Composite material spherical particles for paving ground as well as preparation method and use method of composite material spherical particles

Abstract

The invention discloses a composite material spherical particle for paving a ground, and a preparation method and a use method of the composite material spherical particle. The spherical particle is of a core-shell structure and contains cork particles, coffee grounds powder and polyurethane, the cork particles are located in the middle, and coffee grounds and polyurethane are evenly coated on the outer surface of the cork particles. The preparation method comprises the following steps: granulating on a centrifugal granulator, and gradually and uniformly coating the polyurethane and the coffee residue powder on the outer surfaces of the cork particles to obtain a semi-finished product; and carrying out microwave heating to obtain a finished product. When the ground is paved, a flat plate heating device needs to be used, the spherical particles are placed at the high-position end of a heating plate of the heating device, the spherical particles roll to the ground needing to be paved while being heated, the spherical particles falling in place are compacted immediately, and paving is completed. When the cork-coffee residue-polyurethane composite material spherical particles provided by the invention are used for paving an outdoor runway, the advantages in the aspects of prolonging the service life of the runway, improving the use performance, protecting the environment, reducing the economic cost and the like are outstanding.

Description

TECHNICAL FIELD

[0001] The present application relates to a composite material spherical particle for paving the ground and its preparation method and use method, in particular to a cork-coffee grounds-polyurethane composite material for outdoor sports field runway, belonging to the technical field of building materials. BACKGROUND

[0002] With the enhancement of the national fitness consciousness, the construction scale of outdoor sports field is expanding continuously. As a key component, the performance of the paving material of the outdoor sports field runway is strictly required. At present, the cork and polyurethane composite material has been widely used in the field of outdoor sports field runway paving due to its certain elasticity, good shock absorption and good anti-skid performance.

[0003] However, the existing cork and polyurethane composite material has many drawbacks in actual use. Among them, the most serious problem is that it is easy to crack after long-term use, because the outdoor sports field runway is subjected to the test of natural environment and the influence of frequent activities of athletes. In terms of temperature change, the temperature difference between day and night and between seasons causes the material to repeatedly expand and contract, forming stress concentration in the material. Ultraviolet radiation can accelerate the aging of the material, reduce its toughness and strength. Rainwater erosion may cause the loss of part of the material components, destroy the internal structure stability. And the continuous tread of athletes brings persistent pressure and friction to the surface of the material.

[0004] Under the joint action of these factors, the internal structure of the existing cork and polyurethane composite material is gradually damaged. Due to uneven stress distribution, cracks are easily generated in the stress concentration area. With the passage of time, these cracks continuously expand, forming large cracks, which not only affects the appearance of the runway, but also seriously reduces the use performance of the runway, such as elasticity, anti-skid performance, etc., and even may endanger the safety of athletes and increase the risk of injury.

[0005] In addition, once the runway cracks, the maintenance cost is high. It is necessary to cut, re-pave and other complex operations in the cracking area, which consumes a lot of manpower, material resources and time, affects the normal use of the sports field. At the same time, frequent maintenance will also have negative impact on the environment, such as the problem of disposal of waste materials.

[0006] In summary, the existing cork and polyurethane composite material used for outdoor sports field runway paving has serious cracking problem, which seriously restricts its service life and use effect, and needs to be innovated and improved. SUMMARY

[0007] The technical problem to be solved by the present application is that the existing cork and polyurethane composite material used for outdoor sports field runway is easy to crack after long-term use.

[0008] To solve the above technical problems, the first aspect of the present application provides a kind of composite material spherical particle for paving ground.The composite material spherical particle contains softwood particle, coffee residue powder, polyurethane three components, and the composite material spherical particle has core-shell structure: softwood particle is located in the middle position of the composite material spherical particle, and coffee residue and polyurethane are evenly coated on the outer surface of softwood particle.

[0009] In some embodiments, the proportion of softwood particles in the composite material spherical particle is 10-20% by weight, the proportion of coffee residue powder in the composite material spherical particle is 30-50%, and the proportion of polyurethane in the composite material spherical particle is 30-50%, and the total of the three is 100%.

[0010] In some embodiments, the particle size range of the composite material spherical particle is 5-10 mm.

[0011] The second aspect of the present application provides a preparation method of the above-mentioned composite material spherical particle, comprising the following steps:

[0012] Step 1: remove impurities from softwood, crush and screen softwood particles with appropriate particle size range, and dry for standby;

[0013] Step 2: first defat the coffee residue, then screen coffee residue powder with appropriate particle size range, and dry for standby;

[0014] Step 3: granulate on a centrifugal granulator to gradually and evenly coat polyurethane and coffee residue powder on the outer surface of softwood particles, to obtain a semi-finished product of the composite material spherical particle;

[0015] Step 4: heat the above-mentioned semi-finished product in a microwave heating device to obtain the composite material spherical particle.

[0016] In some embodiments, the particle size range of softwood particles in step 1 is 1-10 mm, and the range of coffee residue powder in step 2 is 20-200 mesh.

[0017] In some embodiments, the particle size range of softwood particles in step 1 is 2-5 mm, and the range of coffee residue powder in step 2 is 100-200 mesh.

[0018] In some embodiments, the granulation in step 3 comprises the following sub-steps:

[0019] Step 3.1: evenly lay coffee residue powder on the tray of the centrifugal granulator;

[0020] Step 3.2: evenly lay softwood particles on the coffee residue powder;

[0021] Step 3.2, liquid polyurethane is sprayed from the atomizing spray opening of the centrifugal granulator to the tray, and as the tray is eccentrically rotated, the liquid polyurethane gradually coats the cork particles with coffee residue powder, obtaining the semi-finished product of the composite spherical particles.

[0022] In some embodiments, the heating temperature of the microwave heating device is 80-120 DEG C, and the heating time is 10-30 minutes.

[0023] In a third aspect, the application provides a use method of the composite spherical particles, comprising the following steps:

[0024] Step a, the plate heating device is placed on the ground to be paved, and the plate heating device is provided with an inclined heating plate;

[0025] Step b, the heating function of the heating plate is turned on to preheat, and the composite spherical particles are placed at the high end of the heating plate, and the composite spherical particles are rolled to the ground to be paved while being heated;

[0026] Step c, the composite spherical particles falling on the ground to be paved are immediately compacted, and the paving is completed.

[0027] In some embodiments, the inclination angle of the heating plate is adjusted in the range of 5-30 degrees, and the heating temperature of the heating plate is 50-150 DEG C.

[0028] The application has the advantages that the cork-coffee residue-polyurethane composite spherical particles are provided, the outdoor runway is paved with the particles, the service life of the runway is prolonged, the use performance is improved, the environment is protected, and the economic cost is reduced, and the new development direction is provided for the field of outdoor sports field runway materials. DETAILED DESCRIPTION

[0029] The existing cork-polyurethane composite material is obtained by mixing the cork particles and the polyurethane as a whole and then curing, and the material has uniform mechanical properties in all directions. However, there are two problems in using the material to build a sports runway.

[0030] The first problem is the paving problem. The composite material is produced in a factory, and the construction site of the runway is usually far away from the factory. Therefore, the composite material can only be prefabricated into small-area paving plates, and then transported to the construction site. After the paving is completed, the adjacent paving plates are connected into a whole by using polyurethane to fill the joints, and the existence of the joints reduces the integrity and practicability of the paving surface.

[0031] The second problem is cracking, which is more difficult to solve. Due to the limitations of the above paving process, the material at the joint is different from the main body of the paving plate, and the joint is prone to cracking. During use, the paving plate is subjected to pressure in the vertical direction and friction (or shear force) in the horizontal direction. The long-term superposition of various forces in these two directions will cause the surface and internal of the paving plate to crack, reducing the service life of the runway.

[0032] The present application comprehensively improves the material composition, preparation process and paving process, aiming to solve the technical problem of easy cracking of existing materials in outdoor sports field runway use, significantly improve the service life and performance of the runway, and create a safer and more stable sports field for athletes.

[0033] The composite spherical particles of the present application contain cork particles, coffee grounds powder and polyurethane, and have a unique core-shell structure. The cork particles are located in the middle of the composite spherical particles, and the coffee grounds and polyurethane are evenly coated on the outer surface of the cork particles. This structure design changes the stress distribution pattern inside the material. Compared with traditional cork-polyurethane composite materials, when subjected to external force, stress can be more evenly distributed in each particle, effectively reducing stress concentration and reducing the risk of cracking.

[0034] By weight, the proportion of cork particles in the composite spherical particles is 10% to 20%, the proportion of coffee grounds powder is 30% to 50%, and the proportion of polyurethane is 30% to 50%, and the total of the three is 100%. A large number of experiments have verified that this proportion range can make the three components synergize with each other, while ensuring good mechanical properties of the material, fully exerting the advantages of each component. For example, the cork particles provide certain elasticity and toughness, the coffee grounds powder not only has a wide source and can reduce costs, but also can enhance the friction and stability of the material, and the polyurethane plays a role in bonding and sealing, ensuring the stability of the overall structure of the composite material.

[0035] The particle size range of the composite spherical particles is set to 5 to 10 millimeters. Such particle size not only ensures the flowability of the particles during paving, facilitating construction operation, but also enables the particles to form a tight and stable structure with each other after forming the runway, further improving the overall performance of the runway.

[0036] The cork-coffee grounds-polyurethane composite material provided by the present application is prepared by the following preparation method.

[0037] The first step is the pretreatment of cork and coffee grounds, respectively obtaining cork particles and coffee grounds powder.

[0038] The cork is removed from impurities, crushed, and then the cork particles with a particle size range of 1-10 mm (preferably 2-5 mm) are screened and dried for use. The cork particles with a suitable particle size can better combine with other components, and have an important influence on the elasticity and strength of the final material. The removal of impurities ensures the purity of the material, and the drying treatment avoids the adverse effects of moisture on the subsequent process and material performance.

[0039] The coffee grounds are first defatted, and then coffee ground powder with a particle size range of 20-200 mesh (preferably 100-200 mesh) is screened and dried for use. The defatting treatment removes the oil component in the coffee grounds, prevents mold growth, and prevents it from affecting the bonding properties of the material. The coffee ground powder with a suitable particle size can be uniformly coated on the surface of the cork particles, enhancing the overall performance of the material.

[0040] The second step is granulation, to obtain semi-finished products of cork-coffee ground-polyurethane composite spherical particles.

[0041] Granulation is performed on a centrifugal granulator, and the specific steps are as follows: first, evenly lay the coffee ground powder on the tray of the centrifugal granulator; then evenly lay the cork particles on the coffee ground powder; finally, spray the liquid polyurethane on the tray. With the eccentric rotation of the tray, the coffee ground powder gradually coats the surface of the cork particles, and semi-finished products of composite spherical particles are obtained. This granulation method can ensure uniform distribution of each component and form a stable core-shell structure.

[0042] The third step is heating and curing to obtain finished products of cork-coffee ground-polyurethane composite spherical particles.

[0043] The above semi-finished products are heated in a microwave heating device, the heating temperature is 80-120℃, and the heating time is 10-30 minutes, to obtain the final composite spherical particles. Microwave heating uniformly heats the above semi-finished products from the inside to the outside, which can further cure the polyurethane, enhance the bonding force between the components, and improve the stability and durability of the material.

[0044] The cork-coffee ground-polyurethane composite spherical particles provided by the present application are particularly suitable for sports tracks when used to pave the ground. Based on the spherical particle shape, a special heating paving process is required, and the track obtained is not easy to crack and is durable. The specific steps of the heating paving process are as follows.

[0045] First, the heating device with a piece of inclined heating plate is placed on the ground that needs to be paved. The inclination angle of the heating plate is adjusted in the range of 5-30 degrees, and the heating temperature is adjusted in the range of 50-150℃. After the heating plate is turned on and heated, the composite spherical particles are placed at the high end of the heating plate, and the particles roll to the low end of the heating plate while being heated, and finally fall on the ground that needs to be paved. This heating method makes the surface layer of the particles slightly melt, and has certain plasticity and adhesion before paving. When the surface of the particles has not yet solidified, the composite spherical particles that have fallen on the ground are compacted as soon as possible to complete the paving. This paving process not only improves the construction efficiency, but also ensures the close combination between the particles, enhances the integrity and stability of the runway.

[0046] The mechanical properties of the single cork-coffee grounds-polyurethane composite spherical particle are uniform. After being paved into a runway, each spherical particle is consolidated with the adjacent spherical particle by surface melting. When the runway is subjected to vertical pressure, each spherical particle will deform, but the degree is different, thereby better absorbing and transmitting energy, avoiding cracking caused by local impact of pressure on the runway. After long-term action of vertical pressure and horizontal shear force, the single cork-coffee grounds-polyurethane composite spherical particle may gradually fall off, exposing the underlying relatively good particles, thereby avoiding large-area damage of the runway. Because the single particle is small, the particles that occasionally fall off are few, and the flatness of the runway surface is basically not affected. If the local particles fall off more, the runway can be repaired at the site by using new cork-coffee grounds-polyurethane composite spherical particles, which has small construction operation difficulty. Before repairing, the surface of the old particles can be heated by a hot air gun to increase the bonding strength between the old particles and the new particles.

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0048] Embodiment 1

[0049] Cork particle screening and pretreatment: high-quality cork raw materials are selected, a vibrating screen is used for screening, the screen aperture is controlled, and cork particles with a particle size of about 2 mm are obtained. The cork particles are carefully inspected, and impurities and rotten parts are manually removed. The screened cork particles are placed in a drying oven and dried at 80℃ for 2 hours to remove moisture.

[0050] Coffee residue powder treatment: supercritical carbon dioxide extraction technology is used for defatting treatment of coffee residue. The coffee residue is placed in the extraction kettle, the temperature is set to 40°C, the pressure is 10 MPa, and the extraction time is 2 hours. After extraction, separate the carbon dioxide and coffee residue by reducing the pressure. The defatted coffee residue is sieved using a standard sieve to obtain coffee residue powder with a particle size of 200 mesh, which is then placed in a drying oven and dried at 60°C for 3 hours.

[0051] Centrifugal granulation: turn on the centrifugal granulator and set the tray speed to 500 rpm. The dried coffee residue powder is evenly spread on the tray, and then the dried cork particles are evenly spread on the coffee residue powder. Spray liquid polyurethane with a concentration of 30% at a pressure of 0.3 MPa on the tray through the atomizing nozzle. As the tray rotates eccentrically, continue to spray for 15 minutes, allowing the coffee residue powder to gradually coat the surface of the cork particles, forming a semi-finished product of composite spherical particles.

[0052] Microwave heating and curing: place the semi-finished product in a microwave heating device, set the heating temperature to 120°C, and the heating time to 15 minutes to fully cure the polyurethane, obtaining composite spherical particles. In the composite spherical particles, the proportion of cork is 20% by weight, the proportion of coffee residue powder is 40% by weight, and the proportion of polyurethane is 40% by weight.

[0053] Example 2

[0054] Cork particle selection and pretreatment: select high-quality cork raw materials, use a vibrating screen for screening, control the screen mesh size, and obtain cork particles with a particle size of 5 mm. Carefully inspect the cork particles and manually remove impurities and rotten parts. Place the screened cork particles in a drying oven and dry at 80°C for 2 hours to remove moisture.

[0055] Coffee residue powder treatment: supercritical carbon dioxide extraction technology is used for defatting treatment of coffee residue. The coffee residue is placed in the extraction kettle, the temperature is set to 40°C, the pressure is 10 MPa, and the extraction time is 2 hours. After extraction, separate the carbon dioxide and coffee residue by reducing the pressure. The defatted coffee residue is sieved using a standard sieve to obtain coffee residue powder with a particle size of 100 mesh, which is then placed in a drying oven and dried at 60°C for 4 hours.

[0056] Centrifugal granulation: turn on the centrifugal granulator and set the tray speed to 500 rpm. The dried coffee residue powder is evenly spread on the tray, and then the dried cork particles are evenly spread on the coffee residue powder. Spray liquid polyurethane with a concentration of 30% at a pressure of 0.3 MPa on the tray through the atomizing nozzle. As the tray rotates eccentrically, continue to spray for 15 minutes, allowing the coffee residue powder to gradually coat the surface of the cork particles, forming a semi-finished product of composite spherical particles.

[0057] Microwave heating and curing: the semi-finished product is placed in a microwave heating device, the heating temperature is set to 120 DEG C, and the heating time is 20 minutes, so that the polyurethane is fully cured to obtain a composite spherical particle. In the composite spherical particle, the cork accounts for 10% by weight, the coffee grounds powder accounts for 45% by weight, and the polyurethane accounts for 45% by weight.

[0058] Example 3

[0059] This example is a construction method for paving a runway with the composite spherical particles prepared in Example 1.

[0060] Ground preparation: use a land leveler to level the runway ground, remove debris, protrusions and recesses, and ensure that the ground flatness error is within ±2mm.

[0061] Heating and paving: place the heating device with an inclined heating plate at the starting position of the runway, adjust the inclination angle of the heating plate to 15 degrees, and the heating temperature to 120 DEG C. Turn on the heating plate, and place the composite spherical particles at the high end of the heating plate. The particles roll to the ground after being heated.

[0062] Compaction and forming: use a small roller to compact the particles on the ground, the weight of the roller is 2 tons, the rolling speed is 20m / min, and the rolling is performed 3 times. According to this step, 5 layers are paved according to the design thickness of the runway, and the runway paving is completed.

[0063] Example 4

[0064] This example is a construction method for paving a runway with the composite spherical particles prepared in Example 2.

[0065] Ground preparation: use a land leveler to level the runway ground, remove debris, protrusions and recesses, and ensure that the ground flatness error is within ±2mm.

[0066] Heating and paving: place the heating device with an inclined heating plate at the starting position of the runway, adjust the inclination angle of the heating plate to 15 degrees, and the heating temperature to 150 DEG C. Turn on the heating plate, and place the composite spherical particles at the high end of the heating plate. The particles roll to the ground after being heated.

[0067] Compaction and forming: use a small roller to compact the particles on the ground, the weight of the roller is 2 tons, the rolling speed is 20m / min, and the rolling is performed 3 times. According to this step, 5 layers are paved according to the design thickness of the runway, and the runway paving is completed.

[0068] The present application combines cork, coffee grounds and polyurethane in an innovative way and uses a unique preparation and paving process, which brings many significant benefits to the outdoor sports field runway.

[0069] Prolong the service life of runway: Traditional cork and polyurethane composite runway is easy to crack due to stress concentration, which shortens the service life. The unique core-shell structure of the composite spherical particles and the optimized component ratio of the invention can effectively disperse the stress between the cork particles, coffee grounds powder and polyurethane. When the runway is subjected to external force, the components work together to avoid excessive stress concentration and crack formation. Compared with traditional materials, the service life of the runway can be prolonged by more than 50%, greatly reducing the replacement frequency and maintenance cost of the runway.

[0070] Improve the performance: The spherical particle structure of 5-10mm provides better elasticity to the runway. When the athletes exercise, the elastic deformation of the particles provides appropriate rebound force to help the athletes perform, while reducing the impact of hard ground on joints and reducing the risk of injury. The gap between the particles allows rainwater to penetrate quickly, avoiding surface water and ensuring good friction of the runway in wet environments, improving safety and reliability.

[0071] Environmental advantages: Cork is a renewable resource, widely available and environmentally friendly. Coffee grounds are recycled as waste, reducing environmental pollution. The invention reasonably controls the amount of materials during preparation to reduce the generation of waste materials. After the service life of the runway, the material is relatively easy to recycle or degrade compared to traditional composite materials, in line with the green and environmentally friendly concept.

[0072] Economic cost reduction: Although initial research and production require investment in equipment for processing cork and coffee grounds, special granulation devices and professional paving equipment, the extension of the service life of the runway, the reduction of maintenance costs and the improvement of performance efficiency of the venue can reduce the overall cost by more than 30% in the long run, with good economic benefits.

[0073] The above describes the preferred embodiments of the invention in detail. It should be understood that those skilled in the art can make many modifications and changes without creative effort based on the concept of the invention. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment based on the existing technology according to the concept of the invention should be within the protection scope determined by the claims.

Claims

1. A composite material spherical particle for paving ground, characterized in that, The composite material spherical particles contain three components: cork particles, coffee grounds powder, and polyurethane. The composite material spherical particles have a core-shell structure: the cork particles are located in the middle of the composite material spherical particles, and the coffee grounds and polyurethane are uniformly coated on the surface of the cork particles.

2. The composite material spherical particles according to claim 1, characterized in that, By weight, the cork particles account for 10% to 20% of the composite spherical particles, the coffee grounds powder accounts for 30% to 50% of the composite spherical particles, and the polyurethane accounts for 30% to 50% of the composite spherical particles, totaling 100%.

3. The composite material spherical particles according to claim 1, characterized in that, The particle size range of the spherical particles of the composite material is 5 to 10 mm.

4. The method for preparing composite spherical particles according to claim 1, comprising the following steps: Step 1: Remove impurities from the cork, crush it, sieve out cork particles of appropriate size range, and dry them for later use. Step 2: First, defatt the coffee grounds, then sift out coffee ground powder with a suitable particle size range, and dry it for later use. Step 3: Granulate the cork particles in a centrifugal granulator so that the polyurethane and coffee grounds powder gradually and evenly coat the cork particles to obtain a semi-finished product of composite material spherical particles. Step 4: Heat the above semi-finished product in a microwave heating device to cure the polyurethane and obtain the spherical particles of the composite material.

5. The method for preparing composite spherical particles according to claim 4, characterized in that, The cork particles mentioned in step 1 have a particle size range of 1 to 10 mm, and the coffee grounds powder mentioned in step 2 has a particle size range of 20 to 200 mesh.

6. The method for preparing composite spherical particles according to claim 5, characterized in that, The cork particles mentioned in step 1 have a particle size range of 2 to 5 mm, and the coffee grounds powder mentioned in step 2 has a particle size range of 100 to 200 mesh.

7. The method for preparing composite spherical particles according to claim 5, characterized in that, The granulation process described in step 3 includes the following sub-steps: Step 3.1: The coffee grounds powder is evenly spread on the feed tray of the centrifugal granulator; Step 3.2: The cork particles are evenly spread on the coffee grounds powder; Step 3.2: Liquid polyurethane is sprayed from the atomizing spray nozzle of the centrifugal granulator onto the material tray. As the material tray rotates eccentrically, the liquid polyurethane, carrying coffee grounds powder, gradually coats the surface of the cork particles, resulting in a semi-finished product of the composite material spherical particles.

8. The method for preparing composite spherical particles according to claim 5, characterized in that, The heating temperature of the microwave heating device in step 4 is 80-120°C, and the heating time is 10-30 minutes.

9. A method of using composite material spherical particles for paving floors, characterized in that, Includes the following steps: Step a: The plate heating device is placed on the ground to be paved, and the plate heating device has an inclined heating plate; Step b: First, turn on the heating function of the heating plate to preheat it. Then, place the composite material spherical particles at the high end of the heating plate. The composite material spherical particles are heated and rolled to the ground to be paved. Step c: Immediately compact the composite material spherical particles that have fallen onto the ground to be paved to complete the paving.

10. The method of using the composite material spherical particles according to claim 9, characterized in that, The tilt angle of the heating plate can be adjusted from 5 to 30 degrees, and the heating temperature of the heating plate is from 50 to 150°C.