Low-density high-strength formaldehyde-free moisture-proof anti-deformation shaving board process

Abstract

The invention discloses a low-density high-strength formaldehyde-free moisture-proof deformation-resistant shaving board process. The process comprises the following steps: a wood shaving production section: processing wood or non-wood plant fiber raw materials into wood shavings; a drying and sorting section: after the wet wood shavings are dried, screening the dry wood shavings into surface layer dry wood shavings and core layer dry wood shavings; the surface layer wood shavings are at least one of phyllostachys heterocycla, dendrocalamus latiflorus or moso bamboo shavings, and the core layer wood shavings are cedarwood shavings; the glue solution is injected into a surface layer and core layer wood shaving glue mixing machine for glue mixing of surface layer and core layer dry wood shavings; a paving and hot pressing section: paving the surface layer and core layer sizing shavings into a continuous plate blank strip with a composite structure; after the plate blank strip is pre-pressed and formed, hot pressing treatment is conducted, and then cooling is conducted; and a sanding and board cutting section, wherein the sanded shaving board is sawed and cut into standard finished boards. The shaving board produced through the technology is light, low in density, high in physical and mechanical strength, free of formaldehyde, low in water absorption expansion rate, resistant to moisture and deformation, suitable for furniture door boards and high in environmental protection grade.

Description

Technical Field

[0001] The invention belongs to the technical field of building material processing, and particularly relates to a process for a low-density, high-strength formaldehyde-free, moisture-proof and deformation-resistant particleboard. Background Art

[0002] Particle board is a type of man-made board made by processing wood or non-wood plant fiber raw materials into shavings (or scraps), applying adhesives (and other additives), assembling and hot pressing. Particle board is mainly used in furniture manufacturing, interior decoration and other industries because of its relatively low cost, uniform structure, good processing performance, and can be processed into large-format boards as needed. It is one of the ideal raw materials for making furniture of various specifications and styles.

[0003] However, since particleboard is a man-made board, it has poor adaptability to moisture and humid environments, so it is necessary to pay attention to moisture-proof and waterproof when using it to extend the service life of the furniture. In addition, particleboard has the characteristics of high density, so the furniture made from it is relatively heavy. Since the main purpose of particleboard is to replace wood, it requires a certain mechanical strength in use, but the particleboard currently on the market has poor strength and is generally not suitable for making larger furniture or furniture with mechanical requirements. In addition, the quality of particleboard on the market is uneven, and inferior particleboard has poor environmental protection and serious formaldehyde content. Therefore, the research and development of low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard is an important technological innovation, which can effectively solve the defects of traditional particleboard, improve its performance, and meet the needs of modern homes. Summary of the invention

[0004] In order to solve some problems existing in the traditional particleboard process, such as formaldehyde release, poor strength, poor moisture-proof effect, etc., the present invention proposes a new particleboard process for preparing a low-density, high-strength formaldehyde-free, moisture-proof and deformation-resistant particleboard.

[0005] The technical solution of the present invention is as follows:

[0006] A low-density, high-strength, formaldehyde-free, moisture-proof, and deformation-resistant particleboard process, comprising the following steps:

[0007] (1) Wood shavings production process

[0008] Processing wood or non-wood plant fiber raw materials into wood chips;

[0009] (2) Drying and sorting section

[0010] After the wet wood shavings are dried, the dry wood shavings are screened into surface dry wood shavings and core dry wood shavings; wherein the surface wood shavings are at least one of bamboo shavings, bamboo shavings or bamboo shavings, and the core wood shavings are Chinese fir shavings;

[0011] (3) Glue application section

[0012] The glue liquid is injected into the surface and core layer wood shavings glue mixing machines respectively to mix the surface and core layer dry wood shavings with glue;

[0013] (4) Paving and hot pressing section

[0014] The surface and core layers of glued wood chips are laid out to form a continuous slab strip of composite structure; after the slab strip is pre-pressed and formed, it is subjected to hot pressing treatment and then cooled;

[0015] (5) Sanding and cutting section

[0016] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0017] Preferably, the surface wood shavings are water bamboo.

[0018] Preferably, in step (2), the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings, and the core shavings are a mixture of 100mm×10mm×1mm Chinese fir shavings and 70mm×10mm×1mm Chinese fir shavings.

[0019] Preferably, the mixing is equal mass mixing.

[0020] Preferably, the amount of glue applied to the wood chips is 5% to 8% of the mass of the wood chips.

[0021] Preferably, the hot pressing process parameters are: the pressure in the pressurizing stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the holding time is 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0022] Preferably, the glue of particleboard is composed of silane-modified polyurethane resin, diphenylmethane diisocyanate, boric acid, dimethyl silicone oil, silicon dioxide, and PEG400. Silane-modified polyurethane resin and diphenylmethane diisocyanate provide gluing action, strengthen the bonding strength with wood chips, strengthen the board strength, water resistance and stability, boric acid promotes the curing of glue, improves the water resistance of the board, silicon dioxide regulates the hardness and density of the board, improves the strength of the board, dimethyl silicone oil improves the water resistance of the board, and dimethyl silicone oil and PEG400 improve the stability and compatibility of glue. The comprehensive use of these additives is conducive to improving the overall quality and performance of particleboard, so that it has higher physical and mechanical strength, water resistance and deformation resistance.

[0023] The glue comprises 56% to 67% of diphenylmethane diisocyanate, 18.5% to 21.6% of silane-modified polyurethane resin, 0% to 3.24% of boric acid, 0% to 5.4% of dimethyl silicone oil, 0% to 7.56% of silicon dioxide and 4000% to 5.4% of PEG.

[0024] Preferably, by mass percentage, the glue includes 56% to 67% diphenylmethane diisocyanate, 18.5% to 21.6% silane-modified polyurethane resin, 2.77% to 3.24% boric acid, 4.63% to 5.4% dimethyl silicone oil, 6.48% to 7.56% silicon dioxide, and 4.62% to 5.4% PEG400.

[0025] More preferably, the glue comprises, by mass percentage, 60% diphenylmethane diisocyanate, 20% silane-modified polyurethane resin, 3% boric acid, 5% dimethyl silicone oil, 7% silicon dioxide, and 5% PEG400.

[0026] Preferably, the preparation method of the silane-modified polyurethane resin is: mixing polypropylene glycol 3000 and toluene diisocyanate in a molar ratio of 1:2, reacting at a temperature of 80-90°C for 2-4 hours; obtaining a precursor; mixing γ-aminopropyltriethoxysilane, dibenzoyl peroxide, 2-imidazolidinone and the precursor, and reacting at a temperature of 50-60°C for 2-4 hours.

[0027] In the following specific embodiments of the present invention, the preparation method of the silane-modified polyurethane resin is as follows: polypropylene glycol 3000 and toluene diisocyanate are mixed in a molar ratio of 1:2, and reacted at a temperature of 80-90°C for 2 hours to obtain a precursor; γ-aminopropyltriethoxysilane, dibenzoyl peroxide, 2-imidazolidinone and the precursor are mixed, and reacted at a temperature of 50-60°C for 2 hours.

[0028] A low-density, high-strength formaldehyde-free moisture-proof and deformation-resistant particleboard is produced by adopting the process of the invention.

[0029] Beneficial effects of the present invention:

[0030] The particle board produced by the process of the invention is light and low in density, has high physical and mechanical strength, is formaldehyde-free, has low water absorption and expansion rate, is moisture-proof and deform-resistant, is suitable for furniture door panels, and has a high environmental protection level.

[0031] The mechanical properties of particleboard are affected by many factors, including density, particle shape, glue, glue amount, hot pressing process conditions, etc. Correct selection of materials, glue and hot pressing process are crucial for producing high-quality particleboard. The present invention reasonably handles these factors to ensure that the particleboard has sufficient physical and mechanical strength, thereby meeting the needs of furniture manufacturing and other fields. DETAILED DESCRIPTION

[0032] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0033] Example 1 Particleboard Production Process

[0034] The particleboard production process is divided into particleboard production section, drying and sorting section, gluing section, paving and hot pressing section, rough board processing section and sanding and cutting section.

[0035] (1) Wood shavings production process

[0036] Processing wood or non-wood plant fiber raw materials into wood chips;

[0037] (2) Drying and sorting section

[0038] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0039] (3) Glue application section

[0040] The glue solution is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue, the glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. The glue solution is uniformly wrapped on the wood chip surface by mutual friction in the glue mixer to form the surface and core layer glued wood chips. The glue solution includes 60% of diphenylmethane diisocyanate, 20% of silane modified polyurethane resin, 3% of boric acid, 5% of dimethyl silicone oil (Dow Corning PMX-200, USA), 7% of silicon dioxide, and 5% of PEG400 by mass%.

[0041] (4) Paving and hot pressing section

[0042] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0043] (5) Sanding and cutting section

[0044] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0045] Embodiment 2:

[0046] In this example, Dendrocalamus latiflorus was used to replace the water bamboo in Example 1, and other parameters were referred to Example 1.

[0047] Embodiment 3:

[0048] In this example, Phyllostachys pubescens was used to replace the water bamboo in Example 1, and other operations were referred to Example 1.

[0049] Embodiment 4 particleboard production process

[0050] This embodiment changes the adhesive ratio in embodiment 1. That is, no silane-modified polyurethane resin is added, and diphenylmethane diisocyanate is used to supplement the silane-modified polyurethane resin.

[0051] (1) Wood shavings production process

[0052] Processing wood or non-wood plant fiber raw materials into wood chips;

[0053] (2) Drying and sorting section

[0054] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0055] (3) Glue application section

[0056] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue, and the glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. In the glue mixer, the glue liquid is evenly wrapped on the wood chip surface by mutual friction to form the surface and core layer glued wood chips. The glue liquid includes 80% diphenylmethane diisocyanate, 3% boric acid, 5% dimethyl silicone oil, 7% silicon dioxide, and 5% PEG400 by mass%.

[0057] (4) Paving and hot pressing section

[0058] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0059] (5) Sanding and cutting section

[0060] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0061] Example 5 Particleboard Production Process

[0062] This embodiment changes the adhesive ratio in embodiment 1. That is, diphenylmethane diisocyanate is not added, and the amount of diphenylmethane diisocyanate is supplemented by silane-modified polyurethane resin.

[0063] (1) Wood shavings production process

[0064] Processing wood or non-wood plant fiber raw materials into wood chips;

[0065] (2) Drying and sorting section

[0066] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0067] (3) Glue application section

[0068] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue. The glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. The glue liquid is evenly wrapped on the wood chip surface by mutual friction in the glue mixer to form the surface and core layer glued wood chips. The glue liquid includes 80% of silane modified polyurethane resin, 3% of boric acid, 5% of dimethyl silicone oil, 7% of silicon dioxide, and 5% of PEG400 by mass%.

[0069] (4) Paving and hot pressing section

[0070] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0071] (5) Sanding and cutting section

[0072] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0073] Example 6 Particleboard Production Process

[0074] This embodiment changes the adhesive ratio in embodiment 1. That is, no boric acid is added, and diphenylmethane diisocyanate is used to supplement the amount of boric acid.

[0075] (1) Wood shavings production process

[0076] Processing wood or non-wood plant fiber raw materials into wood chips;

[0077] (2) Drying and sorting section

[0078] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0079] (3) Glue application section

[0080] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue, and the glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. In the glue mixer, the glue liquid is evenly wrapped on the wood chip surface by mutual friction to form the surface and core layer glued wood chips. The glue liquid includes 63% of diphenylmethane diisocyanate, 20% of silane modified polyurethane resin, 5% of dimethyl silicone oil, 7% of silicon dioxide, and 5% of PEG400 by mass%.

[0081] (4) Paving and hot pressing section

[0082] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0083] (5) Sanding and cutting section

[0084] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0085] Example 7 Particleboard Production Process

[0086] This embodiment changes the adhesive ratio in embodiment 1. That is, dimethyl silicone oil is not added, and diphenylmethane diisocyanate is used to supplement the amount of dimethyl silicone oil.

[0087] (1) Wood shavings production process

[0088] Processing wood or non-wood plant fiber raw materials into wood chips;

[0089] (2) Drying and sorting section

[0090] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0091] (3) Glue application section

[0092] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue, the glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. The glue liquid is uniformly wrapped on the surface of the wood chips by mutual friction in the glue mixer to form the surface and core layer glued wood chips. The glue liquid includes 65% of diphenylmethane diisocyanate, 20% of silane modified polyurethane resin, 3% of boric acid, 7% of silicon dioxide, and 5% of PEG400 by mass%.

[0093] (4) Paving and hot pressing section

[0094] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0095] (5) Sanding and cutting section

[0096] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0097] Example 8 Particleboard Production Process

[0098] This embodiment changes the adhesive ratio in embodiment 1. That is, silicon dioxide is not added, and diphenylmethane diisocyanate is used to supplement the amount of silicon dioxide.

[0099] (1) Wood shavings production process

[0100] Processing wood or non-wood plant fiber raw materials into wood chips;

[0101] (2) Drying and sorting section

[0102] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0103] (3) Glue application section

[0104] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue, and the glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. In the glue mixer, the glue liquid is evenly wrapped on the surface of the wood chips through mutual friction to form the surface and core layer glued wood chips. The glue liquid includes 67% of diphenylmethane diisocyanate, 20% of silane modified polyurethane resin, 3% of boric acid, 5% of dimethyl silicone oil, and 5% of PEG400 by mass%.

[0105] (4) Paving and hot pressing section

[0106] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0107] (5) Sanding and cutting section

[0108] The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

[0109] Example 9 Particleboard Production Process

[0110] This embodiment changes the ratio of the glue solution in Embodiment 1, that is, the amount of the glue solution components is adjusted by about ±8%.

[0111] (1) Wood shavings production process

[0112] Processing wood or non-wood plant fiber raw materials into wood chips;

[0113] (2) Drying and sorting section

[0114] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0115] (3) Glue application section

[0116] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue. The glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. The glue liquid is evenly wrapped on the wood chip surface by mutual friction in the glue mixer to form the surface and core layer glued wood chips. The glue liquid includes 56% of diphenylmethane diisocyanate, 18.5% of silane-modified polyurethane resin, 3.24% of boric acid, 4.63% of dimethyl silicone oil, 7.56% of silicon dioxide, 5.4% of PEG400, and the balance is water.

[0117] (4) Paving and hot pressing section

[0118] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0119] (5) Sanding and cutting section

[0120] The particleboard is sanded by a sanding machine, and the sanded particleboard is sawn into finished boards of specifications. The test results of the finished boards are not significantly different from those of Example 1, and the test data are omitted.

[0121] Example 10 Particleboard Production Process

[0122] This embodiment changes the ratio of the glue solution in Embodiment 1, that is, the amount of the glue solution components is adjusted by about ±8%.

[0123] (1) Wood shavings production process

[0124] Processing wood or non-wood plant fiber raw materials into wood chips;

[0125] (2) Drying and sorting section

[0126] The wet shavings enter the single-channel drum shaving dryer for drying. The dry shavings are screened into surface dry shavings and core dry shavings, wherein the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings in equal weight, and the core shavings are a mixture of 100mm×10mm×1mm fir shavings and 70mm×10mm×1mm fir shavings in equal weight.

[0127] (3) Glue application section

[0128] The glue liquid is injected into the glue mixer for the surface and core layer wood chips respectively to mix the surface and core layer dry wood chips with glue. The glue amount of the surface layer wood chips is 8% of the wood chip mass, and the glue amount of the core layer wood chips is 5% of the wood chip mass. The glue liquid is evenly wrapped on the surface of the wood chips by mutual friction in the glue mixer to form the surface and core layer glued wood chips. The glue liquid includes 56% of diphenylmethane diisocyanate, 21.6% of silane-modified polyurethane resin, 2.77% of boric acid, 5.4% of dimethyl silicone oil, 6.48% of silicon dioxide, 4.62% of PEG400, and the balance is water.

[0129] (4) Paving and hot pressing section

[0130] The surface and core layers of glued wood chips are paved to form a continuous slab strip with a three-layer composite structure (surface layer-core layer-surface layer of equal quality). After the slab strip is pre-pressed (the role of pre-pressing is to compress the paved loose body to an appropriate thickness, which is conducive to subsequent hot pressing), it enters the continuous hot press for hot pressing. The hot-pressed continuous rough board strip enters the cooling flip machine for cooling. The hot pressing process parameters are: the pressure in the pressurization stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged and the pressure is held for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

[0131] (5) Sanding and cutting section

[0132] The particleboard is sanded by a sanding machine, and the sanded particleboard is sawn into finished boards of specifications. The test results of the finished boards are not significantly different from those of Example 1, and the test data are omitted.

[0133] Product testing:

[0134] According to the national standard GB / T 4897-2015, the particleboard performance test was carried out with 10 parallel tests. The results are shown in the table below.

[0135] Table 1

[0136] project unit Example 1 Example 2 Example 3 Quality Standards MOR MPa 53.5 55.7 55.0 ＞20 Modulus of elasticity (MOE) MPa 5713 5919 5828 ＞3100 Internal bonding strength MPa 0.96 0.72* 0.70* ＞0.70 24h water absorption thickness expansion rate ％ 1.0 2.78* 1.82* ＜8.0 Static bending strength after immersion in 70℃ water MPa 37.4 16.6* 12.6* ＞12.0 Formaldehyde emission <![CDATA[mg / m 3 ]]> Not detected Not detected Not detected ＜0.124 density <![CDATA[g / cm 3 ]]> 0.42 0.52* 0.59* -

[0137] Table 2

[0138] project unit Example 1 Example 4 Example 5 Example 6 Example 7 Example 8 MOR MPa 53.5 40.5* 43.8* 52.9 50.2* 49.3* Modulus of elasticity (MOE) MPa 5713 4316* 4659* 5802 5800 5516* Internal bonding strength MPa 0.96 0.80* 0.85* 0.90* 0.95 0.94 24h water absorption thickness expansion rate ％ 1.0 1.28* 1.19* 1.15* 1.20* 1.05 Static bending strength after immersion in 70℃ water MPa 37.4 26.5* 20.1* 32.0* 30.1* 35.6 Formaldehyde emission <![CDATA[mg / m 3 ]]> Not detected Not detected Not detected Not detected Not detected Not detected density <![CDATA[g / cm 3 ]]> 0.42 0.42 0.41 0.42 0.41 0.38

[0139] Note: * indicates significant difference compared with the same test item in Example 1, p < 0.05

[0140] The experimental research results show that the type of wood material has a significant impact on the gluing strength and moisture resistance of particleboard. Compared with the combination of fir + bamboo and fir + bamboo, the combination of fir + bamboo can further improve the water resistance of particleboard, and the bonding ability between the wood fibers of the two is stronger. After using the corresponding glue, the obtained particleboard has the properties of low density, high strength, formaldehyde-free, moisture-proof and anti-deformation, and the product quality is higher. The results in Table 2 show that the various components in the glue cooperate with each other to improve the overall performance of the particleboard.

[0141] The above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall fall within the protection scope of the present invention.

Claims

1. A low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard process, characterized in that: The following steps are involved: (1) Wood shavings production process Processing wood or non-wood plant fiber raw materials into wood chips; (2) Drying and sorting section After the wet wood shavings are dried, the dry wood shavings are screened into surface dry wood shavings and core dry wood shavings; wherein the surface wood shavings are at least one of bamboo shavings, bamboo shavings or bamboo shavings, and the core wood shavings are Chinese fir shavings; (3) Glue application section Mix glue on the surface and core layer dry shavings; (4) Paving and hot pressing section The surface and core layers of glued wood chips are laid out to form a continuous slab strip of composite structure; after the slab strip is pre-pressed and formed, it is subjected to hot pressing treatment and then cooled; (5) Sanding and cutting section The particle board is sanded by a sanding machine and then cut into finished boards of specified specifications.

2. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: The surface wood shavings are water bamboo.

3. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: In step (2), the surface shavings are a mixture of 5-6 mesh and 30mm×8mm×1mm water bamboo shavings, and the core shavings are a mixture of 100mm×10mm×1mm Chinese fir shavings and 70mm×10mm×1mm Chinese fir shavings.

4. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 3, characterized in that: The mixing is equal mass mixing.

5. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: The amount of glue applied to the wood chips is 5% to 8% of the wood chip mass.

6. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: The hot pressing process parameters are as follows: the pressure in the pressurizing stage is 3.5±0.2MPa, the temperature is 190-250℃, and the hot pressing speed is (500±10)mm / s; the pressure in the holding stage remains unchanged for 10min; the pressure in the low-pressure stage is 0.3~0.5MPa, the temperature is 180~200℃, and the hot pressing speed is (500±10)mm / s.

7. The process for making low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: Calculated by mass percentage, the adhesive comprises 56% to 67% of diphenylmethane diisocyanate, 18.5% to 21.6% of silane-modified polyurethane resin, 0% to 3.24% of boric acid, 0% to 5.4% of dimethyl silicone oil, 0% to 7.56% of silicon dioxide, and 4000% to 5.4% of PEG.

8. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: Calculated by mass percentage, the adhesive comprises 56% to 67% of diphenylmethane diisocyanate, 18.5% to 21.6% of silane-modified polyurethane resin, 2.77% to 3.24% of boric acid, 4.63% to 5.4% of dimethyl silicone oil, 6.48% to 7.56% of silicon dioxide, and 4.62% to 5.4% of PEG400.

9. The process for producing low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard according to claim 1, characterized in that: The preparation method of the silane-modified polyurethane resin is as follows: polypropylene glycol 3000 and toluene diisocyanate are mixed at a molar ratio of 1:2, and reacted at a temperature of 80-90° C. for 2-4 hours to obtain a precursor; γ-aminopropyltriethoxysilane, dibenzoyl peroxide, 2-imidazolidinone and the precursor are mixed, and reacted at a temperature of 50-60° C. for 2-4 hours.

10. A low-density, high-strength, formaldehyde-free, moisture-proof and deformation-resistant particleboard, characterized in that: The invention is manufactured by the process described in any one of claims 1 to 9.