Fabrication, properties, and failure of composite sandwiches made with sheet extrusion method

Abstract

Fiber-reinforced polymer composites are commonly used in different fields because the evenly distributed fibers in polymer can efficiently transmit the load of a force and mechanically reinforce the polymer matrices. This study proposes producing composite sandwiches using thermoplastic polyurethane sheets as the top and bottom layers and a polypropylene/Kevlar nonwoven fabric the interlayer. Thermoplastic polyurethane sheets and a polypropylene/Kevlar nonwoven fabric are combined using the sheet extrusion method, during which the polypropylene staple fibers are melted and firmly bond the thermoplastic polyurethane sheets. The mechanical properties, thermal behavior, and surface morphology of composite sandwiches are evaluated, examining the influence of parameters. The test results show that the composite sandwiches are mechanically reinforced as a result of using the nonwoven covers. Moreover, the improved interfacial bonding between the cover layers and the interlayer inhibits delamination, and the stabilized structure subsequently decreases the level of combustion which is in conformity of the differential scanning calorimetry results. The manufacturing is creative and efficient due to one-step shaping, creating a refined composite sandwich with good mechanical properties and combustion resistance.

Effect of Melting–Recycling Cycles and Mechanical Fracture on the Thermoplastic Materials Composed of Thermoplastic Polyurethane and Polypropylene Waste Blends

“…The speed of testing was based on the specifications of the specimen type, and T/P and T/P/MA groups were classified as rigid and semirigid groups. Moreover, type IV samples were chosen to be tested at a speed of 5 mm/min [30]. Five samples for each specification were used to obtain the average value.…”

“…The melting and cooling loops were repeated for two cycles to remove the thermal history of the T/P and T/P/MA blends. Furthermore, DSC analysis was also used to evaluate the crystallization performance, as related to the presence of a compatibilizer, after the T/P and T/P/MA blends had undergone multiple thermal cycles [30].…”

Mechanically Robust Foamed Polypropylene/Bamboo Powder Composite Basketworks by CO2 Extrusion Foaming

“…However, there are some spaces for improvement in the above process, such as easier operation processes, shorter production cycles, and simpler equipment. In addition, the foaming process can introduce cellular structures inside the materials and has the potential to develop sandwich structures. , Typically, foam injection molding can regulate skin–cellular–skin sandwich structures for the polymer foams, but the solid structure on both sides limits its softness and the fixed mold also limits the difficulty of preparing large-size samples. In comparison, supercritical CO 2 continuous extrusion foaming with the advantages of economical and energy-saving can be used to prepare polymer foams with various morphologies, such as foam beads, foam strips, foam boards, and foam sheets .…”