A method of analysing the quality of a welding area of an absorbent sanitary article is disclosed. During a learning step, a plurality of welding operations are performed both with a sufficient quality and with an insufficient quality, and the welding area generated for each welding operation is monitored via a camera. During a training step, the pixel data of the welding areas monitored during the learning step is processed for training a classifier configured to estimate a welding quality as a function of respective pixel data of a respective welding area. Accordingly, during a normal welding operating step, the welding quality may be estimate via the classifier, thereby improving the environmental sustainability of the production process.