Patent Publication Number: US-2021189134-A1

Title: Wood Composite Board and Preparation Method Thereof

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to the technical field of manufacturing composite boards, in particular to a wood composite board and a preparation method thereof. 
     2. Background Art 
     Wood finish materials have low moisture content, easy processing, and the most widely use, at present, in domestic and foreign markets, the finish materials mainly used in the production of block board are: 1) solid wood board with a thickness of 0.10-0.75 mm, wood species including poplar, mahogany, mangosteen, etc .; 2) integrated materials with a thickness of 0.2-0.6 mm, such as engineered wood; 3) high density fiberboard with a thickness of 1-3 mm; 
     The above-mentioned wood finish material pressing process refers to that: the lower surface of plywood or block board is pressed to form into base materials of ecological board or finish products through procedures such as coating, cold-pressing, hot-pressing etc., the the finished products of ecological boards are made by pressing and sticking impregnated paper on the base materials of ecological board; 
     the finished products of ecological boards made by the finish material pressing process: using the base materials of ecological board or finish products pressed from two kinds of finish materials in above mentioned 1) and 2) and pressing and sticking impregnated paper on the upper and lower surfaces of the base materials of ecological board, has the defects of poor surface evenness, low surface bonding strength, high moisture content, poor dimensional stability, and poor anti-cracking and anti-thermocycling performance; the finished products of ecological boards made by the finish material pressing process: using the base materials of ecological board or finish products pressed from two kinds of finish materials in above mentioned 3) and pressing and sticking impregnated paper on the upper and lower surfaces of the base materials of ecological board, has the problems of formaldehyde pollution, low surface bonding strength, large thickness swelling rate of water absorption, large thickness, and high production costs. 
     SUMMARY OF THE INVENTION 
     In order to solve above technical problems, the invention provides the following technical schemes: A wood composite board and preparation method thereof, comprising following steps: 
     step 1, selecting wood materials and adhesives, wherein the moisture content of the wood materials is 0%-9%, and the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood materials and stirring, adhesive consumption is 7%-35% of the weight of the wood materials, applying waterproof agent and mildew preventive into the wood materials, and thereafter drying the wood materials to a moisture content of 3%-15%; 
     step 2, selecting board, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 100 g/m 2 -120 g/m 2 , evenly paving the wood materials prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 0.5 kg/m 2 -3.9 kg/m 2  and paving depth is 1 mm-3 mm; 
     step 3, after the paving in step 2, the wood composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 100° C-150° C., hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.7 MPa-0.9 MPa for the time of 3-10 min, in the second stage, the pressure is 0.3 MPa-0.5 MPa for the time of 1-10 min, in the third stage, the pressure is 0.0 MPa-0.3 MPa for the time of 1-10 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     Preferably, the wood materials is wood fiber, the fineness degree thereof is 0.2-0.6 mm, the moisture content of the selected wood fiber is 0%-9%; when the wood materials is wood fiber, the added amount of waterproof agent is 0.3% -0.6% of the weight of the wood materials, the added amount of mildew preventive is 0.1%-0.4% of the weight of the wood materials, and after applying, drying the wood materials to a moisture content of 3%-15%. 
     Preferably, when the wood materials is wood fiber, the paving amount thereof on the board is 0.7 kg/m 2 -3.9 kg/m 2 . 
     Preferably, the wood materials is wood particle, screen mesh size thereof is less than or equal to 1.53*1.53 mm and greater than or equal to 0.11*0.11 mm, the moisture content of the selected wood particle is 0%-3%; when the wood materials is wood particle, the added amount of waterproof agent is 0.05%-3.4% of the weight of the wood materials, the added amount of mildew preventive is 0.01%-4.5% of the weight of the wood materials, and after applying, drying the wood materials to a moisture content of 5%-12%. 
     Preferably, when the wood materials is wood particle, the paving amount thereof on the board is 0.5 kg/m 2 -3.5 kg/m 2 . 
     Preferably, the selected board in step 2 has a thickness of 5-21 mm, a length of 2450-2750 mm, and a width of 1230-1310 mm. 
     Preferably, the selected board in step 2 is plywood, block board, oriented particle board, straw board or any combination of artificial boards. 
     By adapting above methods, the invention has following advantages: 1. the wood artificial composite board of the invention has good evenness, high surface bonding strength, low moisture content, good dimensional stability, anti-cracking and anti-thermocycling performance. 
     2. The wood material of the invention uses compound adhesives such as polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives (urea-formaldehyde, phenol-formaldehyde, and melamine-formaldehyde), waterproofing agent, mildew preventive, etc., and has a low thickness swelling rate of water absorption, the thickness can be less than 1 mm, and the production cost is low. 
     3. Plywood, block board, oriented particle board, straw board or any combination of artificial boards are formed by paving glue blending wood materials and through hot-pressing, the surfaces of the artificial boards can be glue-free, which saves production costs. 
     4. The wood materials can be made from waste materials such as branches wood and small logs, recycling waste materials, and solving the problem of lack of wood raw materials. 
     5. The wood materials has a certain thickness, when the thickness of finished products remains unchanged, the thickness of plywood, block board, oriented particle board, straw board or any combination of artificial boards used for direct sticking is reduced, which saves production costs. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preparing wood fiber composite board 
     Embodiment 1 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood fiber and adhesives, wherein the fineness degree thereof is 0.2 mm, the moisture content thereof is 3%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood fiber and stirring, adhesive consumption is 7% of the weight of the wood fiber, applying waterproof agent into the wood fiber, additive amount thereof is 0.3% of the weight of the wood fiber, and applying mildew preventive, additive amount thereof is 0.1% of the weight of the wood fiber, and thereafter drying the wood fiber to a moisture content of 3%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 5 mm, a length of 2450 mm, and a width of 1230 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 100 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 0.7 kg/m 2  and paving depth is 1 mm; 
     step 3, after the paving in step 2, the wood fiber composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 100° C. , hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.7 MPa for the time of 3 min, in the second stage, the pressure is 0.3 MPa for the time of 1 min, in the third stage, the pressure is 0.0 MPa for the time of 1 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood fiber composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood fiber composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     Embodiment 2 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood fiber and adhesives, wherein the fineness degree thereof is 0.6 mm, the moisture content thereof is 9%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood fiber and stirring, adhesive consumption is 35% of the weight of the wood fiber, applying waterproof agent into the wood fiber, additive amount thereof is 0.6% of the weight of the wood fiber, and applying mildew preventive, additive amount thereof is 0.4% of the weight of the wood fiber, and thereafter drying the wood fiber to a moisture content of 15%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 21 mm, a length of 2750 mm, and a width of 1310 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 120 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 3.9 kg/m 2  and paving depth is 3 mm; 
     step 3, after the paving in step 2, the wood fiber composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 150 , hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.9 MPa for the time of 10 min, in the second stage, the pressure is 0.5 MPa for the time of 10 min, in the third stage, the pressure is 0.3 MPa for the time of 10 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood fiber composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood fiber composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     Embodiment 3 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood fiber and adhesives, wherein the fineness degree thereof is 0.4 mm, the moisture content thereof is 5%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood fiber and stirring, adhesive consumption is 20% of the weight of the wood fiber, applying waterproof agent into the wood fiber, additive amount thereof is 0.5% of the weight of the wood fiber, and applying mildew preventive, additive amount thereof is 0.3% of the weight of the wood fiber, and thereafter drying the wood fiber to a moisture content of 9%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 13 mm, a length of 2650 mm, and a width of 1280 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 110 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 2 kg/m 2  and paving depth is 2 mm; 
     step 3, after the paving in step 2, the wood fiber composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 130° C. , hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.8 MPa for the time of 6 min, in the second stage, the pressure is 0.4 MPa for the time of 6 min, in the third stage, the pressure is 0.2 MPa for the time of 6 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood fiber composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood fiber composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Test Results of Wood Fiber Composite Board in the Invention 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Standard 
                 Test Results 
                 Inspection 
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Test Items 
                 Unit 
                 Requirement 
                 Embodiment 1 
                 Embodiment 2 
                 Embodiment 3 
                 Standards 
                 Others 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Surface Bonding 
                 MPa 
                 ≥1.0  
                 1.2 
                 1.3 
                 1.4 
                 GB/T17657- 
                 Between the 
               
               
                 Strength 
                   
                   
                   
                   
                   
                 2013 Test 
                 fiber layer 
               
               
                   
                   
                   
                   
                   
                   
                 Methods of 
                 and the 
               
               
                   
                   
                   
                   
                   
                   
                 Evaluating 
                 wood-based 
               
               
                   
                   
                   
                   
                   
                   
                 the 
                 panel layer 
               
               
                 Thickness 
                 % 
                 ≤15   
                 10 
                 10 
                 11 
                 Properties of 
                 — 
               
               
                 Swelling Rate of 
                   
                   
                   
                   
                   
                 Wood-based 
                   
               
               
                 Water Absorption 
                   
                   
                   
                   
                   
                 Panels and 
                   
               
               
                 in 24 h 
                   
                   
                   
                   
                   
                 Surface 
                   
               
               
                 Formaldehyde 
                 mg/L 
                 &lt;0.10 
                 0.09 
                 0.07 
                 0.05 
                 Decorated 
                 — 
               
               
                 Emission 
                   
                   
                   
                   
                   
                 wood-based 
                   
               
               
                 Surface 
                 degree 
                 ≤5   
                 4 
                 5 
                 5 
                 panels 
                   
               
               
                 Anti-thermocycling 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Performance 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Surface 
                 degree 
                 ≤5   
                 3 
                 4 
                 5 
                   
                   
               
               
                 Anti-cracking 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Performance 
               
               
                   
               
            
           
         
       
     
     Preparing wood particle composite board 
     Embodiment 4 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood particle and adhesives, wherein the screen mesh size thereof is less than or equal to 1.53*1.53 mm and greater than or equal to 0.11*0.11 mm, the moisture content thereof is 1%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood materials and stirring, adhesive consumption is 7% of the weight of the wood materials, applying waterproof agent into the wood materials, additive amount thereof is 0.05% of the weight of the wood materials, and applying mildew preventive, additive amount thereof is 0.01% of the weight of the wood materials, and thereafter drying the wood materials to a moisture content of 3%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 5 mm, a length of 2450 mm, and a width of 1230 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 100 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 0.5 kg/m 2  and paving depth is 1 mm; 
     step 3, after the paving in step 2, the wood composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 100° C. , hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.7 MPa for the time of 3 min, in the second stage, the pressure is 0.3 MPa for the time of 1 min, in the third stage, the pressure is 0.0 MPa for the time of 1 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     Embodiment 5 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood particle and adhesives, wherein the screen mesh size thereof is less than or equal to 1.53*1.53 mm and greater than or equal to 0.11*0.11 mm, the moisture content thereof is 3%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood materials and stirring, adhesive consumption is 35% of the weight of the wood materials, applying waterproof agent into the wood materials, additive amount thereof is 3.4% of the weight of the wood materials, and applying mildew preventive, additive amount thereof is 4.5% of the weight of the wood materials, and thereafter drying the wood materials to a moisture content of 15%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 21 mm, a length of 2750 mm, and a width of 1310 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 120 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 3.5 kg/m 2  and paving depth is 3 mm; 
     step 3, after the paving in step 2, the wood composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 150° C., hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.9 MPa for the time of 10 min, in the second stage, the pressure is 0.5 MPa for the time of 10 min, in the third stage, the pressure is 0.3 MPa for the time of 10 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     Embodiment 6 
     A preparation method of a wood composite board, comprising following steps: 
     step 1, selecting wood particle and adhesives, wherein the screen mesh size thereof is less than or equal to 1.53*1.53 mm and greater than or equal to 0.11*0.11 mm, the moisture content thereof is 2%, the adhesive is polyurethane adhesive, formaldehyde-free biomass adhesive or formaldehyde-type adhesives; applying the adhesives into the wood materials and stirring, adhesive consumption is 20% of the weight of the wood materials, applying waterproof agent into the wood materials, additive amount thereof is 1.7% of the weight of the wood materials, and applying mildew preventive, additive amount thereof is 2.3% of the weight of the wood materials, and thereafter drying the wood materials to a moisture content of 9%; 
     step 2, selecting board, the board is plywood, block board, oriented particle board, straw board or any combination of artificial boards, and the selected board has a thickness of 13 mm, a length of 2550 mm, and a width of 1280 mm, evenly coating the adhesives on the upper and lower surfaces of the board, and coating amount of each surface is 110 g/m 2 , evenly paving the wood fiber prepared in step 1 on the upper and lower surfaces of the board, paving amount thereof is 2 kg/m 2  and paving depth is 2 mm; 
     step 3, after the paving in step 2, the wood composite board is made through high-temperature and hot-pressing, hot-pressing temperature is 120° C. , hot-pressing pressure and time are divided into three stages: in the first stage, the pressure is 0.8 MPa for the time of 6 min, in the second stage, the pressure is 0.4 MPa for the time of 6 min, in the third stage, the pressure is 0.2 MPa for the time of 6 min; 
     step 4, after the hot-pressing in step 3, air cooling the wood composite board for more than 5 min, and then collecting and stacking thereof; reconditioning the wood composite board naturally for more than 7 days, and trimming and sanding to determine the thickness, the thickness error of the board is controlled in ±0.1 mm. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Test Results of Wood Particle Composite Board in the Invention 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                 Standard 
                 Test Results 
                 Inspection 
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Test Items 
                 Unit 
                 Requirement 
                 Embodiment 4 
                 Embodiment 5 
                 Embodiment 6 
                 Standards 
                 Others 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Surface Bonding 
                 MPa 
                 ≥1.0  
                 1.2 
                 1.3 
                 1.4 
                 GB/T17657- 
                 Between the 
               
               
                 Strength 
                   
                   
                   
                   
                   
                 2013 Test 
                 particle layer 
               
               
                   
                   
                   
                   
                   
                   
                 Methods of 
                 and the  
               
               
                   
                   
                   
                   
                   
                   
                 Evaluating 
                 wood-based 
               
               
                   
                   
                   
                   
                   
                   
                 the 
                 panel layer 
               
               
                 Thickness 
                 % 
                 ≤15   
                 13 
                 12 
                 11 
                 Properties of 
                 — 
               
               
                 Swelling Rate of 
                   
                   
                   
                   
                   
                 Wood-based 
                   
               
               
                 Water Absorption 
                   
                   
                   
                   
                   
                 Panels and 
                   
               
               
                 in 24 h 
                   
                   
                   
                   
                   
                 Surface 
                   
               
               
                 Formaldehyde 
                 mg/L 
                 &lt;0.10 
                 0.09 
                 0.07 
                 0.05 
                 Decorated 
                 — 
               
               
                 Emission 
                   
                   
                   
                   
                   
                 wood-based 
                   
               
               
                 Surface 
                 degree 
                 ≤5   
                 4 
                 5 
                 5 
                 panels 
                   
               
               
                 Anti-thermocycling 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Performance 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Surface 
                 degree 
                 ≤5   
                 3 
                 4 
                 5 
                   
                   
               
               
                 Anti-cracking 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Performance 
               
               
                   
               
            
           
         
       
     
     The invention and embodiments thereof have been described above, and the description is not restrictive, in conclusion, the similar structures and embodiments with the technical scheme of the invention, which are designed by those skilled in the art inspired by the invention, without creativity and without departing from the spirit of the invention, should be included in the protection scope of the invention.