Abstract: A process for producing pull-up diapers including: feeding a composite elastic web along a path; cutting out openings for the legs in an intermediate portion of the composite elastic web while the composite elastic web advances, so as to substantially cancel the supply percentage elastic elongation in a central band of an elastic element of such web; applying absorbing inserts on the intermediate portion of the composite elastic web and between successive openings for the previously cut-out legs, so as to define a series of precursors of pull-up diapers, wherein the intermediate portion of the composite elastic web corresponds to crotches of the pull-up diapers, each provided with the absorbing insert, and two opposite lateral longitudinal portions of the composite elastic web correspond to the waistbands of the pull-up diapers and wherein transverse separation zones separate one precursor from the next.

Abstract: A method for applying absorbing inserts in a process for the production of pull-up diapers, includes: feeding a composite elastic web, including at least one elastic element, along a path and according to an advancing direction, conferring said composite elastic web with an application tension such that the composite elastic web has an elongation lower than a nominal maximum elongation thereof and the elastic element has a second percentage elastic elongation lower than first percentage elastic elongation corresponding to the nominal maximum elongation; applying absorbing inserts on an intermediate portion of the composite elastic web while the composite elastic web advances with said application tension, such that, once the tension is completely released, the absorbing inserts remain substantially flat and do not form substantial folds or wrinkles.

Abstract: A method for feeding elastic threads in a process for the production of layered composite articles includes: feeding at least one elastic thread along a path extending from a reel of an elastic thread up to a joining zone with at least one web material. Feeding the elastic thread along the above path includes: giving the elastic thread a first percentage elongation along a first section of the path extending between the reel and a control zone; giving the elastic thread a second percentage elongation along a second section of the path extending between the control zone and the joining zone. The second percentage elongation is greater than the first percentage elongation and a length of the first section is greater than a length of the second section.

Abstract: An unwinder for web material includes: a first and second reel holder, a dynamic storage device, a junction device arranged between the first or second reel holder and the dynamic storage device and configured to join an end portion of web material running out on the first reel to an initial portion of web material of the second reel, an actuator configured to pull the web material. The dynamic storage device includes: a plurality of first return rollers, a carriage mounted on a guide and free to move along the guide approaching or moving away from the first return rollers, a plurality of second return rollers mounted idly on the carriage. The return rollers define a zigzag path for the web material. The dynamic storage device includes a plurality of motorized shafts and each first return roller is mounted by means of two rolling bearings on a respective motorized shaft.

Abstract: A device for folding web material in a plant for producing layered composite articles includes: a first guide defining a feeding plane for feeding a web material; a second guide positioned downstream of the first guide and defining a receiving plane for receiving the web material, wherein the receiving plane is substantially orthogonal to the feeding plane. A folder is arranged between the first guide and the second guide and includes an elongated edge having a first end close to the first guide and a second end close to the second guide. The elongated edge is extended from the first guide towards the second guide in the receiving plane and away from the feeding plane, in order to progressively move an intermediate portion of the web material away from the feeding plane and fold in two the web material as it travels from the first guide towards the second guide.

Abstract: A method for feeding elastic threads in a process for the production of layered composite articles includes: feeding at least one elastic thread along a path extending from a reel of an elastic thread up to a joining zone with at least one web material. Feeding the elastic thread along the above path includes: giving the elastic thread a first percentage elongation along a first section of the path extending between the reel and a control zone; giving the elastic thread a second percentage elongation along a second section of the path extending between the control zone and the joining zone. The second percentage elongation is greater than the first percentage elongation and a length of the first section is greater than a length of the second section.

Abstract: A carousel for transporting articles includes: a body rotated by a motor around a main axis, a stationary cam around the main axis and a plurality of transfer units mounted on the body to rotate around the main axis. Each unit includes a transfer element having a radially external portion to retain or release an article. The element is pivoted on the body around an auxiliary axis radial to the main axis and is coupled to the body to move along the auxiliary axis. The element is coupled to the stationary cam to rotate around the auxiliary axis. A pair of auxiliary cams is coupled to the element and integral with the body and auxiliary cam-followers are interposed between the element and the auxiliary cam to move on the auxiliary cams during rotation of the element around the auxiliary axis and move the element along the auxiliary axis.

Abstract: A device for folding web material in a plant for producing layered composite articles includes: a first guide defining a feeding plane for feeding a web material; a second guide positioned downstream of the first guide and defining a receiving plane for receiving the web material, wherein the receiving plane is substantially orthogonal to the feeding plane. A folder is arranged between the first guide and the second guide and includes an elongated edge having a first end close to the first guide and a second end close to the second guide. The elongated edge is extended from the first guide towards the second guide in the receiving plane and away from the feeding plane, in order to progressively move an intermediate portion of the web material away from the feeding plane and fold in two the web material as it travels from the first guide towards the second guide.

Abstract: An unwinder for web material includes: a first and second reel holder, a dynamic storage device, a junction device arranged between the first or second reel holder and the dynamic storage device and configured to join an end portion of web material running out on the first reel to an initial portion of web material of the second reel, an actuator configured to pull the web material. The dynamic storage device includes: a plurality of first return rollers, a carriage mounted on a guide and free to move along the guide approaching or moving away from the first return rollers, a plurality of second return rollers mounted idly on the carriage. The return rollers define a zigzag path for the web material. The dynamic storage device includes a plurality of motorized shafts and each first return roller is mounted by means of two rolling bearings on a respective motorized shaft.

Abstract: A carousel for transporting articles includes: a body rotated by a motor around a main axis, a stationary cam around the main axis and a plurality of transfer units mounted on the body to rotate around the main axis. Each unit includes a transfer element having a radially external portion to retain or release an article. The element is pivoted on the body around an auxiliary axis radial to the main axis and is coupled to the body to move along the auxiliary axis. The element is coupled to the stationary cam to rotate around the auxiliary axis. A pair of auxiliary cams is coupled to the element and integral with the body and auxiliary cam-followers are interposed between the element and the auxiliary cam to move on the auxiliary cams during rotation of the element around the auxiliary axis and move the element along the auxiliary axis.