A high-strength plastic pallet and preparation method thereof

Abstract

The present application discloses a high-strength plastic pallet and a preparation method, wherein the high-strength plastic pallet comprises the following raw materials by weight: 70-95 parts of high-density polypropylene, 5-10 parts of epoxidized soybean oil, 1-3 parts of polytetrafluoroethylene, 4-8 parts of hydroxypropyl methylcellulose, 2-5 parts of silane coupling agent, 20-30 parts of filler, 14-20 parts of styrene-butadiene rubber, 10-15 parts of polyaromatic oxadiazole fiber, 5-10 parts of calcium carbonate whisker, and 1-2 parts of antioxidant. The high-strength plastic pallet provided by the present application has strong tensile strength and high temperature resistance.

Description

Technical Field

[0001] The present application relates to the technical field, and in particular to a high-strength plastic pallet and a preparation method thereof. Background Art

[0002] At present, the pallets on the market are mainly wooden pallets and plastic pallets. Wooden pallets have a large demand for wood, which is not conducive to the protection of forest resources. In addition, they need to be fumigated or sterilized at high temperature. While wooden pallets are subject to various restrictions, some non-wood pallets have emerged. Although these non-wood pallets, such as plywood pallets, paper pallets, plastic pallets and other new material pallets, do not need to be sterilized, they are not perfect. Innate material defects or high manufacturing costs prevent these pallets from completely replacing wooden pallets. For this reason, plastic wood materials have emerged. Plastic wood materials can produce many products and have been initially recognized by the market. Such products can replace the corresponding wooden pallets, thereby saving a lot of forest resources, which can greatly help protect and improve the ecological environment. It is an environmentally friendly new material that is in line with the development direction of the 21st century. However, the tensile strength and temperature resistance of the plastic pallets currently used are poor. Therefore, a plastic pallet with high tensile strength and better temperature resistance is needed. Summary of the invention

[0003] In order to solve at least one of the above technical problems, a high-strength plastic pallet with excellent tensile strength and temperature resistance is developed. The present application provides a high-strength plastic pallet and a preparation method.

[0004] In the first aspect, the present application provides a high-strength plastic pallet, which comprises the following raw materials by weight: 70 to 95 parts of high-density polypropylene, 5 to 10 parts of epoxidized soybean oil, 1 to 3 parts of polytetrafluoroethylene, 4 to 8 parts of hydroxypropyl methylcellulose, 2 to 5 parts of silane coupling agent, 20 to 30 parts of filler, 14 to 20 parts of styrene-butadiene rubber, 10 to 15 parts of polyaromatic oxadiazole fiber, 5 to 10 parts of calcium carbonate whiskers, and 1 to 2 parts of antioxidant.

[0005] By adopting the above technical scheme, the present application can prepare a high-strength plastic pallet with better tensile strength and high temperature resistance. The present application can prepare a high-strength plastic pallet with better comprehensive performance through a specific formula and ratio. When preparing the plastic pallet, the present application adds polyaromatic oxadiazole fiber and filler, wherein the polyaromatic oxadiazole fiber can provide the plastic pallet with strong tensile strength and high temperature resistance, and the addition of filler can further improve the density of the plastic pallet. Therefore, the compound use of polyaromatic oxadiazole fiber and filler has a significant effect on the improvement of the tensile strength and high temperature resistance of the plastic pallet. In addition, the present application also adds high-density polypropylene, and the addition of high-density polypropylene can provide the plastic pallet with strong tensile strength and rigidity, so that the plastic pallet has sufficient bearing capacity. The addition of epoxidized soybean oil can improve the flexibility and impact resistance of the material. Moreover, epoxidized soybean oil is a renewable resource, which makes the plastic pallet have the advantage of environmental protection. Polytetrafluoroethylene provides the plastic pallet with better wear resistance and chemical corrosion resistance, which can prevent wear and corrosion on the surface of the plastic pallet and extend the service life of the pallet. Hydroxypropyl methylcellulose can effectively bind the raw materials together tightly, thereby effectively inhibiting the agglomeration of fillers and effectively promoting the uniform dispersion of the mixture, thereby effectively improving the tensile strength and stability of plastic pallets. Silane coupling agents can promote the bonding between the components and enhance the weather resistance of the material. Styrene-butadiene rubber can provide the material with better elasticity and wear resistance, which can increase the durability and service life of the plastic pallet. Calcium carbonate whiskers can increase the filling performance and tensile strength of the material. Antioxidants can delay the aging and degradation of the material.

[0006] Optionally, the pallet comprises the following raw materials by weight: 81-95 parts of high-density polypropylene, 8-10 parts of epoxidized soybean oil, 2-3 parts of polytetrafluoroethylene, 6-8 parts of hydroxypropyl methylcellulose, 3-5 parts of silane coupling agent, 24-30 parts of filler, 17-20 parts of styrene-butadiene rubber, 12-15 parts of polyaromatic oxadiazole fiber, 8-10 parts of calcium carbonate whiskers, and 1.5-2 parts of antioxidant.

[0007] Optionally, the weight ratio of the polyaromatic oxadiazole fiber to the filler is (1.7-2.1):1.

[0008] By adopting the above technical solution, when preparing a high-strength plastic pallet, when the weight ratio of the polyaromatic oxadiazole fiber to the filler is (1.7-2.1):1, the tensile strength and high temperature resistance of the obtained plastic pallet are better.

[0009] Optionally, the average chopped length of the polyaromatic oxadiazole fibers is 20-30 μm; and the average length of the calcium carbonate whiskers is 20-30 μm.

[0010] Optionally, the filler includes at least one of diatomaceous earth, kaolin, glass beads and silicon dioxide.

[0011] Optionally, the high-density polypropylene is shrimp shell powder modified high-density polypropylene; the shrimp shell powder modified high-density polypropylene is made of shrimp shell powder, pimelic acid solution, coupling agent and high-density polypropylene in a weight ratio of (1-3):20:(1-2):20.

[0012] By adopting the above technical scheme, the present application can improve the tensile strength and high temperature resistance of the prepared high-density polypropylene by modifying the high-density polypropylene when preparing the high-strength plastic pallet, thereby being able to better improve the tensile strength and high temperature resistance of the prepared high-strength plastic pallet.

[0013] Optionally, the method for preparing the shrimp shell powder modified high-density polypropylene comprises the following steps:

[0014] A1, washing, drying, and crushing the discarded shrimp shells to obtain discarded shrimp shell powder;

[0015] A2, taking the discarded shrimp shell powder obtained in step A1, roasting at 280-300° C. for 2-3 hours to obtain shrimp shell powder;

[0016] A3, taking the shrimp shell powder obtained in step A2 by weight, adding it to a 0.1-0.15 mol / L pimelic acid solution, stirring and reacting in a water bath for 2-3 hours, to obtain shrimp shell powder with surface covered with calcium pimelate; A4, adding high-density polypropylene and a coupling agent to the shrimp shell powder with surface covered with calcium pimelate obtained in step A3, mixing evenly, to obtain shrimp shell powder modified high-density polypropylene.

[0017] By adopting the above technical solution, the present application can modify high-density polypropylene through the above preparation method, and can better improve the tensile strength and high temperature resistance of the prepared high-density polypropylene.

[0018] In a second aspect, the present application provides a method for preparing a high-strength plastic pallet, the method comprising the following steps:

[0019] S1, putting high-density polypropylene, epoxidized soybean oil, polytetrafluoroethylene, filler, and styrene-butadiene rubber into a high-speed mixer, and mixing them evenly to obtain a first mixed material;

[0020] S2, adding ethanol to the silane coupling agent to dissolve it, and adding polyaromatic oxadiazole fiber and calcium carbonate whisker to mix and stir, let it stand for 2 to 3 hours, remove the ethanol, and obtain a second mixture;

[0021] S3, mixing the first mixed material, the second mixed material and the remaining raw materials uniformly, and sending them into a twin-screw extruder for melt blending and granulation;

[0022] S4. First apply a release agent to the mold, preheat it to 50-60°C, and then use a plastic injection machine to inject the pellets into the mold. The barrel temperature is 235-250°C, the tool temperature is 25-30°C, the injection pressure is 85-90MPa, and the injection time is 5-8s.

[0023] S5. After demoulding, the formed pallet is cooled, trimmed, and shaped, sprayed with anti-slip paint, and packaged after curing to obtain the required high-strength plastic pallet.

[0024] By adopting the above technical solution, a high-strength plastic pallet with good tensile strength and high temperature resistance can be prepared by the preparation method of the present application. In addition, the preparation method provided by the present application has the advantage of simple preparation process and can meet the needs of large-scale production.

[0025] Optionally, during the step, the extruder barrel temperature is 160-185°C, and the die head temperature is 165-205°C.

[0026] Optionally, the release agent in step S4 is fatty acid.

[0027] In summary, the present invention includes at least one of the following beneficial technical effects:

[0028] 1. The present application can prepare a high-strength plastic pallet with good tensile strength and high temperature resistance. The present application can prepare a high-strength plastic pallet with good comprehensive performance through a specific formula and ratio. When preparing the plastic pallet, the present application adds polyaromatic oxadiazole fiber and filler, wherein the polyaromatic oxadiazole fiber can provide the plastic pallet with strong tensile strength and high temperature resistance, and the addition of filler can further improve the density of the plastic pallet. Therefore, the compound use of polyaromatic oxadiazole fiber and filler has a significant effect on improving the tensile strength and high temperature resistance of the plastic pallet. In addition, the present application also adds high-density polypropylene, and the addition of high-density polypropylene can provide the plastic pallet with strong tensile strength and rigidity, so that the plastic pallet has sufficient bearing capacity. The addition of epoxidized soybean oil can improve the flexibility and impact resistance of the material. Moreover, epoxidized soybean oil is a renewable resource, which makes the plastic pallet have the advantage of environmental protection. Polytetrafluoroethylene provides the plastic pallet with better wear resistance and chemical corrosion resistance, which can prevent wear and corrosion on the surface of the plastic pallet and extend the service life of the pallet. Hydroxypropyl methylcellulose can effectively bind the raw materials together tightly, thereby effectively inhibiting the agglomeration of fillers and effectively promoting the uniform dispersion of the mixture, thereby effectively improving the tensile strength and stability of plastic pallets. Silane coupling agents can promote the bonding between the components and enhance the weather resistance of the material. Styrene-butadiene rubber can provide the material with better elasticity and wear resistance, which can increase the durability and service life of the plastic pallet. Calcium carbonate whiskers can increase the filling performance and tensile strength of the material. Antioxidants can delay the aging and degradation of the material.

[0029] 2. The preparation method of the present application can produce a high-strength plastic pallet with good tensile strength and high temperature resistance. In addition, the preparation method provided by the present application has the advantage of a simple preparation process and can meet the needs of large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the high-strength plastic pallet prepared in Example 1. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] High-density polypropylene: Dongguan Jinshixiang Plastic Raw Materials Co., Ltd., model ERC361N.

[0033] Epoxidized soybean oil: CAS No. 8013-07-8; purity 99%.

[0034] Polytetrafluoroethylene: CAS No. 9002-84-0; purity 99%.

[0035] Hydroxypropyl methylcellulose: purity 99%.

[0036] KH560: Active ingredient content 99%.

[0037] KH550: Active ingredient content 99%.

[0038] Diatomaceous earth: purity 99%.

[0039] Styrene butadiene rubber: CAS No. 9003-55-8; purity 99%.

[0040] Polyaromatic oxadiazole fiber: The average short cut length is 20 to 30 μm.

[0041] Calcium carbonate whiskers: average length 20-30 μm

[0042] Antioxidant 1010: CAS No. 6683-19-8; purity 99%.

[0043] Glass microspheres: Foreign International Chemical Store, average particle size is 40 microns.

[0044] Silicon dioxide: CAS number is 7631-86-9, purity is 99%.

[0045] Kaolin: Purity 99%.

[0046] Anti-slip paint: Hebei Biaoying Environmental Protection Technology Co., Ltd., active ingredient content 99%. Specific embodiments

[0048] Preparation Examples 1 to 3

[0049] Preparation Example 1

[0050] This preparation example provides a shrimp shell powder modified high-density polypropylene, and the preparation method of shrimp shell powder modified high-density polypropylene includes the following steps:

[0051] A1, washing, drying and crushing the discarded shrimp shells to obtain discarded shrimp shell powder;

[0052] A2, taking the discarded shrimp shell powder obtained in step A1, roasting it at 280° C. for 2 h, and passing it through a 50-mesh sieve to obtain shrimp shell powder;

[0053] A3, taking 100 parts by weight of the shrimp shell powder obtained in step A2, adding it to a 0.1 mol / L pimelic acid solution, stirring and reacting it in a water bath (60° C.) for 2 hours, to obtain shrimp shell powder with calcium pimelate covered on the surface;

[0054] A4. Add high-density polypropylene and a coupling agent to the shrimp shell powder with the surface covered with calcium pimelate obtained in step A3, mix well, and obtain shrimp shell powder modified high-density polypropylene.

[0055] The shrimp shell powder modified high-density polypropylene is prepared from shrimp shell powder, calcium pimelate solution, coupling agent and high-density polypropylene in a weight ratio of 1:20:1:20.

[0056] The coupling agent in this preparation example is KH550.

[0057] Preparation Example 2

[0058] This preparation example provides a shrimp shell powder modified high-density polypropylene, and the preparation method of shrimp shell powder modified high-density polypropylene includes the following steps:

[0059] A1, washing, drying, and crushing the discarded shrimp shells to obtain discarded shrimp shell powder;

[0060] A2, taking the discarded shrimp shell powder obtained in step A1, roasting at 290° C. for 2.5 h to obtain shrimp shell powder;

[0061] A3, taking the shrimp shell powder obtained in step A2 by weight and passing through a 50-mesh sieve, adding it to a 0.12 mol / L pimelic acid solution, stirring and reacting for 2.5 hours in a water bath (60° C.), to obtain shrimp shell powder with calcium pimelate covered on the surface;

[0062] A4. Add polypropylene and a coupling agent to the shrimp shell powder with the surface covered with calcium pimelate obtained in step A3, mix well, and obtain shrimp shell powder modified high-density polypropylene.

[0063] The shrimp shell powder modified high-density polypropylene is prepared from shrimp shell powder, calcium pimelate solution, coupling agent and high-density polypropylene in a weight ratio of 2:20:1.5:20.

[0064] The coupling agent in this preparation example is KH550.

[0065] Preparation Example 3

[0066] This preparation example provides a shrimp shell powder modified high-density polypropylene, and the preparation method of shrimp shell powder modified high-density polypropylene includes the following steps:

[0067] A1, washing, drying, and crushing the discarded shrimp shells to obtain discarded shrimp shell powder;

[0068] A2, taking the waste shrimp shell powder obtained in step A1, roasting at 300° C. for 3 h to obtain shrimp shell powder;

[0069] A3, taking the shrimp shell powder obtained in step A2 by weight and passing through a 50-mesh sieve, adding it to a 0.15 mol / L pimelic acid solution, stirring and reacting for 3 hours in a water bath (60° C.), to obtain shrimp shell powder with calcium pimelate covered on the surface;

[0070] A4. Add polypropylene and a coupling agent to the shrimp shell powder with the surface covered with calcium pimelate obtained in step A3, mix well, and obtain shrimp shell powder modified high-density polypropylene.

[0071] The shrimp shell powder modified high-density polypropylene is prepared from shrimp shell powder, calcium pimelate solution, coupling agent and high-density polypropylene in a weight ratio of 3:20:2:20.

[0072] The coupling agent in this preparation example is KH550.

[0073] Example 1

[0074] The present embodiment provides a high-strength plastic pallet, which includes the following raw materials by weight: 70 parts of high-density polypropylene, 5 parts of epoxidized soybean oil, 1 part of polytetrafluoroethylene, 4 parts of hydroxypropyl methylcellulose, 2 parts of silane coupling agent, 20 parts of filler, 14 parts of styrene-butadiene rubber, 10 parts of polyaromatic oxadiazole fiber, 5 parts of calcium carbonate whisker, and 1 part of antioxidant.

[0075] The preparation method comprises the following steps:

[0076] S1, putting high-density polypropylene, epoxidized soybean oil, polytetrafluoroethylene, filler, and styrene-butadiene rubber into a high-speed mixer, and mixing them evenly to obtain a first mixed material;

[0077] S2, add ethanol (the amount of ethanol is 100 parts) to the silane coupling agent to dissolve it, and add polyarylene oxadiazole fiber and calcium carbonate whisker to mix and stir, let it stand for 2 hours, remove the ethanol, and obtain a second mixture;

[0078] S3, the first mixed material, the second mixed material and the remaining raw materials are mixed evenly, and sent into a twin-screw extruder for melt blending and granulation, the extruder barrel temperature is 160° C., and the die head temperature is 165° C.;

[0079] S4. First apply a release agent to the molding mold, preheat it to 50°C, and then use a plastic injection machine to inject the pellets into the molding mold. The barrel temperature is 235°C, the tool temperature is 25°C, the injection pressure is 85MPa, and the injection time is 5s.

[0080] S5. After demoulding, the formed pallet is cooled, trimmed, and shaped, and then sprayed with anti-skid paint (the anti-skid paint is purchased from Hebei Biaoying Environmental Protection Technology Co., Ltd., with an effective ingredient content of 99%). After curing, it is packaged to obtain the required high-strength plastic pallet.

[0081] The release agent in step S4 is fatty acid.

[0082] The average chopped length of the polyaromatic oxadiazole fibers in this embodiment is 20-30 μm; the average length of the calcium carbonate whiskers in this embodiment is 20-30 μm.

[0083] The filler in this embodiment is diatomaceous earth.

[0084] The structural diagram of the high-strength plastic pallet prepared in this embodiment is shown in Figure 1 .

[0085] The antioxidant in this embodiment is antioxidant 1010.

[0086] The silane coupling agent in this embodiment is KH560.

[0087] Embodiments 2 to 5

[0088] The differences between Examples 2 to 5 and Example 1 are shown in Table 1.

[0089] Table 1 - Differences between Examples 2 to 5 and Example 1

[0090]

[0091]

[0092] Comparative Examples 1 to 4

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 4 is that, in this comparative example, no polyaromatic oxadiazole fiber is added when preparing the high-strength plastic pallet.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 4 is that, in this comparative example, no filler is added when preparing the high-strength plastic pallet.

[0097] Comparative Example 3

[0098] The difference between this comparative example and Example 4 is that in this comparative example, no calcium carbonate whiskers are added when preparing the high-strength plastic pallet.

[0099] Comparative Example 4

[0100] The difference between this comparative example and Example 4 is that, in this comparative example, no polyaromatic oxadiazole fiber and filler are added when preparing the high-strength plastic pallet.

[0101] Experimental testing:

[0102] High temperature resistance test: test the heat deformation temperature.

[0103] Tensile strength test: Referring to the tensile strength test method for polypropylene in GB / T 1040-92 "Test method for tensile properties of plastics", each sample is made into a pattern of specified size, and the pattern is tested and the data is recorded, and the tensile strength (MPa) of the patterns in Examples 1 to 17 and Comparative Examples 1 to 4 is calculated.

[0104] The experimental test results of Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 2.

[0105] Table 2 - Experimental test results of Examples 1 to 5 and Comparative Examples 1 to 4

[0106]

[0107]

[0108] Result analysis: The difference between Examples 2 to 5 and Example 1 is that the weight proportions of the components are different when preparing the high-strength plastic pallet. Combined with the experimental test data in Table 2, it can be seen that the high-strength plastic pallet prepared by Example 4 has better tensile strength and high temperature resistance, and can maintain a stable state for a long time.

[0109] The difference between Comparative Example 1 and Example 4 is that in this comparative example, no polyaromatic oxadiazole fiber is added when preparing the high-strength plastic pallet.

[0110] The difference between Comparative Example 2 and Example 4 is that, in this comparative example, no filler is added when preparing the high-strength plastic pallet.

[0111] The difference between Comparative Example 3 and Example 4 is that no calcium carbonate whiskers are added when preparing the high-strength plastic pallet in this comparative example. Combined with the test data provided in Table 2, it can be seen that when preparing the high-strength plastic pallet, if calcium carbonate whiskers are added, the tensile strength and high temperature resistance of the prepared high-strength plastic pallet can be improved.

[0112] The difference between Comparative Example 4 and Example 4 is that, in this comparative example, no polyaromatic oxadiazole fiber and filler are added when preparing the high-strength plastic pallet.

[0113] Combining the experimental test results of Comparative Examples 1 to 2 and Comparative Example 4, it can be seen that when the filler and the polyaromatic oxadiazole fiber are used in combination, the tensile strength and high temperature resistance of the high-strength plastic pallet can be improved.

[0114] Embodiments 6 to 9

[0115] Example 6

[0116] The difference between this embodiment and embodiment 4 is that in this embodiment, when preparing the high-strength plastic pallet, the total weight of the filler and the polyaromatic oxadiazole fiber is 39 parts, wherein the weight ratio of the filler to the polyaromatic oxadiazole fiber is 1.7:1.

[0117] Example 7

[0118] The difference between this embodiment and embodiment 4 is that in this embodiment, when preparing the high-strength plastic pallet, the total weight of the filler and the polyaromatic oxadiazole fiber is 39 parts, wherein the weight ratio of the filler to the polyaromatic oxadiazole fiber is 1.8:1.

[0119] Example 8

[0120] The difference between this embodiment and embodiment 4 is that in this embodiment, when preparing the high-strength plastic pallet, the total weight of the filler and the polyaromatic oxadiazole fiber is 39 parts, wherein the weight ratio of the filler to the polyaromatic oxadiazole fiber is 1.9:1.

[0121] Example 9

[0122] The difference between this embodiment and embodiment 4 is that in this embodiment, when preparing the high-strength plastic pallet, the total weight of the filler and the polyoxadiazole fiber is 39 parts, wherein the weight ratio of the filler to the polyoxadiazole fiber is 2.1:1.

[0123] The experimental test results of Examples 6 to 9 are shown in Table 3.

[0124] Table 3 - Experimental test results of Examples 6 to 9

[0125] Detection items High temperature resistance test (℃) Tensile strength test (MPa) Example 4 100 48 Example 6 102 49 Example 7 103 51 Example 8 105 53 Example 9 98 52

[0126] Result analysis: The difference between Examples 6 to 9 and Example 4 is that, when preparing the high-strength plastic pallet, the total weight of the filler and the polyaromatic oxadiazole fiber remains unchanged, while the weight ratio of the filler and the polyaromatic oxadiazole fiber changes. Combined with the experimental test data in Table 3, it can be seen that the high-strength plastic pallet prepared by Example 8 has better tensile strength and high temperature resistance.

[0127] Embodiments 10 to 12

[0128] The difference between this embodiment and embodiment 8 is that when preparing the high-strength plastic pallet in this embodiment, the filler in this embodiment is kaolin.

[0129] Embodiment 11

[0130] The difference between this embodiment and embodiment 8 is that when preparing the high-strength plastic pallet in this embodiment, the filler in this embodiment is glass beads.

[0131] Example 12

[0132] The difference between this embodiment and embodiment 8 is that when preparing the high-strength plastic pallet in this embodiment, the filler in this embodiment is silicon dioxide.

[0133] The experimental test results of Examples 10 to 12 are shown in Table 4.

[0134] Table 4 - Experimental test results of Examples 10 to 12

[0135]

[0136]

[0137] Result analysis: The difference between Examples 10 to 12 and Example 8 is that the choice of fillers is different when preparing the high-strength plastic pallet. Combined with the experimental test data in Table 4, it can be seen that the comprehensive performance of the high-strength plastic pallet prepared by Example 11 is better.

[0138] Embodiments 13 to 15

[0139] Example 13

[0140] The difference between this embodiment and embodiment 11 is that in this embodiment, when preparing the high-strength plastic pallet, the high-density polypropylene used is shrimp shell powder modified high-density polypropylene. The shrimp shell powder modified high-density polypropylene in this embodiment is prepared by Preparation Example 1.

[0141] Embodiment 14

[0142] The difference between this embodiment and embodiment 13 is that in this embodiment, when preparing the high-strength plastic pallet, the high-density polypropylene used is shrimp shell powder modified high-density polypropylene. The shrimp shell powder modified high-density polypropylene in this embodiment is prepared by Preparation Example 2.

[0143] Embodiment 15

[0144] The difference between this embodiment and embodiment 13 is that in this embodiment, when preparing the high-strength plastic pallet, the high-density polypropylene used is shrimp shell powder modified high-density polypropylene. The shrimp shell powder modified high-density polypropylene in this embodiment is prepared by Preparation Example 3.

[0145] The experimental test results of Examples 13 to 15 are shown in Table 5.

[0146] Table 5 - Experimental test results of Examples 13 to 15

[0147] Detection items High temperature resistance test (℃) Tensile strength test (MPa) Embodiment 11 115 59 Example 13 120 61 Embodiment 14 123 64 Embodiment 15 121 62

[0148] Result analysis: The difference between Examples 13 to 15 and Example 11 is that when preparing the high-strength plastic pallet, the high-density polypropylene used is shrimp shell powder modified high-density polypropylene. Combined with the experimental test data in Table 5, it can be seen that the tensile strength and high temperature resistance of the plastic pallet prepared by Example 14 are better. In addition, by modifying polypropylene with shrimp shell powder, the tensile strength and high temperature resistance of the prepared plastic pallet can be improved.

[0149] Embodiments 16 to 17

[0150] Example 16

[0151] The difference between this embodiment and embodiment 14 is that in this embodiment, when preparing a high-strength plastic pallet, the preparation method is as follows:

[0152] S1, adding shrimp shell powder modified high-density polypropylene, epoxidized soybean oil, polytetrafluoroethylene, filler, and styrene-butadiene rubber into a high-speed mixer, mixing them evenly to obtain a first mixed material;

[0153] S2, add ethanol (the amount of ethanol is 100 parts) to the silane coupling agent to dissolve it, and add polyarylene oxadiazole fiber and calcium carbonate whisker to mix and stir, let it stand for 2.5 hours, remove the ethanol, and obtain a second mixture;

[0154] S3, the first mixed material, the second mixed material and the remaining raw materials are mixed evenly, and sent into a twin-screw extruder for melt blending and granulation, the extruder barrel temperature is 175° C., and the die head temperature is 195° C.;

[0155] S4. First, apply a release agent to the molding mold, preheat it to 55°C, and then use a plastic injection machine to inject the pellets into the molding mold. The barrel temperature is 245°C, the tool temperature is 28°C, the injection pressure is 88MPa, and the injection time is 7s.

[0156] S5. After demoulding, the formed pallet is cooled, trimmed, and shaped, sprayed with anti-slip paint, and packaged after curing to obtain the required high-strength plastic pallet.

[0157] The release agent in step S4 is fatty acid.

[0158] The average chopped length of the polyaromatic oxadiazole fibers in this embodiment is 20-30 μm; the average length of the calcium carbonate whiskers in this embodiment is 20-30 μm.

[0159] The filler in this embodiment is diatomaceous earth.

[0160] The antioxidant in this embodiment is antioxidant 1010.

[0161] The silane coupling agent in this embodiment is KH560.

[0162] Embodiment 17

[0163] The difference between this embodiment and embodiment 14 is that in this embodiment, when preparing a high-strength plastic pallet, the preparation method is as follows:

[0164] S1, adding shrimp shell powder modified high-density polypropylene, epoxidized soybean oil, polytetrafluoroethylene, filler, and styrene-butadiene rubber into a high-speed mixer, mixing them evenly to obtain a first mixed material;

[0165] S2, add ethanol (the amount of ethanol is 100 parts) to the silane coupling agent to dissolve it, and add polyarylene oxadiazole fiber and calcium carbonate whisker to mix and stir, let it stand for 3 hours, remove the ethanol, and obtain a second mixture;

[0166] S3, the first mixed material, the second mixed material and the remaining raw materials are mixed evenly, and sent into a twin-screw extruder for melt blending and granulation, the extruder barrel temperature is 185° C., and the die head temperature is 205° C.;

[0167] S4. First apply a release agent to the molding mold, preheat it to 60°C, and then use a plastic injection machine to inject the pellets into the molding mold. The barrel temperature is 250°C, the tool temperature is 30°C, the injection pressure is 90MPa, and the injection time is 8s.

[0168] S5. After demoulding, the formed pallet is cooled, trimmed, and shaped, sprayed with anti-slip paint, and packaged after curing to obtain the required high-strength plastic pallet.

[0169] The release agent in step S4 is fatty acid.

[0170] The average chopped length of the polyaromatic oxadiazole fibers in this embodiment is 20-30 μm; the average length of the calcium carbonate whiskers in this embodiment is 20-30 μm.

[0171] The filler in this embodiment is diatomaceous earth.

[0172] The antioxidant in this embodiment is antioxidant 1010.

[0173] The silane coupling agent in this embodiment is KH560.

[0174] The experimental test results of Examples 16 to 17 are shown in Table 6.

[0175] Table 6 - Experimental test results of Examples 16 to 17

[0176] Detection items High temperature resistance test (℃) Tensile strength test (MPa) Embodiment 14 123 64 Example 16 128 67 Embodiment 17 125 65

[0177] Result analysis: The difference between Examples 16 to 17 and Example 14 is that the preparation parameters are different when preparing the high-strength plastic pallet. Combined with the experimental test data in Table 6, it can be seen that the high-strength plastic pallet prepared by Example 16 has better tensile strength and high temperature resistance.

[0178] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-strength plastic pallet, characterized in that: The pallet comprises the following raw materials by weight: 70-95 parts of high-density polypropylene, 5-10 parts of epoxidized soybean oil, 1-3 parts of polytetrafluoroethylene, 4-8 parts of hydroxypropyl methylcellulose, 2-5 parts of silane coupling agent, 20-30 parts of filler, 14-20 parts of styrene-butadiene rubber, 10-15 parts of polyaromatic oxadiazole fiber, 5-10 parts of calcium carbonate whisker, and 1-2 parts of antioxidant; The high-density polypropylene is shrimp shell powder modified high-density polypropylene; the shrimp shell powder modified high-density polypropylene is prepared from shrimp shell powder, pimelic acid solution, coupling agent and high-density polypropylene in a weight ratio of (1-3):20:(1-2):20; The preparation method of shrimp shell powder modified high-density polypropylene comprises the following steps: A1, washing, drying, and crushing the discarded shrimp shells to obtain discarded shrimp shell powder; A2, taking the discarded shrimp shell powder obtained in step A1, roasting at 280-300° C. for 2-3 h to obtain shrimp shell powder; A3, taking the shrimp shell powder obtained in step A2, adding it to a 0.1-0.15 mol / L pimelic acid solution, stirring and reacting in a water bath for 2-3 h, to obtain shrimp shell powder with calcium pimelate covered on the surface; A4, adding high-density polypropylene and a coupling agent to the shrimp shell powder with the surface covered with calcium pimelate obtained in step A3, mixing evenly, to obtain shrimp shell powder modified high-density polypropylene; The weight ratio of the filler to the polyaromatic oxadiazole fiber is 1.7:1, 1.8:1, 1.9:1, 2:1 or 2.1:1; The filler includes at least one of diatomaceous earth, kaolin, glass microspheres and silicon dioxide.

2. The high-strength plastic pallet according to claim 1, characterized in that: The pallet comprises the following raw materials by weight: 81-95 parts of high-density polypropylene, 8-10 parts of epoxidized soybean oil, 2-3 parts of polytetrafluoroethylene, 6-8 parts of hydroxypropyl methylcellulose, 3-5 parts of silane coupling agent, 24-30 parts of filler, 17-20 parts of styrene-butadiene rubber, 12-15 parts of polyaromatic oxadiazole fiber, 8-10 parts of calcium carbonate whisker, and 1.5-2 parts of antioxidant.

3. The high-strength plastic pallet according to claim 1, characterized in that: The average chopped length of the polyaromatic oxadiazole fibers is 20-30 μm; the average length of the calcium carbonate whiskers is 20-30 μm.

4. A method for preparing the high-strength plastic pallet according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: S1, putting high-density polypropylene, epoxidized soybean oil, polytetrafluoroethylene, filler, and styrene-butadiene rubber into a high-speed mixer, and mixing them evenly to obtain a first mixed material; S2, adding ethanol to the silane coupling agent to dissolve it, and adding polyaromatic oxadiazole fiber and calcium carbonate whisker to mix and stir, let it stand for 2-3 hours, remove the ethanol, and obtain a second mixture; S3, mixing the first mixed material, the second mixed material and the remaining raw materials uniformly, and sending them into a twin-screw extruder for melt blending and granulation; S4. First apply a release agent to the mold, preheat it to 50~60℃, and then use a plastic injection machine to inject the pellets into the mold. The barrel temperature is 235~250℃, the tool temperature is 25-30℃, the injection pressure is 85~90MPa, and the injection time is 5~8s; S5. After demoulding, the formed pallet is cooled, trimmed, and shaped, sprayed with anti-slip paint, and packaged after curing to obtain the required high-strength plastic pallet.

5. The method for preparing a high-strength plastic pallet according to claim 4, characterized in that: In step S3, the extruder barrel temperature is 160-185°C, and the die head temperature is 165-205°C.

6. The method for preparing a high-strength plastic pallet according to claim 4, characterized in that: The release agent in step S4 is fatty acid.

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