The Research Of Electromagnetic Shielding Materials Made Of Wood

Generally, wood doesn't belong to electricity conductor and doesn't have effects of electromagnetic shielding. Wood metal composite not only keeps wood natural decorative effect, but also control electromagnetic disturbance caused by all kinds of electromagnetic wave in space around people. It can also assure the safety of information . To compound wood and metal can improve strength of wood, rectify surface color and lustre of wood, enhances surface hardness of wood and abrasion resistance and so on. In the world, the methods of compounding wood and metal are to plate wood by using electrolyte, dipping melted metal into interior of wood, mixing wood and metal powder or wire. There are many problems in complex techniques. Industrialized production is inconvenient to come true and it has poisonous gas and liquid coming out during the process.The paper deals with sputtering thin film of copper, aluminum and titanium separately on paulownia plywood and MDF by single or two sides, and analyzing combined strength and abrasion resistance of the film.Results show that the optimal technological parameters for the wood closed by MF contained with silane resin were obtained as the vacuum degree 10-2～10-4MPa,the temperature of target metal 200℃, sputtering time 90s. The thickness of the film is 30μm.The shielding effectiveness can achieve over 30dB between 30MHz and 1.5GHz of microwave for the wood sputtering metal test. Sputtering copper is better than that of aluminum, the effect of two-sided sputtering is better than that of single-sided one. But sputtering titanium with the film in 20μm can not achieve test.According to the test of combined strength and abrasion resistance, it shows combined strength of wood and film is higher than wood itself, and abrasion resistance can be improved. The SEM image of copper plating on plywood shows the layer of copper is continuous.