Sludge polymer-based composite board as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of building board processing and solid waste resourceful treatment, particularly relates to a polymer-based composite board prepared by utilizing the gap filling effect of municipal sludge, and further discloses a preparation method of the polymer-based composite board. According to the composite board disclosed by the invention, the treated municipal sludge powder is used for partially replacing a polymer matrix material to prepare the building composite board, so that resource utilization of the municipal sludge is realized, especially the polymer-based composite board is prepared by virtue of a gap filling effect of the municipal sludge, and the mechanical property of the resin is improved. According to the invention, the influence of municipal sludge on the environment can be reduced, effective utilization of resources can be realized, the water treatment cost is reduced, and sustainable development is promoted.

Description

Technical Field

[0001] The present invention belongs to the technical field of building board processing and solid waste resource treatment, and specifically relates to a polymer-based composite board prepared by utilizing the gap-filling effect of municipal sludge, and further discloses a preparation method thereof. Background Art

[0002] Typically, during the sewage treatment process, bacteria and most parasites remain in the sludge. Viruses can attach to wastewater particles and settle in the sludge as the particles settle. Improper disposal and haphazard accumulation not only pollute the environment and severely waste manpower and resources, but also, once entering the human food chain, inevitably lead to the spread of disease. Therefore, the effective resource utilization of municipal sludge has become a key research topic in the environmental protection field.

[0003] Polymer-based composite materials are high-performance materials composed of polymers (such as plastics and rubber) and reinforcing materials (such as fibers and fillers). Compared to materials primarily made of metal and wood, they offer advantages such as lightweight, low cost, and long service life, leading to a growing market share in recent years. Currently, municipal sludge is being used as a reinforcement in the melt blending of composite materials with a polymer matrix, further reducing production costs while also improving mechanical strength and other properties.

[0004] For example, Chinese patent CN104591682A discloses an environmentally friendly biodegradable sludge plastic board. This board utilizes sludge as a resource, along with wood flour, PP powder, coupling agent, plasticizer, flame retardant, waterproofing agent, and release agent. However, in actual production, it has been found that simply replacing polymer-based materials with sludge can affect the board's performance, requiring further optimization.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing a sludge polymer-based composite board by utilizing the gap-filling effect of municipal sludge, thereby improving the mechanical properties of the resin and effectively increasing the comprehensive utilization rate of municipal sludge;

[0007] The second object of the present invention is to provide a sludge polymer-based composite board with better mechanical properties.

[0008] To achieve the above-mentioned purpose, the present invention provides a sludge polymer-based composite plate, wherein the raw materials for preparing the plate include a matrix material and a functional material; wherein,

[0009] The matrix material comprises, based on the total amount thereof, 50-90 wt% of a polymer matrix material and 10-50 wt% of sludge;

[0010] The sludge includes sludge powder with a particle size of 200-1250 mesh;

[0011] The functional material includes at least one of a plasticizer, a coupling agent or a stabilizer.

[0012] In some embodiments of the present invention, the sludge comprises a mixture of a first sludge powder having a particle size of 400-600 meshes and a second sludge powder having a particle size of 800-1250 meshes.

[0013] In some embodiments of the present invention, the mass ratio of the first sludge powder to the second sludge powder is 1:1-3, preferably 1:2.

[0014] In some embodiments of the present invention, the sludge comprises municipal sludge.

[0015] In some embodiments of the present invention, the polymer matrix material includes at least one of polyethylene, polyvinyl chloride or polypropylene.

[0016] In some embodiments of the present invention, the plasticizer is added in an amount of 5-10 wt % based on the base material;

[0017] Preferably, the plasticizer includes at least one of phthalates or epoxidized soybean oil.

[0018] In some embodiments of the present invention, the coupling agent is added in an amount of 0-1 wt % based on the base material;

[0019] Preferably, the coupling agent includes at least one of a silane coupling agent, a rare earth coupling agent, an aluminate coupling agent or a phthalate coupling agent.

[0020] In some embodiments of the present invention, the stabilizer is added in an amount of 0.5-2 wt % based on the base material;

[0021] Preferably, the stabilizer includes at least one of an antioxidant, a heat stabilizer or a light stabilizer.

[0022] The present invention also discloses a method for preparing the sludge polymer-based composite board, comprising the following steps:

[0023] (1) taking the sludge, performing dehydration treatment and sintering harmless treatment in sequence, grinding and screening into 200-1250 mesh particles, and storing them separately for future use;

[0024] (2) taking a selected amount of the sludge and coupling agent for modification treatment and setting aside;

[0025] (3) mixing the sludge powder, stabilizer, plasticizer, and polymer matrix according to the selected ratio, and melt-blending them to obtain a composite material for later use;

[0026] (4) vulcanizing the composite material under high pressure and demoulding to obtain the composite material.

[0027] In some embodiments of the present invention, in the method for preparing the sludge polymer-based composite board:

[0028] In the step (1), the temperature of the sintering harmless treatment is 300-400° C.; and / or,

[0029] In the step (2), the temperature of the modification treatment is 100-150° C.; and / or,

[0030] In the step (3), the melt blending step is performed using an open rubber mixer or an open plastic mixer; the melt blending parameters include: the front and rear roller temperatures are both set to 164-184°C, the rotation speed is set to 12-18 rpm, and the open mixing process lasts for 8-12 minutes; and / or,

[0031] In the step (4), the vulcanization treatment is performed using a flat vulcanizing press, and the holding pressure is controlled to be: 2-4 MPa, time 2-4 min, preferably pressure 3 MPa, time 3 min.

[0032] Compared to existing technologies, the composite board material described in this invention utilizes treated municipal sludge powder to partially replace the polymer matrix material in the production of building composite board materials. This not only realizes the resource utilization of municipal sludge, but also utilizes the gap-filling effect of municipal sludge to produce polymer-based composite board materials, thereby improving the mechanical properties of the resin. This invention not only reduces the impact of municipal sludge on the environment, but also achieves efficient resource utilization, reduces water treatment costs, and promotes sustainable development.

[0033] The sludge polymer-based composite board of the present invention utilizes the gap-filling effect of the sludge powder itself and optimizes the reasonable graded particle size system, which not only greatly improves the mechanical properties of the composite board, but also provides more options for the particle size selection of the sludge powder used.

[0034] The sludge polymer-based composite board of the present invention can consume a large amount of municipal sludge. For every ton of composite board produced, 300-500 kg of municipal sludge can be consumed. It has the advantages of low production cost (reducing production cost by about 10%-30%), low carbon emissions (reducing carbon emissions by 30%-80%), short production cycle, wide source of raw materials, and simple operation process.

[0035] The sludge polymer-based composite board material of the present invention utilizes municipal sludge as a low-carbon building material, which can alleviate the environmental pollution problems caused by the high maintenance cost and serious occupation of land resources caused by the large-scale accumulation of municipal sludge, broaden the resource utilization channels of municipal sludge, promote the regeneration and efficient utilization of solid waste resources, and reduce carbon emissions in the production process of building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The cross-sectional morphology of the sludge polymer-based composite plate prepared in Example 4 and Example 7, including a comparison diagram of the seamless filling effect;

[0037] Figure 2 This is a cross-sectional morphology of the sludge polymer-based composite plate prepared in Example 7;

[0038] Figure 3 The X-ray photoelectron spectroscopy analysis results of the sludge polymer-based composite board prepared in Example 7 confirm that the combination of sludge powder and the polymer matrix is ​​not a simple physical mixing, but a certain chemical bonding exists;

[0039] Figure 4 The results are a comparison of the carbon emissions and economic costs of the sludge polymer-based composite board prepared in Example 7 and the common calcium carbonate / polyethylene boards on the market. Figure 5 The comparative analysis results of the thermal conductivity of the sludge polymer-based composite plates prepared in Examples 1, 4, and 5 are shown. DETAILED DESCRIPTION

[0040] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0041] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0042] In the following embodiment of the present invention, a sludge polymer-based composite plate is provided, wherein the raw materials for preparing the plate include a matrix material and a functional material; wherein,

[0043] The matrix material comprises, based on the total amount thereof, 50-90 wt% of a polymer matrix material and 10-50 wt% of sludge;

[0044] The sludge includes sludge powder with a particle size of 200-1250 mesh;

[0045] The functional material includes at least one of a plasticizer, a coupling agent or a stabilizer.

[0046] In some embodiments of the present invention, the sludge comprises a mixture of a first sludge powder having a particle size of 400-600 meshes and a second sludge powder having a particle size of 800-1250 meshes.

[0047] As an exemplary embodiment, the mass ratio of the first sludge powder to the second sludge powder is 1:1-3, preferably 1:2.

[0048] The sludge polymer-based composite board material of the present invention uses municipal sludge for building boards and takes advantage of the gap-filling effect of the sludge itself. By selecting sludge powder of suitable size as the raw material to partially replace the polymer matrix material, it not only greatly improves the mechanical properties of the composite board material, but also provides more options for the particle size selection of the sludge powder used.

[0049] As an exemplary embodiment, the sludge includes:

[0050] A mixture of a first sludge powder having a particle size of 400 mesh and a second sludge powder having a particle size of 800 mesh, wherein the mass ratio of the first sludge powder to the second sludge powder is 1:2; or

[0051] A mixture of a first sludge powder having a particle size of 600 mesh and a second sludge powder having a particle size of 1250 mesh, wherein the mass ratio of the first sludge powder to the second sludge powder is 1:2; or

[0052] A mixture of first sludge powder with a particle size of 400 mesh and second sludge powder with a particle size of 1250 mesh, wherein the mass ratio of the first sludge powder to the second sludge powder is 1:2.

[0053] As an exemplary embodiment, the sludge comprises municipal sludge.

[0054] As an exemplary embodiment, the polymer matrix material includes at least one of polyethylene, polyvinyl chloride, or polypropylene.

[0055] As an exemplary embodiment, the plasticizer is added in an amount of 5-10 wt % based on the base material;

[0056] Preferably, the plasticizer includes at least one of phthalates or epoxidized soybean oil.

[0057] As an exemplary embodiment, the coupling agent is added in an amount of 0-1 wt % based on the base material;

[0058] Preferably, the coupling agent includes at least one of a silane coupling agent, a rare earth coupling agent, an aluminate coupling agent or a phthalate coupling agent.

[0059] As an exemplary embodiment, the stabilizer is added in an amount of 0.5-2 wt % based on the base material;

[0060] Preferably, the stabilizer includes at least one of an antioxidant, a heat stabilizer or a light stabilizer.

[0061] The present invention also discloses a method for preparing the sludge polymer-based composite board, comprising the following steps:

[0062] (1) taking the sludge, performing dehydration treatment and sintering harmless treatment in sequence, grinding and screening into 200-1250 mesh particles, and storing them separately for future use;

[0063] (2) taking a selected amount of the sludge and coupling agent for modification treatment and setting aside;

[0064] (3) mixing the sludge powder, stabilizer, plasticizer, and polymer matrix according to the selected ratio, and melt-blending them to obtain a composite material for later use;

[0065] (4) vulcanizing the composite material under high pressure and demoulding to obtain the composite material.

[0066] As an exemplary embodiment, in the method for preparing the sludge polymer-based composite plate:

[0067] In the step (1), the temperature of the sintering harmless treatment is 300-400° C.; and / or,

[0068] In the step (2), the temperature of the modification treatment is 100-150° C.; and / or,

[0069] In the step (3), the melt blending step is performed using an open rubber mixer or an open plastic mixer; the melt blending parameters include: the front and rear roller temperatures are both set to 164-184°C, the rotation speed is set to 12-18 rpm, and the open mixing process lasts for 8-12 minutes; and / or,

[0070] In the step (4), the vulcanization treatment is performed using a flat vulcanizing press, with the holding pressure controlled to be 2-4 MPa and the holding time being 2-4 min.

[0071] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0072] Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations such as "include" or "comprising", etc., will be understood to include the stated elements or components but not to exclude other elements or other components.

[0073] Example 1

[0074] The municipal sludge polymer-based composite board described in this embodiment is prepared from the following raw materials, in parts by weight: 70 parts polyethylene polymer matrix, 30 parts sludge powder, 6 parts DOP plasticizer, 0.4 parts silane coupling agent (KH-550), and 0.9 parts solid calcium zinc stabilizer. The sludge powder has an 800-mesh particle size.

[0075] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0076] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to about 800 mesh and store it for future use;

[0077] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0078] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; and melt the mixed raw materials in the open rubber mixing mill, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0079] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes, then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material, and finally maintained under pressure for 3 minutes to allow the composite material to be fully vulcanized under high pressure; the prepared composite material is cooled at room temperature for 24 hours and then taken out of the mold to obtain a composite sheet.

[0080] Example 2

[0081] The municipal sludge polymer-based composite board described in this embodiment is prepared from the following raw materials, in parts by weight: 60 parts of a polymer matrix such as polyethylene, 40 parts of sludge powder, 5 parts of a DOP plasticizer, 0.43 parts of a silane coupling agent (KH-550), and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder has a particle size of 800 mesh.

[0082] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0083] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to about 800 mesh and store it for future use;

[0084] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0085] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; and melt the mixed raw materials in an open rubber (plastic) mixing machine. During the process, pay attention to adjust the distance between the two rollers to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0086] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0087] Example 3

[0088] The municipal sludge polymer-based composite board described in this embodiment is prepared from the following raw materials, in parts by weight: 50 parts of a polymer matrix such as polyethylene; 50 parts of sludge powder; 5.3 parts of a DOP plasticizer; 0.47 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder has an 800-mesh particle size.

[0089] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0090] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to about 800 mesh and store it for future use;

[0091] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0092] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; melt the mixed raw materials in the open rubber (plastic) mixing machine, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0093] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0094] Example 4

[0095] The municipal sludge polymer-based composite board described in this embodiment is prepared from the following raw materials, in parts by weight: 60 parts of a polymer matrix such as polyethylene; 40 parts of sludge powder; 5 parts of a DOP plasticizer; 0.51 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder has an 800-mesh particle size.

[0096] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0097] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to about 800 mesh and store it for future use;

[0098] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0099] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; melt the mixed raw materials in the open rubber (plastic) mixing machine, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0100] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0101] Example 5

[0102] The municipal sludge polymer-based composite board described in this example is prepared from the following raw materials, in parts by weight: 60 parts of a polymer matrix such as polyethylene; 40 parts of sludge powder; 5 parts of a DOP plasticizer; 0.51 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder includes two particle sizes, 600 mesh and 1250 mesh, with a mass ratio of 1:2.

[0103] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0104] (1) Dewater the municipal sludge, sinter it at 300-400°C for harmless treatment, grind it into 600 mesh and 1250 mesh and store it for future use;

[0105] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0106] (3) According to the designed experimental ratio, the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices were weighed and all the materials were added to the high-speed mixer at the same time. They were first stirred slowly for 5 minutes, and then stirred rapidly for 5 minutes for mixing. The mixed raw materials were melted and blended in an open rubber (plastic) mixing machine. During the process, the distance between the two rollers was adjusted to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine were as follows: the temperature of the front and rear rollers were set to 164-184℃, the speed was set to 15r / min, and the entire mixing process lasted for 10 minutes.

[0107] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0108] Example 6

[0109] The municipal sludge polymer-based composite board described in this example is prepared from the following raw materials, in parts by weight: 60 parts of a polymer matrix such as polyethylene; 40 parts of sludge powder; 5 parts of a DOP plasticizer; 0.51 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder includes two particle sizes: 400 mesh and 800 mesh, with a mass ratio of 1:2.

[0110] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0111] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to 400 mesh and 800 mesh and store it separately for future use;

[0112] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0113] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; melt the mixed raw materials in the open rubber (plastic) mixing machine, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0114] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0115] Example 7

[0116] The municipal sludge polymer-based composite board described in this example is prepared from the following raw materials, in parts by weight: 60 parts of a polymer matrix such as polyethylene; 40 parts of sludge powder; 5 parts of a DOP plasticizer; 0.51 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder includes two particle sizes: 400 mesh and 1250 mesh, with a mass ratio of 1:2.

[0117] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0118] (1) Dewater the municipal sludge, sinter it at 300-400°C for harmless treatment, grind it to 400 mesh and 1250 mesh and store them separately for future use;

[0119] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0120] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; melt the mixed raw materials in the open rubber (plastic) mixing machine, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0121] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0122] Example 8

[0123] The municipal sludge polymer-based composite board described in this example is made from the following raw materials, in parts by weight: 60 parts of a polymer matrix, such as polyethylene; 40 parts of sludge powder; 5 parts of a DOP plasticizer; 0.51 parts of a silane coupling agent (KH-550); and 0.83 parts of a solid calcium-zinc stabilizer. The sludge powder includes two particle sizes, 400 mesh and 600 mesh, in a ratio of 1:2.

[0124] The method for preparing the municipal sludge polymer-based composite board described in this embodiment includes the following steps:

[0125] (1) Dehydrate the municipal sludge, sinter it at 300-400℃ for harmless treatment, grind it to 400 mesh and 600 mesh and store it separately for future use;

[0126] (2) The sludge powder and the coupling agent were modified in an oven at 120°C for 3 hours and then stored for later use;

[0127] (3) According to the designed experimental ratio, weigh the dried sludge powder, stabilizer, plasticizer and polyethylene and other polymer matrices, add all the materials into the high-speed mixer at the same time, stir slowly for 5 minutes, and then stir quickly for 5 minutes to mix; melt the mixed raw materials in the open rubber (plastic) mixing machine, and pay attention to adjust the distance between the two rollers during the process to ensure sufficient mixing between the raw materials. During the experiment, the specific setting parameters of the open rubber (plastic) mixing machine are as follows: the temperature of the front and rear rollers are set to 164-184℃, the speed is set to 15r / min, and the entire mixing process lasts for 10 minutes;

[0128] (4) The fully melt-blended composite material is placed in a standard mold and placed in a flat vulcanizer for preheating for two minutes. The material is then deflated five times with a deflation interval of 5 seconds to fully expel the bubbles inside the material. The pressure is then maintained for 3 minutes to allow the composite material to be fully vulcanized under high pressure. The prepared composite material is cooled at room temperature for 24 hours and then removed from the mold to obtain a composite sheet.

[0129] Example 9

[0130] The raw material system and preparation method of the composite plate in this embodiment are the same as those in Example 1, with the only difference being that the silane coupling agent is not added but is replaced by a quantitative titanate coupling agent.

[0131] Example 10

[0132] The raw material system and preparation method of the composite board in this embodiment are the same as those in Example 1, with the only difference being that the DOP plasticizer is not added but is replaced by a fixed amount of DIDP plasticizer.

[0133] Comparative Example 1

[0134] The raw material system and preparation method of the composite board in this comparative example are the same as those in Example 1, with the only difference being that the sludge powder is not added but is replaced by a certain amount of polymer matrix material.

[0135] Experimental example

[0136] 1. Mechanical properties test

[0137] The composite panels prepared in Examples 1-10 and Comparative Example 1 were respectively subjected to mechanical property tests, wherein the tensile strength was based on the national standard "Test Method for Tensile Properties of Plastics" (GB / T 1040-92), the flexural strength was based on the national standard "Plastic Flexural Properties Test" (GB / T 9341-2008), and the impact strength was based on the national standard "Determination of Izod Impact Strength of Plastics" (GB / T 1843-2008). The results are shown in Table 1 below.

[0138] Table 1

[0139] serial number Tensile strength / MPa Bending strength / MPa <![CDATA[Impact strength / KJ / m 2 > Example 1 25.45 31.65 16.37 Example 2 28.85 34.21 17.62 Example 3 27.15 34.21 18.29 Example 4 29.42 35.17 18.66 Example 5 39.62 41.38 22.65 Example 6 37.56 38.38 20.74 Example 7 39.25 41.62 26.02 Example 8 27.34 33.45 19.04 Example 9 23.98 31.39 15.38 Example 10 24.87 30.87 17.28 Comparative Example 1 18.29 25.49 11.29

[0140] It can be seen that the present invention applies municipal sludge to partially replace polymer-based materials in polymer-based composite boards, which can effectively ensure the mechanical properties of the composite boards. At the same time, by utilizing the gap-filling effect of municipal sludge and selecting graded particle size particles with a suitable ratio, the smaller particles fill the gaps between the larger particles and the matrix, making the matrix and the reinforcement, as well as the reinforcements each other, more tightly bonded, thereby greatly improving the mechanical application performance of the composite boards.

[0141] 2. Morphological observation

[0142] Attachment Figure 1 Cross-sectional morphologies of the sludge polymer-based composite boards prepared in Examples 4 and 7 are included, including a comparison showing the seamless gap-filling effect. This demonstrates that the present invention, through particle size grading and screening of municipal sludge powder, effectively leverages the gap-filling effect, significantly improving the performance of the composite boards.

[0143] Attachment Figure 2 This is a cross-sectional morphology of the sludge polymer-based composite plate prepared in Example 7; Figure 3 The X-ray photoelectron spectroscopy analysis results of the sludge-polymer-based composite board prepared in Example 7 show that the composite board of the present invention uses sludge powder and a polymer matrix as raw materials. The combination of the two is not a simple physical mixing, but a certain chemical bonding, which effectively ensures the mechanical properties of the composite board.

[0144] 3. Cost calculation

[0145] Figure 4 The results are a comparison of the carbon emissions and economic costs of the sludge polymer-based composite board prepared in Example 7 and the common calcium carbonate / polyethylene boards on the market.

[0146] It can be seen that the composite board material of the present invention utilizes municipal sludge for resource utilization, and has the advantages of low production cost (reducing production cost by about 10%-30%), low carbon emissions (reducing carbon emissions by 30%-80%), short production cycle, wide source of raw materials, and simple operation process.

[0147] 4. Thermal conductivity test

[0148] Figure 5 The comparative analysis results of the thermal conductivity of the sludge polymer-based composite plates prepared in Examples 1, 4, and 5 are shown.

[0149] It can be seen that with the increase of filling amount, the thermal conductivity of the composite material increases, and at the same time, the gap filling effect of sludge powder with different particle sizes further improves the thermal conductivity of the composite material.

[0150] In summary, the composite board material described in the present invention utilizes treated municipal sludge powder to partially replace the polymer matrix material to prepare the building composite board material, especially utilizing the gap filling effect of the sludge powder itself, and through the optimization of the reasonable graded particle size system, not only the mechanical properties of the composite board material are greatly improved, but also the resource utilization of municipal sludge is realized.

[0151] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A sludge polymer-based composite board, characterized in that: The raw materials for preparing the plate include base material and functional material; wherein, The matrix material comprises, based on the total amount thereof, 50-90 wt% of a polymer matrix material and 10-50 wt% of sludge; The sludge includes sludge powder with a particle size of 200-1250 mesh; The functional material includes at least one of a plasticizer, a coupling agent or a stabilizer.

2. The sludge polymer-based composite plate according to claim 1, characterized in that: The sludge comprises a mixture of first sludge powder with a particle size of 400-600 meshes and second sludge powder with a particle size of 800-1250 meshes.

3. The sludge polymer-based composite plate according to claim 2, characterized in that: The mass ratio of the first sludge powder to the second sludge powder is 1:1-3, preferably 1:

2.

4. The sludge polymer-based composite board according to any one of claims 1 to 3, characterized in that: The sludge includes municipal sludge.

5. The sludge polymer-based composite board according to any one of claims 1 to 4, characterized in that: The polymer matrix material includes at least one of polyethylene, polyvinyl chloride or polypropylene.

6. The sludge polymer-based composite board according to any one of claims 1 to 5, characterized in that: The amount of the plasticizer added based on the base material is 5-10 wt%; Preferably, the plasticizer includes at least one of phthalates or epoxidized soybean oil.

7. The sludge polymer-based composite board according to any one of claims 1 to 6, characterized in that: The coupling agent is added in an amount of 0-1 wt% based on the base material; Preferably, the coupling agent includes at least one of a silane coupling agent, a rare earth coupling agent, an aluminate coupling agent or a phthalate coupling agent.

8. The sludge polymer-based composite board according to any one of claims 1 to 7, characterized in that: The stabilizer is added in an amount of 0.5-2 wt% based on the base material; Preferably, the stabilizer includes at least one of an antioxidant, a heat stabilizer or a light stabilizer.

9. A method for preparing the sludge polymer-based composite board according to any one of claims 1 to 8, characterized in that: The steps include: (1) taking the sludge, performing dehydration treatment and sintering harmless treatment in sequence, grinding and screening into 200-1250 mesh particles, and storing them separately for future use; (2) taking a selected amount of the sludge and coupling agent for modification treatment and setting aside; (3) mixing the sludge powder, stabilizer, plasticizer, and polymer matrix according to the selected ratio, and melt-blending them to obtain a composite material for later use; (4) vulcanizing the composite material under high pressure and demoulding to obtain the composite material.

10. The method for preparing the sludge polymer-based composite board according to claim 9, characterized in that: In the step (1), the temperature of the sintering harmless treatment is 300-400° C.; and / or, In the step (2), the temperature of the modification treatment is 100-150° C.; and / or, In the step (3), the melt blending step is performed using an open rubber mixer or an open plastic mixer; the melt blending parameters include: the front and rear roller temperatures are both set to 164-184°C, the rotation speed is set to 12-18 rpm, and the open mixing process lasts for 8-12 minutes; and / or, In the step (4), the vulcanization treatment is performed using a flat vulcanizing press, with the holding pressure controlled to be 2-4 MPa and the holding time being 2-4 min.

Images