Shaving board processing technology based on farmland waste raw materials

Abstract

The invention discloses a shaving board processing technology based on farmland waste raw materials, and belongs to the technical field of shaving board processing, and the shaving board processing technology comprises the following steps: carrying out crushing, impurity removal and drying treatment on crop straws, and respectively obtaining a core layer material and a surface layer material with different particle sizes through graded crushing; mixing the core layer material with an adhesive to prepare a core layer plate raw material; mixing the surface layer material with a filling material and an adhesive to prepare a surface layer plate raw material; paving the core layer plate raw material and the surface layer plate raw material to form a plate blank, and performing pre-pressing treatment; carrying out hot pressing treatment on the plate blank to obtain a finished shaving board; by the adoption of the technical scheme, the recycling problem of the field waste is solved, environmental pollution is reduced, carbon emission is reduced, meanwhile, the raw materials are all recycled from the field waste, and the raw material cost is greatly reduced. And meanwhile, through the hot-pressing seamless gluing technology of a multi-layer composite structure, the high-strength and high-stability shaving board is formed.

Description

Technical Field

[0001] This invention relates to the field of particleboard processing technology, and in particular to a particleboard processing technology based on agricultural waste raw materials. Background Technology

[0002] Crop straw, as a major byproduct of agricultural production, is a abundant and renewable biomass resource.

[0003] Straw particleboard, made primarily from agricultural waste, offers dual benefits of resource utilization and environmental protection, aligning with national policies promoting a circular economy and green, low-carbon development. However, existing straw particleboard production technologies still suffer from several shortcomings: First, the high impurity content of straw raw materials leads to complex pretreatment processes and low production efficiency; second, the fiber structure of straw differs from that of wood, resulting in unsatisfactory bonding performance and insufficient mechanical strength to meet usage requirements; third, process parameters lack systematic optimization, leading to inconsistencies in product quality; and fourth, some processes still utilize formaldehyde-containing urea-formaldehyde resin adhesives, necessitating improvements in the environmental performance of the products. These issues hinder the widespread application and industrialization of straw particleboard. Therefore, developing a straw particleboard processing technology that is rationally designed, highly efficient in impurity removal, produces high-performance products, and is environmentally friendly and energy-saving is of significant practical importance and application value for promoting the resource utilization of agricultural waste, facilitating the green transformation of the particleboard industry, and contributing to the achievement of national carbon emission targets. Summary of the Invention

[0004] The purpose of this invention is to provide a particleboard processing technology based on agricultural waste raw materials, thereby optimizing the shortcomings of existing straw particleboard production technology.

[0005] The processing technology provided by this invention includes the following steps: S1: Crop straw is crushed, impurities removed and dried, and then core material and surface material of different particle sizes are obtained by grading and crushing. S2: Mix the core material with an adhesive to prepare core board raw material; mix the surface material with filler and adhesive to prepare surface board raw material; S3: The core layer material and the surface layer material are laid together to form a slab blank, and then pre-pressed. S4: Hot pressing is performed on the slab to obtain particleboard slab; S5: The particleboard is shaped to obtain the finished particleboard.

[0006] Preferably, in the raw material processing step: The crushing process includes shredding and coarse crushing in sequence. The length of the straw after coarse crushing is 50~150mm. Impurity removal processes include screening and air separation. Grading includes fine grinding and high-precision grinding.

[0007] Preferably, the particle size of the core material is 0.8~2mm, and the particle size of the surface material is 0.2~0.3mm.

[0008] Preferably, the moisture content of the dried straw is 10% to 14%.

[0009] Preferably, the adhesive is MDI glue and the filler is wood flour.

[0010] The mass ratio of the surface material to wood flour is 0.60~0.66:0.34~0.40; The mass ratio of straw raw material to adhesive is 0.95~0.96:0.04~0.05.

[0011] Preferably, in the hot pressing molding step, the hot pressing temperature is 165℃~190℃, the hot pressing time is 70~90s, and the hot pressing pressure is 15~18MPa.

[0012] Preferably, before the hot pressing step, a release agent is applied to the hot pressing equipment and the surface of the slab, and preheating treatment is performed.

[0013] Preferably, the release agent comprises an alcohol solvent and a polymer component, and the preheating treatment is performed at a temperature of 170°C to 185°C for 25 to 40 minutes.

[0014] Preferably, the shaping process includes cutting, stabilization, and surface sanding performed sequentially; the stabilization process takes 48 to 72 hours, the ambient temperature is 20 to 25°C, and the air humidity is 45% to 55%.

[0015] Preferably, the crop straw is cotton straw.

[0016] The particleboard processing technology based on agricultural waste provided by this invention has significant environmental benefits. This technology uses agricultural waste such as cotton stalks as the main raw material, effectively solving the problem of disposing of tens of thousands of tons of cotton stalks annually in Xinjiang, and realizing the high-value utilization of agricultural waste. By converting straw into particleboard products, it avoids the air, soil, and water pollution problems caused by traditional straw burning or rotting, eliminating the potential harm of agricultural waste to the ecological environment at its source. Simultaneously, the solidification of straw into particleboard enables long-term carbon sequestration, significantly reducing greenhouse gas emissions compared to straw burning or natural degradation, contributing to the achievement of national dual-carbon goals. Furthermore, using straw instead of traditional wood as the main raw material for particleboard reduces dependence on and consumption of forest resources, which is beneficial to ecological environmental protection and sustainable development.

[0017] This invention also offers significant economic benefits. Cotton stalks, as an agricultural byproduct, are widely available and inexpensive, significantly reducing production costs and enhancing product market competitiveness compared to traditional timber raw materials. Xinjiang has over 30 million mu of cotton cultivation area, with abundant and sustainable stalk resources, providing a reliable raw material guarantee for large-scale production. This invention transforms low-value agricultural waste into high-value-added building materials, extending the cotton industry chain and creating new growth points for increasing farmers' income and local economic development.

[0018] The particleboard product prepared by this invention possesses excellent comprehensive performance. Employing a multi-layer composite structure design, through differentiated formulations of the core and surface layers and seamless hot-pressing bonding technology, the finished particleboard exhibits superior mechanical strength and structural stability. Regarding dimensional stability, a rigorous stabilization process ensures the finished board maintains stable dimensions and is not easily deformed, meeting the requirements for building decoration materials. The product is non-permeable, adaptable to varying humidity environments, and maintains good physical properties even under humid conditions, expanding its application scenarios. In terms of environmental friendliness and health, MDI adhesive is used, resulting in extremely low formaldehyde emissions compared to traditional urea-formaldehyde adhesives, making the product more environmentally friendly and aligning with the modern trend of healthy home furnishings.

[0019] In summary, this technology provides an effective approach for the green treatment of agricultural waste, promoting the establishment and improvement of a circular economy model in agriculture. This invention aligns with the green and low-carbon development trend of the building materials industry, providing the market with a new type of environmentally friendly board product. The successful application of this technical solution in Xinjiang can provide a replicable and scalable technical model for other major cotton-producing areas and regions rich in agricultural straw resources, which is of great significance for solving the environmental pollution caused by agricultural waste and realizing the green treatment and recycling of agricultural waste.

[0020] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by those skilled in the art.

[0023] like Figure 1As shown, the particleboard processing technology based on agricultural waste raw materials provided by this invention specifically includes the following steps: The main components are cotton stalks, wood flour, and MDI adhesive, with release agents, stabilizers, and other auxiliary materials.

[0024] The cotton stalks collected from the cotton fields are shredded by a shredder. To facilitate actual transportation, the length of the collected cotton stalks should be controlled to about 500mm. Then, the shredded stalks are crushed into short rods of 50-150mm by a coarse crusher.

[0025] The treated straw is screened by a three-stage vibrating screen to remove sand, cotton husks, and drip irrigation tape impurities. Then, it enters a negative pressure air classifier to remove fine sand, ash, residual cotton, mulch, and other light impurities. After that, the moisture content of the qualified short cotton stalks is controlled at about 10% to 14%, and then it enters a fine pulverizer for fine pulverization. A portion of it is further pulverized by a pneumatic conveying fine pulverizer to finally obtain the required core material and surface material. The particle size of the core material is about 0.8 to 2 mm, and the particle size of the surface material is about 0.2 to 0.3 mm, to meet the raw material requirements of the preparation process.

[0026] The core layer material, MDI adhesive, stabilizer, etc. are mixed to prepare the core layer board raw material, and the surface layer material, wood flour, MDI adhesive, stabilizer, mildew inhibitor, etc. are mixed to prepare the surface layer board raw material. The mass ratio of surface layer material to wood flour is approximately 0.60~0.66:0.34~0.40, and the mass ratio of cotton stalk raw material to adhesive is approximately 0.95~0.96:0.04~0.05.

[0027] The cotton stalk raw material is mixed evenly with the adhesive. The mixture is laid into a board and then pre-pressed by a hot press. A release agent is evenly coated on the surface of the lining board, the hot press plate, and the mixed hot press material. The board is baked at 170°C~185°C for 25~40 minutes. The main components of the release agent are isopropanol, ethylene glycol, diethyl ether, and naphthyl methanol polymer. Then, the hot press is controlled at a temperature of about 165°C~190°C, a hot pressing time of about 80 seconds, and a hot pressing pressure of 15~18MPa to hot press the board to obtain the hot-pressed particleboard.

[0028] The hot-pressed cotton stalks are cut according to the preset cutting size. The cotton stalk particleboard cut according to the size is then stabilized to obtain cotton stalk particleboard products. The stabilization time is 48~72h, the workshop temperature is 20~25℃, and the air humidity is 45%~55%. The surface is then sanded by a sander, and finally sorted and packaged into products.

[0029] Several specific examples are provided below.

[0030] Example 1 This embodiment provides a method for preparing a standard cotton stalk particleboard, the specific steps of which are as follows: S1: Cotton stalks recovered from cotton fields in Xinjiang are selected as raw materials, with an initial moisture content of approximately 35%. First, the cotton stalks are shredded to a length of about 500mm using a shredder for easier transportation and processing. Then, the shredded stalks are fed into a coarse crusher to break them into short rods approximately 100mm in length. The crushed material is then screened through a three-stage vibrating screen to remove impurities such as sand, cotton husks, and drip irrigation tape. The screened material then enters a negative pressure air separator for air separation to remove fine sand, ash, residual cotton, and mulch film. The cleaned material is then sent to a drying device to control the moisture content to 12%. The dried material is divided into two parts: one part is crushed in a fine crusher to obtain a core layer material with a particle size of 1.2mm; the other part is finely crushed and then further crushed in a precision crusher to obtain a surface layer material with a particle size of 0.25mm.

[0031] S2: Take 100kg of core layer material, add 4.5kg of MDI adhesive and 0.3kg of stabilizer, and stir evenly in a high-speed mixer for 5 minutes to obtain the core layer board raw material. Take 63kg of surface layer material and 37kg of wood flour, add 4.8kg of MDI adhesive, 0.3kg of stabilizer and 0.2kg of mildew inhibitor, and stir evenly in a high-speed mixer for 8 minutes to obtain the surface layer board raw material.

[0032] S3: Lay the lower surface layer, core layer, and upper surface layer sequentially on the paving machine to form a three-layer structure slab. The lower and upper surface layers each account for 20% of the total mass, and the core layer accounts for 60% of the total mass. After paving, the slab is sent to a pre-pressing machine for pre-pressing treatment. The pre-pressing pressure is 1.5 MPa, and the pre-pressing time is 30 seconds.

[0033] S4: The release agent is evenly applied to the liner plate, the surface of the hot press plate, and the upper and lower surfaces of the blank. The release agent consists of 45% isopropanol, 25% ethylene glycol, 15% diethyl ether, and 15% naphthyl methanol polymer. After coating, it is baked at 180℃ for 30 minutes. Then, the blank is fed into the hot press for hot pressing at 175℃, 16MPa, and 80 seconds to obtain a particleboard sheet with a thickness of 18mm.

[0034] S5: The hot-pressed particleboard is cut to a size of 1220mm × 2440mm. The cut boards are then sent to a stabilization workshop for curing. The workshop temperature is controlled at 23℃, the air humidity at 50%, and the stabilization time is 72 hours. After stabilization, the boards are sanded on both sides to a thickness of 17.5mm. Finally, quality inspection, sorting, and packaging are performed to obtain the finished particleboard.

[0035] Example 2 This embodiment provides a method for preparing high-strength cotton stalk particleboard. By optimizing the formula and process parameters, the mechanical properties of the product are improved. The specific steps are as follows: S1: Cotton stalks recovered from cotton fields in Xinjiang are selected as raw materials, with an initial moisture content of approximately 40%. The cotton stalks are shredded and then fed into a coarse crusher to break them into short, rod-shaped stalks approximately 80mm in length. The crushed material is then sequentially screened by a three-stage vibrating screen and a negative pressure air separator to remove various impurities. The impurity-removed material is then dried to control the moisture content at 10%. The dried material is then graded and crushed to obtain core material with a particle size of 0.8mm and surface material with a particle size of 0.20mm.

[0036] S2; Take 100kg of core layer material, add 5.0kg of MDI adhesive and 0.4kg of stabilizer, and stir evenly in a high-speed mixer for 6 minutes to obtain the core layer board raw material. Take 60kg of surface layer material and 40kg of wood flour, add 5.2kg of MDI adhesive, 0.4kg of stabilizer and 0.2kg of mildew inhibitor, and stir evenly in a high-speed mixer for 10 minutes to obtain the surface layer board raw material.

[0037] S3: A three-layer paving structure is adopted, with the lower and upper surface layers each accounting for 25% of the total mass, and the core layer accounting for 50% of the total mass. After paving, pre-loading is performed with a pre-loading pressure of 1.8 MPa and a pre-loading time of 35 seconds.

[0038] S4: The release agent formulation and coating method are the same as in Example 1. After coating, bake at 185°C for 35 minutes. Hot pressing parameters: hot pressing temperature is 185°C, hot pressing pressure is 18MPa, and hot pressing time is 85 seconds, resulting in a particleboard board with a thickness of 18mm.

[0039] S5: Cutting dimensions are 1220mm × 2440mm. Stabilization treatment conditions: workshop temperature 22℃, air humidity 48%, stabilization time 72 hours. The thickness of the board after sanding is 17.5mm. After quality inspection, sorting and packaging, the finished particleboard is obtained.

[0040] Compared to Example 1, this example significantly improves the mechanical strength of the product by increasing the amount of adhesive, increasing the surface layer ratio, and increasing the hot pressing temperature and pressure.

[0041] Example 3 This embodiment provides a method for preparing lightweight cotton straw particleboard. By adjusting process parameters to reduce product density, it is suitable for applications with special weight requirements. The specific steps are as follows: S1: Cotton stalks recovered from cotton fields in Xinjiang are selected as raw materials, with an initial moisture content of approximately 30%. The cotton stalks are shredded and then fed into a coarse crusher to break them into short, rod-shaped stalks approximately 150mm in length. The crushed material is then sequentially screened by a three-stage vibrating screen and a negative pressure air separator to remove various impurities. The impurity-removed material is then dried to control the moisture content at 14%. The dried material is then graded and crushed to obtain core material with a particle size of 2.0mm and surface material with a particle size of 0.30mm.

[0042] S2: Take 100kg of core layer material, add 4.0kg of MDI adhesive and 0.2kg of stabilizer, and stir evenly in a high-speed mixer for 5 minutes to obtain the core layer board raw material. Take 66kg of surface layer material and 34kg of wood flour, add 4.5kg of MDI adhesive, 0.3kg of stabilizer and 0.15kg of mildew inhibitor, and stir evenly in a high-speed mixer for 7 minutes to obtain the surface layer board raw material.

[0043] S3: A three-layer paving structure is adopted, with the lower and upper surface layers each accounting for 18% of the total mass, and the core layer accounting for 64% of the total mass. After paving, pre-compression treatment is carried out with a pre-compression pressure of 1.2 MPa and a pre-compression time of 25 seconds.

[0044] S4: The release agent formulation and coating method are the same as in Example 1. After coating, bake at 170°C for 25 minutes. Hot pressing parameters: hot pressing temperature is 165°C, hot pressing pressure is 15MPa, and hot pressing time is 75 seconds, resulting in a particleboard board with a thickness of 18mm.

[0045] S5: Cutting dimensions are 1220mm × 2440mm. Stabilization conditions: workshop temperature 25℃, air humidity 55%, stabilization time 48 hours. After sanding, the board thickness is 17.5mm. After quality inspection, sorting, and packaging, the finished particleboard is obtained.

[0046] Compared to Example 1, this example effectively reduces the product density while ensuring the basic performance of the product by using core material with a larger particle size, reducing hot pressing pressure and temperature, and increasing the core layer ratio. It is suitable for applications that are sensitive to weight, such as partition boards and ceiling boards.

[0047] The above three embodiments represent three product types: standard, high-strength, and lightweight. By adjusting the raw material particle size, formula ratio, laying structure, and hot pressing parameters, cotton stalk particleboard products that meet different application needs can be prepared, fully demonstrating the flexibility and adaptability of the process of this invention.

[0048] It should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents; that is, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A particleboard processing technology based on agricultural waste raw materials, characterized in that, Includes the following steps: S1: Crop straw is crushed, impurities removed and dried, and then core material and surface material of different particle sizes are obtained by grading and crushing. S2: Mix the core material with an adhesive to prepare core board raw material; mix the surface material with filler and adhesive to prepare surface board raw material; S3: The core layer material and the surface layer material are laid together to form a slab blank, and then pre-pressed. S4: Hot pressing is performed on the slab to obtain particleboard slab; S5: The particleboard is shaped to obtain the finished particleboard.

2. The particleboard processing technology according to claim 1, characterized in that, In the raw material processing steps: The crushing process includes shredding and coarse crushing in sequence. The length of the straw after coarse crushing is 50~150mm. Impurity removal processes include screening and air separation. Grading includes fine grinding and high-precision grinding.

3. The particleboard processing technology according to claim 1, characterized in that, The core material has a particle size of 0.8~2mm, and the surface material has a particle size of 0.2~0.3mm.

4. The particleboard processing technology according to claim 1, characterized in that, The moisture content of the dried straw is 10% to 14%.

5. The particleboard processing technology according to claim 1, characterized in that, The adhesive is MDI glue, and the filler is wood flour; The mass ratio of the surface material to wood flour is 0.60~0.66:0.34~0.40; The mass ratio of straw raw material to adhesive is 0.95~0.96:0.04~0.

05.

6. The particleboard processing technology according to claim 1, characterized in that, In the hot pressing molding step, the hot pressing temperature is 165℃~190℃, the hot pressing time is 70~90s, and the hot pressing pressure is 15~18MPa.

7. The particleboard processing technology according to claim 1, characterized in that, Before the hot pressing step, a release agent is applied to the hot pressing equipment and the surface of the slab, and preheating treatment is performed.

8. The particleboard processing technology according to claim 7, characterized in that, The release agent comprises an alcohol solvent and a polymer component, and the preheating treatment is performed at a temperature of 170°C to 185°C for 25 to 40 minutes.

9. The particleboard processing technology according to claim 1, characterized in that, The shaping process includes cutting, stabilization, and surface sanding performed sequentially; the stabilization process takes 48 to 72 hours, the ambient temperature is 20 to 25°C, and the air humidity is 45% to 55%.

10. The particleboard processing technology according to any one of claims 1 to 9, characterized in that, The crop straw mentioned is cotton straw.

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