Study of several variables in the penetration stage of a vegetable tannage using ultrasound

This study concerns the implementation and improvement of a system that applies ultrasound technology in vegetable tanning, which is an eco-friendly tanning process. The system is versatile and requires no major modifications or expenses for tanneries. In particular, the study investigated the influence of several variables on the tannins absorption by the hides. The results show significant differences in the tanning degree of the leathers tested in relation to the work system tested, the ultrasonic power used and the resting time of the leather after tanning. The leathers we obtained showed no scratches, which is the main cause for their devaluation when applying the traditional tanning system, and were suitable for commercialization as high-end leather goods. Ultrasound technology can increase the use of vegetable tannage versus other less eco-friendly kind of tannages. •Ultrasound is applied to vegetable tanning floats.•The influence of work system, ultrasound power applied and resting time was studied.•The tanning degree depends on the level of each variable studied.•The penetration of tannins can be regulated.•Leather without scratches was obtained in less time.