Degradable decorative wall base material based on agricultural waste fibers

Abstract

The invention discloses a degradable decorative wall surface base material based on agricultural waste fibers, and belongs to the technical field of indoor decorative materials. Palm and hemp agricultural waste fibers such as pineapple leaf fibers, coconut fibers and hemp fibers are used as core raw materials of the base material, in addition, the base material further comprises an environment-friendly binder, a reinforcing agent, a waterproof agent and an additive, and 2-3 parts of palm plant powder can be selectively added. The environment-friendly binder is starch-based or formaldehyde-free degradable, and the reinforcing agent, the waterproof agent and the additive are all selected from environment-friendly functional components. The preparation process is completed through the procedures of dry mixing, wet mixing, forming and drying, and the product appearance can be optimized in cooperation with surface treatment. High-value utilization of agricultural waste is achieved, a circulating chain of new agricultural by-products and green building materials is constructed, and the product has degradability and practical performance, is suitable for green buildings and environment-friendly home scenes and has remarkable economic, ecological and social benefits.

Description

Technical Field

[0001] This invention belongs to the field of interior decoration materials technology, and in particular relates to a biodegradable decorative wall substrate based on agricultural waste fiber. Background Technology

[0002] Interior wall cladding materials are the foundation of wall decoration, and their performance directly affects the decorative effect and functionality of the walls. Traditional wall cladding materials such as plywood, blockboard, and MDF, while possessing certain performance advantages, also have some drawbacks. For example, plywood requires a large amount of glue during production, potentially leading to excessive formaldehyde release; blockboard is susceptible to moisture, requiring careful moisture prevention during construction; and MDF has poor moisture resistance and is prone to deformation when exposed to water. Furthermore, most of these traditional materials are non-biodegradable, posing a burden on the environment upon disposal.

[0003] In this context, developing green, low-carbon, and recyclable alternative materials has become an urgent need for the industry. Agricultural waste fibers (such as pineapple leaf fiber, coconut fiber, hemp fiber, and other palm and hemp agricultural waste fibers) have become ideal raw materials for a new generation of environmentally friendly interior decorative wall substrates due to their wide availability, renewability, biodegradability, and carbon sequestration potential.

[0004] From a full life-cycle perspective, the environmental advantages of agricultural waste fiber substrates are reflected in three core aspects:

[0005] Raw material acquisition stage: Agricultural wastes such as palm and hemp have short growth cycles and a considerable amount of carbon sequestration per hectare during the growth process, which significantly reduces the carbon footprint of raw materials;

[0006] Production and processing stage: Physical cold pressing process is used instead of high-temperature sintering, reducing energy consumption by more than 60%;

[0007] Waste disposal stage: The material can degrade by more than 90% in the natural environment within 6-12 months. The degradation products are carbon dioxide, organic matter and trace elements, which do not cause secondary pollution to the soil.

[0008] Compared to traditional petrochemical-based materials, the core breakthrough of agricultural waste fiber-based wall materials lies in their dual environmental protection attributes of eliminating pollution at the source and recycling at the end. Under composting conditions, the fiber components can be transformed into humus through microbial action, completing a "cradle-to-cradle" closed loop. Furthermore, this process has been certified by internationally recognized authorities to ensure that the degradation products are free of ecotoxicity.

[0009] In terms of indoor health and safety, agricultural waste fiber substrates do not contain formaldehyde, benzene compounds, or heavy metals, and have low VOC (volatile organic compound) emissions, far lower than E0 grade engineered wood products.

[0010] The core challenge in applying agricultural waste fibers lies in the interfacial bonding defects caused by the mismatch in their chemical polarities. Agricultural waste fibers are mainly composed of cellulose, hemicellulose, and lignin, and their surfaces are rich in hydrophilic hydroxyl groups, while mainstream biodegradable resins or engineering resins are hydrophobic. The poor interfacial compatibility between the two leads to the formation of a non-homogeneous phase at the microscopic level, affecting the material's performance.

[0011] The production cost of agricultural waste fiber substrates is currently 20%-30% higher than that of traditional materials, mainly due to complex raw material pretreatment, lack of specialized equipment, and difficulty in controlling performance consistency. Furthermore, the long-term stability of agricultural waste fiber substrates faces challenges under complex indoor environments (temperature and humidity cycles, light exposure).

[0012] With increasing environmental awareness and growing health demands, the market urgently needs a formaldehyde-free, biodegradable, and stable decorative wall substrate; however, how to solve the problems of existing agricultural waste fiber substrates is a direction that the industry needs to study now. Summary of the Invention

[0013] The purpose of this invention is to propose a biodegradable decorative wall substrate based on agricultural waste fiber and its preparation process. By using renewable agricultural waste fiber as the main raw material and formaldehyde-free adhesive as an auxiliary material, combined with a low-energy molding process, the substrate achieves environmental friendliness, biodegradability, and excellent physical properties, thus meeting the needs of interior decoration for health and sustainable development.

[0014] To achieve the above objectives, the present invention provides a biodegradable decorative wall substrate, comprising the following components by weight:

[0015]

[0016] The palm and hemp agricultural waste fibers include at least one of pineapple leaf fiber, coconut fiber, and hemp fiber, with a particle size of 0.1-1 mm and a total SiO2 and Al2O3 content of ≥60%.

[0017] Preferably, it also includes 2-3 parts of palm plant powder; the particle size of the palm plant powder is 50-100μm.

[0018] Preferably, the environmentally friendly adhesive is a starch-based adhesive or a formaldehyde-free biodegradable adhesive with a solid content of 30%-50% and a viscosity of 500-1000 mPa·s.

[0019] Preferably, the reinforcing agent is at least one of calcium carbonate, talc, and cellulose ether;

[0020] When the reinforcing agent is calcium carbonate, the particle size of calcium carbonate is ≤50μm;

[0021] When the reinforcing agent is talc, the particle size of the talc is ≤30μm;

[0022] When the reinforcing agent is cellulose ether, the molecular weight of the cellulose ether is 100K-200K.

[0023] Preferably, the waterproofing agent is a bio-based waterproofing agent.

[0024] Preferably, the additive is at least one of flame retardant and preservative.

[0025] Preferably, the method for preparing the palm and hemp agricultural waste fibers includes the following steps:

[0026] S1: Take agricultural waste materials from palm and hemp, remove impurities, wash and dry them to obtain crude raw materials;

[0027] S2: Take a portion of the raw material and cut it into 3-5cm segments; then use the steam explosion method to prepare short fibers, then screen out the components within 0.1-1mm, then acid wash, dry, and obtain crude fibers;

[0028] S3: Take another crude raw material and calcine it at ≥600℃ in an inert atmosphere for at least 2 hours, then grind it until D50≤15μm to obtain waste ash;

[0029] S4: Mix waste ash and coarse fiber to make the total content of SiO2 and Al2O3 ≥60%, i.e., agricultural waste fiber from palm and hemp.

[0030] Another object of the present invention is to provide a method for preparing the aforementioned biodegradable decorative wall substrate, comprising the following steps:

[0031] S1: Dry mix palm and hemp agricultural waste fibers, reinforcing agents, and additives;

[0032] S2: Add adhesive and waterproofing agent, then add water and mix to form a plastic mixture with a moisture content of 20%-30%;

[0033] S3: The plastic mixture is placed in a mold and pressed to form a preform; or the preform is formed by extrusion molding using an extruder.

[0034] S4: The blank is dried to the specified moisture content, which is the biodegradable decorative wall substrate.

[0035] Preferably, it also includes the following steps:

[0036] S5: Surface treatment of the biodegradable decorative wall substrate, wherein the surface treatment is at least one of sanding, spraying and applying.

[0037] The present invention has the following advantages:

[0038] First, the raw materials are renewable, the resource utilization rate is high, and it conforms to the circular economy.

[0039] The core raw material is agricultural waste: mainly composed of agricultural waste fibers from palm and hemp, which are renewable wastes in agricultural production. They are widely available, inexpensive, and reduce environmental pollution caused by the incineration of agricultural waste through resource utilization, thus turning waste into treasure.

[0040] Raw material processing balances performance and resource maximization: Palm and hemp agricultural waste fibers are processed in stages through steam explosion (to produce coarse fibers) and high-temperature calcination (to produce waste ash). This process preserves the structural support of the fibers while utilizing the high SiO2 / Al2O3 content (total ≥60%) of the waste ash to improve the material's hardness and heat resistance, thus achieving efficient graded utilization of agricultural waste resources.

[0041] Second, it is highly environmentally friendly, with no harmful residues and is biodegradable.

[0042] No release of toxic substances: Starch-based adhesives or formaldehyde-free biodegradable adhesives (replacing traditional formaldehyde-containing urea-formaldehyde resins, etc.) are used, avoiding the release of volatile organic compounds (VOCs) such as formaldehyde from the source; the waterproofing agent is bio-based, and the additives (flame retardants, preservatives) are also environmentally friendly, so the overall material is harmless to the human body and the environment during use.

[0043] Biodegradable after disposal: The main body is natural agricultural waste fiber, and the binder and auxiliary agents are all biodegradable components. After the material is disposed of, it can be decomposed by microorganisms in the natural environment, and will not form "white pollution" or occupy landfills for a long time, thus solving the environmental pain point of traditional wall materials being difficult to degrade.

[0044] III. Performance is comprehensively adapted to wall surface requirements, and functionality is expandable.

[0045] Stable mechanical properties: The main structure is made of agricultural waste fibers from palm and hemp. Reinforcing agents are used to fill, toughen or improve the interfacial bonding to improve the compressive and flexural strength of the material and meet the structural strength requirements of the wall substrate.

[0046] Functional adaptation scenarios:

[0047] The addition of waterproofing agents improves the water resistance of materials, preventing mold or deformation in humid environments;

[0048] Additives (flame retardants, preservatives) can enhance fire resistance or anti-mold properties as needed, making them suitable for special scenarios such as kitchens and bathrooms;

[0049] Optional palm plant powder can be used to further refine the surface, and combined with surface treatments (sanding, spraying, and applying), it can achieve a variety of decorative effects (such as wood-like and stone-like textures).

[0050] IV. The preparation process is simple and easy to scale up.

[0051] The process is simple and controllable: it can be produced by "dry mixing, wet mixing, molding (pressurization or extrusion), and drying", without the need for high-temperature sintering or complex chemical synthesis. The equipment requirements are low (ordinary mixers, presses or extruders are sufficient), making it suitable for small and medium-sized enterprises to start production.

[0052] Flexible molding methods: It can be molded with pressure to customize the size of the board and extruded to produce the board in batches. With subsequent surface treatment, it can quickly adapt to different wall decoration needs and has high production efficiency.

[0053] In summary, this invention has the core advantages of "resource recycling, environmental protection and harmlessness, performance adaptability and simple process". It not only solves the environmental problems of traditional wall materials, but also meets the actual use needs through raw material and process optimization. It is suitable as a wall substrate for green buildings and environmentally friendly home scenarios and has high economic and social value. Detailed Implementation

[0054] To better understand the present invention, the present invention will be further described below with reference to specific embodiments. The terminology used in the embodiments is for describing specific implementation schemes and does not constitute a limitation on the scope of protection of the present invention.

[0055] In the specific implementation, unless otherwise specified, the experimental methods used are all conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0056] In a specific implementation:

[0057] The particle size of the calcium carbonate used is ≤50μm;

[0058] The talc powder used has a particle size ≤30μm;

[0059] The cellulose ether used has a molecular weight of 100K-200K.

[0060] The flame retardant used is aluminum hydroxide.

[0061] The preservative used is chitosan.

[0062] The waterproofing agent used was hydrogenated castor oil.

[0063] The environmentally friendly binder used is a gelatinized starch binder.

[0064] The palm plant powder used has a particle size of 50-100μm.

[0065] The particle size of the palm and hemp agricultural waste fibers used is within 0.1-1mm; the total content of SiO2 and Al2O3 is ≥60%.

[0066] The palm and hemp agricultural waste fibers used are prepared through the following steps:

[0067] S1: Take agricultural waste materials from palm and hemp, remove impurities, wash and dry them to obtain crude raw materials;

[0068] S2: Take a portion of the raw material and cut it into 3-5cm segments; then use the steam explosion method to prepare short fibers, then screen out the components within 0.1-1mm, then acid wash, dry, and obtain crude fibers;

[0069] S3: Take another crude raw material and calcine it at 600℃ in an inert atmosphere for 2 hours, then grind it until D50≤15μm to obtain waste ash;

[0070] S4: Mix waste ash and coarse fiber at a mass ratio of 2:1 to make the total content of SiO2 and Al2O3 ≥60%, i.e., agricultural waste fiber from palm and hemp.

[0071] Example 1: Preparation of a biodegradable decorative wall substrate, comprising the following steps:

[0072] S1: Weigh the raw materials as follows:

[0073]

[0074] S2: Add palm and hemp agricultural waste fibers, palm plant powder, and calcium carbonate to a mixer and dry mix at 100 rpm for 5 minutes;

[0075] S3: Add the remaining raw materials and an appropriate amount of water to the mixer, wet mix at 150 rpm for 10 minutes to form a plastic mixture with a moisture content of 30%;

[0076] S4: The plastic mixture is filled into the mold, and the hydraulic press is gradually pressurized to 15MPa. The pressure is maintained at room temperature for 10 minutes to obtain the green body;

[0077] S5: The green body is dried to a moisture content of 12%, and then polished with 120-240 grit sandpaper in sequence, with a surface roughness Ra≤1.0μm;

[0078] An environmentally friendly water-based coating with a film thickness of 0.05-0.1mm is used to obtain a biodegradable decorative wall substrate.

[0079] Example 2: Preparation of biodegradable decorative wall substrate, including the following steps:

[0080] S1: Weigh the raw materials as follows:

[0081]

[0082] S2: Add palm and hemp agricultural waste fibers, palm plant powder, and talc powder to a mixer and dry mix at 200 rpm for 2 minutes;

[0083] S3: Add the remaining raw materials and an appropriate amount of water to the mixer, wet mix at 250 rpm for 5 minutes to form a plastic mixture with a moisture content of 20%;

[0084] S4: The plastic mixture is filled into the mold, and the hydraulic press is gradually pressurized to 5MPa. The pressure is maintained at 60℃ for 30 minutes to obtain the green body;

[0085] S5: The green body is dried to a moisture content of 12%, and then polished with 120-240 grit sandpaper in sequence, with a surface roughness Ra≤1.0μm;

[0086] An environmentally friendly water-based coating with a film thickness of 0.05-0.1mm is used to obtain a biodegradable decorative wall substrate.

[0087] Example 3: Preparation of biodegradable decorative wall substrate, including the following steps:

[0088] S1: Weigh the raw materials as follows:

[0089]

[0090] S2: Add palm and hemp agricultural waste fibers, palm plant powder, and cellulose ether to a mixer and dry mix at 200 rpm for 2 minutes;

[0091] S3: Add the remaining raw materials and an appropriate amount of water to the mixer, wet mix at 250 rpm for 5 minutes to form a plastic mixture with a moisture content of 20%;

[0092] S4: The plastic mixture is filled into the mold, and the hydraulic press is gradually pressurized to 5MPa. The pressure is maintained at 60℃ for 30 minutes to obtain the green body;

[0093] S5: The green body is dried to a moisture content of 12%, and then polished with 120-240 grit sandpaper in sequence, with a surface roughness Ra≤1.0μm;

[0094] An environmentally friendly water-based coating with a film thickness of 0.05-0.1mm is used to obtain a biodegradable decorative wall substrate.

[0095] Example 5 describes the preparation of a biodegradable decorative wall substrate, which differs from Example 1 in that the amount of palm and hemp agricultural waste fiber is 30 parts, and the remaining components are adjusted proportionally.

[0096] Example 6 describes the preparation of a biodegradable decorative wall substrate, which differs from Example 1 in that it does not use a steam explosion process to treat agricultural waste fibers such as palm and hemp.

[0097] The biodegradable decorative wall substrates prepared in Examples 1-6 were subjected to performance tests, including the following specific items:

[0098] Formaldehyde emission: The test method is in accordance with GB 18580-2017 Interior decoration and renovation materials—Formaldehyde emission from wood-based panels and their products;

[0099] Degradability: The test method is in accordance with GB / T 19277.1-2011 Determination of the final aerobic biodegradability of materials under controlled composting conditions by means of the determination of carbon dioxide released - Part 1: General method;

[0100] Compressive strength, flexural strength, and water absorption: The test methods are in accordance with "JC / T 1024-2019 Wall Finishing Mortar".

[0101] The results are shown in Table 1 below:

[0102] Table 1

[0103]

[0104] As shown in Table 1, the mechanical properties of Example 4 decreased slightly due to the lack of palm plant powder filling effect. In Example 5, the insufficient content of palm and hemp agricultural waste fibers weakened the supporting structure, resulting in a significant reduction in both compressive and flexural strength. In Example 6, the lack of steam explosion treatment for the fibers resulted in ineffective fiber structure optimization and insufficient interfacial bonding, leading to a significant decrease in all properties, particularly in biodegradability and mechanical properties.

[0105] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A biodegradable decorative wall substrate, characterized in that, The following components are included in parts by mass: The palm and hemp agricultural waste fibers include at least one of pineapple leaf fiber, coconut fiber, and hemp fiber, with a particle size of 0.1-1 mm and a total SiO2 and Al2O3 content of ≥60%.

2. The biodegradable decorative wall substrate according to claim 1, characterized in that, It also includes 2-3 parts of palm plant powder; the particle size of the palm plant powder is 50-100μm.

3. The biodegradable decorative wall substrate according to claim 1, characterized in that, The environmentally friendly adhesive is a starch-based adhesive or a formaldehyde-free biodegradable adhesive with a solid content of 30%-50% and a viscosity of 500-1000 mPa·s.

4. The biodegradable decorative wall substrate according to claim 1, characterized in that, The reinforcing agent is at least one of calcium carbonate, talc, and cellulose ether; When the reinforcing agent is calcium carbonate, the particle size of calcium carbonate is ≤50μm; When the reinforcing agent is talc, the particle size of the talc is ≤30μm; When the reinforcing agent is cellulose ether, the molecular weight of the cellulose ether is 100K-200K.

5. The biodegradable decorative wall substrate according to claim 1, characterized in that, The waterproofing agent is a bio-based waterproofing agent.

6. The biodegradable decorative wall substrate according to claim 1, characterized in that, The additive is at least one of flame retardant and preservative.

7. The biodegradable decorative wall substrate according to claim 1, characterized in that, The method for preparing the agricultural waste fibers from palm and hemp includes the following steps: S1: Take agricultural waste materials from palm and hemp, remove impurities, wash and dry them to obtain crude raw materials; S2: Take a portion of the raw material and cut it into 3-5cm segments; then use the steam explosion method to prepare short fibers, then screen out the components within 0.1-1mm, then acid wash, dry, and obtain crude fibers; S3: Take another crude raw material and calcine it at ≥600℃ in an inert atmosphere for at least 2 hours, then grind it until D50≤15μm to obtain waste ash; S4: Mix waste ash and coarse fiber to make the total content of SiO2 and Al2O3 ≥60%, i.e., agricultural waste fiber from palm and hemp.

8. The method for preparing the biodegradable decorative wall substrate according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Dry mix palm and hemp agricultural waste fibers, reinforcing agents, and additives; S2: Add adhesive and waterproofing agent, then add water and mix to form a plastic mixture with a moisture content of 20%-30%; S3: The plastic mixture is placed in a mold and pressed to form a preform; or the preform is formed by extrusion molding using an extruder. S4: The blank is dried to the specified moisture content, which is the biodegradable decorative wall substrate.

9. The method for preparing the biodegradable decorative wall substrate according to claim 8, characterized in that, It also includes the following steps: S5: Surface treatment of the biodegradable decorative wall substrate, wherein the surface treatment is at least one of sanding, spraying and applying.

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