A device for folding a web for producing absorbent sanitary articles along at least one longitudinal fold line parallel to its feed direction includes two diverting elements positioned on opposite sides of the web one after the other, to operate in succession on respective lateral portions of the web and allow transversal folding of one lateral portion on the other and both on the web. Each diverting element has a diverting surface which is used for folding and which is equipped with a plurality of holes to emit jets of air under pressure at a tangent to the diverting surface, directed transversely to the feed direction of the web along the same direction as the direction along which the two lateral portions are transversely folded by the diverting surface and defining between the latter and the web a laminar fluid bed.

Apparatus and methods are provided to minimize waste and improve quality and production in web processing operations. The apparatus and methods provide defect detection both before and after application of component patches to a traveling web to create a product. Web defect detection may be provided by way of at least one visual inspection station located upstream from the patch applicator. Patch defect detection may be accomplished by way of a visual inspection station located proximate the patch applicator. If defects are detected in either the traveling web or the component patch prior to patch application, patch application may be prevented until both a satisfactory web and patch are provided. If defects are detected after patch application, the resulting product may be culled. Furthermore, the apparatus may be provided with diagnostic software to warn against extant or imminent machine complications.

An apparatus for treating a moving continuous web includes a tool holder roller, an anvil roller and a control device configured to rotate the tool holder roller and the anvil roller around respective rotation axes in at least one first operating condition and one second operating condition, so as to carry out a change of format of the apparatus with a selection via software.

An apparatus for treating a moving continuous web includes a tool holder roller, an anvil roller and a control device configured to rotate the tool holder roller and the anvil roller around respective rotation axes in at least one first operating condition and one second operating condition, so as to carry out a change of format of the apparatus with a selection via software.