Research On Preparation And Properties Of Tubular Particleboard Via Multidimensional-interface Extrusion

In this research,aiming at the defects of the traditional vertical extrusion process in the production of tubular particleboard(poor lengthwise mechanical properties and dimensional stability,difficult to produce thick boards),the traditional flat punch in the vertical extrusion equipment is improved to a multidimensional interface punch,combined with internal and external dual heat source cascade heating technology,the process parameters for the production of five different thickness multidimensional interface extruded tubular particleboards were determined.It laid the foundation for the follow-up research on high-performance wood structure building wall materials and promoting the development of my country's wood structure building wall materials industry.By referring to relevant standards to test the physical and lengthwise mechanical properties,thermal insulation properties and sound insulation properties of five thickness tubular particleboards,the following conclusions are obtained:1.Through multidimensional-interface extrusion,internal and external dual-source step heating technology for inner molding tubes and outer molding plates,the best process parameters for producing 24 mm,28 mm,35 mm,40 mm,60 mm thickness multidimensional-interface extruded tubular particleboard are determined:shavings drying temperature is 160?;shavings moisture content is 5%-7%;sizing content is 10%;formaldehyde scavenger is 4%;moisture content after sizing is 10%-12%;initial curing temperature of 40mm thin board is 80°C,60 mm thick board is 100°C;extrusion temperature:160?for thin board within 40 mm and 180?for 60mm thick board;extrusion speeds are 0.44 m/min,0.40 m/min,0.36 m/min,0.33 m/min and 0.12m/min,respectively;target density is 0.40 g/cm~3.2.The physical and lengthwise mechanical properties of the above five thickness multidimensional interface extruded tubular particleboards were tested,and it was concluded that the lengthwise mechanical properties decreased as the board thickness increased,and the physical properties increased.The lengthwise MOR and MOE of the multidimensional-interface extruded tubular particleboard are similar to the lengthwise MOR and MOE of the flat-pressed tubular particleboard and the crosswise MOR and MOE of the traditional extruded tubular particleboard.Compared with the lengthwise mechanical properties of traditional extruded tubular particleboard,MOR and MOE are increased by about 5.8 times and 3.7 times,respectively,and the IB is increased by about 1.4 times.TS and LDC are respectively 38%and 62%of traditional extruded tubular particleboard,and TS is only 11%of flat-pressed tubular particleboard.3.As the thickness of the above 5 kinds of thickness multidimensional-interface extruded tubular particleboards increases,the thermal insulation performance is better.The average thermal conductivity of the multidimensional interface tubular particleboard is 0.131 W/(m·K),which is an insulation material with low density and good insulation effect.The thermal insulation performance of multidimensional interface extruded tubular particleboard with a thickness of less than 40 mm is similar to that of 190-340 mm thick concrete blocks,solid sintered bricks,280 mm thick reinforced concrete walls and clay brick masonry walls.The thermal insulation performance of the multidimensional interface extruded tubular particleboard with a thickness of 60 mm is similar to that of the 280 mm thick porous brick wall,the 50 mm thick bamboo-wood composite wall and the 80-160 mm thick traditional tubular particleboard composite wall,which shows its excellent thermal insulation performance.4.The thickness of the above 5 kinds of thickness multidimensional interface extruded tubular particleboard increases,the sound insulation capacity increases,and there are poor low-frequency sound insulation effects and good high-frequency sound insulation effects.Compared with ordinary reinforced concrete and solid brick walls,the sound insulation performance needs to be improved.The sound insulation of multidimensional interface extruded tubular particleboard with a thickness of less than 40 mm is 30 dB,which is higher than that of a 120 mm thick wooden structure filled with glass wool wall.The sound insulation of the board of 60 mm thick multidimensional interface extruded tubular particleboard is 34 dB,which can be similar to the sound insulation of some 100 mm thick wood structure composite walls,which shows its excellent sound insulation performance.