P. Levoni

Foam evolution in a processed liquid solution

Foam formation in a carbonated solution undergoing pouring and decompression is investigated with the use of high-speed imaging. Operational conditions similar to those encountered in industrial bottling processes are applied to inspect the mechanisms that control the foaming behaviour in practical filling applications. The evolution of the foam column during pressure release is analysed in quantitative terms by extracting the foam thickness from the images. The bubble dynamics inside the solution, and the destabilization processes on the foam column are seen to have a paramount effect on the observed foam evolution trend. The contributions to foam formation given by the nuclei entrained in the bulk liquid and by the bubble-generating sites on the container walls are finally distinguished and discussed.