Experimental Study On Magnetic Shielding Performance Of Al / PET / Rayon Needle Punched Web Under The Exposure To Mobile Phone Field

To obtain the intuitive data of magic field changes with nonwoven metal shielding material, the Al / PET / Rayon needle punched webs was processed with varied parameters, which were position of Al film, mass proportion of Al, needle punched density, and needle punched depth. Magnetic flux density values of Al / PET / Rayon needle punched webs were measured to calculate their magnetic flux density attenuation (MFDA) values under the exposure to mobile phone field. It was found that position of Al film, Al proportion, and needle punched density have a great effect on magnetic flux density attenuation. When Al proportion in needle punched web increases from 10% to 18%, MFDA values increase accordingly, and tend to converge around Al mass ratio 18%. Besides, the promotion range of MFDA values is particularly obvious in the case of needle punched density 50 g m⁻². When needle punched density increases from 50 g m⁻² to 150 g m⁻², MFDA values decrease or first increase and then decrease. When needle punched depth rises from 4 mm to 5 mm, the MFDA values of Al/PET/Rayon needle punched webs are almost the same value. Needle punched density and a high mass ratio of Al will contribute to magnetic shielding performance. (paper)