Observation and Analysis of Gypsum Particleboard using SEM

The microstructures of gypsum board and gypsum particleboard were observed by SEM. The effects of retarder and waterproof agent on the shape and the average dimension of the gypsum crystal were discussed. The mechanism was investigated as well. Four typical instances, i e, the gypsum crystal shape, the gypsum combined with particles on the particles surface, the gypsum combined with particles on the wood cross section and the gypsum combined with particles inside the wood cell cavity were selected and observed. Furthermore, the agglomeration and cementation mechanism between gypsum and particle were studied.     

Mechanical properties of nano SiO2 filled gypsum particleboard

Nano SiO2 was filled into gypsum particleboard. Effect of the amount of nano SiO2 particles filled, ultrasonic dissipating duration and treating the nano particles with different coupling agents on the mechanical properties of the board were studied respectively. The results show that nano SiO2 is helpful for the improvement of the properties. Adding 3%（mass fraction） nano SiO2 is the best for the improvement of both modulus of rupture（MOR） and modulus of elasticity（MOE） of the boards formed at 30 ℃ or 40 ℃. For the boards formed at 30 ℃, their MOR and MOE can be improved by 8.77% and 12.24%, and MOR and MOE of the boards formed at 40 ℃ can be improved by 44.44% and 108.38%.3% is also the best addition proportion to improve internal bond（IB） of the boards formed at 30 ℃, while 5% is the best for that of the boards formed at 40 ℃. At room temperature, dissipating nano Si02 into flake by ultrasonic has better effect on the properties of the final products. Through ultrasonic treating for 1 h and the best treating duration, the MOR and MOE can be increased by 41.99% and 47.80%. In addition, different coupling agents have different effects on the final properties too, and silane coupling agent KH570 is better for the improvement of properties of the boards formed at room temperature.     

两种不同原料制备无粘结剂高强度炭材料的研究

分别以生石油焦和煤系原料改性炭粉为原料成功制得了无粘结荆高强度炭材料。实验表明：原料挥发分含量较高对粉料的成型有利，但挥发分含量过高，不利于无粘结剂炭材料的烧结；另外，随着成型压力的增加，生坯密度和无粘结荆炭材料烧结制品的密度都呈升高的趋势。研究结果表明：成型压力为IOOMPa，烧结温度为1000℃，生石油焦粉制得的无粘结剂炭材料的抗折强度为42．90MPa，抗压强度为90．23MPa；煤系原料改性炭粉制得的无粘结剂炭材料的抗折强度为61．58MPa，抗压强度为116．12MPa。     

Effects of dowels produced from various materials on withdrawal strength in MDF and Pb

Wood dowels are commonly used in the construction furniture, but little information is available about the additive effects of dowels on the ultimate withdrawal strength of single or multidowel joints. This study was carried out to determine the tensile strength of 10‐mm‐diameter dowels produced from medium‐density fiberboard (MDF), plywood, scotch pine (Pinus sylvestris L.), and beech (Fagus orientalis lipsky), bonded parallel and vertical to the surface of MDF and particleboard (Pb) with poly(vinyl acetate) (PVAc) and Desmodur‐VTKA (D‐VTKA). Tensile strength was applied to the dowels according to the procedure in the ASTM‐D 1037 standard. The effects of dowel species, direction of tensile, composite material, and type of adhesive on tensile strength were determined. The results showed that the highest tensile strength was obtained in beech dowels bonded vertically with PVAc adhesive to the surface of MDF at 7.91 N/mm². If the dowels used in furniture production are subjected to great tensile strength, beech dowels bonded with PVAc adhesive on MDF should be used. However, when dowels produced from MDF and plywood waste are used, they also can produce positive results. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 531–535, 2003     

保证钢丝网架夹芯板抹灰质量的技术措施

对基层采用C25米石混凝土、合理设置技术间歇和加强洒水养护等技术措施，可有效解决钢丝网架夹芯板表面抹灰困难、抹灰层易产生通长裂缝的质量缺陷，可大幅度提高墙体的整体强度、刚度、隔声、保温、防火和阻燃等各项指标。     

刨花板施胶随动控制系统设计

介绍了刨花板施胶技术和系统构成;提出了搅拌机随动控制方案;阐述了刨花板搅拌机随动控制系统的设计。     

Processing of urea‐formaldehyde‐based particleboard from hazelnut shell and improvement of its fire and water resistance

The purpose of this study was to manufacture urea‐formaldehyde‐based particleboard from hazelnut shell and eliminate its disadvantages such as flammability, water absorption, swelling thickness by using fly ash and phenol‐formaldehyde. Synthesized urea‐formaldehyde and grained hazelnut shells were blended at different ratios ranging from 0.8 to 3.2 hazelnut shell/urea‐formaldehyde and dried at 70°C in an oven until constant weight was reached. In addition, other parameters affecting polymer composite particleboard from hazelnut shell and urea‐formaldehyde were investigated to be the amount of fly ash, amount of phenol formaldehyde and the effects of these parameters on bending stress, limit oxygen index, water absorption capacity and swelling in the thickness. The optimization results showed that the maximum bending strength was 4.1N/mm², at urea‐formaldehyde ratio of 1.0, reaction temperature of 70°C, reaction time of 25 min, hazelnut shell/urea‐formaldehyde resin of 2.4 and mean particle size of 0.1 mm. Although the limited oxygen index and smoke density of composite particleboard without fly ash has 22.3 and 1.62, with fly ash of 16% (w/w) according to the filler has 38.2 and 1.47, respectively. Water absorption and increase in the swelling thickness exponentially decreased with increasing phenol formaldehyde. Copyright © 2009 John Wiley & Sons, Ltd.     

挤压法生产刨花板的现状和发展前景

阐述了挤压法生产刨花板的现状、成型原理、优良特性,并对挤压法生产空芯刨花板的发展前景进行了展望.     

马尾松刨花板新工艺的研究

从抽提物影响胶合角度出发,采用不同的水热处理时间、温度等工艺参数对马尾松刨花进行水热处理,实现刨花表面钝化或活化,压制刨花板.结果表明当水热处理温度为100℃、处理时间为60min、施胶量为7.5%时,刨花板甲醛释放量为10.2mg/100g,达到国家E2级标准;其他各项力学性能指标如静曲强度、内结合强度等均满足国家标准要求.