中文摘要：

软包装封口处的热封性能对产品的保质起决定性作用。将超声无损检测技术应用于软包装热封性能检测中,采用背散射回波包络积分成像技术,对塑料软包装封口处直径为50～150μm的6种通道型缺陷进行实验研究。实验中,采用中心频率为22.66 MHz的液浸式点聚焦探头,对试样上2.98 mm×1.5 mm的矩形区进行扫描并进行超声成像。同时,理论分析了扫描步长小于探头横向分辨率时,探头横向分辨率对超声检测结果的影响,给出了不同尺寸范围内的缺陷尺寸与超声检测结果两者间的关系。实验结果表明：超声无损检测技术可应用于检测包装封口缺陷,且由于受探头横向分辨率的影响,超声检测值大于缺陷实际尺寸,与理论分析相吻合。

英文摘要：

The sealing of flexible packages plays an important role in product quality. Ultrasonic non-destructive testing technique is introduced to detect flexible package seal quality. The channel defects with diameters between 50 μm and 150 μm in the seal area of flexible packages are detected using backscattered echo envelope integral imaging method. The images are formed with an immersion spot focused 22.66 MHz ultrasound transducer scanning over a 2.98 mm ×1.5 mm rectangular gird. Theoretical analysis for the influence of the transducer lateral resolution on ultrasonic testing result is carried out while the scanning step size is less than lateral resolution of the transducer; and the relation between ultrasonic testing result and actual defect size is given in different scope of defect size. The results show that the channel defects in flexible packages can be effectively detected using ultrasonic backscattered echo envelope integral imaging method, and the size of defects on the ultrasonic image is larger than its actual size, which is correlated with the lateral resolution of the transducer. The experimental results are in good agreement with the theoretical analysis.