Determining seal quality by multivariate analysis of sound waves collected during sealing process

摘要

Defective heat seals in packages (eg tube or pouch containing foodstuffs, confectionary, beverages etc) are detected by measuring the sound wave generated during the sealing operation with one or more transducers (eg microphones) at a plurality of locations and performing an analysis of more than one variable of the sound wave(s). The analysis comprises analysing the collected data with stored reference data. The collected data may be transformed into the frequency domain using a fast fourier transform. The analysis comprises producing a k-dimensional feature vector which is compared with a plurality of target vectors each indicative of a sealing quality, the quality of sealing of the package being determined by determining the target vector closest to the feature vector.