Study On Low Density Binderless Particleboard And Retardant Properties

In this study, paulownia, poplar and bagasse were used as raw material for making low density binderless particleboard. During board manufacturing process, no any synthetic resin was added, instead, a small amount of additive organic acid and sucrose were sprayed into the particles.The effects of board density,additive content,flame retardant content and waterproof agent on physical and mechanical properties of low density binderless retardant particleboard were also investigated by the methods of single factor experiment.Bonding mechanism,thermal stability,heat-eonducting properties and combustion properties of the plate are evaluated by using Fourier Transform Infrared Spectroscopy(FTIR), X-ray Diffraction(XRD), thermogravimetric (TG), thermal conductivity detetor and cone calorimeter and other equipments.Paulownia, poplar and bagasse were used as raw materia, adding a small amount of additives can suppress a certain intensity of low density binderless particleboard. The results show that the hot temperature of 180℃, pressing time of 8min, additive content of 15%, the target density of 0.4g/cm3 and the waterproof agent of 1.5% can meet the the requirement of the National Forestry Industry standard LY/T 1718-2007. Under the condition of 0.45g/cm3 and 15% additive, the MOR value of paulownia was the highest and the MOR value of poplar was higher than bagasse. When did not add waterproofing agent, under the condition of 0.45g/cm3, the TS value of bagasse was the lowest and the TS value of paulownia was lower than poplar.When adding waterproofing agent, the TS value of paulownia was the lowest and the TS value of bagasse was lower than poplar.By the analysis of FTIR spectra, X-ray diffraction and thermogravimetric (TG), the changes of the functional groups, the crystal degree of cellulose, the main components and additive chemical components were investigated during the processing after adding additive and compare different materials from binderless bonding to probable bonding mechanism of the binderless fiberboard. The addition of the additive which promote the degradation of cellulose and hemicellulose, the glycoside bond rupture of cellulose and hemicellulose to generate more -OH so that more hydrogen bonds. Organic acid play a bridging role lead to the cellulose crystallinity increased and the mechanical strength of binderless board was reinforced.The thermal conductivity of the binderless particleboard is during 0.0709W/(m·k)-0.098W/(m·k), which can meet the requirement of the national standard LY/T1718-2007. The value of MOR decreased with increasing flame retardant content and do not influence obviously to the value of TS. The thermal stability of the binderless particleboard was increased after adding flame retardant.The flame retardant could change the cleavage direction of wood that generated more carbon and water which decreased the initial decomposition temperature.In addition, the THR and the SPR of the binderless particleboard also decreased.Therefore, the purpose of reducing smoke and efficient flame retardant with the use of APP used as flame retardant for binderless particleboard were achieved.