Research On Preparation Of High Performance Composite Materials By Waste Wood Materials

Nowaday our forest resources are increasingly tense and wood-based panel industry is demand for wood, while small diameter timber supply shortage greatly restrict its development. The wood-based panel industry is facing the problem of upgrading urgent technology and seeking new sources of raw materials to improve the utilization technology of wood raw materials. At the same time, home furniture upgrading faster and faster, which produce millions tons of waste wood annually. as landfill or fuel burning to deal with them, it will waste much of its value. Reasonable utilization of recycled wood materials has become the important measures for the development of the "second forest" resources, it has important significance for the wood-based panel industry, market prospects.The main research is use recycled wood materials as raw materials, and use it to make a kind of high performance composite materials—phenol resin/wood composite materials. Different from previous studies, broken recycled wood materials in this study can be used in the process of utilization. No hot water or chemical treatment reduced material fiber morphology or particle shape, or remove surface stains. The complex sources of recycled wood materials, such as wood and wood-based panel, can use together, without the use of classification.In order to solve the problem of insufficient mechanical properties of wood powder materials, using of different methods of wood powder mesh; at the same time, through the broken waste MDF to be small fiber as reinforcing material into sheet, improving material performance; and the use of influence on the heat transfer rate and product performance of humidifying treatment research the best amount of humidification; through laboratory method and field method of material corrosion resistance, mildew resistance and resistance evaluation of blue degeneration by TG-DSC method; of flame resistant materials were determined.The results of this study are summarized as follows:(1) Recycled wood materials by reasonable process can be prepared by artificial board is superior to trail material preparation. By using the powdery phenol resin to fill the mechanical performance of wood powder is difficult to use the problem. Because of the wood powder specific surface area, good hygroscopic, powdery phenol resin and wood powder can be mixed more evenly, avoiding the liquid adhesive aggregation problem. At the same time, raw materials use high moisture content, greatly reduces the cost of drying.(2) The optimal preparation process of phenol resin wood composite material is: 20 × 60 wood powder, the ratio of 3:7 or 40×60, 5:5 ratio, waste fiber is 10%, resin content is 10%, humidifying treatment is 5%, special mixing paving way, hot pressing time is 450 s, pressure is 1.8MPa, piecewise depressurization; under this optimum conditions, the prepared phenol resin wood composite performance for static bending strength is 40.11 MPa, inner strength is 3.85 MPa, screw holding force 2773.65 N, 24 h thickness swelling rate is 3.99%.(3) Laboratory materials against corrosion test, corrosion resistant to high grade level; field corrosion test in grade 9.5, resistant to termites grade is10; anti blue degeneration in 0-1. Field corrosion test of composite materials after static bending strength has good mechanical property. Has a large outdoor development potential. Powdery phenol resin as adhesive and as a preservative, reduce the production cost.(4) The phenol resin materials with flame resistance, by increasing the content of phenol resin can improve the flame resistance of materials, to meet different application requirements. The phenol resin when the heating temperature reached 500 degrees above, will form a hard glass carbon. The need to absorb a lot of heat in the process, reduce the material temperature.(5) Rapid heating material in the process of hot pressing temperature increase, there is a rapid rise in temperature for subsequent approaching and hot plate temperature, humidifying treatment of rapid warming influence. 5% humidification process, rapid heating time is shortened by about 31%, the center layer end temperature close to the temperature of hot pressing plate. Increasing material density was significantly increased after wet processing, static bending strength increased by an average of 41.2%, the highest reached 65.4%, the bond strength increased by an average of 21.2%, the highest reached 31.4%. At the same time, powdery phenol resin used for proper humidification treatment to improve its liquidity.