Environment-friendly anti-skid noise-reduction composite floor based on cork oak bark and preparation method

Abstract

An environment-friendly anti-skid noise-reduction composite floor based on cork oak bark sequentially comprises a protective layer, a cork oak layer, a damp-proof sound-insulation middle layer, a reinforcing layer and a damp-proof mute layer from the surface layer to the bottom layer. The cork oak layer is a whole block so as to ensure that the porosity of the cork oak layer is 40%-60%. The water content of the cork oak layer is 12%-15%, the reinforcing layer is formed by pressing poplar veneers and bamboo fiber sheets in a staggered mode, and the water content of the reinforcing layer is 10%-16%, so that it is guaranteed that the static bending intensity of the reinforcing layer is larger than or equal to 30 MPa. The moisture-proof sound-insulation middle layer is formed by mixing and pressing perlite powder, rubber particles and environment-friendly resin according to the mass ratio of 3: 5: 2. The multi-layer composite structure of the composite floor achieves the synergistic effect of all functional layers, the high-strength reinforcing layer ensures the static bending strength and the deformation resistance of the floor, the moisture-proof sound insulation middle layer effectively blocks water vapor permeation, and therefore the service life can be prolonged, and the composite floor can adapt to complex use environments such as damp and large personnel mobility.

Description

Technical Field

[0001] This invention relates to the field of board manufacturing technology, and in particular to an environmentally friendly, non-slip, and noise-reducing composite flooring based on cork oak bark and its preparation method. Background Technology

[0002] Currently, the surface materials of mainstream flooring products mostly rely on hardwoods such as oak and walnut, engineered wood panels, and stone. Such flooring presents several problems. First, traditional hardwood resources are non-renewable; over-harvesting can easily lead to ecological damage. Furthermore, the grain and color of traditional hardwoods are limited by natural growth, making it difficult to meet the diverse and personalized needs of consumers. Second, existing flooring generally suffers from insufficient slip resistance, especially in humid environments, potentially causing safety hazards. Additionally, noise control is poor, with footsteps and collisions affecting indoor comfort. Third, some composite flooring uses large amounts of adhesives, preservatives, and other chemical reagents in its production process, posing a risk of releasing harmful substances such as formaldehyde. This process is energy-intensive and highly polluting, contradicting the current trend of green and environmentally friendly industrial development. Finally, single-structure or simple composite flooring struggles to balance multiple properties such as wear resistance, moisture resistance, and strength, making it prone to deformation and cracking in complex environments with high humidity and large temperature fluctuations.

[0003] Cork oak, a special tree species, has renewable bark, which can be harvested every 10-15 years without affecting the tree's normal growth, making it an ideal green and environmentally friendly material. Furthermore, cork oak bark itself has a unique natural texture and warm color, and is soft and elastic, possessing certain sound absorption and noise reduction potential. Patent number 201811606161.X, entitled "A Processing Method for Anti-Slip Full-Gold Star Cork Flooring," discloses a technical solution for making flooring using cork oak. In this technical solution, cork oak bark scraps are fed into a waffle shaving machine to produce large waffle shavings, which are then mixed evenly with pyrite ore and urea-formaldehyde resin adhesive. The mixture is then hot-pressed to form a blank, followed by longitudinal grooves machined into the sidewalls of the blank. Finally, after sanding and painting, the anti-slip full-gold star cork flooring is produced.

[0004] However, the aforementioned flooring only uses cork oak as a type of softwood without optimizing its structure or integrating its technology to achieve synergistic effects such as anti-slip properties, noise reduction, and high strength. As a result, the advantages of cork oak have not been fully utilized. Summary of the Invention

[0005] In view of this, the present invention provides an environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark and its preparation method. Through innovative material selection, integrated technology, and optimized structure, the flooring achieves multiple improvements in recyclability, anti-slip properties, noise reduction, high strength, and environmental friendliness, meeting the needs of complex usage environments and personalized requirements.

[0006] This environmentally friendly, non-slip, and noise-reducing composite flooring, based on the bark of the cork oak tree, comprises, from the top layer to the bottom layer, at least one protective layer, at least one cork oak layer, at least one moisture-proof and sound-insulating middle layer, one reinforcing layer, and one moisture-proof and sound-absorbing layer. The cork oak layer is a single piece to ensure a porosity of 40%–60%. The moisture content of the cork oak layer is 12%–15%. The reinforcing layer is made of poplar veneer and bamboo fiber sheets, cross-laminated, and has a moisture content of 10%–16% to ensure a static bending strength greater than or equal to 30 MPa. The moisture-proof and sound-insulating middle layer is made by mixing and pressing perlite powder, rubber granules, and environmentally friendly resin in a mass ratio of 3:5:2. The perlite powder has a particle size of 0.075–0.15 mm. The rubber granules have a particle size of 0.5–1 mm. The rubber granules and perlite powder form a graded structure with large particles supporting small particles to prevent the perlite powder from sticking together and clumping.

[0007] Furthermore, the method for controlling the porosity of the cork oak layer to 40%–60% is as follows: First, select cork oak bark that is over 20 years old; then soften the cork oak bark by using steam softening at a softening temperature of 80–90℃ and a softening time of 30–40 minutes to adjust the fiber elasticity in the cork oak layer; finally, apply a light pressure of 0.1–0.5 MPa during hot-pressing to adjust the porosity to 40%–60%.

[0008] Furthermore, during the softening of the cork oak bark, steam is used to soften the bark at a temperature of 80–90°C for 30–40 minutes. The setting of the softening temperature and time ranges is to ensure the processing accuracy of the anti-slip texture. Since the cork oak layer needs to be processed with micro-grooved anti-slip textures, a softening temperature of 80–90°C allows the cork oak fibers to soften sufficiently, preventing brittleness or crumbling during processing. By controlling the softening time, ensuring a 30–40 minute softening time, the softening effect can penetrate evenly to the interior, avoiding uneven texture caused by surface softening and excessive hardening of the inner layer, thus laying the foundation for anti-slip performance.

[0009] Furthermore, the surface of the cork oak layer is processed with microgrooved anti-slip texture, the depth of the microgrooves is 0.1 to 0.3 mm, the spacing is 5 to 30 mm, and the abrasion roughness is Ra1.2 to Ra2.0 μm.

[0010] Furthermore, the extension direction of each groove of the microgroove is obliquely distributed at 45° to 60° relative to the length direction of the plate, and the anti-slip texture of the microgroove is formed by the intersection of two sets of oblique grooves to form a grid.

[0011] Furthermore, the moisture-proof and sound-insulating middle layer has uniformly distributed sound-absorbing holes with a diameter of 1-2 mm and a spacing of 5-8 mm.

[0012] Furthermore, the method for forming the sound-absorbing holes is as follows: First, the raw materials are pretreated by drying the perlite powder at 115℃~125℃ for about 2 hours to remove moisture and prevent excessive shrinkage of the resin due to moisture. Second, the ratio of the raw materials is controlled, that is, the mass ratio of perlite powder, rubber particles, and environmentally friendly resin is strictly followed as 3:5:2 to ensure that the spacing effect of the rubber particles and the filling effect of the perlite powder are balanced, and to avoid the gaps being too large or too small. Finally, the pressing parameters are strictly controlled during pressing, that is, the applied pressure is between 1~2MPa, the pressing temperature is controlled between 80~100℃, and the pressing time is controlled between 15~20min, to ensure that the resin is fully cured while forming the sound-absorbing holes with the above parameters.

[0013] Furthermore, the raw materials of the moisture-proof and sound-absorbing layer include reclaimed rubber powder, nano-silica, water-based epoxy resin adhesive, silane coupling agent, and antibacterial agent, wherein the weight percentage content of the reclaimed rubber powder is 60% to 70%, the weight percentage content of the nano-silica is 5% to 10%, the weight percentage content of the water-based epoxy resin adhesive is 20% to 30%, the weight percentage content of the silane coupling agent is 1% to 2%, and the weight percentage content of the antibacterial agent is 0.5% to 1%.

[0014] Further, the method for producing the moisture-proof and sound-absorbing layer is as follows: First, pretreatment is performed by drying the recycled rubber powder at 75℃~85℃ for 0.8 hours to 1.2 hours to remove moisture, while modifying the nano-silica with a silane coupling agent to improve its compatibility with the rubber powder; second, mixing is performed by adding all raw materials to a high-speed mixer and stirring at 1000~1200r / min for 15~20min to form a uniform mixture; third, pressing is performed by feeding the mixture into a mold, applying a pressure of 1.5~2MPa, and holding it at 100~110℃ for 25~30min to cure and shape; finally, post-treatment is performed by cooling the moisture-proof and sound-absorbing layer 14 to room temperature and polishing the surface to ensure uniform thickness of 3~4mm.

[0015] Furthermore, the antibacterial agent can be nano-silver powder.

[0016] Compared with existing technologies, the environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark provided by this invention is the first to use cork oak bark as the core material of the flooring surface. Cork oak bark is renewable, and the trees can continue to grow after harvesting, avoiding the excessive consumption of traditional hardwood resources. At the same time, the natural texture and color of the bark are rich and diverse, which can meet the personalized decoration needs of different scenarios and break the pattern of single material selection in traditional flooring. In addition, through the dual texture treatment of micro-grooves and frosted surface, the anti-slip coefficient of the flooring surface is greater than or equal to 0.65, effectively solving the safety hazards in humid environments. Meanwhile, the natural honeycomb structure of cork oak cork and the sound-absorbing holes of the moisture-proof and sound-insulating middle layer work together to achieve a sound absorption coefficient of 0.35-0.45, which is more than 40% better than ordinary composite flooring in terms of noise reduction. At the same time, the multi-layer composite structure realizes the synergistic effect of each functional layer. The high-strength reinforcing layer ensures the static bending strength and deformation resistance of the flooring, while the moisture-proof and sound-insulating middle layer effectively blocks water vapor penetration. The moisture-proof and sound-insulating layer can extend the service life and adapt to complex use environments such as humid and high-traffic environments. The entire process of manufacturing the composite flooring adopts low-energy consumption technology, avoids extreme production conditions such as high temperature and high pressure, and uses environmentally friendly adhesives and chemical-free treatment methods. The formaldehyde emission of the finished product is less than 0.02mg / m³, which is far lower than the 0.124mg / m³ of the GB 18580-2025 standard. In addition, the scraps are recycled and reused, which is in line with the development direction of green building materials. Attached Figure Description

[0017] Figure 1 This invention provides a structural schematic diagram of an environmentally friendly, anti-slip, and noise-reducing composite floor based on cork oak bark. Detailed Implementation

[0018] The following provides a more detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0019] like Figure 1 The diagram shows a structural schematic of an environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark provided by this invention. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark comprises, from the surface to the bottom, at least one protective layer 10, at least one cork oak layer 11, at least one moisture-proof and sound-insulating middle layer 12, one reinforcing layer 13, and one moisture-proof and sound-absorbing layer 14. It is conceivable that the composite flooring also includes an interlocking mechanism disposed on the side walls, and an environmentally friendly adhesive layer disposed between the aforementioned layers, etc., which are technologies known to those skilled in the art and will not be described in detail here.

[0020] The protective layer 10 can be a decorative layer, a wear-resistant layer, etc. The protective layer 10 can also be a paint layer. However, it should be noted that the paint used in the paint layer should be a flexible paint. A flexible paint is essentially a coating that, after film formation, has good flexibility and elasticity, capable of adapting to minor deformations or cracks in the substrate, while being itself not easily broken. Since the cork oak layer 11 described in this application has good softness and will deform when stepped on, a flexible paint is required as the paint layer. It is conceivable that the protective layer 10 can also be other forms of decorative layer, such as kraft paper impregnated with a stretchable resin, on which various patterns are printed or laser-printed for aesthetic decoration. The protective layer 10 can also include multiple layers, such as a paint layer and a decorative layer, with the decorative layer applied to the cork oak layer 11.

[0021] The cork oak layer 11 can be a single layer or multiple layers bonded together, with a total thickness between 2 and 4 mm. The raw material for the cork oak layer 11 is selected from trees with a longer growth age, such as cork oak trees older than 20 years. During the vigorous growth period in spring, a special tool is used to ring-peel the bark, controlling the peeling thickness to 5-8 mm to protect the tree's subsequent normal growth. The peeled bark is then naturally dried until its moisture content reaches 12%-15%. Maintaining the moisture content of the cork oak bark at 12%-15% is for compatibility with the reinforcing layer 13. This is because the cork oak layer 11, near the surface of the composite flooring, only absorbs moisture from the air, while the reinforcing layer 13, near the bottom layer of the composite flooring, absorbs moisture not only from the air but also from the room walls. Therefore, if the moisture content of the cork oak layer 11 and the reinforcing layer 13 are not compatible, the composite flooring will warp and deform due to the excessive difference in moisture content. In addition, it is also necessary to ensure that the difference in internal stress is not too large due to excessive differences in moisture content during the manufacturing process. Since the reinforcing layer 13 is made of poplar veneer and bamboo fiber sheets through cross-lamination, its optimal moisture content is 10% to 16%. Therefore, the moisture content of the cork oak layer is kept at 12% to 15%, so that its moisture content range highly overlaps with that of the reinforcing layer 13. This avoids internal stress caused by excessive differences in moisture content during hot pressing, which could lead to warping and cracking of the floor. It also ensures that the two layers are firmly bonded, thereby guaranteeing that the static bending strength of the reinforcing layer 13 is greater than or equal to 30 MPa, so that the performance of the reinforcing layer 13 can be stably maintained. Meanwhile, the moisture content of the cork oak layer 11 is maintained at 12% to 15%, and it also needs to work together with the moisture-proof and sound-insulating middle layer 12 to prevent moisture. This is because the moisture-proof and sound-insulating middle layer 12 contains porous perlite powder. Therefore, if the moisture content of the cork oak layer 11 is lower than 12%, it will excessively absorb the moisture of the moisture-proof and sound-insulating middle layer 12, causing the moisture-proof and sound-insulating middle layer 12 to dry and clump, and lose its sound absorption and noise reduction function. However, if the moisture content of the cork oak layer 11 is higher than 15%, the moisture in the cork oak layer 11 itself cannot dissipate in time, and the moisture will penetrate into the moisture-proof and sound-insulating middle layer 12, damaging its porous structure and reducing the moisture-proof effect of the moisture-proof and sound-insulating middle layer 12. In other words, a moisture content of 12% to 15% can allow the cork oak layer 11 and the moisture-proof and sound-insulating middle layer 12 to form a moisture balance, which not only prevents the moisture-proof and sound-insulating middle layer 12 from becoming damp and clumping, but also helps the moisture-proof and sound-insulating middle layer 12 to be moisture-proof by utilizing the natural water absorption of the cork oak layer 11, thereby improving the overall moisture-proof performance.

[0022] The bark of the cork oak is then softened by steam at a temperature of 80–90°C for 30–40 minutes. The specific softening temperature and time ranges are designed to ensure the precision of the anti-slip texture. Since the cork oak layer 11 needs to be processed with microgrooved anti-slip textures, a softening temperature of 80–90°C allows the cork oak fibers to soften sufficiently, preventing brittleness and chipping during processing. This ensures that the depth of the microgrooves can be processed to 0.1–0.3 mm and the spacing can be controlled between 5–30 mm. By controlling the softening time, ensuring a 30–40 minute softening period, the softening effect can penetrate evenly to the interior, avoiding uneven texture caused by surface softening and an overly hardened inner layer, thus laying the foundation for anti-slip performance.

[0023] The purpose of softening the bark of the cork oak is primarily to enhance the bonding strength between the cork oak layer 11 and the moisture-proof and sound-insulating middle layer 12. This is because the softened cork oak layer 11 has increased flexibility, allowing it to better adhere to the surface of the moisture-proof and sound-insulating middle layer 12 during hot-pressing, increasing the contact area, enabling the environmentally friendly adhesive layer to fully penetrate, improving interlayer bonding, and, in conjunction with the structural design of the reinforcing layer, ensuring that the overall strength of the flooring meets the standards.

[0024] Furthermore, since the natural honeycomb-like pores of the cork oak are the core of the flooring's noise-reducing function, a softening temperature range of 80–90°C can prevent high temperatures from damaging the pore structure. Temperatures exceeding 90°C cause pore shrinkage and collapse, while temperatures below 80°C result in insufficient softening, making the pores prone to breakage during processing. A softening time of 30–40 minutes balances pore retention with processing plasticity, stabilizing the porosity of the cork oak layer at 40%–60%. This, combined with the sound-absorbing pores of the moisture-proof and sound-insulating middle layer, forms a "dual noise reduction" system, enhancing the noise reduction effect.

[0025] After softening, the cork oak bark is cleaned of surface impurities and dead bark layers, and then cut into surface board blanks with dimensions of 1220mm × 2440mm. Each surface board blank is a single piece, using whole pieces of harvested cork oak bark as the base material, rather than pressed fragments, thus preserving the natural texture and overall mechanical properties.

[0026] The porosity of the cork oak layer 11 should be stable at 40%–60%. The porosity of natural cork oak is approximately 35%–65%. This invention achieves precise control of the porosity of the cork oak layer 11 through "harvesting and screening, softening regulation, and mild compression." First, cork oak bark aged over 20 years with a uniform growing environment is selected, as its natural pore distribution is more uniform, thus stabilizing the basic porosity at 45%–55%. During the softening process, steam softening at a temperature of 80–90℃ for 30–40 minutes adjusts the fiber elasticity in the cork oak layer 11, preventing excessive pore expansion or contraction. Finally, mild compression maintains its porosity. By applying a mild pressure of 0.1–0.5 MPa during hot-pressing, the porosity is precisely controlled to 40%–60%. By stabilizing the porosity of the cork oak layer 11 at 40% to 60%, not only can the porous structure required for noise reduction be guaranteed, but also the strength of the cork oak layer can be avoided due to excessive porosity. In this way, it can form a strength synergy of "flexible buffer and rigid support" with the reinforcing layer 13.

[0027] The surface of the cork oak layer 11 also needs to be processed with microgrooves and sanded to form an anti-slip texture. The depth of each microgroove is 0.1-0.3 mm, the spacing between two adjacent microgrooves is 5-30 mm, and the sanding roughness is Ra1.2-Ra2.0 μm. The grooves are preferably obliquely intersecting grid grooves, meaning that each groove in the microgroove is obliquely distributed at 45°-60° relative to the length of the board. The anti-slip texture of the microgroove is formed by two sets of oblique grooves intersecting to form a grid, rather than straight or oblique grooves in a single direction. The reason for controlling the depth of the microgrooves to 0.1-0.3 mm is that when the depth is less than 0.1 mm, the contact area between the anti-slip texture and the sole is insufficient, and the coefficient of friction is less than 0.5, which cannot meet the anti-slip requirements. When the depth is greater than 0.3 mm, it will damage the natural porous structure of the cork oak layer, leading to a decrease in noise reduction performance and easy accumulation of dirt. Therefore, at this depth, the surface coefficient of friction can be increased to 0.6-0.8 without affecting noise reduction, achieving the anti-slip target. The spacing of the microgrooves is controlled between 5 and 30 mm. If the spacing is less than 5 mm, the texture becomes too dense, increasing the surface rigidity of the cork oak layer 11, reducing its softness and elasticity, and weakening the noise reduction effect. If the spacing is greater than 30 mm, the anti-slip texture distribution is uneven, resulting in insufficient local friction coefficients and potential safety hazards. Therefore, within this spacing range, the anti-slip texture can evenly cover the surface, working in synergy with the elasticity of the cork oak to achieve a balance between anti-slip and noise reduction. The abrasive roughness of the cork oak layer 11 is controlled between Ra1.2 and Ra2.0 μm. If the roughness is lower than Ra1.2 μm, the surface is too smooth, significantly reducing the anti-slip effect in wet environments. If it is higher than Ra2.0 μm, the surface is too rough, reducing walking comfort and easily wearing down the sole. This roughness further enhances the anti-slip performance while retaining the warm touch of the cork oak, meeting the innovative requirements of environmental protection and comfort.

[0028] The moisture-proof and sound-insulating middle layer 12 has a thickness of 3-5mm and is made by mixing and pressing perlite powder, rubber granules, and environmentally friendly resin in a mass ratio of 3:5:2. The moisture-proof and sound-insulating middle layer 12 can also be one or more layers. When it is multiple layers, the layers can be bonded together with environmentally friendly adhesives.

[0029] The perlite powder is a lightweight, porous mineral powder produced from natural perlite ore through crushing, screening, and grinding processes. It possesses low density, high porosity, high chemical stability, and excellent properties such as heat insulation, sound insulation, and fire resistance. In terms of characteristics, perlite powder has an extremely low thermal conductivity, making it an ideal heat insulation material. The perlite powder has a particle size of 0.075–0.15 mm, and its porous structure also endows it with good sound absorption properties, making it suitable for applications requiring noise reduction. Furthermore, perlite powder is non-toxic, odorless, and environmentally friendly, meeting the safety requirements of modern industry. However, prolonged exposure to high humidity may cause the perlite powder to clump. To address this clumping problem, rubber granules are added. These rubber granules are granular materials made from waste rubber, shoe soles, car tires, and other waste rubber products, processed through crushing and processing. They include recycled rubber granules and desulfurized rubber granules. The rubber granules have a particle size of 0.5–1 mm. The rubber particles mainly serve as a "skeleton support". The selected rubber particles are 0.5-1mm in size, and their particle size forms a "large particle support and small particle filling" graded structure with the perlite powder. At the same time, because the rubber particles have good elasticity and do not absorb water, they will form a three-dimensional elastic skeleton after mixing and pressing. This will evenly separate the perlite powder particles and prevent them from sticking together and clumping due to moisture adsorption in high humidity environments.

[0030] In addition, since the rubber particles have a "hydrophobic isolation" effect, that is, the surface of the rubber particles is hydrophobic, a hydrophobic film can be formed on the surface of the perlite powder particles, thereby reducing the contact area between the perlite powder and water molecules and reducing its moisture absorption probability. At the same time, the elasticity of the rubber particles can buffer the stress generated by the expansion of perlite powder due to moisture absorption, which can further prevent the particles from agglomerating and forming hard lumps.

[0031] Since the porous structure of perlite powder is responsible for sound absorption and noise reduction, while the skeletal support and hydrophobic effect of rubber particles can ensure the stability of the perlite powder structure, the perlite powder and rubber particles can work together to ensure that the moisture-proof and sound-insulating middle layer 12 can still maintain a porous structure in a high humidity environment, avoid clumping and failure, and improve the environmental adaptability of the floor.

[0032] When rubber granules with a particle size of 0.5–1 mm are mixed with perlite powder and environmentally friendly resin, gaps will form during the pressing process. These gaps are the core source of the sound-absorbing holes. Setting the particle size of the rubber granules to 0.5–1 mm ensures that the diameter of the sound-absorbing holes is stable at 1–2 mm. If the particle size is less than 0.5 mm, the resulting gaps will be too small, such as less than 1 mm, weakening the sound absorption effect. Conversely, if the particle size is greater than 1 mm, the gaps will be too large, such as greater than 2 mm, reducing the structural strength of the moisture-proof and sound-insulating middle layer 12 and affecting its adhesion to the upper and lower layers.

[0033] The elasticity of the rubber particles can also enhance the cushioning performance of the moisture-proof and sound-insulating middle layer 12. It forms a "double buffer" with the elasticity of the cork oak layer, enhancing the noise reduction effect and reducing impact noise by 15-20 dB. Furthermore, the rubber particles can improve interlayer adhesion stability. This is because rubber particles of this size form tiny protrusions on their surface after pressing, increasing the contact area with the cork oak layer 11 and the reinforcing layer 13, allowing the environmentally friendly adhesive layer to penetrate better, improving interlayer bonding strength, and preventing the middle layer from peeling off from the upper and lower layers.

[0034] The moisture-proof and sound-insulating middle layer 12 is formed by mixing perlite powder, rubber particles, and environmentally friendly resin. This layer contains uniformly distributed sound-absorbing pores. These pores efficiently absorb low- and mid-frequency noise, forming a comprehensive noise reduction system that absorbs both high- and low-frequency sounds together with the porosity of the cork oak layer 11. These sound-absorbing pores are actively formed during the mixing and pressing of perlite powder, rubber particles, and environmentally friendly resin through particle size distribution and resin bonding, rather than being formed naturally by the mixing of these components. Specifically, rubber particles act as spacers, while perlite powder fills the gaps between them. Environmentally friendly resin acts as a binder, fixing both materials in place. The resulting mixture of large particles, small particles, and binder creates a system that retains gaps during pressing, thus forming uniformly distributed sound-absorbing pores. The diameter of these pores is 1–2 mm, and the spacing between them is 5–8 mm. To form the sound-absorbing holes with the above parameters, the raw materials must first be pretreated by drying the perlite powder at 120℃ for about 2 hours to remove moisture and prevent excessive resin shrinkage, which would affect the size of the sound-absorbing holes. Secondly, the ratio of raw materials must be controlled, strictly adhering to a mass ratio of perlite powder, rubber granules, and environmentally friendly resin of 3:5:2. This ensures a balance between the spacing effect of the rubber granules and the filling effect of the perlite powder, avoiding gaps that are too large or too small. Finally, the pressing parameters must be strictly controlled: the applied pressure should be between 1 and 2 MPa, the pressing temperature between 80 and 100℃, and the pressing time between 15 and 20 minutes. This ensures that the resin fully cures while forming the sound-absorbing holes with the above parameters. Through the above manufacturing process control, the diameter of the produced sound-absorbing holes is 1 to 2 mm, and the hole spacing is 5 to 8 mm. Controlling the hole diameter to 1 to 2 mm is essential; therefore, if the hole diameter is less than 1 mm, its absorption effect on mid-to-low frequency noise, such as walking sounds and object collision sounds, will be poor. However, if the pore size is greater than 2mm, the structural strength of the moisture-proof and sound-insulating middle layer 12 will decrease, and it will be easier for moisture to penetrate, affecting the moisture-proof performance. At the same time, it is also necessary to control the pore spacing of the sound-absorbing holes to be between 5 and 8mm. If the spacing is less than 5mm, the sound-absorbing holes are too dense, the structural density of the moisture-proof and sound-insulating middle layer 12 is insufficient, and the moisture-proof performance and strength will decrease. If the spacing is greater than 8mm, it will lead to uneven distribution of sound-absorbing holes, and the noise reduction effect will also fluctuate.

[0035] The thickness of the reinforcing layer 13 is 5-8mm. It is made of poplar veneer and bamboo fiber sheets in an alternating layer ratio of 2:1. The thickness of the veneer is 0.8-1.2mm. The bamboo fiber content accounts for 30%-40% of the total mass of the base layer. After high temperature hot pressing treatment, the static bending strength of the base layer is ≥30MPa and the internal bond strength is ≥1.5MPa.

[0036] The poplar veneer is made from sawn poplar wood, while the bamboo fiber sheets are made from split bamboo. The thickness of a single layer of poplar veneer and bamboo fiber sheet is 0.8–1.2 mm. The reinforcing layer 13 is formed by stacking the poplar veneer and bamboo fiber sheets. During stacking, a layer of bamboo fiber sheet is placed after every two layers of poplar veneer. The content of the bamboo fiber sheet is controlled so that its weight accounts for 30%–40% of the total weight of the reinforcing layer 13. By ensuring that the weight of the bamboo fiber sheet accounts for 30%–40% of the total weight of the reinforcing layer 13, a synergistic effect can be achieved between the flexible cushioning provided by the cork oak layer and the rigid support provided by the reinforcing layer 13, thus effectively ensuring both high strength and comfort in the manufactured flooring. Simultaneously, ensuring that the weight of the bamboo fiber sheet accounts for 30%–40% of the total weight of the reinforcing layer 13 also meets the requirement of synergistic strength requirements. Because the static bending strength of bamboo fiber sheets is generally greater than 80 MPa, while that of poplar veneer is generally around 15 MPa, the static bending strength of bamboo fiber sheets is significantly greater than that of poplar veneer. Therefore, a minimum content of 30% of the total weight of the reinforcing layer 13 (the bamboo fiber sheets constitute 30%) ensures that the static bending strength of the reinforcing layer 13 reaches over 30 MPa, providing sufficient rigidity for the flooring and preventing deformation over long-term use. Conversely, if the content is less than 30%, the rigidity of the reinforcing layer 13 will be insufficient, failing to balance the flexibility of the cork oak layer 11, leading to a tendency for the flooring to collapse. However, if the weight of the bamboo fiber sheets exceeds 40% of the total weight of the reinforcing layer 13, the reinforcing layer 13 will become too rigid, losing the elasticity of the cork oak layer 11, reducing noise reduction and walking comfort. Furthermore, controlling the weight of the bamboo fiber sheets to be between 30% and 40% of the total weight of the reinforcing layer 13 is also a requirement for structural stability. Specifically, because bamboo fiber sheets have better dimensional stability than poplar veneer, a content of 30%–40% can form a staggered laminated structure of two layers of poplar veneer and one layer of bamboo fiber sheets. This can counteract the anisotropy of wood and reduce deformation of the flooring caused by temperature and humidity changes. The moisture content of the reinforcing layer 13 is matched with that of the cork oak layer 11 and the moisture-proof and sound-insulating middle layer 12, further improving overall stability. In addition, bamboo fiber is a renewable resource, and poplar is a fast-growing wood. The combination of the two can reduce dependence on hardwoods, which is in line with the concept of environmental protection and innovation. The 30%–40% bamboo fiber content can control costs while ensuring strength, making it easy for industrial promotion.

[0037] Before stacking the poplar veneer and bamboo fiber sheets, an adhesive is first uniformly applied to the contact surfaces of the poplar veneer and bamboo fiber sheets, and then the reinforcing layer 13 is formed after high-temperature hot pressing. The adhesive can be a water-based polyurethane adhesive, with 1% to 2% bamboo powder modifier added to the water-based polyurethane adhesive by weight. This adhesive releases no formaldehyde, meets environmental protection requirements, and has high bonding strength and good water resistance. The bamboo powder modifier is homologous to the bamboo fiber sheet composition, improving compatibility and thus enhancing the bonding force between the bamboo fiber sheet and the poplar veneer. In fabricating the reinforcing layer, adhesive is first evenly applied to the contact surfaces of the poplar veneer and bamboo fiber sheets, with an adhesive application rate of 100–120 g / m². The layers are then stacked alternately in the order of “poplar veneer, bamboo fiber sheets, poplar veneer”, and subsequently fed into a hot press. The hot pressing temperature is controlled at 120–140°C, the pressure at 2–3 MPa, and the hot pressing time at 15–20 minutes to allow the adhesive to fully cure, achieving interlayer chemical bonding and ensuring that the internal bond strength of the reinforcing layer 13 is greater than or equal to 1.5 MPa. Therefore, the finished reinforcing layer 13 has a static bending strength greater than or equal to 30 MPa and an internal bond strength greater than or equal to 1.5 MPa. The static bending strength characterizes the material's ability to resist bending failure. When the static bending strength of the reinforcing layer 13 is greater than or equal to 30 MPa, it ensures that the floor will not bend or break under daily walking or heavy loads, especially when the cork oak layer 11 is flexible, preventing the entire floor from collapsing. Meanwhile, this strength can also meet the high-frequency use requirements of public places such as shopping malls and offices, extending the service life. The internal bond strength is used to characterize the firmness of the interlayer bonding. When the internal bond strength of the reinforcing layer 13 is greater than or equal to 1.5MPa, it can ensure that the poplar veneer and bamboo fiber sheet of the reinforcing layer 13 will not delaminate, thereby ensuring the overall bonding stability of each layer of the floor, avoiding the decline in moisture resistance and noise control failure caused by interlayer delamination, and ensuring the long-term stable operation of multiple functions.

[0038] The moisture-proof and sound-absorbing layer 14 is made from recycled rubber powder, nano-silica, water-based epoxy resin adhesive, silane coupling agent, and antibacterial agent. The recycled rubber powder comprises 60%–70% by weight, the nano-silica comprises 5%–10% by weight, the water-based epoxy resin adhesive comprises 20%–30% by weight, the silane coupling agent comprises 1%–2% by weight, and the antibacterial agent comprises 0.5%–1% by weight. The antibacterial agent can be nano-silver powder. During manufacturing, a pretreatment process is first performed by drying the recycled rubber powder at 75℃–85℃ for 0.8–1.2 hours to remove moisture. Simultaneously, the nano-silica is modified with silane coupling agent KH-570 to improve its compatibility with the rubber powder. Next, mixing is performed by adding all raw materials to a high-speed mixer and stirring at 1000–1200 r / min for 15–20 min to form a homogeneous mixture. The mixture is then pressed again, which involves feeding it into a mold, applying a pressure of 1.5–2 MPa, and holding it at 100–110°C for 25–30 minutes to cure and shape it. Finally, post-processing is performed, which involves cooling the moisture-proof and sound-absorbing layer 14 to room temperature and then polishing the surface to ensure uniform thickness, which is 3–4 mm.

[0039] In the aforementioned materials, the nano-silica and silane coupling agent form a hydrophobic network. Combined with the hydrophobicity of the recycled rubber powder, the water absorption rate of the moisture-proof and sound-absorbing layer 14 is less than or equal to 3%, thereby preventing surface moisture from penetrating upwards and protecting the reinforcing layer and the moisture-proof and sound-absorbing middle layer. Simultaneously, the elasticity of the recycled rubber powder further absorbs impact sound, thus forming a triple noise reduction effect with the cork oak layer 11 and the moisture-proof and sound-absorbing middle layer 12, reducing floor impact sound by more than 25 dB. Furthermore, the 3-4 mm thick moisture-proof and sound-absorbing layer 14 balances the moisture-proof and sound-absorbing effect with the overall thickness of the floor. Its elasticity buffers the stress caused by uneven ground, and combined with the rigidity of the reinforcing layer 13, improves the overall stability of the floor. Example

[0040] An environmentally friendly, non-slip, and noise-reducing composite flooring based on cork oak bark, with an overall thickness of 15mm, and the thickness and parameters of each layer are as follows: Protective layer: Clear varnish layer; Cork oak veneer: 3mm thick, microgrooves 0.2mm deep and 3mm spaced, sandblasting roughness Ra1.5μm, porosity 50%; Moisture-proof and sound-insulating middle layer: 4mm thick, perlite powder, rubber granules and environmentally friendly resin in a mass ratio of 3:5:2, sound-absorbing hole diameter 1.5mm and hole spacing 6mm; High-strength layer: 6mm thick, poplar veneer to bamboo fiber layer ratio 2:1, bamboo fiber content 35%, static bending strength 32MPa, internal bond strength 1.6MPa; Moisture-proof and sound-absorbing layer: 3.5mm thick, wherein the weight percentage content of the recycled rubber powder is 63%, the weight percentage content of nano silica is 7%, the weight percentage content of water-based epoxy resin adhesive is 28.7%, the weight percentage content of silane coupling agent is 0.5%, and the weight percentage content of antibacterial agent is 0.8%.

[0041] In its preparation method, the bark of *Quercus variabilis* is harvested to a thickness of 6 mm, dried to a moisture content of 13%, and steam softened at 85℃ for 35 minutes. The composite pressing temperature is 95℃, the pressure is 9 MPa, and the time is 22 minutes. The finished product testing results show: anti-slip coefficient of 0.70, sound absorption coefficient of 0.40 in the 1500Hz frequency band, formaldehyde release of 0.018 mg / m³, moisture resistance reaching the highest level, and static bending strength of 31 MPa, meeting design requirements. Example

[0042] An environmentally friendly, non-slip, and noise-reducing composite flooring based on cork oak bark, with an overall thickness of 18mm, and the thickness and parameters of each layer are as follows: Protective layer: Clear varnish layer: Cork oak veneer: 4mm thick, microgrooves 0.3mm deep and 5mm spaced, roughness Ra 2.0μm, porosity 60%; Moisture-proof and sound-insulating middle layer: 5mm thick, perlite powder, rubber granules and environmentally friendly resin in a mass ratio of 3:5:2, sound-absorbing hole diameter 2mm, hole spacing 8mm; High-strength base layer: 7mm thick, poplar veneer to bamboo fiber layer ratio 2:1, bamboo fiber content 40%, static bending strength 35MPa, internal bond strength 1.8MPa; Moisture-proof and sound-absorbing layer: 3.5mm thick, wherein the weight percentage content of the recycled rubber powder is 68%, the weight percentage content of nano silica is 9%, the weight percentage content of water-based epoxy resin adhesive is 21.7%, the weight percentage content of silane coupling agent is 0.5%, and the weight percentage content of antibacterial agent is 0.8%.

[0043] In its preparation method, the bark of *Quercus variabilis* is harvested to a thickness of 8mm, dried to a moisture content of 15%, and steam-softened at 90℃ for 40 minutes; the composite pressing temperature is 100℃, the pressure is 10MPa, and the time is 25 minutes. The finished product testing results show: anti-slip coefficient of 0.75, sound absorption coefficient of 0.45 in the 2000Hz frequency band, formaldehyde release of 0.015mg / m³, moisture resistance reaching the highest level, and static bending strength of 34MPa. It is suitable for office and educational spaces with high personnel traffic.

[0044] The two types of boards were placed in a sealed test chamber at 40°C and left to stand for 5 months. After that, warpage and static bending strength tests were performed. The results showed that the warpage in the width direction of both boards was less than 0.5%, and the warpage in the length direction was less than 1.0%, indicating that they meet the requirements of GB / T 18103-2022.

[0045] The static bending strength was tested using a three-point bending test, which was applied until fracture. The pressure at which the board of the first embodiment fractured was 39 MPa, and the pressure at which the board of the second embodiment fractured was 47 MPa. This may be because the board of the second embodiment had an increased bamboo fiber content. All of the above data meet the requirements of GB / T 18103-2022.

[0046] Compared with existing technologies, the environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark provided by this invention is the first to use cork oak bark as the core material of the flooring surface. Cork oak bark is renewable, and the trees can continue to grow after harvesting, avoiding the excessive consumption of traditional hardwood resources. At the same time, the natural texture and color of the bark are rich and diverse, which can meet the personalized decoration needs of different scenarios and break the pattern of single material selection in traditional flooring. In addition, through the dual texture treatment of micro-grooves and frosted surface, the anti-slip coefficient of the flooring surface is greater than or equal to 0.65, effectively solving the safety hazards in humid environments. Meanwhile, the natural honeycomb structure of cork oak cork and the sound-absorbing holes of the moisture-proof and sound-insulating middle layer 12 work together to achieve a sound absorption coefficient of 0.35-0.45, which is more than 40% better than ordinary composite flooring in terms of noise reduction. Meanwhile, the multi-layered composite structure enables the synergistic effect of each functional layer. The high-strength reinforcing layer 13 ensures the static bending strength and deformation resistance of the flooring, while the moisture-proof and sound-insulating middle layer 12 effectively blocks water vapor penetration. The moisture-proof and sound-insulating layer 14 can extend the service life and adapt to complex usage environments such as humid conditions and high personnel flow. The entire process of manufacturing the composite flooring adopts low-energy consumption technology, avoiding extreme production conditions such as high temperature and high pressure. Environmentally friendly adhesives and chemical-free treatment methods are used, resulting in a formaldehyde emission of less than 0.02 mg / m³, which is far lower than the 0.124 mg / m³ standard of GB 18580-2025. Furthermore, scrap materials are recycled and reused, which is in line with the development direction of green building materials.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions or improvements within the spirit of the present invention are covered within the scope of the claims of the present invention.

Claims

1. An environmentally friendly, non-slip, and noise-reducing composite flooring based on cork oak bark, characterized by: The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark comprises, from the surface to the bottom, at least one protective layer, at least one cork oak layer, at least one moisture-proof and sound-insulating middle layer, one reinforcing layer, and one moisture-proof and sound-absorbing layer. The cork oak layer is a single piece to ensure a porosity of 40%–60% and a moisture content of 12%–15%. The reinforcing layer is made of poplar veneer and bamboo fiber sheets, laminated together, and has a moisture content of 10%–16% to ensure a static bending strength greater than or equal to 30 MPa. The moisture-proof and sound-insulating middle layer is made by mixing and pressing perlite powder, rubber granules, and environmentally friendly resin in a mass ratio of 3:5:

2. The perlite powder has a particle size of 0.075–0.15 mm, and the rubber granules have a particle size of 0.5–1 mm. The rubber granules and perlite powder form a graded structure with large particles supporting small particles to ensure that the perlite powder does not stick together and clump.

2. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 1, characterized in that: The method for controlling the porosity of the cork oak layer to 40%–60% is as follows: First, select cork oak bark that is over 20 years old; then soften the cork oak bark by using steam softening at a softening temperature of 80–90℃ and a softening time of 30–40 minutes to adjust the fiber elasticity in the cork oak layer; finally, apply a light pressure of 0.1–0.5 MPa during hot pressing to adjust the porosity to 40%–60%.

3. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 2, characterized in that: When softening the bark of the cork oak, steam is used to soften the bark at a temperature of 80–90°C for 30–40 minutes. The softening temperature and time ranges are set to ensure the processing accuracy of the anti-slip texture. Since the cork oak layer needs to be processed with micro-grooved anti-slip textures, a softening temperature of 80–90°C can fully soften the cork oak fibers, preventing brittleness or crumbling during processing. By controlling the softening time, ensuring a softening time of 30–40 minutes, the softening effect can be evenly penetrated to the interior, avoiding uneven processing texture caused by surface softening and excessive hardening of the inner layer, thus laying the foundation for anti-slip performance.

4. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 3, characterized in that: The surface of the cork oak layer is processed with micro-grooved anti-slip texture. The depth of the micro-grooves is 0.1 to 0.3 mm, the spacing is 5 to 30 mm, and the abrasion roughness is Ra1.2 to Ra2.0 μm.

5. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 1, characterized in that: Each groove of the microgroove extends at an angle of 45° to 60° relative to the length of the plate, and the anti-slip texture of the microgroove is formed by two sets of intersecting oblique grooves to form a grid.

6. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 1, characterized in that: The moisture-proof and sound-insulating middle layer has uniformly distributed sound-absorbing holes with a diameter of 1-2 mm and a spacing of 5-8 mm.

7. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 6, characterized in that: The method for forming the sound-absorbing holes is as follows: First, the raw materials are pretreated by drying the perlite powder at 115℃~125℃ for about 2 hours to remove moisture and prevent excessive shrinkage of the resin. Second, the ratio of raw materials must be controlled, strictly adhering to a mass ratio of perlite powder, rubber granules, and environmentally friendly resin of 3:5:2, to ensure a balance between the spacing effect of the rubber granules and the filling effect of the perlite powder, avoiding gaps that are too large or too small. Finally, the pressing parameters must be strictly controlled during pressing, namely, the applied pressure should be between 1~2MPa, the pressing temperature should be controlled between 80~100℃, and the pressing time should be controlled between 15~20min, to ensure that the resin is fully cured while forming the sound-absorbing holes with the above parameters.

8. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 1, characterized in that: The raw materials of the moisture-proof and sound-absorbing layer include reclaimed rubber powder, nano-silica, water-based epoxy resin adhesive, silane coupling agent, and antibacterial agent, wherein the weight percentage content of the reclaimed rubber powder is 60% to 70%, the weight percentage content of the nano-silica is 5% to 10%, the weight percentage content of the water-based epoxy resin adhesive is 20% to 30%, the weight percentage content of the silane coupling agent is 1% to 2%, and the weight percentage content of the antibacterial agent is 0.5% to 1%.

9. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 8, characterized in that: The method for producing the moisture-proof and sound-absorbing layer is as follows: First, pretreatment is performed by drying the recycled rubber powder at 75℃~85℃ for 0.8 hours to 1.2 hours to remove moisture, while modifying the nano-silica with a silane coupling agent to improve its compatibility with the rubber powder; second, mixing is performed by adding all raw materials to a high-speed mixer and stirring at 1000~1200r / min for 15~20min to form a uniform mixture; third, pressing is performed by feeding the mixture into a mold, applying a pressure of 1.5~2MPa, and holding it at 100~110℃ for 25~30min to cure and shape; finally, post-treatment is performed by cooling the moisture-proof and sound-absorbing layer 14 to room temperature and polishing the surface to ensure uniform thickness of 3~4mm.

10. The environmentally friendly, anti-slip, and noise-reducing composite flooring based on cork oak bark as described in claim 8, characterized in that: The antibacterial agent can be nano silver powder.

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