Environment-friendly air conditioner packaging foam and preparation method thereof

Abstract

This application relates to the field of foam materials, and more specifically to an environmentally friendly air conditioner packaging foam and its preparation method. The environmentally friendly air conditioner packaging foam, by weight, comprises at least the following raw materials: 90-130 parts of a main resin composition, 10-25 parts of an auxiliary resin composition, 5-9 parts of a foaming agent, 1.2-2.5 parts of a nucleating agent, and 0.5-1.5 parts of a chain extender. The foam material ultimately obtained by this application not only effectively solves the environmental protection problem, but also maintains good mechanical properties, corrosion resistance, aging resistance, and waterproof and moisture-proof properties, thereby meeting the higher standard requirements of existing air conditioner transport packaging.

Description

Technical Field

[0001] This application relates to the field of foam materials, and more specifically to an environmentally friendly air conditioning packaging foam and its preparation method. Background Technology

[0002] With the continuous development of modern industrial technology and the sustained improvement of people's living standards, air conditioners, as an important household appliance, have been widely used in homes, offices, businesses, and other places. During the production, transportation, and sales of air conditioners, effective packaging protection of the indoor and outdoor units is usually required to ensure that the products are protected from external impacts, vibrations, and moisture during distribution. Packaging foam, as a key cushioning material, is widely used to fill gaps inside the packaging box, fix the air conditioner unit, and absorb mechanical impacts during transportation, thereby effectively preventing product damage. Currently, the mainstream air conditioner packaging foam on the market mostly uses petroleum-based foam materials such as polystyrene (EPS), polyethylene (PE), or polyurethane (PU). These materials have long dominated the packaging field due to their excellent cushioning performance, lightweight characteristics, and low production costs.

[0003] With the widespread use of foam packaging, its environmental problems have become increasingly prominent. Traditional petroleum-based foam is difficult to degrade under natural conditions, and after disposal, it is mostly disposed of through incineration or landfill, which not only occupies land resources but may also release harmful substances or greenhouse gases. In addition, EPS material is relatively brittle and easily breaks under repeated stress or localized pressure, producing white particulate pollution, further exacerbating the environmental burden. Although some companies have tried to use polyethylene foam (EPE) to replace EPS to improve flexibility and resilience, it is still a non-degradable plastic material and cannot fundamentally solve the waste pollution problem.

[0004] In recent years, in response to environmental policies and the need for sustainable development, some improved packaging materials have emerged in the industry. For example, biodegradable polymers such as polylactic acid (PLA) or starch-based foam materials are used to partially replace traditional plastics. These materials are derived from renewable resources and have a certain degree of biodegradability, decomposing into water and carbon dioxide under specific composting conditions. However, these environmentally friendly materials still have significant drawbacks when actually applied to air conditioner packaging, such as mechanical strength, cushioning energy absorption capacity, and moisture resistance often being inferior to traditional foams. Summary of the Invention

[0005] In summary, while existing air conditioner packaging foam technology can meet product protection requirements to a certain extent, it still faces significant technical challenges. For example, traditional petroleum-based foams are difficult to degrade, leading to severe environmental pollution, and existing environmentally friendly alternatives have not yet met the higher standards required for air conditioner transport packaging in terms of mechanical properties, corrosion resistance, aging resistance, and moisture resistance. Therefore, the industry urgently needs an air conditioner packaging foam material that combines excellent comprehensive performance with environmental friendliness. Through continuous in-depth research in this technical field, the applicant has ultimately proposed an environmentally friendly air conditioner packaging foam and its preparation method in this application. The foam material ultimately obtained in this application not only effectively solves the environmental protection issue but also maintains good mechanical properties, corrosion resistance, aging resistance, and waterproof and moisture-proof properties, thereby meeting the higher standards required for existing air conditioner transport packaging.

[0006] An environmentally friendly air conditioner packaging foam, by weight, comprises at least the following raw materials: 90-130 parts of main resin composition, 10-25 parts of auxiliary resin composition, 5-9 parts of foaming agent, 1.2-2.5 parts of nucleating agent, and 0.5-1.5 parts of chain extender.

[0007] Preferably, the main resin combination is a combination of polylactic acid and poly(butylene adipate / terephthalate).

[0008] Preferably, the mass ratio of polylactic acid to poly(adipate) / butyl terephthalate is (7~9):(1.5~3).

[0009] More preferably, the mass ratio of polylactic acid to poly(adipate) / butyl terephthalate is (7.5~8.5):(2~3).

[0010] Preferably, the polylactic acid has a melt index of 5-15 g / 10 min and a melt index of 190°C / 2.16 kg.

[0011] Preferably, the poly(butylene adipate) has a concentration of 3-8 g / 10 min at 190°C and 2.16 kg.

[0012] Preferably, the mass ratio of the main resin composition, the auxiliary resin composition and the foaming agent is (10~12):(1.5~2.2):(0.6~0.8).

[0013] More preferably, the mass ratio of the main resin composition, the auxiliary resin composition and the foaming agent is (11~11.5):(1.8~2):(0.6~0.7).

[0014] Most preferably, the mass ratio of the main resin composition, the auxiliary resin composition, and the foaming agent is 11:2:0.6.

[0015] Preferably, the auxiliary resin combination is a combination of polyether block amide and polycaprolactone.

[0016] Preferably, the mass ratio of the polyether block amide to polycaprolactone is (6~9):(2~4).

[0017] More preferably, the mass ratio of the polyether block amide to polycaprolactone is (7~8):(2~3).

[0018] Most preferably, the mass ratio of the polyether block amide to polycaprolactone is 7.5:2.5.

[0019] More preferably, the polyether block amide is Rnew® 72R53, from Arkema, France.

[0020] More preferably, the polycaprolactone is Capa™ 6500, sourced from Perstork, Sweden.

[0021] The auxiliary resin combination added in this application, as a key component of the environmentally friendly air conditioning packaging foam, comprehensively enhances the overall performance of the foam while ensuring its biodegradability and environmental friendliness. The combination of Rnew® 72R53 and Capa™ 6500 forms a highly efficient multiphase composite structure with the main resin combination, providing a solid skeletal support, significantly enhancing the material's mechanical strength, heat resistance, and dimensional stability, while also providing moisture resistance and hydrophobic properties. On the other hand, polycaprolactone effectively improves the interfacial bonding between the components, promotes uniform phase dispersion, thereby avoiding the performance shortcomings of some raw materials, and further enhances the material's flexibility and low-temperature impact resistance. Ultimately, this ensures that the foam has sufficient cushioning and protective functions, and more importantly, endows the product with excellent environmental durability, including excellent water resistance, wide temperature range adaptability, and anti-aging properties.

[0022] Preferably, the foaming agent is supercritical carbon dioxide.

[0023] Preferably, the nucleating agent is at least one selected from talc, calcium carbonate, silica, boehmite, and ethylene bis-stearamide.

[0024] More preferably, the nucleating agent is talc, calcium carbonate, or silicon dioxide.

[0025] Most preferably, the nucleating agent is silicon dioxide.

[0026] Preferably, the average particle size of the silicon dioxide is 50~120nm.

[0027] Preferably, the chain extender is at least one of acrylate copolymers, oxazoline compounds, and pyromellitic anhydride.

[0028] More preferably, the chain extender is an acrylate copolymer or pyromellitic anhydride.

[0029] Most preferably, the chain extender is pyromellitic anhydride.

[0030] More preferably, the environmentally friendly air conditioning packaging foam, by weight, further includes: 3-5 parts compatibilizer, 0.8-1.4 parts anti-hydrolysis agent, 0.3-0.8 parts lubricant, and 8-15 parts composite additives.

[0031] Preferably, the mass ratio of the main resin composition to the composite additive is (10~12):(1~1.3).

[0032] More preferably, the mass ratio of the main resin composition to the composite additive is (11~11.5):(1.1~1.2).

[0033] Most preferably, the mass ratio of the main resin composition to the composite additive is 11:1.2.

[0034] Preferably, the compatibilizer is at least one of glycidyl methacrylate, polyethylene grafted maleic anhydride, and polylactic acid grafted glycidyl methacrylate.

[0035] More preferably, the compatibilizer is polyethylene grafted with maleic anhydride.

[0036] Preferably, the anti-hydrolysis agent is polycarbodiimide or an oxazoline.

[0037] More preferably, the anti-hydrolysis agent is polycarbodiimide.

[0038] Preferably, the lubricant is at least one of calcium stearate, oxidized polyethylene wax, pentaerythritol stearate, and complex esters.

[0039] More preferably, the lubricant is calcium stearate or pentaerythritol stearate.

[0040] Most preferably, the lubricant is pentaerythritol stearate.

[0041] Preferably, the composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt.

[0042] Preferably, the mass ratio of the nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt is (3~5):(2~4):(1~2).

[0043] More preferably, the mass ratio of the nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt is (4~4.5):(2.5~3):(1~1.5).

[0044] More preferably, the nanocellulose is CNF grade.

[0045] Preferably, the polyurethane acrylate is Desmolux® U 680, sourced from Covestro, Germany.

[0046] The addition of composite additives significantly enhances the overall performance of environmentally friendly air conditioning packaging foam, substantially improving the material's mechanical properties, water resistance, moisture resistance, and durability. Through their synergistic effect, they form a supporting network within the matrix, providing structural reinforcement while improving the flexibility and impact resistance of the molecular chain network. This significantly enhances the molecular chain network's resistance to slippage, thus creating a stable reinforcing system internally and optimizing the material's internal structure. Ultimately, while ensuring more balanced mechanical properties, it significantly improves environmental adaptability and durability, better meeting the protective requirements of air conditioning products for packaging materials, while maintaining excellent environmentally friendly characteristics.

[0047] A method for preparing environmentally friendly air conditioner packaging foam includes the following steps: S1: Drying the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven until the moisture content is ≤300ppm. Then, accurately weighing all raw materials except the foaming agent and sequentially adding them to a high-speed mixer until they are mixed evenly to obtain a premix; S2: Adding the premix to a twin-screw extruder and extruding and granulating to obtain a base material; S3: Placing the base material into a high-pressure foaming kettle, sealing it, raising the kettle temperature to 126~128℃ and holding it at that temperature for 40~45min, injecting the foaming agent into the kettle through a high-pressure pump, slowly increasing the pressure to 21~22MPa, holding the pressure for 4.5~5h to ensure saturation, opening the pressure relief valve and rapidly reducing the pressure inside the kettle to atmospheric pressure to complete foaming, then placing it at room temperature for curing and shaping, and finally cutting and shaping to obtain the final product.

[0048] Preferably, the preparation method of the environmentally friendly air conditioner packaging foam specifically includes the following steps: S1: Drying the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven at 70~80℃ for 4~5 hours until the moisture content is ≤300ppm; then accurately weighing all raw materials except the foaming agent and sequentially adding them to a high-speed mixer, mixing at 500~600rpm for 30~40min until uniformly mixed to obtain a premix; S2: Adding the premix to a twin-screw extruder, mixing at 160℃~175℃. During the process, the die head is 165℃ and the screw speed is 220~250rpm for extrusion granulation to obtain the base material; S3: The base material is placed in a high-pressure foaming kettle, sealed, and the kettle temperature is raised to 126~128℃ and kept at that temperature for 40~45min. The foaming agent is injected into the kettle through a high-pressure pump, and the pressure is slowly increased to 21~22MPa. The pressure is maintained for 4.5~5h to ensure saturation. The pressure relief valve is opened and the pressure inside the kettle is rapidly reduced to normal pressure within 3~4s to complete the foaming. After that, it is placed at room temperature for 24~28h to mature and set, and then cut into shape to obtain the final product.

[0049] The beneficial effects of this application are:

[0050] 1. The environmentally friendly air conditioner packaging foam proposed in this application not only effectively solves the environmental protection problem of existing air conditioner foam materials, but also maintains good mechanical properties, corrosion resistance, aging resistance, and waterproof and moisture-proof properties, thereby meeting the higher standard requirements of existing air conditioner transport packaging.

[0051] 2. This application incorporates auxiliary resins as key components of environmentally friendly air conditioning packaging foam, which comprehensively enhances the overall performance of the foam while ensuring its biodegradability and environmental friendliness. In particular, the combination of Rnew® 72R53 and Capa™ 6500 forms a highly efficient multiphase composite structure with the main resin, providing a solid skeletal support and significantly enhancing the material's mechanical strength, heat resistance, and dimensional stability. It also provides moisture resistance and humidity resistance while maintaining hydrophobic properties. Furthermore, polycaprolactone effectively improves the interfacial bonding between the components, promotes uniform phase dispersion, and avoids the performance shortcomings of some raw materials. It further enhances the material's flexibility and low-temperature impact resistance, ultimately ensuring that the foam has sufficient cushioning and protective functions.

[0052] 3. The composite additives further incorporated in this application significantly enhance the overall performance of the environmentally friendly air conditioning packaging foam, substantially improving the material's mechanical properties, water resistance, moisture resistance, and durability. Through their synergistic effect, they form a supporting network within the matrix, providing structural reinforcement while improving the flexibility and impact resistance of the molecular chain network. This significantly enhances the molecular chain network's resistance to slippage, thereby forming a stable reinforcing system internally. This optimizes the material's internal structure, ultimately ensuring more balanced mechanical properties while significantly improving environmental adaptability and durability. Attached Figure Description

[0053] Figure 1 This is a photograph of the environmentally friendly air conditioner packaging foam prepared according to Example 1 of this application.

[0054] Figure 2 and Figure 3 This is a graph showing the results of the heavy metal content test report for the environmentally friendly air conditioner packaging foam prepared in Example 1 of this application. Detailed Implementation

[0055] Example 1

[0056] An environmentally friendly air conditioner packaging foam, by weight, comprises the following raw materials: 110 parts of main resin composition, 20 parts of auxiliary resin composition, 6 parts of foaming agent, 1.4 parts of nucleating agent, 0.8 parts of chain extender, 4.2 parts of compatibilizer, 0.8 parts of anti-hydrolysis agent, 0.5 parts of lubricant, and 12 parts of composite additives.

[0057] The main resin composition is a combination of polylactic acid and poly(butylene adipate) / terephthalate, with a mass ratio of 8:3.

[0058] The melt index of polylactic acid is 10 g / 10 min, 190°C / 2.16 kg, and REVODE190 is from China's Haizheng Biotechnology; the melt index of poly(butylene adipate / terephthalate) is 6.5 g / 10 min, 190°C / 2.16 kg, and Blend C1200 is from BASF, Germany.

[0059] The auxiliary resin combination is a combination of polyether block amide and polycaprolactone in a mass ratio of 7.5:2.5.

[0060] The polyether block amide is Rnew® 72R53, from Arkema, France; the polycaprolactone is Capa™ 6500, from Perstork, Sweden.

[0061] The foaming agent is supercritical carbon dioxide.

[0062] The nucleating agent is silicon dioxide with an average particle size of 80 nm.

[0063] The chain extender is pyromellitic anhydride; the compatibilizer is polyethylene grafted maleic anhydride, and 18302 is from Arkema, France.

[0064] The hydrolysis inhibitor is polycarbodiimide, industrial grade, sourced from Tangyi Chemical in Jining, China; the lubricant is pentaerythritol stearate.

[0065] The composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt in a mass ratio of 4:3:1.5.

[0066] The nanocellulose is CNF grade and sourced from Wuhan Huaxiang Kejie, China. The polyurethane acrylate is Desmolux® U680 and sourced from Covestro, Germany; the organosilicon quaternary ammonium salt is octadecyl dimethyltrimethylsilylpropylammonium chloride, industrial grade, and sourced from Hubei Langbowan, China.

[0067] A method for preparing environmentally friendly air conditioner packaging foam includes the following steps: S1: Drying the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven at 75℃ for 5 hours until the moisture content is ≤300ppm. Then, accurately weighing all raw materials except the foaming agent, and sequentially adding them into a high-speed mixer, mixing at 600rpm for 30min until uniformly mixed to obtain a premix; S2: Adding the premix to a twin-screw extruder, at 160 / 165 / 175 / 1 Extrusion granulation is performed at 70 / 165℃, die head 165℃, and screw speed 240rpm to obtain the base material; S3: The base material is placed in a high-pressure foaming kettle, sealed, and the kettle temperature is raised to 128℃ and kept at that temperature for 40 minutes. The foaming agent is injected into the kettle through a high-pressure pump, and the pressure is slowly increased to 22MPa and kept at that pressure for 4.5 hours to ensure saturation. The pressure relief valve is opened, and the pressure inside the kettle is rapidly reduced to normal pressure within 3 seconds to complete the foaming. After that, the material is placed at room temperature for 24 hours to mature and set, and then cut and shaped to obtain the final product.

[0068] The actual product of the environmentally friendly air conditioner packaging foam prepared in this embodiment is as follows: Figure 1 As shown.

[0069] The heavy metal content test report for the environmentally friendly air conditioner packaging foam prepared in this embodiment is as follows: Figure 2 and Figure 3 As shown.

[0070] Example 2

[0071] An environmentally friendly air conditioner packaging foam, by weight, comprises the following raw materials: 120 parts of main resin composition, 15 parts of auxiliary resin composition, 6 parts of foaming agent, 1.4 parts of nucleating agent, 0.8 parts of chain extender, 4.2 parts of compatibilizer, 0.8 parts of anti-hydrolysis agent, 0.5 parts of lubricant, and 10 parts of composite additives.

[0072] The main resin composition is a combination of polylactic acid and poly(butylene adipate) / terephthalate, with a mass ratio of 9:3.

[0073] The melt index of polylactic acid is 10 g / 10 min, 190°C / 2.16 kg, and REVODE190 is from China's Haizheng Biotechnology; the melt index of poly(butylene adipate / terephthalate) is 6.5 g / 10 min, 190°C / 2.16 kg, and Blend C1200 is from BASF, Germany.

[0074] The auxiliary resin combination is a combination of polyether block amide and polycaprolactone in a mass ratio of 8:2.

[0075] The polyether block amide is Rnew® 72R53, from Arkema, France; the polycaprolactone is Capa™ 6500, from Perstork, Sweden.

[0076] The foaming agent is supercritical carbon dioxide.

[0077] The nucleating agent is silicon dioxide with an average particle size of 80 nm.

[0078] The chain extender is pyromellitic anhydride; the compatibilizer is polyethylene grafted maleic anhydride, and 18302 is from Arkema, France.

[0079] The hydrolysis inhibitor is polycarbodiimide, industrial grade, sourced from Tangyi Chemical in Jining, China; the lubricant is pentaerythritol stearate.

[0080] The composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt in a mass ratio of 5:2:1.2.

[0081] The nanocellulose is CNF grade and sourced from Wuhan Huaxiang Kejie, China. The polyurethane acrylate is Desmolux® U680 and sourced from Covestro, Germany; the organosilicon quaternary ammonium salt is octadecyl dimethyltrimethylsilylpropylammonium chloride, industrial grade, and sourced from Hubei Langbowan, China.

[0082] A method for preparing environmentally friendly air conditioner packaging foam includes the following steps: S1: Drying the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven at 75℃ for 5 hours until the moisture content is ≤300ppm. Then, accurately weighing all raw materials except the foaming agent, and sequentially adding them into a high-speed mixer, mixing at 600rpm for 30min until uniformly mixed to obtain a premix; S2: Adding the premix to a twin-screw extruder, at 160 / 165 / 175 / 1 Extrusion granulation is performed at 70 / 165℃, die head 165℃, and screw speed 240rpm to obtain the base material; S3: The base material is placed in a high-pressure foaming kettle, sealed, and the kettle temperature is raised to 128℃ and kept at that temperature for 40 minutes. The foaming agent is injected into the kettle through a high-pressure pump, and the pressure is slowly increased to 22MPa and kept at that pressure for 4.5 hours to ensure saturation. The pressure relief valve is opened, and the pressure inside the kettle is rapidly reduced to normal pressure within 3 seconds to complete the foaming. After that, the material is placed at room temperature for 24 hours to mature and set, and then cut and shaped to obtain the final product.

[0083] Example 3

[0084] An environmentally friendly air conditioner packaging foam, by weight, comprises the following raw materials: 110 parts of main resin composition, 22 parts of auxiliary resin composition, 7 parts of foaming agent, 1.4 parts of nucleating agent, 0.8 parts of chain extender, 4.2 parts of compatibilizer, 0.8 parts of anti-hydrolysis agent, 0.5 parts of lubricant, and 10 parts of composite additives.

[0085] The main resin composition is a combination of polylactic acid and poly(butylene adipate) / terephthalate, with a mass ratio of 9:2.

[0086] The melt index of polylactic acid is 10 g / 10 min, 190°C / 2.16 kg, and REVODE190 is from China's Haizheng Biotechnology; the melt index of poly(butylene adipate / terephthalate) is 6.5 g / 10 min, 190°C / 2.16 kg, and Blend C1200 is from BASF, Germany.

[0087] The auxiliary resin combination is a combination of polyether block amide and polycaprolactone in a mass ratio of 8:2.

[0088] The polyether block amide is Rnew® 72R53, from Arkema, France; the polycaprolactone is Capa™ 6500, from Perstork, Sweden.

[0089] The foaming agent is supercritical carbon dioxide.

[0090] The nucleating agent is silicon dioxide with an average particle size of 80 nm.

[0091] The chain extender is pyromellitic anhydride; the compatibilizer is polyethylene grafted maleic anhydride, and 18302 is from Arkema, France.

[0092] The hydrolysis inhibitor is polycarbodiimide, industrial grade, sourced from Tangyi Chemical in Jining, China; the lubricant is pentaerythritol stearate.

[0093] The composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt in a mass ratio of 4.5:2.5:1.

[0094] The nanocellulose is CNF grade and sourced from Wuhan Huaxiang Kejie, China. The polyurethane acrylate is Desmolux® U680 and sourced from Covestro, Germany; the organosilicon quaternary ammonium salt is octadecyl dimethyltrimethylsilylpropylammonium chloride, industrial grade, and sourced from Hubei Langbowan, China.

[0095] A method for preparing environmentally friendly air conditioner packaging foam includes the following steps: S1: Drying the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven at 75℃ for 5 hours until the moisture content is ≤300ppm. Then, accurately weighing all raw materials except the foaming agent, and sequentially adding them into a high-speed mixer, mixing at 600rpm for 30min until uniformly mixed to obtain a premix; S2: Adding the premix to a twin-screw extruder, at 160 / 165 / 175 / 1 Extrusion granulation is performed at 70 / 165℃, die head 165℃, and screw speed 240rpm to obtain the base material; S3: The base material is placed in a high-pressure foaming kettle, sealed, and the kettle temperature is raised to 128℃ and kept at that temperature for 40 minutes. The foaming agent is injected into the kettle through a high-pressure pump, and the pressure is slowly increased to 22MPa and kept at that pressure for 4.5 hours to ensure saturation. The pressure relief valve is opened, and the pressure inside the kettle is rapidly reduced to normal pressure within 3 seconds to complete the foaming. After that, the material is placed at room temperature for 24 hours to mature and set, and then cut and shaped to obtain the final product.

[0096] Comparative Example 1

[0097] This comparative example differs from Example 1 only in the following aspects: An environmentally friendly air conditioning packaging foam, by weight, comprises the following raw materials: 140 parts of main resin composition, 10 parts of auxiliary resin composition, 6 parts of foaming agent, 1.4 parts of nucleating agent, 0.8 parts of chain extender, 4.2 parts of compatibilizer, 0.8 parts of anti-hydrolysis agent, 0.5 parts of lubricant, and 15 parts of composite additives.

[0098] The remaining implementation methods are the same.

[0099] Comparative Example 2

[0100] This comparative example differs from Example 1 only in the following aspects: An environmentally friendly air conditioning packaging foam, by weight, comprises the following raw materials: 130 parts of main resin composition, 25 parts of auxiliary resin composition, 6 parts of foaming agent, 1.4 parts of nucleating agent, 0.8 parts of chain extender, 4.2 parts of compatibilizer, 0.8 parts of anti-hydrolysis agent, 0.5 parts of lubricant, and 2 parts of composite additives.

[0101] The remaining implementation methods are the same.

[0102] Comparative Example 3

[0103] This comparative example differs from Example 1 only in the following way: the auxiliary resin combination is a combination of polyether block amide and polycaprolactone in a mass ratio of 9:1.

[0104] The remaining implementation methods are the same.

[0105] Comparative Example 4

[0106] This comparative example differs from Example 1 only in the following way: the auxiliary resin combination is a combination of polyether block amide and polycaprolactone in a mass ratio of 2:3.

[0107] The remaining implementation methods are the same.

[0108] Comparative Example 5

[0109] The only difference between this comparative example and Example 1 is that the composite additive is a combination of nanocellulose and organosilicon quaternary ammonium salt in a mass ratio of 4:1.5.

[0110] The remaining implementation methods are the same.

[0111] Comparative Example 6

[0112] The only difference between this comparative example and Example 1 is that the composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt in a mass ratio of 8:1:0.5.

[0113] The remaining implementation methods are the same.

[0114] Performance testing

[0115] 1. Compressive strength: The test was conducted according to ISO 844. A cube specimen with dimensions of 50mm × 50mm × 50mm was cut and compressed using a universal testing machine at a deformation of 50% of the initial thickness of the specimen. The compression speed was 10mm / min. The compressive strength results were obtained, and the average of 10 parallel tests was recorded in Table 1.

[0116] 2. Falling ball impact rebound rate: The test follows ISO 8307. A 100mm × 100mm × 50mm sample is cut. Using a falling ball rebound tester, a steel ball with a diameter of 16mm and a mass of approximately 16g is dropped freely from a height of 460mm onto the sample surface. The maximum height of the first rebound is measured to obtain the rebound rate. The average of 10 parallel tests is recorded in Table 1.

[0117] 3. Waterproof and moisture-resistant: The test follows ISO 2896. Samples with dimensions of 150mm × 150mm × 25mm are cut and completely immersed in distilled water at 50℃ for 96 hours. After immersion, the surface moisture is quickly absorbed with filter paper. The mass before and after immersion is measured to obtain the water absorption rate. The average of 10 parallel tests is recorded in Table 1.

[0118] 4. Biodegradability: The test was conducted according to ISO 14855-1, and the biodegradability results were obtained within 180 days. The average value of 10 parallel tests was recorded in Table 1.

[0119] 5. Temperature resistance: The test was conducted according to ISO 2796. Samples with dimensions of 100mm × 100mm × 50mm were prepared and placed in a constant temperature oven at 70°C for 48 hours. After removal, the samples were placed under standard conditions for 1 hour, and the dimensions were measured again to obtain the dimensional change rate under high temperature resistance. The average value of 10 parallel tests was recorded in Table 1.

[0120] Table 1 Performance Test Results

[0121]

[0122] Based on the final test results, Examples 1-3, by employing the corresponding technical solutions defined in this application, resulted in the formation of a highly efficient multiphase composite structure within the main resin, providing robust skeletal support and promoting uniform phase dispersion. This avoided some of the performance shortcomings of the raw materials, significantly enhanced the resistance of the molecular chain network to slippage, and thus formed a stable reinforcing system internally, optimizing the internal structure of the material and achieving superior performance results. Comparative Examples 1 and 2, however, did not use the appropriate proportions of raw materials defined in this application, leading to a significant weakening of the aforementioned effects, and therefore, they obtained worse performance test results compared to the Examples 1-3.

[0123] Comparative Examples 3-6, however, employed composite additives and auxiliary resins different from those specified in this application, resulting in significant deviations in their effects compared to the examples, ultimately impacting the performance of the resulting foam materials. For instance, Comparative Example 6 used less polyurethane acrylate and organosilicon quaternary ammonium salt, failing to effectively improve the flexibility and impact resistance of the molecular chain network. The reduced resistance of the molecular chain network to slippage weakened this resistance, thus affecting the final overall performance.

Claims

1. An environmentally friendly air conditioner packaging foam, characterized in that: By weight, the raw materials include at least: 90-130 parts of main resin composition, 10-25 parts of auxiliary resin composition, 5-9 parts of foaming agent, 1.2-2.5 parts of nucleating agent, 0.5-1.5 parts of chain extender, 3-5 parts of compatibilizer, 0.8-1.4 parts of anti-hydrolysis agent, 0.3-0.8 parts of lubricant, and 8-15 parts of composite additives; The main resin composition is a combination of polylactic acid and poly(butylene adipate) / terephthalate, with a mass ratio of (7~9):(1.5~3). The auxiliary resin combination is a combination of polyether block amide and polycaprolactone, with a mass ratio of (6~9):(2~4). The mass ratio of the main resin composition to the composite additive is (10~12):(1~1.3). The composite additive is a combination of nanocellulose, polyurethane acrylate and organosilicon quaternary ammonium salt, with a mass ratio of (3~5):(2~4):(1~2).

2. The environmentally friendly air conditioner packaging foam according to claim 1, characterized in that: The mass ratio of the main resin composition, auxiliary resin composition and foaming agent is (10~12):(1.5~2.2):(0.6~0.8).

3. The environmentally friendly air conditioner packaging foam according to claim 1, characterized in that: The foaming agent is supercritical carbon dioxide.

4. The environmentally friendly air conditioner packaging foam according to claim 1, characterized in that: The nucleating agent is at least one of talc, calcium carbonate, silica, boehmite, and ethylene bis-stearamide.

5. The environmentally friendly air conditioner packaging foam according to claim 1, characterized in that: The chain extender is at least one of acrylate copolymers, oxazoline compounds, and pyromellitic anhydride.

6. A method for preparing environmentally friendly air conditioner packaging foam according to any one of claims 1 to 5, characterized in that: S1: Dry the raw materials of the main resin combination and auxiliary resin combination in a vacuum oven until the moisture content is ≤300ppm. Then, accurately weigh all raw materials except the foaming agent and put them into a high-speed mixer until they are mixed evenly to obtain a premix. S2: Add the premix to a twin-screw extruder and extrude and granulate to obtain the base material. S3: Put the base material into a high-pressure foaming kettle, seal it, raise the kettle temperature to 126~128℃ and keep it at that temperature for 40~45min. Inject the foaming agent into the kettle through a high-pressure pump, slowly increase the pressure to 21~22MPa, and keep it at that pressure for 4.5~5h to ensure that it reaches saturation. Open the pressure relief valve and rapidly reduce the pressure in the kettle to atmospheric pressure to complete the foaming. Then, let it mature and set at room temperature, and then cut it into shape to obtain the final product.

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