Category Archives: GREEN BIORENEWABLE. BIOCOMPOSITES

THE FACTORS THAT AFFECT SOUND ABSORPTION

The first major step in noise control is to determine the source of the noise be­fore designing the sound absorber. To give an automotive-related example where biocomposites find applications; the engine, the tire-road interaction and the wind are the three major factors that affect the acoustics of the passenger department of a vehicle. Hence, the floor coverings, the headliner, and […]

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SOUND ABSORPTION COEFFICIENT

Normal specific sound absorption coefficient of the materials has been determined by using an impedance tube, two microphones, dual channel frequency analyzer and the Indian Institute of Technology Kharagpur developed MATPRO software36. Test has been done as per ASTM E-1050 standard19. The impedance tube fabricated at the Indian Institute of Technology Khaargpur is used to measure the normal specific sound […]

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INJECTION MOLDING PROCESS

Injection molding process is the most extensively used molding method in the in­dustry used for the production of polymer composites due to its simplicity and fast processing cycle. Injection molding machine mixes and injects a measured amount of matrix and fiber mixture into the mold resulting in the desired product. It consists of three major sections: the injection unit, mold, […]

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FLAX /PLA BASED BIOCOMPOSITES

Among all the natural fiber reinforced biocomposites, the flax based composite shows the best properties when compared to other natural composites, including glass-reinforced traditional composites. Flax fibers offer higher reinforcing prop­erties than hemp and kenaf natural fibers. Namely, comparison of the mechanical properties of the natural fiber reinforced composites has shown that composites based on flax fibers exhibited higher tensile […]

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WATER ABSORPTION, THICKNESS CHANGES AND SPECTROPHOTOMETRIC RESPONSES

Water absorption is due to the hydrogen bonding of water molecules to the hydroxyl groups on the cells walls of the wood or lignocellulosic fibers.4870 The long-term water absorption as a function of time for the various LPCs at room temperature is shown in Fig. 13.5. All composites tested absorbed water during the incubation peri­od and no distinct saturation levels […]

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BIONANOCOMPOSITES: PROCESSING ASPECTS AND PRODUCTS

Bionanocomposites are a novel class of nanosized materials in the modern day world. The terminology “bionanocomposites” is introduced several years ago to classify an emerging class of biohybrid materials. Bionanocomposites are the com­bination of biopolymers such as proteins, polysaccharides, nucleic acids, etc. with a reinforcing agent having at least one dimension in the nanometer range. The rein­forcing agent may include […]

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BIO-BASED EPOXY RESINS AND HARDENERS

4.2.1 BIO-BASED EPOXY RESINS Bio-based aliphatic epoxy resins such as glycerol polyglycidyl ether (GPE), poly­glycerol polyglycidyl ether (PGPE), sorbitol polyglycidyl ether (SPE), epoxidized soybean oil (ESO), epoxidized linseed oil (ELO), diglycidyl ester of dimer aid (DGEDA) and limonene diepoxide (LMDE), etc. are industrially available in large volumes at a reasonable cost (Fig. 4.1). Glycerol is an abundant and inexpensive bio-based […]

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AIR GAP

It is a common practice to leave an air gap between the absorber material and the hard backing wall in applications such as suspended acoustical ceilings, although the practical use is relatively limited.68 The highest NAC will be achieved when the distance between the absorber and the wall is odd multiples of a quarter wavelengths for the sound frequency of […]

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