Method and apparatus for forming an absorbent core with a pleated outer wrap

A method of forming a wrapped absorbent structure, the method comprising:

• feeding a continuous web layer from a first material source in a machine direction;
• drawing the continuous web layer onto a forming drum rotating in the machine direction at a first location, the forming drum including at least one depression provided on an outer circumferential surface of the forming drum onto which at least a portion of the continuous web layer is drawn;
• depositing an absorbent material onto the continuous web layer and within the at least one depression;
• enclosing the absorbent material between the continuous web layer and another continuous web layer at a second location downstream from the first location in the machine direction;
• and
• wherein for one of or both of the continuous web layer and the another continuous web layer, the method further comprises:
• forming a pleated web layer comprising one or more folds that overlap portions of the pleated web in a cross-machine direction, each of the one or more folds comprising a continuous fold running in the machine direction;
• and
• bonding the overlapped portions of the pleated web layer together to create substantially detachable or temporary bonds having a strength less than a separating force imparted by the absorbent material being exposed to a liquid;
• wherein the substantially detachable or temporary bonds retain the one or more folds in the continuous pleated web layer during forming of the wrapped absorbent structure and when the absorbent material is in a substantially dry state.

An apparatus for forming a wrapped absorbent structure, the apparatus comprising:

• a core-forming drum rotating about an axis of rotation, the core-forming drum comprising at least one depression provided on an outer circumferential surface of the forming drum;
• a deposition system configured to apply absorbent material into the at least one depression to provide one or more bulks of absorbent material;
• a feeding mechanism configured to feed a continuous web layer in a machine direction;
• a pleating unit configured to form one or more folds in the continuous web layer, each of the one or more folds comprising a continuous fold running in the machine direction so as to form a pleated web layer having portions overlapped in a cross-machine direction;
• an attachment means configured to form substantially temporary bonds in the overlapped portions of the pleated web layer, the substantially temporary bonds having a bond strength great enough to maintain the continuous fold in the wrapped absorbent core during forming of the wrapped absorbent structure and when the absorbent material is in a substantially dry state;
• a transfer mechanism configured to transfer the one or more bulks of absorbent material off of the core-forming drum and onto the pleated web layer moving in the machine direction;
• and
• a folding unit positioned downstream from the transfer mechanism in the machine direction, the folding unit configured to fold side sections of the pleated web layer over the one or more bulks of absorbent material to wrap the absorbent material.