Abstract:

Some hybrid electroconductive elements of fiber/powder, fiber/fiber type composed of copper fiber（SF）,stainless steel fiber（CF）,nickel powder（Ni）graphite powder（CP）were added to urea formaldehyde（UF） resin to make 3 layers Larix plywood with electromagnetic shield effectiveness（SE）.The influence of different electroconductive element spreading and hybrid type on electromagneticshield effectiveness and shear strength（ST）of Larix plywood was researched. The results show that the all the ST can meet or exceed the nation standard. The SE is 5.62～21.14 dB with SF/CP; the SE is 000～21.14 dB with SF/Ni; the SE is 10.53～28.76 dB with CF/CP; the SE is 12.30～28.76 dB with CF/Ni; the SE is 6.34～21.14 dB with SF/CF. The model of SE is significant; the model ST is insignificant. In comparison with powder element, fiber has more advantageous influence on SE. SF has more advantageous influence on SE than CF.

Key words: Larixplywood, electro conductive element, electromagneticshield effectiveness, shear strength