Impact-resistant and heavy-load-resistant floor and method for manufacturing the same

Abstract

This invention provides an impact-resistant and heavy-duty floor and its preparation method. The floor includes a wear-resistant layer, a composite core layer, and a substrate layer, which are fixedly connected from top to bottom. The composite core layer includes an integrally formed elastic skeleton with multiple arched portions. The composite core layer also includes polyurethane foam material filling a portion of the internal cavity of the arched portions and the outer portion of the arched portions. The polyurethane foam material in the arched portions and the outer portion of the arched portions is connected to the wear-resistant layer, and the elastic skeleton is connected to the substrate layer. The stiffness of the elastic skeleton is greater than or equal to the stiffness of the polyurethane foam material.

Description

Technical Field

[0001] This invention relates to the field of flooring technology, and in particular to an impact-resistant and heavy-pressure-resistant floor and its preparation method. Background Technology

[0002] As industrial, commercial, and sports venues place increasingly higher demands on the performance of flooring materials, flooring not only needs to possess excellent wear resistance and aesthetics, but also needs to maintain structural integrity and long-term stability under harsh conditions such as heavy impacts, forklift crushing, and static loads from equipment. Traditional flooring typically uses a single material (such as PVC, rubber, epoxy resin, etc.) or a simple multi-layer composite structure, making it difficult to simultaneously meet the dual requirements of high impact resistance and high pressure resistance.

[0003] In existing technologies, impact energy is absorbed by incorporating elastic layers (such as foam layers), but these layers are prone to permanent creep and indentation under long-term heavy pressure. While rigid layers (such as stone-plastic or metal layers) can improve resistance to heavy pressure, they cannot effectively absorb impacts and are prone to brittle cracking. Therefore, there is an urgent need for a floor structure that combines high impact resistance with high resistance to heavy pressure. Summary of the Invention

[0004] This invention provides an impact-resistant and heavy-pressure resistant floor and its preparation method. By synergistically combining an elastic skeleton with polyurethane foam material, a mechanical mechanism of "skeleton-led load bearing and foam-assisted buffering" is achieved, solving the technical problem that existing flooring is difficult to balance impact resistance and heavy-pressure resistance.

[0005] An impact-resistant and heavy-duty flooring includes, from top to bottom, a wear-resistant layer, a composite core layer, and a substrate layer, fixedly connected. The composite core layer includes an integrally molded elastic skeleton with multiple arched portions. The composite core layer also includes polyurethane foam material filling a portion of the internal cavity of the arched portions and the outer portion of the arched portions. The polyurethane foam material in the arched portions and the outer portion of the arched portions is connected to the wear-resistant layer, and the elastic skeleton is connected to the substrate layer. The stiffness of the elastic skeleton is greater than or equal to the stiffness of the polyurethane foam material.

[0006] Preferably, the polyurethane foam material fills the bottom region of the internal cavity of the arched portion, with the filling height accounting for 30%-50% of the total height of the internal cavity, and the top of the internal cavity is an empty cavity or filled with a filling material with a stiffness less than that of the polyurethane foam material.

[0007] Preferably, the arched portions of the elastic skeleton are arranged in a periodic array, forming arched ribs or domes; connecting ribs are provided between adjacent arched portions, and the connecting ribs are covered with polyurethane foam material in the outer region.

[0008] Preferably, the elastic skeleton is made of polyurethane elastomer or thermoplastic elastomer with an elastic modulus of 150-300 MPa; the polyurethane foam material has a compression modulus of 20-100 MPa.

[0009] Preferably, the polyurethane foam material includes a first polyurethane foam covering a portion of the internal cavity of the arch and the outer region of the arch, and a second polyurethane foam covering the first polyurethane foam, wherein the stiffness of the first polyurethane foam is greater than that of the second polyurethane foam.

[0010] A method for preparing impact-resistant and heavy-duty flooring includes the following steps: (1) Provide an elastic skeleton having a plurality of arches; (2) The elastic skeleton is placed into the foaming mold for foaming to form a polyurethane foam material covering part of the internal cavity of the arched part and the outer part of the arched part, thus obtaining a composite core layer. (3) A wear-resistant layer is fixedly connected to the upper surface of the composite core layer and a substrate layer is fixedly connected to the lower surface to obtain an impact-resistant and heavy-pressure-resistant floor.

[0011] Furthermore, an opening is formed at the top of the arched portion, and the step of forming polyurethane foam material includes: placing a water-soluble material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and forming polyurethane foam material after curing; injecting hot water through the opening to remove the water-soluble material; or, placing a filler material with a stiffness less than that of polyurethane foam material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and forming polyurethane foam material after curing.

[0012] Preferably, the water-soluble material is a water-soluble salt core or a starch-based water-soluble core material, the hot water temperature is 60-80℃, and the soaking time is 15-30 minutes; the filling material is low-density polyurethane foam, EPP foam, or soft elastomer material.

[0013] Preferably, before the elastic skeleton is placed into the foaming mold, at least a portion of the surface of the elastic skeleton is coated with moisture-curing polyurethane resin with a coating thickness of 10-30 μm, and then cured in an environment with a temperature of 20-30°C and a relative humidity of 50-70% for 30-60 minutes.

[0014] Preferably, the injection amount of foaming material is 105%-110% of the mold cavity volume, the injection time is 10-15 seconds, the mold temperature is controlled at 50-70℃, and the curing time is 20-40 minutes.

[0015] Preferably, the formation process of the polyurethane foam material includes two foaming stages: The elastic skeleton is placed in the foaming mold. After the mold is closed, the first polyurethane foaming material with a volume of 40%-60% of the total volume of the mold cavity is injected into the mold. Foaming is carried out once under the conditions of mold temperature of 50-70℃ and injection pressure of 0.2-0.5MPa. The foaming time is 5-15 minutes to form the first polyurethane foam. Release the pressure inside the mold to normal pressure and maintain it for 1-3 minutes. Then, inject a second polyurethane foaming material into the mold again, with a volume of 30%-40% of the total volume of the mold cavity. Perform secondary foaming under the conditions of mold temperature of 70-90℃ and injection pressure of 0.5-0.8MPa for 10-20 minutes to form the second polyurethane foam. Maintain the mold temperature at 80-100℃ and cure for 20-40 minutes to obtain the composite core layer.

[0016] Beneficial effects

[0017] Compared with the prior art, the present invention has the following beneficial effects: The impact-resistant and heavy-duty flooring provided by this invention features an elastic frame with a stiffness greater than that of the foam material. Under impact loads, the foam material first compresses to absorb energy, while the frame then deforms to bear the load, achieving a two-stage "buffering-support" response that balances impact resistance and heavy-duty load resistance. The bottom of the elastic frame is in direct contact with the substrate layer, allowing long-term static loads to be transferred from the frame to the substrate, preventing floor sagging due to foam material creep. The internal cavities of the arched sections are only partially filled with foam material, leaving the top cavity empty to provide space for frame deformation, while the bottom filling provides auxiliary support, achieving non-linear stiffness. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the impact-resistant and heavy-pressure-resistant floor provided by the present invention; Figure 2 This is a schematic flowchart illustrating the preparation method of the impact-resistant and heavy-pressure-resistant flooring provided by the present invention. Detailed Implementation

[0019] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0020] like Figure 1As shown, an impact-resistant and heavy-duty flooring includes a wear-resistant layer 1, a composite core layer 2, and a substrate layer 3, which are fixedly connected from top to bottom. The composite core layer includes an integrally molded elastic skeleton 21 with multiple arched portions. The composite core layer also includes polyurethane foam material 22 filling a portion of the internal cavity of the arched portions and the outer portion of the arched portions. The polyurethane foam material 22 in the arched portions and the outer portion of the arched portions is connected to the wear-resistant layer 3, and the elastic skeleton 21 is connected to the substrate layer 3. The stiffness of the elastic skeleton 21 is greater than or equal to the stiffness of the polyurethane foam material 22. Upon impact, the softer foam material first undergoes compression deformation, absorbing energy; when the deformation increases to a certain extent, the harder elastic skeleton begins to bear the load and provide rebound. This gradient response of "soft first absorbs energy, hard then bears the load" gives the flooring both high impact absorption rate and high pressure resistance. At the same time, the stiffness matching prevents the foam material from collapsing due to excessive deformation and also avoids the skeleton from intervening too early under light loads, resulting in an overly hard feel underfoot.

[0021] Preferably, the polyurethane foam material fills the bottom region of the internal cavity of the arched portion, with a filling height accounting for 30%-50% of the total height of the internal cavity. The top of the internal cavity is hollow or filled with a filling material with stiffness less than that of the polyurethane foam material. The bottom filling layer provides auxiliary support and limits excessive deformation of the frame; the top hollow cavity or extremely soft material reserves space for elastic deformation of the frame, allowing the frame to bend freely under light loads, while the bottom filling layer is compacted under heavy loads. This "partial filling" design achieves non-linear stiffness—the floor is soft under light loads and gradually hardens under heavy loads, thus balancing comfort and load-bearing capacity.

[0022] Preferably, the arched portions of the elastic skeleton are arranged in a periodic array, forming arched ribs or domes; connecting ribs are provided between adjacent arched portions, and the connecting ribs are covered with polyurethane foam material in the outer region.

[0023] Preferably, the elastic skeleton is made of polyurethane elastomer or thermoplastic elastomer with an elastic modulus of 150-300 MPa; the polyurethane foam material has a compression modulus of 20-100 MPa.

[0024] Preferably, the polyurethane foam material includes a first polyurethane foam covering a portion of the internal cavity of the arched portion and the outer region of the arched portion, and a second polyurethane foam covering the first polyurethane foam, wherein the stiffness of the first polyurethane foam is greater than that of the second polyurethane foam. Through a double foaming or gradient foaming process, a "hard at the bottom, soft at the top" gradient foaming structure is formed in the same composite core layer. The upper soft foam (second foam) compresses first under light loads, eliminating the "empty feeling" of the cavity and improving the feel underfoot; the lower rigid foam (first foam) provides solid support under heavy loads and works in conjunction with the frame to bear the weight. The gradient design makes the stress-strain curve smoother and avoids abrupt changes in stiffness.

[0025] like Figure 2 As shown, a method for preparing an impact-resistant and heavy-pressure-resistant floor includes the following steps: (1) Provide an elastic skeleton having a plurality of arches; (2) The elastic skeleton is placed into the foaming mold for foaming to form a polyurethane foam material covering part of the internal cavity of the arched part and the outer part of the arched part, thus obtaining a composite core layer. (3) A wear-resistant layer is fixedly connected to the upper surface of the composite core layer and a substrate layer is fixedly connected to the lower surface to obtain an impact-resistant and heavy-pressure-resistant floor.

[0026] Furthermore, an opening is formed at the top of the arched portion. The step of forming the polyurethane foam material includes: placing a water-soluble material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and curing to form the polyurethane foam material; injecting hot water through the opening to remove the water-soluble material; or, placing a filler material with a stiffness lower than that of the polyurethane foam material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and curing to form the polyurethane foam material. The opening serves as a channel for water or solvent to enter and exit. The soluble core material (salt core) is dissolved and removed with water after foaming, forming a cavity; the permanent filler material (low-density foam) remains directly on top as a low-stiffness buffer layer. Both methods can reliably achieve "partial filling," preventing the foaming raw material from accidentally filling the entire cavity.

[0027] Preferably, the water-soluble material is a water-soluble salt core or a starch-based water-soluble core material, the hot water temperature is 60-80℃, and the soaking time is 15-30 minutes; the filling material is low-density polyurethane foam, EPP foam, or soft elastomer material.

[0028] Preferably, before the elastic skeleton is placed into the foaming mold, at least a portion of the surface of the elastic skeleton is coated with moisture-curing polyurethane resin with a coating thickness of 10-30 μm, and then cured in an environment with a temperature of 20-30°C and a relative humidity of 50-70% for 30-60 minutes.

[0029] Preferably, the injection amount of foaming material is 105%-110% of the mold cavity volume, the injection time is 10-15 seconds, the mold temperature is controlled at 50-70℃, and the curing time is 20-40 minutes.

[0030] Preferably, the formation process of the polyurethane foam material includes two foaming stages: The elastic skeleton is placed in the foaming mold. After the mold is closed, the first polyurethane foaming material with a volume of 40%-60% of the total volume of the mold cavity is injected into the mold. Foaming is carried out once under the conditions of mold temperature of 50-70℃ and injection pressure of 0.2-0.5MPa. The foaming time is 5-15 minutes to form the first polyurethane foam. Release the pressure inside the mold to normal pressure and maintain it for 1-3 minutes. Then, inject a second polyurethane foaming material into the mold again, with a volume of 30%-40% of the total volume of the mold cavity. Perform secondary foaming under the conditions of mold temperature of 70-90℃ and injection pressure of 0.5-0.8MPa for 10-20 minutes to form the second polyurethane foam. Maintain the mold temperature at 80-100℃ and cure for 20-40 minutes to obtain the composite core layer.

[0031] The first foaming process takes place at lower pressure and temperature, forming a dense, high-strength bottom foam (first foam). After depressurization, the internal gas escapes, reserving space for the second foaming. The second foaming process increases the temperature and pressure, causing the remaining raw material to expand and form a coarse, low-density top foam (second foam). This step-by-step control achieves a stiffness gradient within the same mold cavity, eliminating the need for secondary molding and significantly improving production efficiency.

[0032] Example 1

[0033] 1. Prepare a flexible frame The frame has a wall thickness of 3mm, an arch height of 12mm, a base height of 8mm, and a center-to-center distance of 50mm between adjacent domes.

[0034] 2. Surface treatment of the skeleton Spray a moisture-curing polyurethane primer (Desmodur E23, Bayer) on the areas where the skeleton and the foam material come into contact (foot, side wall and outer surface of connecting ribs) to a thickness of 20 μm, and cure for 45 minutes at 25°C and 60% relative humidity.

[0035] 3. Core material placement The water-soluble salt core (made by pressing and roasting KCl / KNO3 in a mass ratio of 6:4) was placed inside the cavity of the skeleton dome, with the height of the salt core being 50% of the total height of the cavity.

[0036] 4. Foaming molding The skeleton and salt core are placed into the foaming mold, which is preheated to 65°C and then closed. The A / B components of the high-density rigid polyurethane foam raw material (density 400 kg / m³) are preheated to 27°C, mixed using a high-pressure foaming machine, and then injected into the mold cavity at 108% of the cavity volume over 12 seconds. The mold temperature is maintained at 65°C for 35 minutes for curing. After demolding, the composite board is immersed in 80°C hot water for 30 minutes to dissolve the salt core, forming a dome-shaped internal cavity structure with a filled bottom and an empty top.

[0037] 5. Composite top layer and bottom layer A PVC wear-resistant layer (0.5mm thick) is hot-pressed onto the upper surface of the composite core layer, and an SPC substrate layer (5mm thick) is hot-pressed onto the lower surface to obtain an impact-resistant and heavy-pressure-resistant floor.

[0038] The obtained product was tested, and the results showed that the impact absorption rate was 62%, the interfacial peel strength was 6.5 N / cm, and the compressive strength (10% deformation, MPa) was 8.5 MPa.

[0039] Example 2

[0040] The difference from Example 1 is that a two-stage foaming process is used to form a gradient foam. In the first foaming stage, polyurethane raw material with a density of 450 kg / m³ is injected to fill the bottom and outer areas of the dome; in the second foaming stage, polyurethane raw material with a density of 200 kg / m³ is injected to fill the upper area of ​​the dome. The resulting floor has an impact absorption rate of 65%, an interfacial peel strength of 7.2 N / cm, and a compressive strength (10% deformation, MPa) of 9.3 MPa.

[0041] Example 3

[0042] The difference between this embodiment and Embodiment 1 is that the water-soluble salt core is replaced with a soft thermoplastic elastomer (TPE, hardness Shore A 20, compression modulus 3 MPa) pre-filled block, and the step of immersing in 80°C hot water for 30 minutes during foaming is omitted.

[0043] The obtained product was tested, and the results showed that the impact absorption rate was 64%, the interfacial peel strength was 6.2 N / cm, and the compressive strength (10% deformation, MPa) was 9.1 MPa.

[0044] Example 4

[0045] The difference between this embodiment and Embodiment 1 is that: connecting ribs are provided between adjacent arched parts of the elastic skeleton, and the connecting ribs are covered with polyurethane foam material in the outer area to form a three-dimensional interlocking network.

[0046] A connecting rib cavity is added to the skeleton mold, so that transverse connecting ribs are automatically formed between adjacent domes during the skeleton molding process. The design parameters of the connecting ribs are as follows: connecting rib width 4 mm; connecting rib thickness 2.5 mm; connecting rib height flush with the bottom of the skeleton (8 mm); connecting rib spacing (along the X direction) 50 mm (consistent with the dome spacing); connecting rib spacing (along the Y direction) 50 mm.

[0047] The resulting flooring exhibited an impact absorption rate of 63% and an interfacial peel strength of 7.8 N / cm. Its compressive strength (10% deformation, MPa) was 11.2 MPa. It is evident that the presence of the connecting ribs does not interfere with the elastic deformation of the dome's top, maintaining good impact absorption performance.

[0048] Example 5

[0049] Based on Example 3, this embodiment further employs a two-stage foaming process and simultaneously applies the top low-stiffness filling scheme of Example 2 to construct a multi-level gradient structure of "connecting rib skeleton + bottom high-stiffness foaming + top low-stiffness filling".

[0050] (The specific process can be referred to in combination of Examples 2 and 3, and will not be repeated here.) Tests showed that it has the best overall performance: impact absorption rate of 66%, interfacial peel strength of 8.5 N / cm, and compressive strength of 12.5 MPa.

[0051] Comparative Example 1 The difference from Example 1 is that the dome is not filled with any material (completely hollow). Impact absorption rate: 58%.

[0052] Comparative Example 2 The difference from Example 1 is that the interior of the dome is completely filled with high-density foam material (no cavities). The impact absorption rate is 35%, and the impact resistance is significantly reduced.

[0053] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An impact-resistant and heavy-pressure-resistant floor, characterized in that, The material comprises, from top to bottom, a wear-resistant layer, a composite core layer, and a substrate layer, all fixedly connected. The composite core layer includes an integrally formed elastic skeleton with multiple arched portions. The composite core layer also includes polyurethane foam material filling a portion of the internal cavity of the arched portions and the outer portion of the arched portions. The polyurethane foam material in the arched portions and the outer portion of the arched portions is connected to the wear-resistant layer, and the elastic skeleton is connected to the substrate layer. The stiffness of the elastic skeleton is greater than or equal to the stiffness of the polyurethane foam material.

2. The impact-resistant and heavy-duty flooring according to claim 1, characterized in that, The polyurethane foam material is filled in the bottom area of ​​the internal cavity of the arched part, and the filling height accounts for 30%-50% of the total height of the internal cavity. The top of the internal cavity is empty or filled with a filling material with less stiffness than the polyurethane foam material.

3. The impact-resistant and heavy-pressure-resistant flooring according to claim 1, characterized in that, The elastic skeleton has periodically arranged arched sections, which are arched ribs or domes; connecting ribs are provided between adjacent arched sections, and the connecting ribs are covered with polyurethane foam material in the outer area.

4. The impact-resistant and heavy-duty flooring according to claim 1, characterized in that, The elastic skeleton is made of polyurethane elastomer or thermoplastic elastomer, the elastic modulus of the elastic skeleton is 150-300 MPa, and the compression modulus of the polyurethane foam material is 20-100 MPa.

5. The impact-resistant and heavy-duty flooring according to claim 1, characterized in that, The polyurethane foam material includes a first polyurethane foam covering a portion of the internal cavity of the arch and the outer region of the arch, and a second polyurethane foam covering the first polyurethane foam, wherein the stiffness of the first polyurethane foam is greater than that of the second polyurethane foam.

6. A method for preparing an impact-resistant and heavy-pressure-resistant floor according to any one of claims 1-5, characterized in that, The process includes the following steps: providing an elastic skeleton with multiple arches; placing the elastic skeleton into a foaming mold for foaming to form a polyurethane foam material covering a portion of the internal cavity of the arches and the outer region of the arches, thus obtaining a composite core layer; fixing a wear-resistant layer to the upper surface of the composite core layer and fixing a substrate layer to the lower surface to obtain an impact-resistant and pressure-resistant floor.

7. The preparation method according to claim 6, characterized in that, An opening is formed at the top of the arched portion. The steps for forming polyurethane foam material include: placing a water-soluble material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and curing it to form polyurethane foam material; injecting hot water through the opening to remove the water-soluble material; or, placing a filler material with a stiffness less than that of the polyurethane foam material into the internal cavity of the arched portion, then placing it into a foaming mold, injecting foaming raw material into the mold, and curing it to form polyurethane foam material.

8. The preparation method according to claim 6, characterized in that, Before placing the elastic skeleton into the foaming mold, at least a portion of the surface of the elastic skeleton is coated with moisture-curing polyurethane resin with a coating thickness of 10-30 μm. After coating, it is placed in an environment with a temperature of 20-30℃ and a relative humidity of 50-70% for 30-60 minutes for curing.

9. The preparation method according to claim 7, characterized in that, The injection method for foaming material is as follows: the injection volume is 105%-110% of the mold cavity volume, the injection time is 10-15 seconds, the mold temperature is controlled at 50-70℃, and the curing time is 20-40 minutes.

10. The preparation method according to claim 7, characterized in that, The formation process of the polyurethane foam material includes two foaming stages, with the specific steps as follows: An elastic skeleton is placed in a foaming mold. After mold closing, a first polyurethane foaming material with a volume of 40%-60% of the total mold cavity volume is injected into the mold. Foaming is performed once at a mold temperature of 50-70℃ and an injection pressure of 0.2-0.5MPa for 5-15 minutes, forming the first polyurethane foam. The pressure inside the mold is then released to atmospheric pressure and maintained for 1-3 minutes. A second polyurethane foaming material with a volume of 30%-40% of the total mold cavity volume is injected into the mold again. Foaming is performed a second time at a mold temperature of 70-90℃ and an injection pressure of 0.5-0.8MPa for 10-20 minutes, forming the second polyurethane foam. The mold temperature is maintained at 80-100℃, and curing is performed for 20-40 minutes to obtain the composite core layer.

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