In this study, fibers recycled via two different methods; hydrothermal and ohmic heating were used to manufacture medium density fiberboard (MDF). The purpose of this study was to determine the ...effect of recycling method on practical properties (bending strength, modulus of elasticity, internal bonding and screw holding in edge and surface and thickness swelling after 24 hours water immersion) of the boards. Also, a morphological analysis was done to evaluate the influence of recycling process on fiber dimensions. Also the existence of UF residues were observed by SEM.The results related to classification and dimension analyze of fibers confirmed the negative influence of recycling process on quality of fibers. Also degree of deterioration in hydrothermal recycling was higher than that of ohmic recycling due to sever condition of heating.Furthermore, the results showed that recycling of MDF wastes via ohmic heating method resulted in better physical and mechanical propertied as compared to the hydrothermal method. Overall results showed that MDF panels made from recycled fibers via ohmic heating method exceed the minimum values required by EN standards (EN 622-5, 2006) for all properties except thickness swelling. About ohmic heating method, increasing the time of ohmic heating led to improving the practical properties of recycled MDF boards. It was observed by SEM that much more residues of cured UF resin adhesive were existed on the surface of recycled fibers via hydrothermal method. According to the results it can be said that ohmic heating method is a useful process for recycling the wastes of MDF.
In recent years, noise pollution is one of the serious social problems, and many efforts have been paid to the development of efficient sound absorbing material. Normal sound absorbing materials are ...made of inorganic fibers, and inorganic fiber has difficulty with processing after the disposal. From the viewpoint of environmental protection, therefore, sound absorbing material made of natural fiber is expected. Furthermore, normal sound absorbing materials consist of single-layered structure and the sound absorbing properties have a limit level of frequency. Now, it is expected that the multi-layered structure improve the sound absorbing properties. Under these circumstances, eco-friendly and also high performance sound absorbing material with density graded structure was developed by using wool fibers in this study. As a result, it was cleared here that the density graded structure is good for the sound absorbing performance.
We built a highly airtight and well thermally insulated house in Tokyo.Using new heating and cooling technology, the electricity costs for heating and cooling became lower.An external thermal ...insulation compound system with thick wooden fiber board was used.
Wastewater from a hardboard mill characterized by a high organic content (15-30 g/L COD) was studied in a bench scale sequential aerated system in order to define a start up strategy. Inlet COD ...concentration varied from 0.5 to 25 g/L and the hydraulic retention time was maintained at 5 days. The sequential system proposed could reduce BOD, COD, TSS and phenol over 90% except when the inlet COD concentration was lower than 25 g/L.
Água residual proveniente de uma indústria de tabuleiro de fibra dura caracterizada por ter um elevado conteúdo orgânico (15-30 g/L DQO) foi estudada utilizando um sistema arejado seqüêncial de forma a definir uma estratégia de start up. A concentração de DQO na entrada do sistema variou na faixa de 0,5-25 g/L e o tempo de residência hidráulico foi mantido em 5 dias. O sistema seqüêncial proposto reduziu DBO, DQO, SST e fenol sobre 90% quando a concentração de DQO na entrada foi menor a 25 g/L.
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