacterial performance test, antistatic performance test and load-bearing capacity test. After passing the inspection, the finished antibacterial and antistatic turnover pallet is obtained.

[0028] As a further description of the above technical solution:

[0029] In the step S6, the temperature of the hot pressing mold is 160-170° C., the pressure is 8-10 MPa, and the hot pressing time is 5-8 min.

[0030] As a further description of the above technical solution:

[0031] The modified high-density polyethylene is modified by introducing fluorine-containing chain segments, and the fluorine-containing chain segments account for 3% to 5% of the total mass of the modified high-density polyethylene.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] 1. The present invention incorporates a nano-scale silver-loaded zeolite antimicrobial agent surface-modified with sodium dodecyl sulfate into the antimicrobial and antistatic turnover pallet. Silver ions possess broad-spectrum antimicrobial properties and can bind to biomacromolecules such as proteins and enzymes on bacterial cell walls and membranes, disrupting bacterial cell structure and interfering with their normal physiological metabolism, thereby inhibiting bacterial growth and reproduction. Furthermore, the porous structure of the zeolite supports the silver ions, slowly releasing them for a sustained antimicrobial effect. This results in an antimicrobial rate of over 99% against both Escherichia coli and Staphylococcus aureus, effectively reducing the risk of bacterial contamination during storage and transportation.

[0034] 2. In the present invention, the antibacterial and antistatic turnover pallet is prepared by adding a polythiophene conductive polymer through chemical oxidation polymerization. Sulfonic acid groups are introduced into the molecular chain to enhance the compatibility with the SBS (polystyrene-butadiene-styrene block copolymer) matrix. In the pallet, the conductive polymer forms a conductive network. When static electricity is generated on the surface of the pallet due to friction or other reasons, the static electricity can be quickly conducted and dispersed through the conductive network, so that the surface resistivity of the pallet is stabilized at 10 6 -10 8 Ω, effectively preventing static electricity accumulation and avoiding damage to electronic components and other static-sensitive goods due to electrostatic discharge.

[0035] 3. In this invention, the base material is high-density polyethylene (HDPE) modified by introducing fluorinated segments, with the fluorinated segments comprising 3%-5% of the total mass of the modified HDPE. The modified HDPE achieves a tensile strength of 45-55 MPa and an elongation at break of 300-350%, providing a stable foundation for the pallet's mechanical support, capable of withstanding the weight of the cargo and external forces during transportation, ensuring that the pallet is not easily deformed or damaged during use.

[0036] 4. In the present invention, the surface is coated with a protective coating formed by an aqueous polyurethane emulsion with a solid content of 40%-45%. After curing, the coating forms a dense cross-linked structure with a hardness of 2H-3H and a wear resistance of ≤15mg. The coating can effectively protect the antibacterial and antistatic functional layer from external wear and chemical erosion, thereby extending the service life of the pallet. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1This is a component diagram of an antibacterial and antistatic turnover tray.

[0039] Figure 2 This is a process step diagram for preparing an antibacterial and antistatic turnover tray. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0044] In the description of the embodiments of the present invention, it should be noted that the terms "upper" and "inner" etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are orientations or positional relationships in which the inventive product is usually placed when in use. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0045] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0046] See also Figure 1 The present invention provides a technical solution: an antibacterial and antistatic turnover tray, comprising:

[0047] It is composed of a base layer, an antibacterial and antistatic functional layer and a surface protective coating; the material composition and mass percentage of each layer are as follows;

[0048] The base material: 80-100 parts of modified high-density polyethylene;

[0049] The antibacterial and antistatic functional layer material comprises: 30-40 parts of polystyrene-butadiene-styrene block copolymer, 10-15 parts of silver-loaded zeolite antibacterial agent, 5-8 parts of polythiophene conductive polymer, 5-8 parts of compatibilizer and 1-2 parts of calcium stearate lubricant;

[0050] The surface protective coating material: 20-30 parts of aqueous polyurethane emulsion.

[0051] The pallet's edges are designed with a 20-30mm thick edging, and inside these edgings are honeycomb-shaped, anti-slip bumps with a height of 3-5mm. The edging and anti-slip bumps, along with the reinforcing ribs at the bottom, further enhance the pallet's anti-slip properties and load-bearing capacity, improving the safety and stability of cargo transportation and fully meeting the high-performance demands of turnover pallets in the modern logistics industry.

[0052] A plurality of radially distributed reinforcing ribs are provided at the bottom of the tray, and the reinforcing ribs are integrally formed with the tray.

[0053] The compatibilizer is ethylene-vinyl acetate copolymer.

[0054] See also Figure 2 The present invention also provides a preparation process of an antibacterial and antistatic turnover tray, comprising the following steps:

[0055] S1: Add the modified high-density polyethylene raw material to a twin-screw extruder, set the temperature of each zone of the extruder to: 160-170°C for zone 1, 170-180°C for zone 2, 180-190°C for zone 3, 190-200°C for zone 4, and the die temperature to 195-205°C. The extruded melt is water-cooled, shaped, pulled, and cut to obtain a base sheet;

[0056] S2: adding the polystyrene-butadiene-styrene block copolymer into a high-speed mixer and preheating at 80-90° C. for 10-15 minutes;

[0057] S3: adding the silver-loaded zeolite antibacterial agent surface-modified with sodium lauryl sulfate, the polythiophene conductive polymer, the compatibilizer, and the calcium stearate lubricant in sequence, and mixing at a speed of 100-120 r / min for 20-30 min to fully disperse the components;

[0058] S4: adding the mixed material to a twin-screw extruder, setting the temperature of each zone of the extruder to: 150-160°C for zone 1, 160-170°C for zone 2, 170-180°C for zone 3, 180-190°C for zone 4, the die temperature to 185-195°C, the screw speed to 80-100 r / min, and extruding the melt through water cooling, shaping, pulling, and cutting to obtain an antibacterial and antistatic functional layer sheet;

[0059] S5: adding the aqueous polyurethane emulsion to the coating machine trough, adjusting the gap between the coating rollers of the coating machine to control the coating thickness to 0.1-0.2 mm, passing the antibacterial and antistatic functional layer sheet through the coating machine to evenly coat the aqueous polyurethane emulsion on its surface; sending the coated sheet into an infrared drying oven and drying it at 80-90° C. for 15-20 minutes to solidify the coating;

[0060] S6: stacking the base sheet, the antibacterial and antistatic functional layer sheet, and the functional layer sheet coated with the protective coating in sequence, and placing them into a hot pressing mold to tightly laminate the three layers of sheet material together;

[0061] S7: After the hot pressing is completed, cooling water at 15-20°C is introduced into the cooling water channel of the hot pressing mold and cooled for 10-15 minutes to quickly set the tray;

[0062] S8: In the antibacterial and antistatic turnover tray, each component works together to achieve excellent performance.

[0063] Working principle: Modified high-density polyethylene (HDPE) is used as the base material. The introduction of fluorinated chains can improve the tensile strength and good elongation at break, building a solid mechanical support framework for the pallet to withstand the weight of the goods and external force impact during transportation, ensuring the stability of the pallet's overall structure; polystyrene-butadiene-styrene block copolymer (SBS) is used as the matrix resin of the antibacterial and antistatic functional layer. With its own good flexibility and processing performance, it tightly wraps and evenly disperses other functional components, allowing each component to fully play its role, while providing basic physical properties for the functional layer; the silver-loaded zeolite antibacterial agent is evenly dispersed in the SBS matrix. After surface modification with sodium dodecyl sulfate, the nano-particle size of the antibacterial agent can more fully contact with bacteria, releasing silver ions to destroy the bacterial cell structure, achieving high-efficiency antibacterial, and the antibacterial effect is long-lasting and stable; polythiophene conductive polymers are prepared by chemical oxidation polymerization and introduced The incorporation of sulfonic acid groups enhances compatibility with the SBS matrix, building a conductive network in the functional layer that promptly conducts and disperses static electricity generated by friction, stabilizing the pallet's surface resistivity within an effective antistatic range and preventing static electricity accumulation from damaging sensitive goods. Ethylene-vinyl acetate copolymer (EVA) serves as a compatibilizer, with its specific vinyl acetate content (18%-22%) significantly improving the dispersion of the antimicrobial agent and conductive polymer in the SBS matrix, promoting interfacial bonding between the components, avoiding performance degradation due to uneven dispersion, and making the antimicrobial and antistatic properties of the functional layer more uniform and stable. Calcium stearate lubricant improves the processing fluidity of the material, ensuring smooth mixing, extrusion, and molding of the components during the preparation process, reducing processing defects, and improving production efficiency and product quality. The surface protective coating formed by the water-based polyurethane emulsion forms a dense cross-linked structure after curing, with moderate hardness and good wear resistance. It is like a solid shield, tightly attached to the surface of the antibacterial and antistatic functional layer, effectively resisting external wear and chemical erosion, protecting internal functional components from damage, extending the service life of the pallet, and maintaining the neat and beautiful appearance of the pallet.

[0064] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An antibacterial and antistatic turnover tray, characterized in that: It is composed of a base layer, an antibacterial and antistatic functional layer and a surface protective coating; the material composition and mass percentage of each layer are as follows; The base material: 80-100 parts of modified high-density polyethylene; The antibacterial and antistatic functional layer material comprises: 30-40 parts of polystyrene-butadiene-styrene block copolymer, 10-15 parts of silver-loaded zeolite antibacterial agent, 5-8 parts of polythiophene conductive polymer, 5-8 parts of compatibilizer and 1-2 parts of calcium stearate lubricant; The surface protective coating material: 20-30 parts of aqueous polyurethane emulsion.

2. The antibacterial and antistatic turnover tray according to claim 1, characterized in that: The thickness of the base layer is 3-5 mm, the thickness of the antibacterial and antistatic functional layer is 1-2 mm, and the thickness of the surface protection coating is 0.1-0.2 mm.

3. The antibacterial and antistatic turnover tray according to claim 2, characterized in that: The edge of the tray is provided with a 20-30 mm surrounding edge, and the inner side of the surrounding edge is provided with anti-slip protrusions arranged in a honeycomb shape, and the height of the anti-slip protrusions is 3-5 mm.

4. The antibacterial and antistatic turnover tray according to claim 3, characterized in that: A plurality of radially distributed reinforcing ribs are provided at the bottom of the tray, and the reinforcing ribs are integrally formed with the tray.

5. The antibacterial and antistatic turnover tray according to claim 3, characterized in that: The compatibilizer is ethylene-vinyl acetate copolymer.

6. The process for preparing an antibacterial and antistatic turnover tray according to claim 1, characterized in that: The following steps are involved: S1: Add the modified high-density polyethylene raw material to a twin-screw extruder, set the temperature of each zone of the extruder to: 160-170°C for zone 1, 170-180°C for zone 2, 180-190°C for zone 3, 190-200°C for zone 4, and the die temperature to 195-205°C. The extruded melt is water-cooled, shaped, pulled, and cut to obtain a base sheet; S2: adding the polystyrene-butadiene-styrene block copolymer into a high-speed mixer and preheating at 80-90° C. for 10-15 minutes; S3: adding the silver-loaded zeolite antibacterial agent surface-modified with sodium lauryl sulfate, the polythiophene conductive polymer, the compatibilizer, and the calcium stearate lubricant in sequence, and mixing at a speed of 100-120 r / min for 20-30 min to fully disperse the components; S4: adding the mixed material to a twin-screw extruder, setting the temperature of each zone of the extruder to: 150-160°C for zone 1, 160-170°C for zone 2, 170-180°C for zone 3, 180-190°C for zone 4, the die temperature to 185-195°C, the screw speed to 80-100 r / min, and extruding the melt through water cooling, shaping, pulling, and cutting to obtain an antibacterial and antistatic functional layer sheet; S5: adding the aqueous polyurethane emulsion to the coating machine trough, adjusting the gap between the coating rollers of the coating machine to control the coating thickness to 0.1-0.2 mm, passing the antibacterial and antistatic functional layer sheet through the coating machine to evenly coat the aqueous polyurethane emulsion on its surface; sending the coated sheet into an infrared drying oven and drying it at 80-90° C. for 15-20 minutes to solidify the coating; S6: stacking the base sheet, the antibacterial and antistatic functional layer sheet, and the functional layer sheet coated with the protective coating in sequence, and placing them into a hot pressing mold to tightly laminate the three layers of sheet material together; S7: After the hot pressing is completed, cooling water at 15-20°C is introduced into the cooling water channel of the hot pressing mold and cooled for 10-15 minutes to quickly set the tray; S8: The finished pallet is trimmed and polished to remove edge burrs and surface defects. Quality inspection is then carried out, including appearance inspection, dimensional measurement, antibacterial performance testing, antistatic performance testing, and load-bearing capacity testing. After passing these tests, the finished antibacterial and antistatic turnover pallet is obtained.

7. The process for preparing an antibacterial and antistatic turnover tray according to claim 6, characterized in that: In the step S6, the temperature of the hot pressing mold is 160-170° C., the pressure is 8-10 MPa, and the hot pressing time is 5-8 min.

8. The process for preparing an antibacterial and antistatic turnover tray according to claim 6, characterized in that: The modified high-density polyethylene is modified by introducing fluorine-containing chain segments, and the fluorine-containing chain segments account for 3% to 5% of the total mass of the modified high-density polyethylene.

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