Deposition and retention of differently shaped micro-particles on textiles during laundry processing

Particulate additives such as perfume microcapsules are present in detergent formulations to add fragrance to the washed garments. The key challenge is controlling the deposition and retention of such particulates onto textile surfaces, as a large proportion are simply washed down the drain during washing. In this study, the influence of particle shape on the mechanical entrapment of particulates within different fabrics is assessed using a laboratory mixer, which mimics the tumbling action of a washing machine. Using a combination of image analysis and mass balance it is found that with rough, irregular particles, the retention level across all fabric types studied is increased by a factor of up to 3 times when compared to smooth, spherical ones (typically used in industry). The retention rate is also found to be dependent on the tumbling duration, tumbler speed as well as on the fabric characteristics, especially when a combination are used.