导电性包装材料内的金属异物检测研究

Study on Detection of Metal Impurities in Electrically Conductive Packaging Materials

针对铝箔包装产品中混入金属异物时,对高频磁场屏蔽而无法有效检测的问题,提出一种采用低频磁场来检测金属异物的方法。研究结果表明,利用微小磁场检测导电性包装材料内的金属异物的方法可行,检测线圈在最佳检测频率下能够得到较好的区分度,能够检测出金属异物;单线圈检测时,当检测频率为5.5 k Hz时,区分效果最好;双线圈检测时,当检测频率为7 k Hz时,区分效果最好,且检测区分度明显高于单线圈检测,金属异物的尺寸不影响检测线圈的最佳检测频率。

This paper proposed a method to detect metal matters in aluminum foil packaging with low-frequency（ LF） magnetic field aiming to the problem that metal matters can not be effectively detected due to shielding of highfrequency（ HF） magnetic field by aluminum foil packaging when the metal matters are mixed in the products with aluminum foil packaging. The research results show this method is feasible. The detection coil can gain good distinction degree and detect the metal matters under the optimal detection frequency. When the detection frequency is 5. 5 k Hz,the distinction effect is the best with single-coil detection. When the detection frequency is 7 k Hz,the distinction effect is the best with double-coil detection. The distinction degree of double-coil detection is significantly higher than that of single-coil detection. The size of metal matters will not affect the optimal detection frequency of the coil.