Straw-based decorative board with moisture-proof function and process thereof

Abstract

The application discloses a straw-based decorative plate with a moisture-proof function and a process thereof, and relates to the technical field of decorative plates. The straw-based decorative plate comprises a core layer substrate, a hollow framework and a moisture-proof decorative layer attached to the upper and lower surfaces of the core layer substrate. A through hole mechanism is arranged in the core layer substrate. The core layer substrate is prepared from the following raw materials in parts by weight: straw fiber 40-60 parts, environment-friendly formaldehyde-free adhesive 10-18 parts, composite moisture-proof modifier 3-8 parts, coupling agent 0.5-2 parts, functional filler 5-10 parts, curing agent 0.3-1 part and deionized water 8-15 parts. When water leakage occurs at the joint of the plate, the inclined groove is tilted to drain water to both sides of the plate body, so that the damage of the plate body caused by long-term water inflow is avoided. Meanwhile, the hollow framework is arranged to increase the structural strength of the plate.

Description

Technical Field

[0001] This invention relates to the field of decorative panel technology, specifically to a straw-based decorative panel with moisture-proof function and its manufacturing process. Background Technology

[0002] In recent years, the resource utilization of crop straw has become a research hotspot in the building materials industry. Straw-based decorative panels use agricultural waste straw as the core raw material, replacing traditional solid wood panels. They have advantages such as renewable raw materials, green environmental protection, low cost, sound insulation, and heat insulation. They are widely used in interior decoration, furniture manufacturing, and commercial decoration, effectively solving industry pain points such as straw burning pollution and timber resource shortages, and have broad market application prospects.

[0003] Currently, most existing straw-based decorative boards achieve moisture resistance only by simply brushing a waterproofing agent onto the surface. This only provides temporary surface waterproofing and cannot fundamentally improve the hydrophilic properties of straw fibers. After long-term use, the waterproof coating wears off, causing the board's moisture resistance to quickly fail, and the overall strength and stability of the board are insufficient. Therefore, developing a straw-based decorative board that achieves dual internal and external moisture resistance, is environmentally friendly and formaldehyde-free, structurally stable, and has a long service life, along with a suitable preparation process, is a pressing technical problem that needs to be solved in this field.

[0004] In view of this, we propose a straw-based decorative board with moisture-proof function and its process. Summary of the Invention To address the shortcomings of existing technologies, this invention provides a straw-based decorative board with moisture-proof function and its manufacturing process, thus solving the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a straw-based decorative board with moisture-proof function, comprising a core substrate layer, a hollow frame, and a moisture-proof decorative layer attached to the upper and lower surfaces of the core substrate layer. The core substrate layer has through-hole mechanisms and is prepared from the following raw materials in parts by weight: 40-60 parts straw fiber, 10-18 parts environmentally friendly formaldehyde-free adhesive, 3-8 parts composite moisture-proof modifier, 0.5-2 parts coupling agent, 5-10 parts functional filler, 0.3-1 parts curing agent, and 8-15 parts deionized water.

[0006] Optionally, the through-hole mechanism includes a horizontal groove and an inclined groove, which are connected to each other, and the horizontal groove is parallel to the upper and lower surfaces of the core substrate layer.

[0007] Optionally, the straw fiber is one or more of corn straw, wheat straw, and rice straw, which are obtained by crushing, screening, and steam explosion degreasing treatment. The fiber length is 3-5 mm and the moisture content is controlled at 3%-5%.

[0008] Optionally, the composite moisture-proof modifier is composed of nano-silica, paraffin emulsion, diatomaceous earth, and hydrophobic talc powder in a mass ratio of 2:3:2:1, wherein the nano-silica has a particle size of 20-50 nm and the diatomaceous earth is an ultrafine powder of 400-600 mesh.

[0009] Optionally, the environmentally friendly formaldehyde-free adhesive is a soybean protein modified adhesive or a starch-based formaldehyde-free adhesive with a solid content ≥45%; the coupling agent is a silane coupling agent KH-550; the curing agent is an organic amine curing agent; and the functional filler is heavy calcium carbonate or bamboo charcoal powder with a mesh size of 500-800 mesh.

[0010] Optionally, the moisture-proof decorative surface layer is a modified polyurethane moisture-proof coating combined with melamine impregnated decorative paper, with a coating thickness of 0.1-0.3mm, and has waterproof, wear-resistant and fade-resistant properties.

[0011] This invention proposes a preparation process for straw-based decorative panels with moisture-proof function, comprising the following steps: S1. Straw pretreatment: Remove impurities from the collected crop straw, wash and dry it, crush it with a pulverizer and pass it through a 20-40 mesh sieve to obtain straw coarse fiber; send the straw coarse fiber into a steam explosion equipment and treat it for 3-5 minutes under a pressure of 1.2-1.5MPa and a temperature of 180-190℃ to remove pectin, sugar and hydrophilic impurities inside the straw, and then dry it with hot air to a moisture content of 3%-5% for later use; S2. Ingredient Mixing: Add the pretreated straw fiber and functional filler to a high-speed mixer and stir at low speed for 3-5 minutes to achieve initial mixing; then mix the composite moisture-proof modifier, coupling agent, and deionized water evenly and slowly spray it into the mixture, and stir at high speed for 8-12 minutes; finally, add the environmentally friendly formaldehyde-free adhesive and curing agent, and stir at room temperature for 5-8 minutes to obtain a uniform composite mixture; S3. Laying and shaping: The composite mixture is evenly laid in the molding mold, with a uniform and flat laying thickness. It is pre-pressed and shaped, with a pre-pressing pressure of 0.8-1.2MPa and a pre-pressing time of 20-30s. The air inside the mixture is expelled to obtain a slab. S4. Gradient Hot Pressing: A segmented gradient hot pressing process is used to hot press the slab. The first stage: temperature 130-140℃, pressure 3-4MPa, holding pressure for 2-3 minutes to achieve surface curing. The second stage: temperature 145-155℃, pressure 4.5-5.5MPa, holding pressure for 4-6 minutes to achieve dense bonding of the core layer. The third stage: cooling and stabilizing pressure, temperature 110-120℃, pressure 2-3MPa, holding pressure for 1-2 minutes to eliminate internal stress in the slab and obtain the raw slab. S5. Moisture-proof surface curing: Sand the surface of the raw board smooth, apply a modified polyurethane moisture-proof coating evenly on both sides, let it stand and level for 1-2 minutes, then attach melamine-impregnated decorative paper, send it into the curing equipment, and cure at a constant temperature of 80-90℃ for 15-20 minutes to complete the moisture-proof decorative surface layer composite. S6. Curing and finishing: Place the cured board in a constant temperature and humidity curing room for 24-48 hours, with a curing temperature of 20-25℃ and a humidity of 45%-55%. After curing, trim the edges, sand, and inspect the quality to obtain the finished straw-based moisture-proof decorative board.

[0012] Optionally, in S2, the high-speed mixing speed is 800-1000 r / min, and the low-speed mixing speed is 200-300 r / min; in S4, ventilation and exhaust treatment are used throughout the hot pressing process to avoid the generation of air bubbles inside the board and improve the density of the board.

[0013] This invention provides a straw-based decorative board with moisture-proof function and its manufacturing process. It has the following beneficial effects: 1. This invention uses a composite moisture-proof modifier to internally modify straw fibers. Nano-silica and diatomaceous earth can precisely fill the microscopic pores of straw fibers, while paraffin emulsion and hydrophobic talc powder give the fibers hydrophobic properties, blocking moisture adsorption from the source. Combined with the external protection of the surface polyurethane moisture-proof coating and decorative paper, a double moisture-proof structure is formed, which completely solves the problems of moisture absorption, deformation, and cracking of traditional straw boards. The thickness expansion rate of the board is ≤1.8%, which can adapt to high humidity environments for a long time.

[0014] 2. This invention uses soybean protein and starch-based formaldehyde-free environmentally friendly adhesives throughout the entire process, combined with natural functional fillers. It releases no harmful substances such as formaldehyde and benzene, and has extremely low VOC emissions, meeting national environmental protection standards for indoor decoration materials. It can be directly used for decoration of enclosed indoor spaces, and is safe and pollution-free.

[0015] 3. The present invention has a stable structure and higher strength: the surface of straw fiber is activated by steam explosion pretreatment, and the bonding strength of the raw material interface is improved by silane coupling agent. Combined with the segmented gradient hot pressing process, the overall density of the board is uniform, without bubbles or delamination defects. The static bending strength and elastic modulus are significantly better than those of traditional straw boards, and the impact resistance and deformation resistance are strong.

[0016] 3. The preparation process of this invention is simple and the parameters are controllable. It does not require complex high-end equipment and can be produced on a large scale. The core raw material is agricultural waste straw, which is widely available and inexpensive, realizing the efficient utilization of agricultural waste resources and achieving both economic and ecological benefits.

[0017] 4. The present invention, through the through-hole mechanism, allows water to drain to both sides of the board body when water leakage occurs at the joint of the board, thus avoiding damage to the board body caused by long-term water ingress; at the same time, the hollow frame provides greater structural strength to the board body itself. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a cross-sectional structural schematic diagram of the device of the present invention.

[0019] In the diagram: 1. Core substrate layer; 2. Hollow skeleton; 3. Through-hole mechanism; 31. Horizontal groove; 32. Inclined groove; 4. Moisture-proof decorative layer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Please see Figures 1-2 This invention provides a technical solution: a straw-based decorative board with moisture-proof function, comprising a core substrate layer 1, a hollow frame 2, and a moisture-proof decorative layer 4 attached to the upper and lower surfaces of the core substrate layer 1. The core substrate layer 1 has a through-hole mechanism 3. The core substrate layer 1 is prepared from the following raw materials in parts by weight: 40-60 parts straw fiber, 10-18 parts environmentally friendly formaldehyde-free adhesive, 3-8 parts composite moisture-proof modifier, 0.5-2 parts coupling agent, 5-10 parts functional filler, 0.3-1 parts curing agent, and 8-15 parts deionized water.

[0022] The through-hole mechanism 3 includes a horizontal groove 31 and an inclined groove 32, which are connected to each other, and the horizontal groove 31 is parallel to the upper and lower surfaces of the core substrate layer 1.

[0023] It is worth noting that the straw fiber is made from one or more of corn straw, wheat straw, and rice straw, through crushing, sieving, and steam explosion degreasing. The fiber length is 3-5 mm, and the moisture content is controlled at 3%-5%. The composite moisture-proof modifier is composed of nano-silica, paraffin emulsion, diatomaceous earth, and hydrophobic talc powder in a mass ratio of 2:3:2:1. The nano-silica has a particle size of 20-50 nm, and the diatomaceous earth is an ultrafine powder of 400-600 mesh.

[0024] The environmentally friendly formaldehyde-free adhesive is a soybean protein-modified adhesive or a starch-based formaldehyde-free adhesive with a solid content ≥45%; the coupling agent is silane coupling agent KH-550; the curing agent is an organic amine curing agent; the functional filler is heavy calcium carbonate or bamboo charcoal powder with a mesh size of 500-800 mesh. The moisture-proof decorative surface layer is a modified polyurethane moisture-proof coating combined with melamine-impregnated decorative paper, with a coating thickness of 0.1-0.3mm, possessing waterproof, wear-resistant, and fade-resistant properties.

[0025] This embodiment also proposes a preparation process for straw-based decorative panels with moisture-proof function, including the following steps: S1. Straw pretreatment: Remove impurities from the collected crop straw, wash and dry it, crush it with a pulverizer and pass it through a 20-40 mesh sieve to obtain straw coarse fiber; send the straw coarse fiber into a steam explosion equipment and treat it for 3-5 minutes under a pressure of 1.2-1.5MPa and a temperature of 180-190℃ to remove pectin, sugar and hydrophilic impurities inside the straw, and then dry it with hot air to a moisture content of 3%-5% for later use; S2. Ingredient Mixing: Add the pretreated straw fiber and functional filler to a high-speed mixer and stir at low speed for 3-5 minutes to achieve initial mixing; then mix the composite moisture-proof modifier, coupling agent, and deionized water evenly and slowly spray it into the mixture, and stir at high speed for 8-12 minutes; finally, add the environmentally friendly formaldehyde-free adhesive and curing agent, and stir at room temperature for 5-8 minutes to obtain a uniform composite mixture; The high-speed mixing speed is 800-1000 r / min, and the low-speed mixing speed is 200-300 r / min.

[0026] S3. Laying and shaping: The composite mixture is evenly laid in the molding mold, with a uniform and flat laying thickness. It is pre-pressed and shaped, with a pre-pressing pressure of 0.8-1.2MPa and a pre-pressing time of 20-30s. The air inside the mixture is expelled to obtain a slab. S4. Gradient Hot Pressing: A segmented gradient hot pressing process is used to hot press the slab. The first stage: temperature 130-140℃, pressure 3-4MPa, holding pressure for 2-3 minutes to achieve surface curing. The second stage: temperature 145-155℃, pressure 4.5-5.5MPa, holding pressure for 4-6 minutes to achieve dense bonding of the core layer. The third stage: cooling and stabilizing pressure, temperature 110-120℃, pressure 2-3MPa, holding pressure for 1-2 minutes to eliminate internal stress in the slab and obtain the raw slab. The hot pressing process employs ventilation and exhaust treatment throughout to prevent air bubbles from forming inside the board and improve the board's density.

[0027] S5. Moisture-proof surface curing: Sand the surface of the raw board smooth, apply a modified polyurethane moisture-proof coating evenly on both sides, let it stand and level for 1-2 minutes, then attach melamine-impregnated decorative paper, send it into the curing equipment, and cure at a constant temperature of 80-90℃ for 15-20 minutes to complete the moisture-proof decorative surface layer composite. S6. Curing and finishing: Place the cured board in a constant temperature and humidity curing room for 24-48 hours, with a curing temperature of 20-25℃ and a humidity of 45%-55%. After curing, trim the edges, sand, and inspect the quality to obtain the finished straw-based moisture-proof decorative board.

[0028] As one application of this embodiment: In this embodiment, the through-hole mechanism allows water to drain to both sides of the board when leakage occurs at the joints of the boards, preventing damage to the board due to long-term water ingress. At the same time, the hollow frame structure enhances the structural strength of the board itself. Meanwhile, a composite moisture-proof modifier is used to internally modify the straw fiber. Nano-silica and diatomaceous earth can precisely fill the microscopic pores of the straw fiber, while paraffin emulsion and hydrophobic talc powder give the fiber hydrophobic properties, blocking moisture adsorption from the source. Combined with the external protection of the surface polyurethane moisture-proof coating and decorative paper, a double moisture-proof structure is formed inside and out, which completely solves the problems of moisture absorption, deformation and cracking of traditional straw boards. The thickness expansion rate of the board is ≤1.8%, which can adapt to high humidity environment for a long time.

[0029] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A straw-based decorative board with moisture-proof function, characterized in that: It includes a core substrate layer (1), a hollow skeleton (2) and a moisture-proof decorative layer (4) attached to the upper and lower surfaces of the core substrate layer (1). The core substrate layer (1) has a through hole mechanism (3). The core substrate layer (1) is made of the following raw materials in parts by weight: 40-60 parts of straw fiber, 10-18 parts of environmentally friendly formaldehyde-free adhesive, 3-8 parts of composite moisture-proof modifier, 0.5-2 parts of coupling agent, 5-10 parts of functional filler, 0.3-1 parts of curing agent, and 8-15 parts of deionized water.

2. The straw-based decorative board with moisture-proof function according to claim 1, characterized in that: The through-hole mechanism (3) includes a horizontal groove (31) and an inclined groove (32), which are connected to each other, and the horizontal groove (31) is parallel to the upper and lower surfaces of the core substrate layer (1).

3. The straw-based decorative board with moisture-proof function according to claim 1, characterized in that: The straw fiber is one or more of corn straw, wheat straw, and rice straw, which are obtained by crushing, screening, and steam explosion degreasing. The fiber length is 3-5 mm and the moisture content is controlled at 3%-5%.

4. A straw-based decorative board with moisture-proof function according to claim 1, characterized in that: The composite moisture-proof modifier is composed of nano-silica, paraffin emulsion, diatomaceous earth, and hydrophobic talc powder in a mass ratio of 2:3:2:

1. The nano-silica has a particle size of 20-50 nm, and the diatomaceous earth is an ultrafine powder of 400-600 mesh.

5. A straw-based decorative board with moisture-proof function according to claim 1, characterized in that: The environmentally friendly formaldehyde-free adhesive is a soybean protein modified adhesive or a starch-based formaldehyde-free adhesive with a solid content ≥45%; the coupling agent is a silane coupling agent KH-550; the curing agent is an organic amine curing agent; and the functional filler is heavy calcium carbonate or bamboo charcoal powder with a mesh size of 500-800 mesh.

6. A straw-based decorative board with moisture-proof function according to claim 1, characterized in that: The moisture-proof decorative surface layer is a modified polyurethane moisture-proof coating combined with melamine impregnated decorative paper. The coating thickness is 0.1-0.3mm, and it has waterproof, wear-resistant and fade-resistant properties.

7. A preparation process for a straw-based decorative board with moisture-proof function as described in any one of claims 1-6, characterized in that: Includes the following steps: S1. Straw pretreatment: Remove impurities from the collected crop straw, wash and dry it, crush it with a pulverizer and pass it through a 20-40 mesh sieve to obtain straw coarse fiber; send the straw coarse fiber into a steam explosion equipment and treat it for 3-5 minutes under a pressure of 1.2-1.5MPa and a temperature of 180-190℃ to remove pectin, sugar and hydrophilic impurities inside the straw, and then dry it with hot air to a moisture content of 3%-5% for later use; S2. Ingredient Mixing: Add the pretreated straw fiber and functional filler to a high-speed mixer and stir at low speed for 3-5 minutes to achieve initial mixing; then mix the composite moisture-proof modifier, coupling agent, and deionized water evenly and slowly spray it into the mixture, and stir at high speed for 8-12 minutes; finally, add the environmentally friendly formaldehyde-free adhesive and curing agent, and stir at room temperature for 5-8 minutes to obtain a uniform composite mixture; S3. Laying and shaping: The composite mixture is evenly laid in the molding mold, with a uniform and flat laying thickness. It is pre-pressed and shaped, with a pre-pressing pressure of 0.8-1.2MPa and a pre-pressing time of 20-30s. The air inside the mixture is expelled to obtain a slab. S4. Gradient Hot Pressing: A segmented gradient hot pressing process is used to hot press the slab. The first stage: temperature 130-140℃, pressure 3-4MPa, holding pressure for 2-3 minutes to achieve surface curing. The second stage: temperature 145-155℃, pressure 4.5-5.5MPa, holding pressure for 4-6 minutes to achieve dense bonding of the core layer. The third stage: cooling and stabilizing pressure, temperature 110-120℃, pressure 2-3MPa, holding pressure for 1-2 minutes to eliminate internal stress in the slab and obtain the raw slab. S5. Moisture-proof surface curing: Sand the surface of the raw board smooth, apply a modified polyurethane moisture-proof coating evenly on both sides, let it stand and level for 1-2 minutes, then attach melamine-impregnated decorative paper, send it into the curing equipment, and cure at a constant temperature of 80-90℃ for 15-20 minutes to complete the moisture-proof decorative surface layer composite. S6. Curing and finishing: Place the cured board in a constant temperature and humidity curing room for 24-48 hours, with a curing temperature of 20-25℃ and a humidity of 45%-55%. After curing, trim the edges, sand, and inspect the quality to obtain the finished straw-based moisture-proof decorative board.

8. The preparation process of a straw-based decorative board with moisture-proof function according to claim 7, characterized in that: In S2, the high-speed mixing speed is 800-1000 r / min, and the low-speed mixing speed is 200-300 r / min; in S4, ventilation and exhaust treatment are used throughout the hot pressing process to avoid the generation of air bubbles inside the board and improve the density of the board.

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