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Wood Fiber Reinforced Thermoplastic and Thermosets Composites
Published in Omar Faruk , Jimi Tjong , Mohini Sain, Lightweight and Sustainable Materials for Automotive Applications, 2017
The disintegration of larger wood elements into fibers consists of two steps. First, logs are reduced to wood chips, followed by the conversion of the chips to pulp fibers in a refiner or defibrator. Chips are produced in rotating disk chippers, equipped with specialized knives which determine the chip geometry. The mechanical pulping process works without any extra thermal or chemical treatment. The pulping step is essentially a mechanical process that takes place at elevated temperatures. The benefit of using high temperature is that power consumption may be significantly reduced. A laboratory-scale refiner plant, the process, and the resulting fibers and fiberboard panels are shown in Figures 3.6, 3.7, and 3.8.
Agriculture Waste Composites
Published in Magdi El Messiry, Natural Fiber Textile Composite Engineering, 2017
The steps of the defibrillation are shown Figure 7.9. The wood residual defibrillation process involves size-reduction, screening, and washing of the raw material to get a clean and suitable size of the chips for consistent material flow into the Defibrator system [29]. The wood chips are pre-heated by steam and forced into a vertical preheater, then to the Defibrator system which is pressurized under pressure of 0.7–1.0 MPa with temperature 170–190°C. The fibril material will pass through drying section ended by cyclone for further drying. The material is ready to be blended with a polymer and chemical additives and fed to the extruder.
An analysis of cleaner production planning by applying analytic hierarchy process: a wood industry case study
Published in International Journal of Sustainable Engineering, 2021
Fatemeh Hasani Khorshidi, Majid Azizi, Charles Ray, Mohammad Mahdi Faezipour, Hamid Zarea Hosseinabadi
Chips Baking Operation: The chips are placed in a pressurised tank, called a digester, to be cooked and prepared for storage. The chips are cooked with steam energy under pressure to soften the lignin which acts as a mortar between the fibres (Thoemen, Irle, and Sernek 2010).Defibration: The main method of fibre production is a thermodynamic process whereby the particles are evaporated under pressure and converted into separate fibres or bundles of fibre, with the help of defibrator disks. Defibrators are equipped with two disks with rough and grooved surfaces placed in front of each other .Adhesion: In this stage, resin, wax or paraffin, catalysts, and free formaldehyde consumers are added to the fibre. Resin and other additives are added to the fibres either after the blow line defibrator or after the tube dryer and before the delivery line (Thoemen, Irle, and Sernek 2010).Drying: The refined materials from the defibrator flow directly into the dryer by means of a pneumatic valve. Hot air is used for both drying and transporting the fibres along the drying tube. Dryers are usually heated directly, with a natural gas fuel. A heat source based on other wood fuels can also be used for drying.