Flexural Behaviour And Acoustic Property Of Corrugated Cardboard/glass Mat Reinforced Thermosetting Plastics

Recently, fiber reinforced polymer composite(FRP) has played significant role in various fields, such as automotive industry, aircraft industry, ship building, civil engineering. Among them, natural fiber reinforced composite materials are expected as capable materials which may replace the conventional and synthetic materials for the practical applications where manufacture require less weight and energy conservation. As cellulosic materials, paper products are most common use in our daily life for which there are tremendous forests destroyed decades and years. As the attention to paper product recycling is ever-increasing, there is kind of material, corrugated cardboard which has advantages of relatively high strength and light weight due to its hollow and corrugated structure has been applied to practice by reinforcing composites with high strength surfacing. In this study, low-cost and lightweight corrugated cardboard was sandwiched between glass fiber mats to produce corrugated cardboard sandwiched glass fiber reinforced thermosets(Cardboard/GM-FRP) by using hand lay-up and compression molding method. Their flexural properties were evaluated, for which 6 types of Cardboard/GM-FRPs were carried 3-point bending tests,meanwhile, acoustic tests were conducted to analyze its acoustic property. It is aimed at finding out the differences of flexural behaviours and acoustic performances among all types of Gardboard/GM-FRPs, furthermore, exploring favorable structure and applying to practical uses. The bending results show that the bending properties of different kinds of Cardboard/GM-FRPs are obviously different. Among them, type [GM2/A/GM2] has best bending property compared with other types. Meanwhile, there are two fracture modes in MD and TD specimens. In MD fracture process, at previous stage, it overcomes the corrugated structure on the area contacted with pressure head, therefore, the glass layers in the middle area of specimen get closed, after which the specimen fracture with delamination. In TD fracture process, the corrugated structure of two ends firstly inclined, and glass layers in two end get closed, after which middle part of specimen begin to collapse and fracture. And different glass layer break in different time. In acoustic test results, the acoustic property of type [GM2/A/GM2] shows superiority to other types because relatively smaller and more holes provide it with higher reflection, refraction and diffraction frequency.