Bubble Size Distribution During the Application of Foam to Fabrics and Its Effects on Product Quality

A method developed to determine bubble size distribution in flowing foam is targeted to foam application to fabrics, one of the minimum application techniques for applying chemicals to webs in very small volumes of water. Bubble size distribution is known to determine vital properties of the foam, such as viscosity, stability, and draining. The investigations described here reveal that bubble size distribution also affects the uniformity of the textile substrate. A measuring system incorporating a video camera was set up to study flowing foam. An image processing algorithm and analysis program were developed to determine bubble size distribution, and this method was then com pared with one where bubbles were measured individually with photographs. The correlation between the methods was close. The image processing method was used to determine bubble size distributions of various foams. The effects of foam density, residence time of foam in the transport pipe, mixer speed and time-dependent effects on bubble size distribution were demonstrated. The study revealed that foam can be applied uniformly to a cotton web using a closed system in which application of moisture and bubble size distribution vary. However, uniformity deteriorates when foam with a non-uniform bubble distribution is used.