A semi-preformed polyurethane runway mat material and method of making same

Abstract

The application relates to the technical field of sports ground materials, and discloses a semi-precast polyurethane runway cushion material and a manufacturing method thereof. The material is prepared by reacting an isocyanate component (MDI-50, polyether 5000) with a polyether component (polyether 2000, polyether 5000, etc.), and is once formed into an 8mm-thick coiled material through a micro-foaming process, and the performance meets the national standard requirements such as impact absorption of 35-50% and vertical deformation of 0.6-3mm. The manufacturing method comprises vacuum dehydration preparation of the isocyanate and the polyether component, a laminating machine forming process, and the formation of an integral structure without a splicing joint through on-site fixing by a polyurethane adhesive and scraping and coating of a reinforcing layer. The advantages of the application are as follows: factory production solves the performance fluctuation problem of cast-in-place type, a full-polyurethane system eliminates hidden troubles such as splicing joints and delamination, the adhesive strength with a bottom layer / surface layer is greater than or equal to 0.5MPa, the production efficiency is improved by 30%, the comprehensive cost is reduced by 15-20%, and the application has environmental protection and economy.

Description

Technical Field

[0001] This invention relates to the field of sports venue materials technology, specifically a semi-prefabricated polyurethane running track underlayment material and its manufacturing method. Background Technology

[0002] With the improvement of sports venue construction standards, especially the implementation of the new national standard "Synthetic Material Surface Sports Fields for Primary and Secondary Schools" (GB 36246-2018) by the Ministry of Education, the market has placed higher demands on the physical stability, environmental friendliness, and durability of synthetic running tracks. Currently, traditional running track materials mainly suffer from the following technical challenges:

[0003] 1. Performance fluctuation issues of cast-in-place polyurethane running tracks

[0004] Cast-in-place polyurethane running tracks require on-site mixing of raw materials before construction. Their performance is significantly affected by construction conditions (such as material ratios, construction techniques, and climate) and the skill level of the personnel. On-site construction leads to substantial deviations in physical properties at different locations within the same site; for example, key indicators such as impact absorption and vertical deformation can fluctuate by 15%-20%, making it difficult to guarantee consistent track performance. Furthermore, on-site construction procedures are complex, highly dependent on the environment, and present significant challenges in controlling the construction period and quality.

[0005] 2. Joints and aging defects in fully prefabricated rubber roll running tracks

[0006] Although precast rubber rolls are manufactured in factories and offer superior performance stability compared to cast-in-place rolls, on-site construction requires splicing the rolls with adhesives, inevitably resulting in seams. Over time, the aging of the rubber material leads to shrinkage and cracking at these seams, causing delamination, bulging, and other problems. This not only affects the aesthetics of the track but also reduces its mechanical properties and lifespan. Related tests show that after 5000 cycles of rolling, the seam width of precast rubber rolls increases by 0.5-1 mm, and the interlayer bond strength significantly decreases.

[0007] 3. Adhesion compatibility defects of traditional semi-prefabricated subfloor layers

[0008] Existing semi-precast runway underlayment materials mostly use non-polar rubber materials, which are incompatible with the polarity of the underlying base (such as asphalt or cement) and the surface polyurethane materials. This results in insufficient interlayer bonding strength (typically <0.5MPa), making them prone to peeling and bulging after long-term use. In addition, non-polyurethane semi-precast underlayment materials cannot form chemical cross-links with the polyurethane reinforcement layer applied on-site, making it difficult to achieve overall structural stability.

[0009] 4. Upgrading of industry demand for high-performance runway materials

[0010] Existing technologies suffer from unstable performance of cast-in-place running tracks, potential risks associated with the seams of fully prefabricated roll materials, and bonding defects in traditional semi-prefabricated subfloor layers. These issues fail to meet the durability, safety, and environmental requirements of professional sports venues. The market urgently needs a running track material that combines the precision of factory prefabrication with the integrity of on-site construction to address issues such as performance fluctuations, seam aging, and interlayer delamination in existing technologies, while simultaneously meeting the stringent environmental and physical performance standards of the new national standards.

[0011] Based on the above background, this invention proposes a semi-prefabricated polyurethane runway underlayment material and its manufacturing method. Through the design of a full polyurethane system, micro-foaming process and industrial molding technology, a runway structure with stable performance, no splicing seams and high bonding strength is achieved, filling the gap in the existing technology. Summary of the Invention

[0012] The technical problem to be solved by this invention is to overcome the drawbacks of cast-in-place polyurethane running tracks, which suffer from unstable performance (especially physical properties) due to on-site construction and large performance deviations at different locations within the same site, as well as the defects of fully prefabricated rubber roll running tracks, such as splicing seams and easy delamination and bulging due to aging. At the same time, it solves the problem of poor adhesion between existing semi-prefabricated underlayment materials and the bottom and surface layers due to the use of non-polar rubber materials. The invention provides a semi-prefabricated polyurethane running track underlayment material with stable performance, no splicing seams, and good adhesion to surrounding materials, as well as its manufacturing method.

[0013] The technical solution adopted in this invention is: a semi-prefabricated polyurethane running track underlay material, prepared by reacting isocyanate component and polyether component, wherein:

[0014] The isocyanate component is prepared from the following raw materials in parts by weight: 100-120 parts MDI-50, 50-80 parts polyether 5000;

[0015] The polyether component is prepared from the following raw materials in parts by weight: 140-220 parts polyether 2000, 650-850 parts polyether 5000, 20-30 parts ethylene glycol, 5-7 parts foaming agent, 0.8-1.4 parts triethylenediamine, 0.3-0.5 parts stannous octoate, and 2-4 parts foaming agent;

[0016] The thickness of the padding material is 8mm, and the performance indicators meet the following requirements: impact absorption 35-50%, vertical deformation 0.6-3mm, tensile strength ≥0.5MPa, and elongation at break ≥40%.

[0017] As a further aspect of the present invention: the foaming agent is an organosilicon foaming agent, and the foaming agent is one or a combination of physical foaming agents or chemical foaming agents.

[0018] As a further aspect of the present invention: the cushioning material is a full polyurethane system, which is formed in one step through a micro-foaming process, and there are no splicing seams after it is bonded to the polyurethane reinforcing layer during on-site construction.

[0019] A method for manufacturing a semi-prefabricated polyurethane runway underlayment material includes the following steps:

[0020] S1, Preparation of the isocyanate component:

[0021] Pump the prescribed amount of polyether 5000 into the reactor, heat to 100℃, turn on the vacuum degree ≥-80KPa, and dehydrate at 100-115℃ for ≥60 minutes;

[0022] Cool down to below 90℃, add MDI-50, control the temperature at 85-90℃, and keep the reaction at this temperature for ≥60 minutes;

[0023] Cool the material down to 70℃, and after it passes the inspection, unload and package it.

[0024] S2, Preparation of polyether components:

[0025] Add the prescribed amounts of polyether 2000, polyether 5000, and ethylene glycol to the reactor, heat and stir until homogeneous, then disperse at high speed for about 30 minutes.

[0026] Heat to 100℃, turn on the vacuum degree ≥-80KPa, and dehydrate at 100-105℃ for ≥60 minutes;

[0027] Cool to 70℃, add foaming agent and foaming agent, stir for 10 minutes, then discharge and package.

[0028] S3, Laminating machine for producing roll underlayment:

[0029] The isocyanate component and polyether component are injected into the laminator storage tank at a ratio of curing agent to prepolymer of 1:3. The material flow rate and the laminator sheet thickness are set, and the laminator is started to form an 8mm thick semi-prefabricated polyurethane runway mat layer in one step.

[0030] As a further aspect of the present invention: the dehydration process in S1 and S2 needs to remove the moisture from the raw materials through vacuum treatment to ensure that the water content of the system is ≤0.05%.

[0031] As a further aspect of the present invention: the thickness error of the sheet produced by the S3 medium laminator is controlled within ±0.1mm, and the micro-foaming process is achieved through the tracked laminator during the molding process, so that a uniform closed-cell structure is formed inside the padding material.

[0032] As a further aspect of the present invention: during on-site construction, the subbase material is first fixed to the base surface with polyurethane adhesive, and then a 2-3mm thick polyurethane reinforcing layer is scraped on to finally form an integral, seamless track structure.

[0033] As a further aspect of the present invention: the cushioning material prepared by reacting the isocyanate component and the polyether component has an impact absorption performance of 39.41-39.62%, a vertical deformation of 1.27-1.64 mm, a tensile strength of 1.29-1.64 MPa, and an elongation at break of 90.25-91.80%.

[0034] The beneficial effects of this invention are:

[0035] 1. Breakthrough in performance stability: The subbase material is formed in one step in the factory using a tracked laminator. The density and pore structure are precisely controlled by polyurethane micro-foaming technology, which stabilizes the impact absorption performance at 39.41-39.62%, vertical deformation at 1.27-1.64mm, tensile strength at 1.29-1.64MPa, and elongation at break at 90.25-91.80%. All indicators are better than the requirements of the national standard GB36246-2018, which completely solves the performance fluctuation problem caused by on-site construction of cast-in-place running tracks.

[0036] 2. Seamless Structure Advantages: After the 8mm thick semi-prefabricated subbase is fixed on-site with polyurethane adhesive, a 2-3mm polyurethane reinforcement layer is applied to form a continuous, integral runway base layer, eliminating the potential risks associated with seams in fully prefabricated rubber rolls. Long-term use has proven that this structure exhibits no delamination or bulging, avoiding performance degradation caused by seam aging and improving the runway's durability and aesthetics.

[0037] 3. Full polyurethane system compatibility: The padding material is formed by reacting polyurethane prepolymer with polyether components. It is a polarly compatible polyurethane system with the bottom adhesive and the top reinforcing layer, with an adhesion strength ≥0.5MPa. This solves the problem of polar incompatibility between traditional rubber semi-prefabricated padding and polyurethane materials, and eliminates the risk of interlayer delamination from the material's inherent nature.

[0038] 4. Convenience of industrialized production and construction: The standardized preparation process of isocyanate and polyether components enables mass production. The automated molding process of the laminator controls the thickness error within ±0.1mm, and the production efficiency is more than 30% higher than that of cast-in-place type. On-site construction only requires two processes: bonding and scraping. There is no need for complicated mixing and on-site proportioning, which reduces the technical threshold of construction and dependence on climate conditions, and shortens the construction period.

[0039] 5. Balance between environmental protection and cost-effectiveness: The material system does not contain heavy metals or volatile harmful substances, meeting the new national environmental protection standards; at the same time, due to the reduction of on-site material waste and later maintenance costs, the overall cost is reduced by 15-20% compared to a fully prefabricated rubber track, combining functionality and economy. Attached Figure Description

[0040] Figure 1 This is a mixing diagram of the cast-in-place polyurethane running track material during construction, which is a semi-prefabricated polyurethane running track underlayment material and its manufacturing method according to the present invention.

[0041] Figure 2 This is a scraping diagram of the cast-in-place polyurethane running track material during construction, which is a semi-prefabricated polyurethane running track underlayment material and its manufacturing method according to the present invention.

[0042] Figure 3 This is a picture of the completed bottom layer of the cast-in-place polyurethane running track material, which is a semi-prefabricated polyurethane running track underlayment material and its manufacturing method according to the present invention.

[0043] Figure 4 This is an overall view of the completed cast-in-place polyurethane running track material, which is a semi-prefabricated polyurethane running track underlayment material and its manufacturing method according to the present invention.

[0044] Figure 5 This is a shrinkage diagram of the splicing joint of a prefabricated rubber track roll material, which is a semi-prefabricated polyurethane track underlayment material and its manufacturing method according to the present invention.

[0045] Figure 6 This image shows a prefabricated rubber track roll material of a semi-prefabricated polyurethane track underlayment material and its manufacturing method, which has delamination and bulging caused by poor adhesion or aging.

[0046] Figure 7 This is a construction drawing of the on-site bonding of a semi-prefabricated polyurethane runway underlayment material and its manufacturing method according to the present invention.

[0047] Figure 8 This is a completed construction drawing of a semi-prefabricated polyurethane runway underlayment material and its manufacturing method according to the present invention.

[0048] Figure 9 This is a completed construction diagram of a semi-prefabricated polyurethane running track reinforcement layer, which is a semi-prefabricated polyurethane running track underlayment material and its manufacturing method according to the present invention.

[0049] Figure 10 This is a completed semi-prefabricated polyurethane runway surface layer diagram of the present invention, which describes a semi-prefabricated polyurethane runway underlayment material and its manufacturing method.

[0050] Figure 11 This is a chart showing the performance test data of a semi-prefabricated polyurethane runway underlayment material and its manufacturing method according to the present invention.

[0051] Figure 12 This is a chart showing the test data of a semi-prefabricated polyurethane running track subbase material and its manufacturing method according to the present invention.

[0052] Figure 13This is a flowchart illustrating the isocyanate component production process of a semi-prefabricated polyurethane runway underlayment material and its manufacturing method according to the present invention.

[0053] Figure 14 This is a flowchart illustrating the production process of the polyether component in a semi-prefabricated polyurethane runway underlayment material and its manufacturing method according to the present invention. Detailed Implementation

[0054] The present invention will be further described below.

[0055] Please see Figure 1-14

[0056] I. Raw material ratios (parts by weight) for Examples 1-3

[0057]

[0058] II. Common Manufacturing Process Steps in the Examples

[0059] Preparation of isocyanate components:

[0060] Add polyether 5000 to the reactor, heat to 100℃, vacuum degree ≥-80KPa, and dehydrate at 105℃ for 60 minutes;

[0061] Cool to 85℃, add MDI-50, and maintain the temperature for 60 minutes;

[0062] After cooling to 70℃ and passing the inspection, the material is discharged.

[0063] Preparation of polyether components:

[0064] Add polyether 2000, polyether 5000, and ethylene glycol to the reactor, heat to 80°C and stir until homogeneous, then disperse at high speed for 30 minutes;

[0065] Heat to 100℃, vacuum degree ≥ -80KPa, and dehydrate at 102℃ for 60 minutes;

[0066] Cool to 70℃, add foaming agent and foaming agent, stir for 10 minutes and then discharge.

[0067] Lamination process:

[0068] The isocyanate component and the polyether component are mixed in a curing agent:prepolymer ratio of 1:3 and injected into a laminator;

[0069] The sheet thickness is set to 8mm (error ±0.1mm), the temperature of the track laminator is 120℃, and the pad layer is formed in one step.

[0070] III. Comparison of Performance Test Data from Examples

[0071]

[0072] IV. Comparative Analysis of Implementation Examples

[0073] 1. Raw material ratio and performance stability:

[0074] Isocyanate component: Increasing the MDI-50 content (Example 3) can improve the tensile strength (1.64MPa), but when the polyether 5000 is reduced to 50 parts, the vertical deformation decreases to 1.27mm, indicating that increasing the proportion of isocyanate will slightly increase the material hardness, but it is still within the national standard range.

[0075] Polyether component: Increasing the content of polyether 2000 (220 parts in Example 3) can improve the elongation at break (91.80%) because polyether 2000 has a lower molecular weight and better flexibility; while when the content of polyether 5000 is high (850 parts in Example 2), the impact absorption is slightly lower (39.41%), but still meets the requirements.

[0076] 2. The influence of foaming agent type:

[0077] Example 3 uses a chemical foaming agent (azodicarbonamide), which, compared with the physical foaming agent (n-pentane) used in Examples 1-2, has a more uniform internal closed-cell structure and reduces vertical deformation to 1.27 mm, demonstrating that chemical foaming agents can optimize pore structure and improve material resilience.

[0078] 3. Construction compatibility verification:

[0079] The bonding strength between the pad and the polyurethane reinforcement layer in all three embodiments is ≥0.68MPa, which is higher than the implicit bonding requirements of the national standard. This indicates that the all-polyurethane system can guarantee the interlayer bonding force under different ratios, thus solving the bonding defects of the rubber pad.

[0080] 4. Selection of the best implementation method:

[0081] Example 1 exhibits balanced performance indicators (impact absorption 39.58%, tensile strength 1.56 MPa), with the raw material ratio at an intermediate value, resulting in optimal production stability and suitability for large-scale industrial production.

[0082] Example 3 exhibits the best tensile strength and elongation at break, making it suitable for surfaces with higher tear resistance requirements (such as high-frequency professional running tracks).

[0083] Example 2 has lower raw material costs (minimum MDI-50 usage), which can reduce costs while meeting performance requirements, making it suitable for primary and secondary school sites with limited budgets.

[0084] V. Conclusions of Comparison between the Examples and Prior Art

[0085] 1. Compared with cast-in-place running tracks: The performance deviation rate of the example is ≤3% (such as only 0.21% for impact absorption fluctuation), which is much lower than the 15-20% deviation caused by on-site construction of cast-in-place tracks, verifying the stability of factory production.

[0086] 2. Comparison with fully prefabricated rubber rolls: The example shows no seams after on-site construction, and the bonding strength is more than 40% higher than that of rubber rolls. After 5,000 cycles of rolling tests, there is no delamination, while the seam width of rubber rolls increases by 0.5-1mm under the same test.

[0087] 3. Summary of technical advantages: This invention achieves a balance of impact absorption, elasticity and strength with an 8mm pad thickness through optimized raw material ratio and micro-foaming process. Different embodiments can be adapted to diverse scenario requirements, combining technical innovation and engineering practicality.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A semi-prefabricated polyurethane running track underlayment material, characterized in that: It is prepared by reacting isocyanate component and polyether component, wherein: The isocyanate component is prepared from the following raw materials in parts by weight: 100-120 parts MDI-50, 50-80 parts polyether 5000; The polyether component is prepared from the following raw materials in parts by weight: 140-220 parts polyether 2000, 650-850 parts polyether 5000, 20-30 parts ethylene glycol, 5-7 parts foaming agent, 0.8-1.4 parts triethylenediamine, 0.3-0.5 parts stannous octoate, and 2-4 parts foaming agent; The thickness of the padding material is 8mm, and the performance indicators meet the following requirements: impact absorption 35-50%, vertical deformation 0.6-3mm, tensile strength ≥0.5MPa, and elongation at break ≥40%.

2. The semi-prefabricated polyurethane track underlayment material according to claim 1, characterized in that: The foaming agent is an organosilicon foaming agent, and the foaming agent is one or a combination of physical foaming agents or chemical foaming agents.

3. The semi-prefabricated polyurethane track underlayment material according to claim 1, characterized in that: The cushioning material is a full polyurethane system, which is formed in one step through a micro-foaming process. When it is bonded to the polyurethane reinforcing layer during on-site construction, there are no splicing seams.

4. A method for manufacturing a semi-prefabricated polyurethane running track underlay material, characterized in that: Includes the following steps: S1, Preparation of the isocyanate component: Pump the prescribed amount of polyether 5000 into the reactor, heat to 100℃, turn on the vacuum degree ≥-80KPa, and dehydrate at 100-115℃ for ≥60 minutes; Cool down to below 90℃, add MDI-50, control the temperature at 85-90℃, and keep the reaction at this temperature for ≥60 minutes; Cool the material down to 70℃, and after it passes the inspection, unload and package it. S2, Preparation of polyether components: Add the prescribed amounts of polyether 2000, polyether 5000, and ethylene glycol to the reactor, heat and stir until homogeneous, then disperse at high speed for about 30 minutes. Heat to 100℃, turn on the vacuum degree ≥-80KPa, and dehydrate at 100-105℃ for ≥60 minutes; Cool to 70℃, add foaming agent and foaming agent, stir for 10 minutes, then discharge and package. S3, Laminating machine for producing roll underlayment: The isocyanate component and polyether component are injected into the laminator storage tank at a ratio of curing agent to prepolymer of 1:

3. The material flow rate and the laminator sheet thickness are set, and the laminator is started to form an 8mm thick semi-prefabricated polyurethane runway mat layer in one step.

5. The method for manufacturing a semi-prefabricated polyurethane track underlay material according to claim 4, characterized in that: The dehydration processes in S1 and S2 require vacuum treatment to remove moisture from the raw materials, ensuring that the system moisture content is ≤0.05%.

6. The method for manufacturing a semi-prefabricated polyurethane track underlay material according to claim 4, characterized in that: The thickness error of the sheet produced by the S3 medium laminator is controlled within ±0.1mm. During the molding process, the micro-foaming process is achieved through the tracked laminator, so that a uniform closed-cell structure is formed inside the padding material.

7. The semi-prefabricated polyurethane track underlayment material according to claim 1, characterized in that: During on-site construction, the subbase material is first fixed to the base surface with polyurethane adhesive, and then a 2-3mm thick polyurethane reinforcement layer is applied to form a seamless track structure.

8. The method for manufacturing a semi-prefabricated polyurethane track underlay material according to claim 4, characterized in that: The cushioning material prepared by reacting the isocyanate component and the polyether component has an impact absorption performance of 39.41-39.62%, a vertical deformation of 1.27-1.64 mm, a tensile strength of 1.29-1.64 MPa, and an elongation at break of 90.25-91.80%.

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