This research transfers polyester fiber into spiral structure by thermosetting and makes the sprial fiber plated nickel by electorless method. After the process, we put the spiral yarn with nickel into the unsaturated resin to make the composite panel have electric conductivity. We expect that the compsite with spial yarn form the conductive interconnect and with the electromagnetic induction to absorb the electromagnetic wave. From the reseach, at 80℃ and 40 minutes of the electroless nickel plated process, the spiral yarn have the best cover with nickel. And we also find that the absorbent electromagnet effectiveness wave of the single composites with spiral yarn is less than spiral yarn composites covered by the straight copper composites. When the distant of spiral yarn is 0.5cm, the length is 3.5cm to match 5g straight copper wire, the best absorption of electromagnetic wave can reach 38dB.
