Environment-friendly recyclable plastic track and preparation method thereof

Abstract

The invention provides an environment-friendly recyclable plastic runway and a preparation method thereof, and belongs to the technical field of runway preparation. The polyether type foamed thermoplastic polyurethane particles are processed through a steam mold pressing process, the outermost layers of the particles are slightly melted, the particles are bonded into a whole, a polyurethane integrated material with the surface melted and bonded into a whole is obtained, and the thermoplastic polyurethane foamed coiled material can be obtained through condensation curing, demolding and airing. And directly adhering the thermoplastic polyurethane foaming coiled material to the concrete foundation brushed with the polyurethane bottom sealing glue to obtain the environment-friendly recyclable plastic track. The construction method of the plastic track is simple and convenient, free of pollution to the environment and low in cost, and has wide market prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of runway preparation, and in particular relates to an environmentally friendly and recyclable plastic runway and a preparation method thereof. Background Art

[0002] Polyurethane plastic track is currently internationally recognized as the best sports venue. It has the characteristics of good flatness, high compressive strength, appropriate hardness and elasticity, and stable physical properties. This type of venue is not only beneficial to the health of athletes, but also can improve the comfort of exercise. It is widely welcomed by sports and fitness enthusiasts. According to the type of materials used in the venue, polyurethane plastic track can be breathable, full plastic and mixed. The breathable plastic track is directly laid and cured after mixing polyurethane adhesive and EPDM (ethylene propylene diene monomer) rubber particles; the full plastic track is made of two-component polyurethane material, component A is mainly composed of prepolymer synthesized from polyether polyol and isocyanate, and component B is composed of polyether polyol, chain extender, powder filler plasticizer and other raw materials. During on-site construction, components A, B and catalyst are mixed in a certain ratio and then spread; the mixed type is to add a part of EPDM particles when mixing the components A and B of the full plastic venue and spread it.

[0003] However, the above-mentioned polyurethane plastic tracks all have the problem of requiring on-site paving and curing, complicated construction process and low efficiency. In addition, improper materials or construction operations can easily lead to quality problems such as non-curing, bulging, cracking, etc. In addition, during the site preparation process, in order to facilitate construction, a certain amount of diluent is often required to be added to the material to reduce the viscosity, which is undoubtedly not conducive to environmental protection.

[0004] With the development of materials, the concept of prefabricated plastic runway has emerged in the preparation of plastic runway. It is based on natural rubber and artificial rubber, mixed with mineral fillers, stabilizers and colorants for continuous calendering in the factory, and hardened by high temperature of 280-300℃ and vulcanized into one piece, mechanically embossed to form a double-layer structure synthetic rubber with consistent texture. Prefabricated plastic runway is suitable for university stadiums and international competition stadiums. When paving, only the provided adhesive is needed. Under a small amount of manpower and machinery, the runway roll can be laid on a dense foundation. After the runway is installed, it can be put into normal use 24 hours later. Although this prefabricated runway is convenient to use, there are still problems that the joints are difficult to completely seal and the surface cannot be formed into a consistent overall unity. In addition, various types of existing plastic runways have their own advantages and disadvantages, but the common problem is that the venue cannot be recycled and reused after reaching the service life. The runway waste removed every year is a huge pollution and waste, which is obviously not in line with the environmental protection concept of resource recycling.

[0005] E-TPU (foamed thermoplastic polyurethane) is a product processed from thermoplastic polyurethane elastomer (TPU). It is a new type of polymer material composed of countless elastic and lightweight TPU foam balls, also known as popcorn particles. Because E-TPU has the characteristics of environmental protection, ultra-light density, not easy to deform, high wear resistance, temperature change resistance and yellowing resistance, it can be used in any place where light weight, excellent mechanical properties and good durability are required within a wide temperature range. There are already cases of using E-TPU particles in plastic tracks, but the current method of use is to fill E-TPU particles in the track as a filling material, mainly used to increase the elasticity of the track and reduce the amount of other track materials. However, since E-TPU particles have a small density, they often bring a lot of trouble to the construction during use. For example, when they are filled in polyurethane materials, they are easy to float on the surface, resulting in uneven materials, poor site flatness and inconsistent elasticity. In addition, construction cannot be carried out when it is windy on site (the particles will fly all over the site), and the construction conditions are demanding. Therefore, the utilization rate of E-TPU particle materials in plastic tracks needs to be improved.

[0006] In view of the above technical problems, the present invention proposes a novel environmentally friendly and recyclable plastic track. Summary of the invention

[0007] In order to solve the above technical problems, the present invention proposes an environmentally friendly and recyclable plastic runway, which uses polyether E-TPU particles as the main raw material and is processed through a steam molding process to produce a thermoplastic polyurethane foam roll with a thickness that meets the standard of GB36246-2018. The material at the joints of the roll is heated, liquefied and fused to form a whole. After complete curing, the site construction is completed to obtain the preparation of an environmentally friendly and recyclable plastic runway.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] One of the technical solutions of the present invention:

[0010] A preparation method of a thermoplastic polyurethane foam coil comprises the following steps: processing polyether foamed thermoplastic polyurethane particles (E-TPU particles) through a steam molding process, slightly melting the outermost layer of the particles, bonding the particles to each other to form a whole, thereby obtaining a polyurethane integrated material with a melted surface and bonded to form a whole, circulating room temperature condensed water through the polyurethane integrated material in a water cooling channel of a mold, condensing and solidifying, demoulding, and placing the material indoors for natural drying, thereby obtaining the thermoplastic polyurethane foam coil.

[0011] Furthermore, the density of the polyether foamed thermoplastic polyurethane particles is 0.2 g / cm 3 -0.5g / cm 3, the expansion ratio is about 2-5 times. Small particle density means more particle pores. When stretched, the pores will become stress concentration points, resulting in fracture damage, so the strength and elongation will decrease, resulting in a decrease in the performance of the foamed coil. The expansion ratio will affect the strength of the coil. The larger the expansion ratio, the lower the strength. In order to make the foamed coil have appropriate strength, the expansion ratio is set to 2-5 times.

[0012] Furthermore, the steam molding process is specifically as follows: polyether foamed thermoplastic polyurethane particles are filled into the cavity of the mold, the upper pressing plate of the mold is a pressing plate with a pattern, steam is introduced into the cavity of the mold for molding, and a polyurethane integrated material with a melted surface and bonded into one is obtained.

[0013] Furthermore, the temperature of the steam molding is 120-140° C., and the time is greater than 200 s. The temperature and time of the steam molding are such as to ensure that the surface of the foamed particles can be melted and bonded together.

[0014] The steam molding process uses a patterned pressing plate mold to form regular patterns on the surface of the coil, thereby increasing the anti-slip value of the runway. The anti-slip value of the prepared runway meets the new national standard requirements for plastic tracks: track and field venues ≥47 (wet test); ball courts and other activity venues 80-110 (dry test) (anti-slip value BPN, 20°C).

[0015] Furthermore, the condensation and solidification is room temperature condensation, and the condensation time is greater than 120s, so as to ensure that the surfaces of the foamed particles are fused and solidified into an integrated structure.

[0016] The second technical solution of the present invention:

[0017] A thermoplastic polyurethane foam coiled material prepared by the above preparation method, the thickness of the thermoplastic polyurethane foam coiled material is 4mm-20mm, preferably 13mm-15mm.

[0018] The impact absorption of the thermoplastic polyurethane foam coil is 35-47%, the vertical deformation is 1.8-2.7mm, the tensile strength is above 1.73MPa, and the elongation at break is above 40%, which meets the requirements of GB36246-2018 standard.

[0019] The third technical solution of the present invention:

[0020] A method for preparing an environmentally friendly recyclable plastic runway comprises the following steps: after applying polyurethane sealing glue on a concrete foundation, pasting the thermoplastic polyurethane foam coiled material onto the concrete foundation applied with the polyurethane sealing glue, with the embossed side facing upward, and heating and melting the coiled material at the joint with a welding torch to liquefy and fuse its surface layer; after the polyurethane sealing glue is cured, the site is paved to obtain the environmentally friendly recyclable plastic runway.

[0021] Furthermore, the usage of the polyurethane backing glue is 0.2-0.3 kg per square meter.

[0022] Furthermore, after applying the polyurethane sealant, the thermoplastic polyurethane foam roll can be immediately pasted on the concrete foundation with the polyurethane sealant, or before the sealant is cured, that is, within 2 hours.

[0023] The fourth technical solution of the present invention:

[0024] An environmentally friendly and recyclable plastic track prepared by the above preparation method.

[0025] Compared with the prior art, the present invention has the following advantages and technical effects:

[0026] (1) Compared with the traditional polyurethane plastic track, the construction method of the plastic track of the present invention is simple and convenient, and there will be no problems such as material non-solidification, bulging, and inability to construct on rainy days. In addition, when constructing the thermoplastic polyurethane foam coil prepared by the present invention, there is no need to use various additives such as diluents, catalysts, chain extenders, etc., and there is no pollution to the environment, so that the construction site has the advantages of being healthy and environmentally friendly, low density, high strength, good rebound performance, and good wear resistance. Using E-TPU granular material as the main material and through the steam molding process can effectively solve the problem that E-TPU particles are easy to float on the surface and unevenly distributed during use, and the requirements for construction conditions are low, which broadens the use of E-TPU granular materials in plastic tracks and improves the utilization rate.

[0027] (2) Compared with the traditional method, the method of preparing an environmentally friendly and recyclable plastic track of the present invention has lower cost (using less raw materials), and the materials can be completely recovered and recycled when the site is cleared, which has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 This is a schematic diagram of the cross-sectional structure of the environmentally friendly recyclable plastic track prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] The method of brushing the polyurethane bottom sealant in the embodiment of the present invention is a conventional technical means in the field, such as using a sprayer or a brush roller to directly spray or roll, and there is no restriction on the brushing method, as long as the brushing amount per square meter is 0.2-0.3 kg.

[0036] The polyether foamed thermoplastic polyurethane particles (E-TPU particles) used in the embodiments of the present invention were purchased from Ningbo GreenMobil New Material Technology Co., Ltd.; the polyurethane backing glue was purchased from Shandong Yiborun New Material Technology Co., Ltd., model number is YD01.

[0037] The welding gun model used in the embodiment of the present invention is a brushless silent 1800W split plastic welding gun.

[0038] The room temperature in the embodiment of the present invention refers to 25±2°C.

[0039] The parts not described in detail in the embodiments of the present invention are conventional technical means in the art and are not inventive points, so they will not be described in detail.

[0040] The technical solution of the present invention is further illustrated by the following embodiments.

[0041] Example 1

[0042] White polyether foamed thermoplastic polyurethane particles (E-TPU particles, density 0.4g / cm 3 ) is filled into the cavity of the steam molding mold, the upper pressing plate of the steam molding mold is a pressing plate with a pattern, and then steam is introduced into the cavity of the steam molding mold for molding, and the molding temperature is maintained at 140°C for 220 seconds to ensure that the outermost layer of the E-TPU particles is slightly melted, and the particles are bonded to each other as a whole to obtain a polyurethane integrated material with a surface melted and bonded into one, and then room temperature condensed water is circulated in the water cooling channel of the mold for 130 seconds to ensure that the surface of the E-TPU particles is fused and solidified into an integrated structure, and the mold is demolded after condensation and solidification, and the mold is placed indoors for natural drying to obtain a thermoplastic polyurethane foam coil with a thickness of 13 mm, and the amount of raw material white polyether type foamed thermoplastic polyurethane particles per square meter of the thermoplastic polyurethane foam coil is about 5.2 kg.

[0043] Polyurethane sealant is applied on the concrete foundation, and the amount of polyurethane sealant is 0.2 kg per square meter. After standing for 1 hour, the prepared thermoplastic polyurethane foam coil is pasted to the concrete foundation with polyurethane sealant, with the embossed side facing up. After the foam coil is laid neatly, the coil at the joint is heated and melted with a welding torch to liquefy and fuse its surface. After the polyurethane sealant is cured, the site is laid to obtain an environmentally friendly recyclable plastic runway. See the schematic diagram of the cross-sectional structure. Figure 1 .

[0044] Example 2

[0045] Red polyether foamed thermoplastic polyurethane particles (E-TPU particles, density 0.2g / cm 3 ), filled into the cavity of the steam molding mold, the upper pressing plate of the steam molding mold is a pressing plate with a pattern, and then steam is introduced into the cavity of the mold for molding, and the molding temperature is maintained at 130°C for 400s to ensure that the outermost layer of the E-TPU particles is slightly melted, and the particles are bonded to each other as a whole to obtain a polyurethane integrated material with a surface melted and bonded into one, and then room temperature condensed water is circulated in the water cooling channel of the mold for 200s to ensure that the surface of the E-TPU particles is fused and solidified into an integrated structure, demolded after condensation and solidification, and placed indoors for natural drying to obtain a thermoplastic polyurethane foam coil with a thickness of 15mm, and the amount of raw material red polyether type foamed thermoplastic polyurethane particles per square meter of the thermoplastic polyurethane foam coil is about 3 kg.

[0046] Polyurethane sealing glue is applied on the concrete foundation at a dosage of 0.25 kg per square meter. After standing for 1 hour, the prepared thermoplastic polyurethane foam membrane is pasted to the concrete foundation with the polyurethane sealing glue, with the embossed side facing up. After the foam membrane is laid neatly, the membrane at the joints is heated and melted with a welding torch to liquefy and fuse its surface. After the polyurethane sealing glue is cured, the site paving is completed to obtain an environmentally friendly and recyclable plastic track.

[0047] Example 3

[0048] Green polyether foamed thermoplastic polyurethane particles (E-TPU particles, density 0.5g / cm 3 ) is filled into the cavity of the steam molding mold, the upper pressing plate of the steam molding mold is a pressing plate with a pattern, and then steam is introduced into the cavity of the mold for molding, and the molding temperature is maintained at 120°C for 300 seconds to ensure that the outermost layer of the E-TPU particles is slightly melted, and the particles are bonded to each other as a whole to obtain a polyurethane integrated material with a melted surface and bonded into one. Then, room temperature condensed water is circulated in the water cooling channel of the mold for 180 seconds to ensure that the surface of the E-TPU particles is fused and solidified into an integrated structure, and the mold is demoulded after condensation and solidification, and the mold is placed indoors for natural drying to obtain a thermoplastic polyurethane foam coil with a thickness of 15 mm, and the amount of raw material green polyether type foamed thermoplastic polyurethane particles per square meter of the thermoplastic polyurethane foam coil is about 7.5 kg.

[0049] Polyurethane sealing glue is applied on the concrete foundation at a dosage of 0.3 kg per square meter. After standing for 0.5 hours, the prepared thermoplastic polyurethane foam membrane is pasted to the concrete foundation with the polyurethane sealing glue, with the embossed side facing up. After the foam membrane is laid neatly, the membrane at the joints is heated and melted with a welding torch to liquefy and fuse its surface. After the polyurethane sealing glue is cured, the site laying is completed to obtain an environmentally friendly and recyclable plastic track.

[0050] Comparative Example 1

[0051] White polyether foamed thermoplastic polyurethane particles (E-TPU particles, density 0.1 g / cm 3) is filled into the cavity of the steam molding mold, the upper pressing plate of the steam molding mold is a pressing plate with a pattern, and then steam is introduced into the cavity of the steam molding mold for molding, and the molding temperature is maintained at 140°C for 500s to ensure that the outermost layer of the E-TPU particles is slightly melted, and the particles are bonded to each other as a whole to obtain a polyurethane integrated material with a surface melted and bonded into one, and then room temperature condensed water is circulated in the water cooling channel of the mold for 200s to ensure that the surface of the E-TPU particles is fused and solidified into an integrated structure, and the mold is demoulded after condensation and solidification, and placed indoors for natural drying to obtain a foamed coil with a thickness of 13mm, and the amount of raw material green polyether foamed thermoplastic polyurethane particles per square meter of foamed coil is about 1.3 kg.

[0052] Polyurethane sealing glue is applied on the concrete foundation at a dosage of 0.2 kg per square meter. After standing for 1 hour, the prepared thermoplastic polyurethane foam membrane is pasted to the concrete foundation with the polyurethane sealing glue, with the embossed side facing up. After the foam membrane is laid neatly, the membrane at the joints is heated and melted with a welding torch to liquefy and fuse its surface. After the polyurethane sealing glue is cured, the site paving is completed to obtain an environmentally friendly and recyclable plastic track.

[0053] Comparative Example 2

[0054] Traditional method for preparing breathable polyurethane runway elastic layer:

[0055] The single-component polyurethane glue YN1011 produced by Shandong Yiborun New Material Technology Co., Ltd. and EPDM rubber particles (Shandong Jinlu Sports Facilities Co., Ltd., with a rubber content of 15%) were mixed in a mass ratio of 1:6 and poured into a mixer to mix evenly to obtain a mixed material of EPDM and polyurethane glue;

[0056] Apply polyurethane sealing glue on the concrete foundation. The amount of polyurethane sealing glue is 0.2 kg per square meter. After standing for 1 hour, lay the above EPDM and polyurethane glue mixture to a thickness of 13 mm. After curing, it will form a breathable elastic layer.

[0057] Performance Testing

[0058] According to GB36246-2018, the performance of the foam coiled materials prepared in Examples 1-3 and Comparative Example 1 was tested, and the test results are shown in Table 1.

[0059] Table 1 Performance test results of foamed coils of examples and comparative examples

[0060]

[0061]

[0062] As can be seen from Table 1, the impact absorption of the thermoplastic polyurethane foam coil prepared in the embodiment of the present invention is 35-47%, the vertical deformation is 1.8-2.7mm, the tensile strength is above 1.73MPa, and the elongation at break is much greater than 40%, which meets the requirements of GB36246-2018. The difference between Comparative Example 1 and Example 1 is only the difference in the density of E-TPU particles. The smaller the density of E-TPU particles, the more pores there are in the particles. When stretched, the pores will become stress concentration points, resulting in fracture damage, so the strength and elongation will be reduced, resulting in a decrease in the performance of the foam coil.

[0063] The calculation results of the raw material dosage of the floor surface of the embodiment and the comparative example are shown in Table 2.

[0064] Table 2 Calculation results of total amount of raw materials used in Examples and Comparative Examples

[0065] Surface material consumption / kg Example 1 5.2 Example 2 3 Example 3 7.5 Comparative Example 1 1.3 Comparative Example 2 18.2

[0066] In the actual construction process, a mature construction worker in the embodiment of the present invention can construct in 8 hours, and the construction period is greatly shortened compared with the period of preparing the breathable polyurethane runway site by the traditional method of comparative example 2. At the same time, it can be seen from Table 2 that the cost of preparing the breathable polyurethane runway site in the embodiment of the present invention is lower than that of the traditional method of comparative example 2 (less raw materials are used); the curing process of the single-component polyurethane glue used in the traditional method is greatly affected by factors such as temperature and humidity; uneven mixing of the glue will cause local bulging; rainy days will cause the polyurethane glue to cure quickly, affecting the paving of the mixed material; in the case of high viscosity of the glue, a diluent needs to be added to the glue to reduce the viscosity of the material for good construction. The embodiment of the present invention will not have the problems of material non-solidification, bulging, and inability to construct on rainy days that occur in the traditional method, and no diluent is needed, which has the advantages of environmental protection, convenience, and easy construction.

[0067] The thermoplastic polyurethane foam coil prepared in Example 1 was tested for harmful substances. The results are shown in Table 3.

[0068] Table 3 Test results of harmful substances in thermoplastic polyurethane foam coil prepared in Example 1

[0069]

[0070] As can be seen from Table 3, the thermoplastic polyurethane foam coil prepared by the method of the present invention does not require the use of various additives such as diluents, catalysts, chain extenders, etc. during construction, so the harmful substance detection indicators are all qualified. Most importantly, compared with the traditional method, the thermoplastic polyurethane foam coil made of the plastic track can be melted and reused after recycling, and the material can be completely recovered and recycled when the site is cleared, which has broad market prospects.

[0071] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a thermoplastic polyurethane foam coil, characterized in that: The following steps are involved: The polyether type foamed thermoplastic polyurethane particles are subjected to a steam molding process to obtain a polyurethane integrated material, and the polyurethane integrated material is condensed and solidified, demolded, and allowed to stand to obtain the thermoplastic polyurethane foam coil.

2. The method for preparing a thermoplastic polyurethane foam coil according to claim 1, characterized in that: The density of the polyether foamed thermoplastic polyurethane particles is 0.2 g / cm 3 -0.5g / cm 3 , the foaming ratio is 2-5 times.

3. The method for preparing a thermoplastic polyurethane foam coil according to claim 1, characterized in that: The steam molding process is specifically as follows: polyether foamed thermoplastic polyurethane particles are filled into the cavity of a mold, the upper pressing plate of the mold is a pressing plate with a pattern, steam is introduced into the cavity of the mold for molding, and a polyurethane integrated material with a melted surface and bonded together is obtained.

4. The method for preparing a thermoplastic polyurethane foam coil according to claim 3, characterized in that: The temperature of the steam forming is 120-140° C., the time is greater than 200 s, and the time of the pre-pressing treatment is 24 h.

5. The method for preparing a thermoplastic polyurethane foam coil according to claim 1, characterized in that: The condensation solidification is room temperature condensation, and the condensation time is greater than 120s.

6. A thermoplastic polyurethane foam coil prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The thickness is 4mm-20mm.

7. A method for preparing an environmentally friendly and recyclable plastic track, characterized in that: The following steps are involved: After applying polyurethane sealing glue on the concrete foundation, the thermoplastic polyurethane foam roll material described in claim 6 is pasted to the concrete foundation with the polyurethane sealing glue, with the embossed side facing up, and the roll material at the joint is heated and melted to complete the welding. After the polyurethane sealing glue is cured, the site is paved to obtain the environmentally friendly recyclable plastic runway.

8. The method for preparing an environmentally friendly and recyclable plastic track according to claim 7, characterized in that: The usage of the polyurethane backing glue is 0.2-0.3 kg per square meter.

9. An environmentally friendly and recyclable plastic track prepared by the preparation method according to any one of claims 7-8.

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