A high-load-bearing polyurethane wood composite board and preparation method thereof

Abstract

The present invention relates to the technical field of composite board preparation, and discloses a high-load-bearing polyurethane wood composite board and a preparation method thereof, wherein the high-load-bearing polyurethane composite board comprises a substrate layer and a composite layer, wherein the substrate layer is composed of wood strips, and the composite layer is a polyurethane material; the polyurethane material is composed of three components, component A is composed of: polyol, water, catalyst, surfactant, component B is composed of: any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate, and component C is composed of: polyimide, water, polyglycolic acid ester, methyltrimethoxysilane. Compared with the existing composite board, the present invention utilizes the long wood strips cut from the production of multilayer boards in industry, and the composite board is pressed by high-performance three-component polyurethane material, which has the characteristics of environmental protection, zero formaldehyde, adjustable thickness, high load-bearing capacity, and good impact resistance. It is particularly suitable for working conditions with higher requirements for load-bearing capacity and impact force.

Description

Technical Field

[0001] The invention relates to the technical field of composite board preparation, and more specifically discloses a high-load-bearing polyurethane-wood composite board and a preparation method thereof. Background Art

[0002] Compared with solid wood boards, composite boards have good dimensional stability and a variety of decorative textures. Therefore, they are widely used in interior decoration. Current composite boards often use log shavings or log granulation as the basic raw materials, and the basic raw materials are compounded with glue to obtain composite boards. When making composite boards, urea-formaldehyde glue, phenol-formaldehyde glue, white latex, etc. are commonly used as adhesives to bond large wood chips or small wood particles (powder) to prepare composite boards. However, when preparing composite boards, urea-formaldehyde glue, phenol-formaldehyde glue, white latex and other adhesives are coated on the surface of the basic raw materials, and then directly pressed and compounded. The adhesive cannot fully penetrate into the interior of the raw materials, resulting in the low bearing strength of the prepared composite board. It can only be used in some environments with low load requirements, and its use has certain limitations. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a high-load-bearing polyurethane-wood composite board and a preparation method thereof, which can solve the problem of low load-bearing strength of the current composite board.

[0004] To solve the above technical problems, according to one aspect of the present invention, more specifically, a high-load-bearing polyurethane wood composite board comprises a substrate layer and a composite layer, wherein the substrate layer is composed of wood strips and the composite layer is a polyurethane material; the polyurethane material is composed of three components, wherein component A is composed of: polyol, water, catalyst, surfactant, component B is composed of: any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate, and component C is composed of: polyimide, water, polyhydroxy acetate, methyltrimethoxysilane.

[0005] Furthermore, the substrate layer adopts a length-to-diameter ratio wood strip, and uses the long fiber high modulus of the wood strip as a skeleton.

[0006] Furthermore, the component A is composed of the following components in parts by weight: 100 parts of polyol, 0.3-2.5 parts of water, 0.2-1.0 parts of catalyst, and 1.0-3.0 parts of surfactant;

[0007] The B component is composed of the following components in parts by weight: 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate;

[0008] The component C is composed of the following components in parts by weight: 0.3-1.2 parts of polyimide, 0.7-1.5 parts of water, 0.2-1.0 parts of polyglycolic acid ester, and 1.0-2.2 parts of methyltrimethoxysilane.

[0009] According to another aspect of the present invention, there is provided a method for preparing a high-load bearing polyurethane wood composite board, characterized in that it comprises the following steps:

[0010] S1. Select the base material: select the edge strips cut from the production of laminated boards or multi-layer boards, and then dry the wood strips to make the moisture content of the wood below the calibration value, and then you can get a qualified base material;

[0011] S2, substrate processing: placing the qualified substrate wood strips obtained in step S1 on the paving platform, and aligning the two ends of each substrate wood strip;

[0012] S3, polyurethane material preparation: three components of polyurethane material, ABC, are mixed evenly in proportion by a pouring machine to obtain polyurethane material;

[0013] S4, coating: spraying the polyurethane material obtained in step S3 onto the substrate wood strips according to the designed weight, thereby forming a composite layer on the substrate wood strips;

[0014] S5, pressing and compressing: a plurality of substrate wood strips with a composite layer on the surface treated in step S4 are arranged and stacked together in the length direction, and after reaching a predetermined weight, they are placed in a preheated mold, and the mold is closed for pressing and compressing;

[0015] S6, cooling: after the pressed composite board obtained in step S5 is placed in an environment of 15-20° C. for 2.5-4 hours, a high-load-bearing polyurethane composite board can be obtained.

[0016] Furthermore, in step S1, the width of the wood strip is 5-20 mm, the thickness is 1-2 mm, and the length is determined according to the mold.

[0017] Furthermore, in the step S1, during the drying process of the wood strips, the wood strips are qualified if the moisture content is below 8%.

[0018] Furthermore, in step S3, the three components A, B and C of the polyurethane material are mixed by a pouring machine in a ratio of 4-7:2-5:1-3.

[0019] Furthermore, in the step S4, the polyurethane material can be coated on the substrate wood strip by brushing or rolling; and after the polyurethane material is coated on the substrate wood strip, the substrate wood strip is subjected to ultrasonic treatment.

[0020] Furthermore, in step S4, the amount of polyurethane material coated on each substrate wood strip is:

[0021] m=(ρ·L·W·D)+(P·L·W·t)

[0022] While the polyurethane material can fully penetrate into the interior of the wood strips, there is also polyurethane material on the surface of the wood strips that can bond and composite multiple wood strips together. Wherein, m is the amount of polyurethane material coated on each substrate wood strip, ρ is the density of the polyurethane material, L is the length of the substrate wood strip, W is the width of the substrate wood strip, D is the thickness of the coating on the substrate wood strip, P is the permeability of the substrate wood strip, and t is the ultrasonic treatment time.

[0023] Furthermore, in the step S5, during the pressurizing process, the temperature of the mold is 60-80° C., and the pressing time is 1 hour.

[0024] The beneficial effects of the high-load-bearing polyurethane wood composite board and its preparation method of the present invention are as follows: by using a three-component polyurethane material as an adhesive in the preparation process of the composite board, during the preparation process of the composite board, it can fully penetrate into the base wood, and the polyurethane material that penetrates into the base wood can form hydrogen bonds, further strengthening the fiber skeleton of the base wood, thereby increasing the compressive strength of the composite board, and then greatly improving the load-bearing capacity of the composite board. Compared with the existing composite board, the composite board prepared by the present invention has a stronger load-bearing capacity, can be used in an environment with higher requirements for load-bearing capacity, and has a wider range of applications. In addition, the three-component polyurethane material is used as an adhesive in the preparation process of the composite board. Compared with other common ones such as urea-formaldehyde, phenolic formaldehyde, etc., it has high elasticity, good wetting permeability, low curing temperature and low energy consumption. The composite board prepared by combining slender wood strips has the characteristics of high load-bearing capacity and good impact toughness, and can be well compatible with the fibers in the base wood, so that the base wood is firmly compounded together, avoiding the situation where degumming easily occurs during use, thereby causing the composite board to crack. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0026] Figure 1 This is a schematic diagram of the structure of a high-load-bearing polyurethane composite panel.

[0027] In the figure: 1, substrate layer; 2, composite layer. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0029] Embodiment 1

[0030] (1) Selection of substrate: Select the side strips with a width of 5 mm, a thickness of 1 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and you can get a qualified substrate.

[0031] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0032] (3) Preparation of polyurethane material: Component A consisting of 100 parts of polyol, 0.3 parts of water, 0.2 parts of catalyst, and 1.0 parts of surfactant, component B consisting of 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate, and component C consisting of 0.3 parts of polyimide, 0.7 parts of water, 0.2 parts of polyhydroxy acetate, and 1.0 parts of methyltrimethoxysilane are mixed uniformly in a ratio of 4:2:1 by a casting machine to obtain a polyurethane material.

[0033] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip, and then the substrate wood strip is ultrasonically treated.

[0034] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 60°C, and the mold is closed and pressurized for 1 hour.

[0035] (6) Cooling: After the pressed composite board obtained in step (5) is placed at 15° C. for 2.5 hours, a high-load-bearing polyurethane composite board can be obtained.

[0036] Embodiment 2

[0037] (1) Selection of substrate: Select the side strips with a width of 13 mm, a thickness of 1.5 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to reduce the moisture content of the wood to less than 8%, and you can get a qualified substrate.

[0038] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0039] (3) Preparation of polyurethane material: Component A consisting of 100 parts of polyol, 1.6 parts of water, 0.7 parts of catalyst, and 2.0 parts of surfactant, component B consisting of 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate, and component C consisting of 0.8 parts of polyimide, 1.2 parts of water, 0.7 parts of polyhydroxy acetate, and 1.7 parts of methyltrimethoxysilane are mixed uniformly in a ratio of 5:4:2 by a casting machine to obtain a polyurethane material.

[0040] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip, and then the substrate wood strip is ultrasonically treated.

[0041] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 70°C, and the mold is closed and pressurized for 1 hour.

[0042] (6) Cooling: After the pressed composite board obtained in step (5) is placed in an environment of 18° C. for 3 hours, a high-load-bearing polyurethane composite board can be obtained.

[0043] Embodiment 3

[0044] (1) Selection of substrate: Select the side strips with a width of 20 mm, a thickness of 2 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and then you can get a qualified substrate.

[0045] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0046] (3) Preparation of polyurethane material: Component A consisting of 100 parts of polyol, 2.5 parts of water, 1.0 part of catalyst, and 3.0 parts of surfactant, component B consisting of 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate, and component C consisting of 1.2 parts of polyimide, 1.5 parts of water, 1.0 part of polyhydroxyacetate, and 2.2 parts of methyltrimethoxysilane are mixed uniformly in a ratio of 7:5:3 by a casting machine to obtain a polyurethane material.

[0047] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip, and then the substrate wood strip is ultrasonically treated.

[0048] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 80°C, and the mold is closed and pressurized for 1 hour.

[0049] (6) Cooling: After the pressed composite board obtained in step (5) is left to stand at 20° C. for 4 hours, a high-load-bearing polyurethane composite board can be obtained.

[0050] Comparative Example 1

[0051] (1) Selection of substrate: Select the side strips with a width of 20 mm, a thickness of 2 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and then you can get a qualified substrate.

[0052] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0053] (3) Preparation of polyurethane material: 100 parts of component A consisting of polyol and 100 parts of component B consisting of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate are mixed uniformly by a casting machine to obtain a polyurethane material.

[0054] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip.

[0055] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 80°C. The mold is closed and pressurized for 1 hour to obtain a polyurethane composite board.

[0056] Comparative Example 2

[0057] (1) Selection of substrate: Select the side strips with a width of 20 mm, a thickness of 2 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and then you can get a qualified substrate.

[0058] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0059] (3) Preparation of polyurethane material: 100 parts of component A consisting of polyol and 100 parts of component B consisting of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate are mixed uniformly by a casting machine to obtain a polyurethane material.

[0060] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip, and then the substrate wood strip is ultrasonically treated.

[0061] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 80°C. The mold is closed and pressurized for 1 hour to obtain a polyurethane composite board.

[0062] Comparative Example 3

[0063] (1) Selection of substrate: Select the side strips with a width of 20 mm, a thickness of 2 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and then you can get a qualified substrate.

[0064] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0065] (3) Preparation of polyurethane material: Component A consisting of 100 parts of polyol, 2.5 parts of water, 1.0 part of catalyst, and 3.0 parts of surfactant, and component B consisting of 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate are mixed uniformly in a ratio of 1:2 by a casting machine to obtain a polyurethane material.

[0066] (4) Coating: The polyurethane material obtained in step (3) is sprayed onto the substrate wood strip according to the designed weight (the polyurethane material can also be attached to the substrate wood strip by brushing or rolling), thereby forming a composite layer on the substrate wood strip, and then the substrate wood strip is ultrasonically treated.

[0067] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 80°C. The mold is closed and pressurized for 1 hour to obtain a polyurethane composite board.

[0068] Comparative Example 4

[0069] (1) Selection of substrate: Select the side strips with a width of 20 mm, a thickness of 2 mm, and a length determined by the mold to make the laminate or multi-layer board cut from the aspect ratio. Use the long fiber high modulus of the wood strips as the skeleton, and then dry the wood strips to make the moisture content of the wood below 8%, and then you can get a qualified substrate.

[0070] (2) Substrate processing: The qualified substrate wood strips obtained in step S1 are placed on the paving platform, and the two ends of each substrate wood strip are aligned and oriented.

[0071] (4) Coating: Spray PF-30 phenolic adhesive onto the substrate wood strips according to the designed weight (the polyurethane material can also be attached to the substrate wood strips by brushing or rolling), thereby forming a composite layer on the substrate wood strips, and then ultrasonically treat the substrate wood strips.

[0072] (5) Pressing: several substrate wood strips with a composite layer on the surface treated in step (4) are arranged and stacked together in the length direction. After reaching a predetermined weight, they are placed in a mold with a mold temperature of 80°C. The mold is closed and pressurized for 1 hour to obtain a polyurethane composite board.

[0073] The static bending strength, static bending elastic modulus and compressive strength of the composite boards obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were tested according to the "Test Methods for Physical and Chemical Properties of Artificial Boards and Facing Artificial Boards" GB / T17657-2013. At the same time, the impact toughness of the boards obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was tested by the pendulum impact test method. The results are shown in the following table:

[0074]

[0075] From the above data, it can be seen that the polyurethane composite board prepared by the present invention has a higher load-bearing capacity, can be used in environments with certain requirements for load-bearing capacity, and has stronger impact toughness. During use, it is not easy to debond and crack.

[0076] Colorants were added to the polyurethane materials obtained in Examples 1 to 3 and Comparative Examples 1 to 3, and colorants were also added to the ST6245 polyurethane glue in Comparative Example 4. Then, the composite plates with a thickness of 20 mm and a width of 150 mm obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were cut from the middle, and the extension length and coverage area of ​​the colorants in the cross section were measured to determine the penetration of the polyurethane materials. The results are shown in the following table:

[0077] Examples and Comparative Examples Penetration depth (mm) <![CDATA[Coverage area (mm 2 )]]> Embodiment 1 19.2 2819.136 Embodiment 2 19.7 2901.219 Embodiment 3 20.0 2986.80 Comparative Example 1 13.1 1671.691 Comparative Example 2 13.8 1856.652 Comparative Example 3 15.7 2199.582 Comparative Example 4 13.0 1658.41

[0078] It can be seen from the above data that in the process of preparing the polyurethane composite board of the present invention, the polyurethane material can more fully penetrate into the interior of the base wood to increase the performance of the prepared polyurethane board.

[0079] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention also fall within the protection scope of the present invention.

Claims

1. A high-load-bearing polyurethane wood composite board, comprising a substrate layer (1) and a composite layer (2), characterized in that: The substrate layer (1) is made of wood strips, and the composite layer (2) is made of polyurethane material; the polyurethane material is composed of three components, wherein component A is composed of the following components in parts by weight: 100 parts of polyol, 0.3-2.5 parts of water, 0.2-1.0 parts of catalyst, and 1.0-3.0 parts of surfactant; component B is composed of the following components in parts by weight: 100 parts of any one or more of diphenylmethane diisocyanate or polymethylene polyphenyl isocyanate; and component C is composed of the following components in parts by weight: 0.3-1.2 parts of polyimide, 0.7-1.5 parts of water, 0.2-1.0 parts of polyhydroxy acetate, and 1.0-2.2 parts of methyltrimethoxysilane; the ratio of the three components A, B, and C is 4-7:2-5:1-3.

2. The high-load bearing polyurethane wood composite board according to claim 1, characterized in that: The substrate layer (1) is made of wood strips with a high aspect ratio, and the long fiber high modulus of the wood strips is used as a skeleton.

3. A method for preparing a high-load bearing polyurethane wood composite board according to any one of claims 1 to 2, characterized in that: The following steps are involved: S1. Select the base material: select the edge strips cut from the production of laminated boards or multi-layer boards, and then dry the wood strips to make the moisture content of the wood below the calibration value, and then you can get a qualified base material; S2, substrate processing: placing the qualified substrate wood strips obtained in step S1 on the paving platform, and aligning the two ends of each substrate wood strip; S3, polyurethane material preparation: three components of polyurethane material, ABC, are mixed evenly in proportion by a pouring machine to obtain polyurethane material; S4, coating: spraying the polyurethane material obtained in step S3 onto the substrate wood strips according to the designed weight, thereby forming a composite layer on the substrate wood strips; S5, pressing and compressing: a plurality of substrate wood strips with a composite layer on the surface processed in step S4 are arranged and stacked together in the length direction, and after reaching a predetermined weight, they are placed in a preheated mold, and the mold is closed for pressing and compressing; S6, cooling: after the pressed composite board obtained in step S5 is placed in an environment of 15-20° C. for 2.5-4 hours, a high-load-bearing polyurethane composite board can be obtained.

4. The method for preparing a high-load bearing polyurethane wood composite board according to claim 3, characterized in that: In step S1, the width of the wood strip is 5-20 mm, the thickness is 1-2 mm, and the length is determined according to the mold.

5. The method for preparing the high-load bearing polyurethane wood composite board according to claim 3, characterized in that: In the step S1, during the drying process of the wood strips, the wood strips are qualified if the moisture content is below 8%.

6. The method for preparing the high-load bearing polyurethane wood composite board according to claim 3, characterized in that: In the step S4, the polyurethane material can be coated on the substrate wood strip by brushing or rolling; and after the polyurethane material is coated on the substrate wood strip, the substrate wood strip is ultrasonically treated.

7. The method for preparing a high-load bearing polyurethane wood composite board according to claim 3, characterized in that: In the step S5, during the pressurization process, the temperature of the mold is 60-80° C. and the pressing time is 1 hour.

Images