Shielding effectiveness of carbon‐filled nylon 6,6

Abstract

Electrically conductive resins can be made by adding electrically conductive fillers to typically insulating polymers. Resins with an electrical resistivity of approximately 100 ohm‐cm or less can be used for electromagnetic and radio frequency interference shielding applications. This research focused on performing compounding runs followed by injection molding and shielding effectiveness testing of carbon filled nylon 6,6 based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a surface‐treated polyacrylonitrile (PAN)‐based carbon fiber. Conductive resins were produced and tested that contained varying amounts of these single carbon fillers. In addition, combinations of fillers were investigated by conducting a full 23 factorial design and a complete replicate. The objective of this paper was to determine the effects and interactions of each filler on the shielding effectiveness properties of the conductive resins. Carbon fiber caused the largest increase in shielding effectiveness. Also, all the single fillers and combinations of fillers were statistically significant at the 95% confidence level, except the composite containing carbon black and synthetic graphite particles tested at 800 MHz. Polym. Compos. 25:407–416, 2004. © 2004 Society of Plastics Engineers.

In‐plane thermal conductivity modeling of carbon‐filled liquid crystal polymer–based resins

“…The length and aspect ratio of the Thermocarb synthetic graphite particles in the injection molded disks were typically 50 microns and 1.68, respectively. These values are similar to that of the as‐received material and prior work [27, 47]. For the injection molded samples containing Fortafil 243, the length was typically 70 microns.…”

“…Again, the images were collected as described earlier. More details of this test method are shown elsewhere [26, 27].…”

Electromagnetic interference shielding effect of nanocomposites with carbon nanotube and shape memory polymer

“…The shield should be in high conductance, thus metals, such as steel, copper, aluminum, etc., are the most common materials used for EMI shielding. Since metal shielding has shortcomings of heavy weight, corrosion and physical rigidity, polymer composites with discontinuous conducting fillers, such as metal particles, carbon particles, carbon fiber, are extensively employed in EMI shielding [8][9][10][11][12][13]. Although these composites are not strong enough for most structural applications, they are attractive because of their superior molding and more dependable lightweight.…”

Technical feasibility of a new approach to electromagnetic interference (EMI) shielding of injection molded parts using in-mold coated (IMC) nanopaper

“…By adding conductive particles, the electrical conductivity of polymer composites is increased. EMI SE of such materials depends on many factors, including the intrinsic conductivity of filler, concentration of fillers added, particle size and structure, and mixing process [5][6][7][8][9][10][11][12][13][14][15][16]. While conductive fillers may increase the electrical conductivity of polymer composites, the loading of such fillers often cannot reach a high level ( < 10 wt%) due to the dispersion difficulty and exponential increase in viscosity.…”