
PTI’s new Seal-Sensor PQX is a fully automated handling and pouch-seal inspection system that features a built-in conveyor that can be integrated into a production line. The system uses PTI’s Seal-Sensor airborne ultrasound technology to automatically scan the final pouch seal online at high speed.
According to PTI, in order to use ultrasonic inspection effectively, the seal must be placed in a direct line between a pair of transducers, and the transducers moved along the seal. The ultrasound is transmitted and reflected at the transition from one media to the next. The greater the acoustic difference between mediums, the more sound is reflected and the less sound transmitted through. The variation of the material thickness has only a minor effect, the company explains.
Any material fold, foreign media inclusion, and even a microscopic air gap between layers of pouch material causes a significant reflection, so the transmitted signal is lower. A small cut, abrasion, or missing layer in a material causes less reflection, so the transmitted signal is higher. Therefore, the level of a signal received after passing through the seal is a function of the seal quality. In this way, various types of defects, visible and invisible, leaking and non-leaking, process-related and random, are detectable.