A composite bamboo-plastic decorative panel

Abstract

This invention discloses a composite bamboo-plastic decorative panel, comprising a substrate and a coating layer. The substrate uses a bamboo-plastic reinforced composite material board as the core board. The bamboo-plastic reinforced composite material board is made from moso bamboo, which is cut to a fixed length after removing the head, tail, branches, yellow and green parts. The inner nodes are then removed and impurities are cleaned before being split to obtain bamboo skewers. These skewers are shaped into a curtain, impregnated with a reinforcing phenolic resin, and then stacked and hot-pressed in a mold to obtain the final product. An aluminum backing plate is formed on the bottom surface of the core board, and a ceramic silicone rubber filling layer is formed between the core board and the aluminum backing plate. The surface of the core board is coated with an unsaturated polyester resin layer, and a UV coating layer is formed on the surface of this unsaturated polyester resin layer. This invention has a simple and stable structure, a smooth surface, good decorative properties, and excellent acoustic, mechanical, and thermal insulation performance.

Description

Technical Field

[0001] This invention relates to the field of bamboo-based materials in the building materials industry, specifically to a composite bamboo-plastic decorative panel. Background Technology

[0002] As a fast-growing timber, bamboo can largely replace wood through technological processing, thereby reducing timber consumption and achieving the goals of reducing logging and protecting the environment. Currently, bamboo products mainly fall into three categories in the panel industry: bamboo plywood, bamboo woven plywood, and bamboo chipboard. These products have a certain market application and are developing rapidly, becoming a major focus of bamboo resource development and utilization in recent years. However, bamboo plywood has a low utilization rate of bamboo raw materials, bamboo woven plywood and bamboo chipboard have insufficient performance, and bamboo chipboard also has mildew resistance issues. Therefore, their development is limited, and the application of bamboo resources as structural materials has not yet been fully utilized.

[0003] For the reasons mentioned above, bamboo-plastic composite materials have been developed in existing technologies. The manufacturing process is similar to that of wood-plastic composite materials. As a type of polymer bamboo fiber composite material, it mainly uses pre-treated and modified bamboo fibers or bamboo powder, mixed with plastic materials in a certain proportion, and then processed through high-temperature mixing and molding with the help of additives. It combines the characteristics of plant fibers and polymer materials, possessing the texture of natural bamboo, good mechanical properties, and the ability to be drilled and planed. It exhibits low shrinkage and twisting, no formaldehyde release, and is waterproof, overcoming the limitations of traditional bamboo and plastic materials, and has a wide range of applications.

[0004] Due to the aforementioned properties of bamboo-plastic composite materials and their significantly lower price compared to traditional decorative panels, they have broad application prospects in interior decoration, high outdoor weather-resistant materials, and furniture materials, and are increasingly being used as decorative panels. Different manufacturers produce bamboo-plastic composite panels with varying formulas and processes, resulting in different performance focuses. However, existing bamboo-plastic composite materials generally suffer from low overall structural strength, susceptibility to damage, and low bamboo utilization. Under high-intensity decorative conditions or strong physical impacts, their performance is still inferior to traditional stone panels or traditional hardwood panels, limiting their application. Furthermore, due to their material characteristics, bamboo-plastic composite materials often exhibit natural wood or bamboo grain decorative effects and are difficult to attach additional decorative layers, resulting in a limited range of decorative forms. This further restricts the use and market potential of existing bamboo-plastic composite panels in the decoration field. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a composite bamboo-plastic material decorative panel to overcome the shortcomings in the above-mentioned background technology.

[0006] The technical problem solved by this invention is achieved by the following technical solution:

[0007] This invention first discloses a method for preparing a bamboo-plastic reinforced composite material board, which specifically includes the following steps:

[0008] S1 First, take the raw bamboo and remove the head, tail, branches, yellow and green parts in sequence, then cut it to a fixed length. Then, open the bamboo nodes and polish the inner round surface of the bamboo nodes to obtain polished bamboo nodes. At the same time, collect the bamboo waste materials except for the bamboo tail, bamboo leaves, bamboo green parts and bamboo inner membrane, which are the waste intermediate materials.

[0009] S2 processes the bamboo sections that have been treated in step S1 to remove lignin, pectin, sugar and oil from the bamboo. Then, the bamboo sections are longitudinally split and treated with alkali. After the alkali treatment, the bamboo sections are washed with running water and drained. After draining, the bamboo sections are dried and then split to obtain bamboo sticks and scraps.

[0010] S3 uses the bamboo skewers obtained in step S2 as raw materials to make bamboo curtains; the bamboo curtains are then modified by treating them with a coupling agent; the modified bamboo curtains are then treated with an impregnation process, controlling the weight gain of the bamboo curtains after impregnation to be 8-12%;

[0011] The impregnation process uses phenolic resin as the impregnating compound, which contains 10-17 wt% reinforcing filler. The mass ratio of fiber to powder in the reinforcing filler is 5:2-3:1. The fiber is a mixture of trivinyl fiber, polybenzimidazole fiber, and bamboo fiber in a mass ratio of 1:1:3. The powder is a mixture of powders containing at least 65% bamboo powder and at least 15% oyster shell powder.

[0012] S4 involves stacking multiple layers of resin-impregnated bamboo curtains in a mold and then hot-pressing them. After hot pressing, the bamboo curtains are shaped and then cut / trimmed to obtain the finished board material.

[0013] As a further clarification, the raw material is moso bamboo that is five years or older.

[0014] As a further limitation, in step S2, when treating the lignin, pectin, sugar and oil in the bamboo, the cut bamboo sections are first placed in a pressure vessel, and the lignin, pectin and other impurities in the bamboo are removed by high temperature and high pressure cooking. Then, the bamboo after cooking is cooled in the furnace, and under heat preservation conditions, the remaining lignin, pectin, sugar and oil in the bamboo are further removed by biological enzymes.

[0015] As a further limitation, the cross-section of the bamboo skewer obtained by cutting in step S2 is an equilateral triangle, a sector, or an isosceles trapezoid, and the cross-sectional dimension of the bamboo skewer is less than 5mm.

[0016] As a further limitation, the bamboo fiber used in step S3 is prepared using the scraps obtained in step S2 as raw materials and existing bamboo fiber preparation processes.

[0017] As a further limitation, the bamboo powder used in step S3 is obtained by using the waste intermediate material obtained in step S1 as raw material, drying it to absolute dryness using a drying equipment, and then grinding it to obtain bamboo powder after drying.

[0018] As a further limitation, the bamboo powder used in step S3 includes carbonized bamboo powder that has undergone carbonization treatment, with a mass ratio of 7-15%.

[0019] As a further limitation, the powder used in the reinforcing filler also includes one or a combination of sepiolite powder, quartz powder, and mica powder, as well as a mixture of cellulose acetate butyrate and sodium polyacrylate accounting for 3-5 wt% of the powder.

[0020] As a further limitation, the number of layers of bamboo curtain stacked in the mold is 2 to 5. When the stacked bamboo curtain is hot-pressed in the mold, the hot-pressing temperature is controlled at 170 to 190°C, the hot-pressing pressure is 6 to 12 MPa, the hot-pressing time is 6 to 10 minutes, and the hot-pressing time is inversely proportional to the hot-pressing pressure.

[0021] The technical solution of the present invention also discloses a composite bamboo-plastic decorative panel, wherein the composite bamboo-plastic decorative panel uses a bamboo-plastic reinforced composite material board obtained by the above method as the core board; an aluminum backing plate is formed on the bottom surface of the core board, and a ceramic silicone rubber filling layer is formed between the core board and the aluminum backing plate; an unsaturated polyester resin layer is coated on the surface of the core board, and a UV coating layer is formed on the surface of the unsaturated polyester resin layer.

[0022] As a further definition, the UV coating layer comprises, from the unsaturated polyester resin layer to the outside, a UV primer layer, a UV color paint layer, and a high-gloss topcoat layer.

[0023] As a further limitation, the ceramic silicone rubber layer also contains ceramic fibers and / or glass fibers as fibers, and the amount of glass fibers added is 1 / 5 to 1 / 4 of the weight of the rubber compound in the ceramic silicone rubber layer.

[0024] Beneficial effects: The technical solution of the present invention uses natural bamboo fiber and its processing by-products as raw materials to produce bamboo-plastic reinforced composite materials, and uses this bamboo-plastic reinforced composite material as a core board to prepare composite bamboo-plastic decorative panels. The prepared bamboo-plastic reinforced composite material core board has high strength and high density, and all indicators have reached or exceeded the technical performance requirements of most wood-based panels.

[0025] The molded bamboo-plastic reinforced composite material has a high utilization rate of raw bamboo, reaching over 90%, and is characterized by being green, environmentally friendly, safe, and harmless. It is of great significance for developing a circular economy, improving the ecological environment, and increasing resource utilization.

[0026] The composite bamboo-plastic composite decorative panels prepared by it have strong resistance to impact loads and cyclic fatigue damage, and have the best seismic resistance. They exhibit excellent stability and structural integrity in physical impact damage, corrosion, and humid environments, and have excellent building sound insulation and vibration reduction performance. The surface layer can be coated and molded according to actual needs, making it especially suitable for use as interior decorative wall panels, exterior wall panels, or flooring. Attached Figure Description

[0027] Figure 1 A detailed cross-sectional view of a preferred embodiment of the present invention.

[0028] The components are: 1. High-gloss topcoat layer; 2. UV color paint layer; 3. UV primer layer; 4. Unsaturated polyester resin layer; 5. Core board; 6. Ceramic silicone rubber layer; 7. Aluminum backing plate; 8. Dot matrix holes; 9. Raised ribs; 10. Raised rib holes. Detailed Implementation

[0029] To make the technical means, creative features, objectives, and effects of this invention easier to understand, the invention is further described below with reference to specific embodiments. The described embodiments are merely some, not all, of the embodiments of this invention.

[0030] In the following embodiments, those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0031] Under the technical conditions of this embodiment, a bamboo-plastic reinforced composite material board is first prepared, which is prepared by the following method:

[0032] First, select moso bamboo aged five years or more as raw material. The raw bamboo is then processed by removing the head and tail, branches and nodes, and removing yellow and green parts. After processing, it is cut to the desired length according to the length of the board to be processed, leaving a 2-3cm allowance at the head and tail. Then, the inner nodes of the bamboo are opened and the inner round surface of the nodes is polished to obtain polished bamboo sections. The cut polished bamboo sections are then placed in a pressure vessel and superheated steam is used to remove most of the lignin, pectin and other impurities from the raw bamboo and soften the bamboo sections. The bamboo sections are then cooled and drained in the container. After draining, they are placed in an insulated container and further removed by biological enzymes under the insulated condition of 30-40℃ to remove the remaining lignin, pectin, sugar and oil from the bamboo.

[0033] During the above operations, bamboo waste materials other than bamboo tails, bamboo leaves, bamboo green leaves, and bamboo inner membranes are collected during the process of removing the head and tail, removing branches and nodes, removing yellow and green parts, opening up the inner nodes, and polishing the inner circular surface of the bamboo nodes. These are called waste intermediate materials. The waste intermediate materials are treated with pressure vessels and enzymes in the same way as above. After the treatment is completed, they are taken out, drained and washed. Then they are used as raw materials and dried to absolute dryness using drying equipment. After drying, they are ground to obtain bamboo powder.

[0034] After processing, a longitudinal slit is made in the bamboo section from top to bottom, and then it is immersed in a 25% sodium hydroxide solution for alkali treatment. After alkali treatment, it is washed with running water and drained. After draining, the bamboo section is dried in an oven until the moisture content is below 15%, and then cut with a knife to obtain bamboo skewers. In different embodiments, it is necessary to ensure that the cross-section of the cut bamboo skewers is an equilateral triangle, a fan shape, or an isosceles trapezoid, and the cross-sectional dimension of the bamboo skewers is less than 5mm (i.e., any line connecting the cross-sections is less than 5mm). In this embodiment, the cross-section of the corresponding bamboo skewers is controlled to be an equilateral triangle with a side length of 3.5mm. The bamboo skewers are arranged face to face, and then perforated on the same plane. Threads are connected at the perforation positions. After the thread connection is completed, a fabric mesh is attached to both sides of the bamboo mat.

[0035] If the bamboo skewers are not long enough or there are too many short pieces of material during the bamboo curtain forming process, the bamboo curtain can also be formed by splicing.

[0036] The reason for this operation is that the density of bamboo varies along its length, resulting in different shrinkage rates in different parts during the thermoforming process of the bamboo curtain. This makes the bamboo skewers prone to longitudinal bending and internal defects during forming. Processing the bamboo skewers into equilateral triangles, fan shapes, or isosceles trapezoids allows them to be spliced ​​together in an interlaced manner, thereby neutralizing the bending deformation caused by longitudinal shrinkage on different bamboo skewers and ultimately obtaining a relatively stable planar bamboo curtain.

[0037] In the above operation, while cutting the processed bamboo to obtain bamboo skewers, the scraps and offcuts generated during the cutting process are collected and then used as raw materials to prepare bamboo fiber using existing bamboo fiber preparation technology.

[0038] Under the process conditions of this embodiment, the bamboo powder and bamboo fiber obtained can be used directly in subsequent processes or sold as intermediate products, which can effectively improve the utilization rate of bamboo materials.

[0039] Preparation of the adhesive for bamboo curtain impregnation: A phenolic resin adhesive is used as the main material, and 15 wt% reinforcing filler is uniformly dispersed in the adhesive. The reinforcing filler includes fibers and powders, wherein:

[0040] The fibrous material is a mixture of trivinyl fiber, polybenzimidazole fiber, and bamboo fiber in a mass ratio of 1:1:3. The powder consists of 68% bamboo powder, 17% oyster shell powder, 5% quartz powder, 5% mica powder, 2% cellulose acetate butyrate, and 3% sodium polyacrylate by mass. In the above reinforcing filler, the fiber combination of trivinyl fiber, polybenzimidazole fiber, and bamboo fiber can form structural cross-links during the hot-pressing process of the impregnated bamboo curtain. While ensuring the integrity of the formed board, it also works with the bamboo curtain to form overall structural toughness, achieving internal stress buffering under external impact, thereby reducing overall deformation and local impact damage to the board surface. It also gives the formed board excellent nail-holding performance, facilitating subsequent processing. The powder reinforcing filler, in addition to improving the structural strength of the board and the uniformity of fiber dispersion, also provides the board with water repellency, insect resistance, and antistatic properties. In another embodiment, the bamboo powder used in the powder may also include 7-15% by weight of carbonized bamboo powder that has undergone carbonization treatment, and the use of carbonized bamboo powder can also provide antibacterial and antifungal effects for the board.

[0041] The bamboo curtain is impregnated with the above-mentioned adhesive. During impregnation, excess adhesive is scraped off to control the weight gain of the bamboo curtain after impregnation to be between 8% and 12%.

[0042] The above-mentioned resin-impregnated bamboo curtains are stacked in a mold. The stacking can be done in a crisscross pattern, with a maximum of 4 layers. After stacking, hot pressing is performed to set the shape. During hot pressing, the temperature of the stacked bamboo curtains in the mold is controlled at 175°C, the pressure is 10 MPa, and the hot pressing time is 8 minutes. After hot pressing, the bamboo curtains are removed and allowed to cool naturally. After cooling, they are left to stand for 24-36 hours to complete the setting. Then, they are cut / trimmed to obtain the finished board.

[0043] Under the above-described process conditions in this embodiment, the utilization rate of bamboo can be increased from the current 20%~50% for bamboo plywood and bamboo woven plywood, which are used as whole bamboo boards, to over 95%; simultaneously, the product performance indicators of the formed bamboo-plastic reinforced composite material board are as follows:

[0044] It has a density of 1060~1107 kg / m³, a specific modulus of 27600 MPa, a specific strength of 245 MPa, a flexural strength of 345~368 MPa, a tensile strength of 362~372 MPa, a compressive strength of 240~268 MPa, a shear strength of 20~22 MPa, an elastic modulus of 27~32 GPa, and a water-boiling expansion rate of ≤5%.

[0045] The aforementioned mechanical performance indicators are significantly superior to bamboo chipboard and most log boards and plywood on the market.

[0046] Furthermore, the bamboo-plastic reinforced composite material board of this embodiment is sawable and splicable. It can be spliced ​​and combined using methods such as straight splicing, overlapping splicing, staggered splicing, finger jointing, and screw jointing to obtain larger-sized composite boards, which is convenient for use as flooring material. The structure can be constructed using prefabricated methods by splicing the boards, making it suitable for outdoor use as a prefabricated structure. At the same time, since there are no insect infestations or knots like in wood, the processed surface is very clean and requires no puttying. In addition, this bamboo-plastic reinforced composite material board also has good resistance to temperature changes and strong adaptability to climate. It is not easily deformed in rainy and humid climates, making it suitable as a decorative material for exterior walls.

[0047] In addition, this embodiment also discloses a composite bamboo-plastic composite decorative panel. This composite bamboo-plastic composite decorative panel is prepared using the above-mentioned bamboo-plastic reinforced composite material board as the core board 5. The composite bamboo-plastic composite decorative panel specifically includes a substrate and a coating layer. The substrate includes a core board 5 formed from the bamboo-plastic reinforced composite material board prepared by the above process, a ceramic silicone rubber layer 6, and an aluminum backing plate 7. The core board 5 is formed together with an unsaturated polyester resin layer 4 on one side, while the other side is the ceramic silicone rubber layer 6. The ceramic silicone rubber layer 6 also contains glass fiber accounting for 1 / 5 of the weight of the adhesive to improve the sound insulation, temperature change resistance, and physical strength of the decorative panel.

[0048] In this embodiment, the unsaturated polyester resin layer 4 has good surface affinity with the core board 5 material on the inner side. At the same time, due to the material characteristics of the unsaturated polyester resin layer 4, it also has good adhesion to the surface and can be coated with oil and paint. Depending on the specific needs, the surface can be sprayed or brushed with various wood oils, wood wax oils, water-based varnishes, nitrocellulose varnishes, alkyd varnishes, as well as tinted wood wax oils and blended paints, etc. In this embodiment, a coating layer with better decorative effect is used as the finishing layer for surface decoration.

[0049] The coating layer is directly applied onto the unsaturated polyester resin layer 4, including the high-gloss topcoat layer 1, the UV color paint layer 2, and the UV primer layer 3. The three UV paint layers are formed in three stages. The unsaturated polyester resin layer 4, as an interface blending layer, can effectively coordinate the visual effect of the paint layer, achieving a bright color and a full paint film, while reducing the amount of UV paint used.

[0050] The UV decorative panel in this embodiment is used to be molded directly on the concrete wall. In order to facilitate molding, the aluminum backing plate 7 is provided with ribs 9 and rib holes 10, which can effectively improve the additional strength and adhesion area of ​​the UV decorative panel when it is molded on the concrete surface.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a bamboo-plastic reinforced composite panel, characterized in that, The method specifically comprises the following operation steps: S1, first, the raw material of bamboo is cut to a certain length after removing the head and tail, branches, yellow and green, then the inner nodes are punched, and the inner circular surface of the nodes is polished to obtain polished nodes; meanwhile, the bamboo waste except the tail, leaves, green and inner cavity membrane is collected, which is the waste intermediate material; S2, the nodes treated in step S1 are processed to remove lignin, pectin, sugar and oil in the bamboo, then the nodes are vertically cut and subjected to alkali treatment, washed with running water and drained after the alkali treatment, dried, and then cut to obtain bamboo sticks and leftover materials; S3, the bamboo sticks prepared in step S2 are used as raw materials to make bamboo curtains; and the bamboo curtains are modified by coupling agent treatment; The modified bamboo curtains are treated by a dipping process, and the weight gain ratio of the bamboo curtains after dipping is controlled to be 8-12%; The dipping glue used in the dipping process is a phenolic resin glue, and 10-17wt% of reinforcing fillers are added to the glue; the mass ratio of fiber material to powder in the reinforcing fillers is 5:2-3:1, the fiber material is a mixture of tri-vinyl fiber, polybenzimidazole fiber and bamboo fiber in a mass ratio of 1:1:3, the powder is a mixture powder, the content of bamboo powder in the mixture powder is not less than 65%, and not less than 15% of oyster shell powder, and one or a combination of sepiolite powder, quartz powder and mica powder, and a mixture of cellulose acetate butyrate and polyacrylic acid sodium in a mass ratio of 3-5wt% of the powder; The cross section of the bamboo stick is a regular triangle, a sector or an isosceles trapezoid, and the cross section size of the bamboo stick is less than 5mm; S4, the bamboo curtains after multi-layer dipping are stacked in a mold and subjected to hot pressing, and the finished plate is obtained after sizing, cutting and edge trimming.

2. The method for preparing bamboo-plastic reinforced composite material board according to claim 1, characterized in that, The raw material bamboo is a bamboo of more than five years old.

3. The method for preparing the bamboo-plastic reinforced composite material board according to claim 1, characterized in that, In step S2, the cut bamboo nodes are placed in a pressure vessel, and high-temperature and high-pressure cooking is used to remove lignin, pectin and other impurities in the bamboo, then the cooked bamboo is cooled with the furnace, and under the condition of heat preservation, biological enzymes are used to further remove the remaining lignin, pectin, sugar and oil in the bamboo.

4. The method for preparing the bamboo-plastic reinforced composite material board according to claim 1, characterized in that, The bamboo fiber used in step S3 is prepared by using the leftover materials prepared in step S2 as raw materials by using the existing bamboo fiber preparation process.

5. The method for preparing the bamboo-plastic reinforced composite material board according to claim 1, characterized in that, The bamboo powder used in step S3 is prepared by using the waste intermediate material prepared in step S1 as raw material, drying to absolute dryness by using a drying device, and then grinding to obtain bamboo powder.

6. The method for preparing bamboo-plastic reinforced composite material board according to claim 1, characterized in that, The bamboo powder used in step S3 includes 7-15% of carbonized bamboo powder treated by carbonization.

7. The method for preparing bamboo-plastic reinforced composite material board according to claim 1, characterized in that, The number of layers of the bamboo curtains stacked in the mold is 2-5, the hot pressing temperature is controlled to be 170-190℃, the hot pressing pressure is controlled to be 6-12MPa, and the hot pressing time is 6-10min, and the hot pressing time is inversely proportional to the hot pressing pressure.

8. A composite bamboo-plastic material panel, characterized in that, The composite bamboo-plastic material panel uses the bamboo-plastic reinforced composite material panel in any one of claims 1-7 as a core panel; an aluminum lining plate is formed on the bottom surface of the core panel, and a ceramic silicone rubber filling layer is formed between the core panel and the aluminum lining plate; an unsaturated polyester resin layer is coated on the surface of the core panel, and a UV coating layer is formed on the surface of the unsaturated polyester resin layer.

9. The composite bamboo-plastic material panel according to claim 8, characterized in that, The UV coating layer comprises, from the unsaturated polyester resin layer side outward, a UV primer layer, a UV color paint layer, and a high-gloss topcoat layer.

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