High-stability weather-resistant prefabricated rubber track and preparation process thereof

Abstract

This invention discloses a highly stable, weather-resistant precast rubber running track and its manufacturing process, belonging to the field of sports field materials technology. The track is composite-molded from a wear-resistant and weather-resistant surface layer, a highly elastic buffer middle layer, and a stable support bottom layer. The surface layer uses a modified rubber matrix compounded with weather-resistant additives and wear-resistant fillers; the middle layer combines resilience and deformation resistance; and the bottom layer incorporates an anti-slip and stable structure. The three layers are integrally hot-pressed and vulcanized. The manufacturing process optimizes the mixing, vulcanization, and molding steps, introducing gradient vulcanization and interfacial cross-linking processes to improve the interlayer bonding strength, high and low temperature resistance, and aging resistance of the track. This invention solves the problems of easy aging and cracking, interlayer delamination, and deformation instability in traditional precast rubber running tracks. It significantly extends the outdoor service life of the track, maintains stable mechanical properties, is suitable for various outdoor sports fields, and is convenient to construct, environmentally friendly, and odorless.

Description

Technical Field

[0001] This invention relates to the field of sports field paving materials, specifically to a highly stable and weather-resistant precast rubber running track and its preparation process. Background Technology

[0002] Precast rubber running tracks are widely used in schools, stadiums, and outdoor sports fields due to their advantages of quick construction, environmental friendliness, and stable physical properties. However, most precast rubber running tracks on the market currently use single-layer or double-layer rubber structures, which have several technical defects: First, the surface layer of the track is exposed to the outdoor environment for a long time, subjected to ultraviolet radiation, rain erosion, and alternating high and low temperatures, making it prone to aging, fading, cracking, and powdering, resulting in poor weather resistance. Second, the layers are simply pressed and bonded together without an interfacial cross-linking structure, which easily leads to interlayer peeling and warping after long-term use, reducing the overall stability of the track. Third, the single-layer support structure has insufficient resistance to compression and deformation, easily causing indentation and decreased flatness after long-term pressure, affecting the performance during sports activities. Fourth, traditional manufacturing processes often use a single high-temperature vulcanization, which easily leads to uneven cross-linking within the rubber, large fluctuations in mechanical properties, short product lifespan, and high maintenance costs.

[0003] While existing technologies improve track performance by optimizing rubber formulations, they fail to simultaneously address the three core issues of weather resistance, interlayer stability, and structural compressive strength. Furthermore, the manufacturing process lacks gradient curing and interfacial reinforcement, making it difficult to meet the demands of long-term outdoor use. Therefore, developing a precast rubber running track with high stability, strong weather resistance, and robust interlayer bonding, coupled with an efficient and controllable manufacturing process, has become a pressing technical challenge in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to solve the following technical problems: 1. Overcoming the defects of traditional precast rubber running tracks, such as poor weather resistance, easy aging, cracking, and powdering outdoors, and improving the track's outdoor resistance to ultraviolet rays, high and low temperatures, and rain erosion; 2. Solving the problem of weak interlayer bonding and easy peeling and lifting, strengthening the interlayer interface bonding, and improving the overall structural stability of the track; 3. Optimizing the bottom support structure, improving the track's resistance to compression and deformation, and avoiding long-term use leading to a decrease in flatness and denting deformation; 4. Improving the traditional vulcanization preparation process to achieve uniform cross-linking of rubber, improve product performance consistency, and extend the track's service life.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention relates to a highly stable and weather-resistant precast rubber running track, which is a three-layer composite precast roll structure, consisting of a wear-resistant and weather-resistant surface layer, a highly elastic cushioning middle layer, and a stable supporting bottom layer from top to bottom. Each layer uses a differentiated rubber formula, taking into account the wear and weather resistance of the surface layer, the cushioning and rebound of the middle layer, and the compressive strength and stability of the bottom layer. The layers are chemically bonded through an interfacial crosslinking agent and a hot-pressing process, preventing interlayer delamination and resulting in a compact and stable overall structure.

[0007] The wear-resistant and weather-resistant surface layer uses modified styrene-butadiene rubber and ethylene propylene diene monomer (EPDM) rubber as the blend matrix. The excellent weather resistance and aging resistance of EPDM rubber, combined with the wear resistance of modified styrene-butadiene rubber, achieves a balance in surface layer performance. It is compounded with hindered phenolic antioxidants and UV absorbers to provide double protection against UV rays and environmental aging. The addition of nano-silica and colored wear-resistant powder enhances the wear resistance and color fastness of the surface layer. The surface layer thickness is controlled at 3-6mm to ensure wear resistance, slip resistance, and a good feel during sports activities.

[0008] The high-elasticity cushioning middle layer uses a blend of butadiene rubber and natural rubber, which has excellent elasticity and resilience, effectively absorbing the impact of sports and protecting athletes' joints. The interior is uniformly embedded with elastic reinforcing fibers, which enhances the middle layer's tensile and deformation resistance, preventing the middle layer from collapsing under long-term stress. The thickness is set at 8-12mm, balancing cushioning effect and structural support.

[0009] The stable support bottom layer is a high-strength, pressure-resistant rubber layer, using a highly cross-linked rubber formula, which has high compressive strength and is not easily deformed; the bottom is equipped with a matrix of evenly distributed anti-slip and stabilizing protrusions, which can not only enhance the friction between the track and the ground and prevent displacement after installation, but also improve the heat dissipation and drainage performance of the bottom layer, preventing water accumulation at the bottom from eroding the track. The height of the protrusions is controlled at 2-4mm to ensure the stability of the support.

[0010] The preparation process of this invention is a customized gradient vulcanization process for three-layer composite structures. The entire process is divided into five major steps: raw material mixing, hot refining and preforming, interlayer compounding, gradient vulcanization, and cooling and cutting. Low-temperature mixing avoids premature cross-linking of raw materials, interlayer coating with interface cross-linking agent strengthens the bonding force, and gradient temperature and pressure vulcanization ensures that the rubber is fully and uniformly cross-linked, avoiding local over-vulcanization or under-vulcanization, and improving the overall performance stability of the track.

[0011] The present invention has the following advantages over the prior art:

[0012] 1. Significantly improved weather resistance: The surface layer adopts a weather-resistant rubber blend system and is compounded with special weather-resistant and anti-aging additives, which can resist ultraviolet rays, high and low temperatures and rain erosion for a long time. The track is not easy to age, fade, crack or powder, and its outdoor service life is extended by more than 40% compared with traditional tracks.

[0013] 2. The overall structure is extremely stable: the three layers are chemically bonded through interfacial cross-linking, and with the hot-press curing process, the interlayer bonding force is extremely strong, and there are no peeling, lifting or delamination problems after long-term use; the bottom layer has a matrix-style anti-slip protrusion, which improves the stability of the track laying, is not easy to shift or deform, and the flatness meets the standard for a long time.

[0014] 3. Excellent and balanced mechanical properties: The surface layer is wear-resistant and slip-resistant, the middle layer is highly elastic and cushioning, and the bottom layer is pressure-resistant and supportive. The three layers complement each other, which not only meet the elasticity and slip resistance requirements of professional sports, but also have extremely strong pressure resistance, deformation resistance and impact resistance. There are no problems of dents or collapses after long-term use.

[0015] 4. Scientific and controllable preparation process: The gradient vulcanization process ensures uniform cross-linking within the rubber, resulting in high product performance consistency and no local performance defects. The process is suitable for industrial mass production, with high production efficiency, high yield, environmentally friendly and odorless track, and convenient and quick construction and installation.

[0016] 5. Wide range of applicable scenarios: It can be adapted to various outdoor sports venues, is not afraid of the impact of extreme weather, has extremely low maintenance costs, and combines practicality, durability and economy, meeting the paving standards of various sports venues.

[0017] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic cross-sectional view of the prefabricated rubber track of the present invention.

[0020] The attached diagram lists the components represented by each number as follows:

[0021] 1—Abrasion-resistant and weather-resistant surface layer; 2—High-elasticity buffer middle layer; 21—Elastic reinforcing fiber; 3—Stable support bottom layer; 31—Anti-slip and stable protrusion. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] 1. Raw material ratio (parts by weight)

[0025] Wear-resistant and weather-resistant surface layer 1: 60 parts modified styrene-butadiene rubber, 40 parts ethylene propylene diene monomer (EPDM) rubber, 2 parts composite hindered phenolic antioxidant, 1 part ultraviolet absorber, 15 parts nano silica, 12 parts colored wear-resistant powder, 3 parts zinc oxide, 1 part stearic acid, 1.5 parts vulcanizing agent, and 1 part accelerator.

[0026] High-elasticity buffer middle layer 2: 55 parts butadiene rubber, 45 parts natural rubber, 3 parts elastic reinforcing fiber, 4 parts zinc oxide, 1.2 parts stearic acid, 1.5 parts antioxidant, 10 parts reinforcing carbon black, 1.8 parts vulcanizing agent, and 1.2 parts accelerator.

[0027] Stable support layer 3: 80 parts of highly cross-linked styrene-butadiene rubber, 20 parts of butadiene rubber, 25 parts of high-strength filler, 5 parts of zinc oxide, 1.5 parts of stearic acid, 2 parts of antioxidant, 2 parts of vulcanizing agent, and 1.5 parts of accelerator.

[0028] 2. Preparation process

[0029] (1) Raw material ratio and initial mixing: Weigh the raw materials of each layer according to the above ratio, put them into the internal mixer, control the mixing temperature at 100℃ and the mixing time at 20min to obtain the compound rubber of each layer, and cool it for later use.

[0030] (2) Hot-melting preforming: The three layers of compound rubber are put into the open mill, the hot-melting temperature is controlled at 70°C, and calendered to obtain 4mm thick surface blank, 10mm thick middle blank and 5mm thick bottom blank respectively.

[0031] (3) Interlayer composite: Apply an interface crosslinking agent evenly to the upper and lower surfaces of the middle layer blank, stack the top layer blank, middle layer blank and bottom layer blank in sequence, send them into the composite molding machine, preheat at 80°C and bond for 10 minutes to form a composite blank;

[0032] (4) Gradient vulcanization molding: The composite blank is fed into a flat vulcanizing machine. The first stage vulcanization temperature is 135℃ and the pressure is 9MPa, and the temperature is held for 10min. The second stage vulcanization temperature is 155℃ and the pressure is 13MPa, and the temperature is held for 20min. The third stage is held for 5min for heat preservation and pressure setting. The total vulcanization time is 35min. At the same time, the bottom anti-slip and stable protrusion 31 is pressed.

[0033] (5) Cooling and cutting: After vulcanization, the surface is cooled to room temperature and then cut and trimmed according to standard dimensions to obtain the finished prefabricated rubber track.

[0034] Example 2

[0035] The ratio of EPDM rubber to modified styrene-butadiene rubber in the wear-resistant and weather-resistant surface layer 1 was adjusted to 50 parts, and the temperature of the second stage of gradient vulcanization was adjusted to 150℃ and the pressure to 12MPa. The remaining formula and process steps were the same as in Example 1, and the second type of finished runway was obtained.

[0036] Performance testing

[0037] The running tracks prepared in Examples 1 and 2 were compared with traditional double-layer precast rubber running tracks. The test results are as follows:

[0038] Test Project Example 1 Example 2 UV aging resistance No cracking, no fading No cracking, no fading Interlayer peel strength (N / mm) ≥8.5 ≥8.2 Compressive deformation rate (%) ≤2.0 ≤2.2 Outdoor lifespan estimate 8-10 years 7-9 years

[0039] Table 1: Test Table

[0040] Test results show that the precast rubber track of the present invention is far superior to the traditional precast rubber track in terms of weather resistance, interlayer stability, and compressive and deformation resistance, and fully meets the requirements for long-term outdoor use.

[0041] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A highly stable and weather-resistant precast rubber running track, characterized in that, From top to bottom, it includes a wear-resistant and weather-resistant surface layer (1), a high-elasticity buffer middle layer (2), and a stable support bottom layer (3). The three layers are bonded together by interfacial cross-linking and hot pressing. The wear-resistant and weather-resistant surface layer (1) is compounded with weather-resistant and anti-aging additives and wear-resistant inorganic fillers. The high-elasticity buffer middle layer (2) is a high-elasticity cross-linked rubber layer. The stable support bottom layer (3) has anti-slip and stable protrusions (31) at the bottom. The entire track is a prefabricated roll structure.

2. The high-stability, weather-resistant precast rubber running track according to claim 1, characterized in that, The wear-resistant and weather-resistant surface layer (1) is composed of a modified styrene-butadiene rubber, a blend matrix of ethylene propylene diene monomer (EPDM) rubber, a weather-resistant antioxidant, nano-silica, and colored wear-resistant powder, with a thickness of 3-6 mm.

3. The high-stability, weather-resistant precast rubber running track according to claim 1, characterized in that, The high-elasticity buffer middle layer (2) adopts a blend system of butadiene rubber and natural rubber, with elastic reinforcing fibers (21) embedded inside, and a thickness of 8-12mm.

4. The high-stability, weather-resistant precast rubber running track according to claim 1, characterized in that, The stable support bottom layer (3) is a high-strength pressure-resistant rubber layer, and the anti-slip and stable protrusions (31) are evenly distributed in a matrix, with a protrusion height of 2-4mm.

5. The high-stability, weather-resistant precast rubber running track according to claim 2, characterized in that, The weather-resistant antioxidant is a compound system of hindered phenolic antioxidant and ultraviolet absorber.

6. A manufacturing process for a highly stable and weather-resistant precast rubber running track, used to manufacture the precast rubber running track according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Raw material proportioning and initial refining: Weigh the surface layer, middle layer and bottom layer rubber raw materials according to the proportions, put the rubber matrix, filler and additives of each layer into the internal mixer and refining them at low temperature to obtain the compound rubber of each layer. (2) Hot-melting preforming: The three layers of compound rubber are hot-melted separately and then calendered into surface blanks, middle blanks and bottom blanks of corresponding thicknesses by a calender. (3) Interlayer composite: The surface blank, the middle blank and the bottom blank are stacked in sequence and sent into the composite molding machine for preheating and bonding to form a composite blank; (4) Gradient vulcanization molding: The composite blank is fed into the vulcanizing machine and the gradient heating and pressurization vulcanization process is adopted to complete the integrated cross-linking and curing, and the bottom anti-slip and stable protrusion is pressed simultaneously (31). (5) Cooling and cutting: After vulcanization, constant temperature cooling is carried out, and the prefabricated rubber track is cut and trimmed according to standard dimensions to obtain the finished product.

7. The preparation process according to claim 6, characterized in that, Step (1) The mixing temperature is controlled at 90-110℃ and the mixing time is 15-25min.

8. The preparation process according to claim 6, characterized in that, Step (4) Gradient vulcanization is divided into three stages: the first stage has a temperature of 130-140℃ and a pressure of 8-10MPa; the second stage has a temperature of 150-160℃ and a pressure of 12-15MPa; and the third stage is heat preservation and pressure setting. The total vulcanization time is 30-45min.

9. The preparation process according to claim 6, characterized in that, During interlayer lamination, an interfacial crosslinking agent is applied to the upper and lower surfaces of the middle layer blank to improve the interlayer bonding strength.

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