Needle-Bonded Electromagnetic Shielding Thermally Insulating Nonwoven Composite Boards: Property Evaluations

Complicated environmental problems inevitably arise when technology advances. One major environmental problem is the presence of electromagnetic radiation. Long-term exposure to electromagnetic radiation can damage people’s health in many ways. Therefore, this study proposes producing composite boards with electromagnetic shielding effectiveness and thermal insulation by utilizing the structures and properties of materials. Different combinations of flame-retardant polyester fiber (FR fiber), recycled far-infrared polyester fiber (FI fiber), and 4D low-melting-point fibers (LM fiber) were made into flame-retardant and thermally insulating matrices. The matrices and carbon fiber (CF) woven fabric in a sandwich-structure were needle-punched in order to be tightly compact, and then circularly heat dried in order to have a heat set and reinforced structure. The test results indicate that Polyester (PET)/CF composite boards are mechanically strong and have thermal insulation and electromagnetic shielding effectiveness at a frequency between 0.6 MHz and 3 GHz.