Effect of moisture absorption and fiber orientation on electrical conductivity and electromagnetic interference shielding of carbon fiber reinforced bioplastic composites

Wahyu Solafide,Ri-Ichi Murakami

doi:10.1142/s0217979219500826

Abstract

The aim of this study is to discuss the effect of moisture absorption on electrical conductivity and electromagnetic interference of the carbon fiber (CF) reinforced bioplastic composite. The composites were prepared by the hot press machine, and immersed in water for 20 and 40 days. The electrical conductivity measurements were carried out as a function immersed time. The electrical conductivity of CF with two layers is greater than that of one layer, because the electrical conductivity increases with increasing the volume filler of CF. The electrical conductivity slightly increases with increasing the immersion time. The EMI SE (electromagnetic interference shielding effectiveness) of the composite was examined with the frequency from 500 MHz to 2000 MHz. The EMI SE of the CF increases with increasing the content of the CF, and the EMI SE result of composite is around 50 dB to 60 dB. There is scarcely significant effect of orientation on composite on the EMI SE.

Highlights

Electromagnetic interference (EMI) shielding has been widely used in many applications such as mobile telecommunications, radar, Wi-Fi, television, computer and electronic devices, etc.[1]
Two kinds of bioplastic were used as matrix, which consists of 10% of poly lactic acid (PLA), 80% of ecoflex c1200, and 10% of CaCO3(BPM 10), and 45% of PLA, 45% of ecoflex c1200, and 10% of CaCO3 (BPM 45)
The electrical conductivity of the carbon fiber (CF) with two layers is greater than that of one layer, because the electrical conductivity depends on the volume of CF

Summary

Introduction

Electromagnetic interference (EMI) shielding has been widely used in many applications such as mobile telecommunications, radar, Wi-Fi, television, computer and electronic devices, etc.[1] The main mechanism is how the material shields such devices from the penetration of the radiation. The EMI shielding effectiveness increases with increasing the conductivity. The materials with high conductivity are metal, copper, aluminum, carbon fiber, etc.[2,3] Because the EMI leads to affect organism by electronic devices, the applications such as commercial, military and electronic equipment should keep away from EMI. The preparation of EMI shielding materials should give serious attention. There have limits of properties of EMI shielding mechanism such as heavy weight, corrosion, and low process ability. EMI should draw back to reduce the utilization problems for future applications.[4]

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