A novel structure of woven continuous-carbon fiber composites with high electromagnetic shielding

Abstract

A novel structure employing the woven continuous-carbon fiber (CCF) epoxy composite with high electromagnetic (EM) shielding is presented experimentally and theoretically. The influences of weave type, number, and angle of overlapped plates upon the shielding effectiveness (SE) of the woven CCFepoxy composite are investigated. The minimum SE of the single, double, and triple-plain or balanced-twill woven CCF-composite plates was measured to be as high as 50 dB, 60 dB, and 70 dB, respectively. More than 100 dB in SE was obtained for the triple-overlapped, plain-weave CCF composite at a frequency of 0.9 GHz. The weight percentage of the single CCF-composite plate required for electronic application is 4.8% only, which is less than one quarter of the CF content, and the performance in SE is 10 dB higher in comparison with long, CF-filled, liquid-crystal polymer (LCP) composites. The SE calculated theoretically is consistent with that measured by the experiment.

The electromagnetic shielding effectiveness of carbon nanotubes polymer composites

“…Previous work done by the authors suggested several effective solutions [2,3]. One solution is to modify the nylon66/liquid crystal polymers (LCPs) composites by adding short or long electrically conductive discontinuous carbon fibers (CFs) to build a three-dimensional conductive network within the polymeric matrix.…”

“…Although, many EM shielding methods [2][3][4][5][6][7][8][9][10] are available for electronic plastic packaging, not many methods are available for optical-electronic plastic packaging. Low cost, high EM shielding optical laser modules made with the modified thermosets using compression molding technology were reported [5,11].…”

“…Low cost, high EM shielding optical laser modules made with the modified thermosets using compression molding technology were reported [5,11]. Instead of using compressing molding, a systematic investigation on the EM shielding effectiveness (SE) of nylon66 or LCP composites using injection molded thermoplastic packaging was conducted in the author's previous work [2][3][4]. Kim reported a polymer-based composites with 40 wt% CNTs containing Fe catalysts can reach shielding effectiveness of 27 dB [1].…”

“…It has also been shown that if small conductive fillers can be well dispersed to form a network within the composite, lower concentration of fillers will be required for conductive composites [1,2]. If both the polymer base and CNTs are in powder forms then the dispersion of CNTs will be insured in polymer base.…”

“…If both the polymer base and CNTs are in powder forms then the dispersion of CNTs will be insured in polymer base. Our previous work [2,3] showed that the higher the aspect ratio (the ratio of length to diameter) of fillers such as CFs, the higher is the SE of composites. Thus, the author would propose to use high aspect ratio conductive CNTs as a feasible way to reduce the CNTs' content.…”