Electromagnetic interference shielding boards produced using Tetra Paks waste and iron fiber.

Tetra Pak packages (Tetra paks) are one of typical paper/plastic/aluminum composites and widely used in soft drinks and dairy product markets. However, after its service life, serious environmental problems generate due to its non-biodegradable nature. In this paper, a novel electromagnetic interference (EMI) shielding board was developed using recycled Tetra paks waste with addition of iron fibers. The influence of fiber loading level, fiber length and number of iron fiber layer within the matrix on EMI shielding effectiveness (SE) and volume resistivity (VR) was investigated. The results indicated that fiber loading level, fiber length and number of iron fiber layer affected EMI shielding properties significantly. SE increased with the increasing fiber loading, fiber length and number of fiber layer, and VR had an opposite tendency. For the board with 5 mm thickness, the percolation threshold of fiber loading was between 0.008 and 0.02 % (weight of iron fiber/weight of Tetra paks). The boards had excellent total EMI shielding performance in range of 9000 Hz-200 MHz and 600-1500 MHz. This value-added product could be used in packaging, construction and other application fields and exhibited both environmental and economic advantages. It also could be considered as a step toward paper/plastic/aluminum composite waste management and preventing municipal solid wastes environmental pollution. [ABSTRACT FROM AUTHOR]