饮料金属包装实罐产品的腐蚀检测

Corrosion detection of metal cans for beverage packaging

为了检测饮料金属包装实罐产品的腐蚀情况,研制了适用于罐体产品腐蚀监测的电化学传感器,并研究了传感器在某功能饮料中的有效测试面积。应用所研制的传感器对服役期分别为1个月、3个月、27个月、43个月(编号分别为s1、s2、s3、s4)的4个功能饮料实罐产品进行了电化学阻抗谱(EIS)测试和电化学噪声(EN)测试。EIS结果表明,实罐s1的EIS尚未发展成为两个容抗弧的特征,涂层电阻值大于108Ω.cm2,表明涂层防护性能良好;实罐s2、s3和s4的EIS均呈现双容抗弧特征,涂层电阻值均小于108Ω.cm2,表明该有机涂层失去了防护性能。EN结果表明:s3和s4电流噪声的暂态峰数量相比s1和s2多,幅值增大,表明局部腐蚀敏感性增加。电化学测试结果表明4个实罐的性能不同,且与服役期有关,因此所研制的传感器可以进行实罐性能检测,并为评估金属包装产品的货架寿命提供科学依据。

An electrochemical sensor was designed to detect the corrosion degree of metal cans for beverage packaging,and the effective testing area of the sensor was determined.Electrochemical impedance spectroscopy（EIS）and electrochemical noise（EN）were performed to detect the corrosion degree of beverage cans which have been stored for 1 month（named s1）,3 months（named s2）,27 months（named s3）and 43 months（named s4）.EIS results showed that the EIS plot of s1 had not developed to a characteristic of two time-constants and the coating resistance was higher than 108 Ω·cm2,indicating that the coating showed good protective performance.The EIS plots of s2,s3 and s4 showed characteristics of two time-constants and the coating resistance was lower than 108 Ω·cm2,indicating that the organic coatings of s2,s3,s4 had lost their protective performance.EN results showed that quantities and amplitudes of transient peaks increased with increasing storage time,indicating that increasing local corrosion occurred in the cans.The designed electrochemical sensor was successfully used to detect the performance of beverage cans and further provided scientific proof for evaluating the shelf life of metal cans for beverage packaging.