초록 ▼

A folding system is provided for folding at least one wing extending from a central chassis of each of a plurality of absorbent articles formed from a continuous moving web moving in a longitudinal direction. The folding system has a wing-folding conveyor and at least one elongated, folding plow, wh

A folding system is provided for folding at least one wing extending from a central chassis of each of a plurality of absorbent articles formed from a continuous moving web moving in a longitudinal direction. The folding system has a wing-folding conveyor and at least one elongated, folding plow, which has an entrance end, an exit end and an inner edge that define a twist axis. The folding plow has a contoured surface having a configuration defined by a twist angle that increases along the twist axis from zero degrees near the entrance end to 180 degrees near the exit end. The wing-folding conveyor moves the central chassis along the inner edge of the folding plow and the wing slides against the contoured surface from the entrance end to the exit end, such that the wing folds around the central chassis near the inner edge.

대표청구항 ▼

What is claimed is: 1. A folding system for folding at least one flap extending from a central chassis of each of a plurality of absorbent articles formed from a continuous moving web moving in a longitudinal direction, the folding system comprising: a flap-folding conveyor that holds the central c

What is claimed is: 1. A folding system for folding at least one flap extending from a central chassis of each of a plurality of absorbent articles formed from a continuous moving web moving in a longitudinal direction, the folding system comprising: a flap-folding conveyor that holds the central chassis of each absorbent article and moves each absorbent article in the longitudinal direction; at least one elongated, folding plow mounted alongside the flap-folding conveyor and including: an entrance end, an exit end and an inner edge that define a twist axis that is parallel to the longitudinal direction; and a contoured surface having a configuration defined by a twist angle that increases along the twist axis from zero degrees near the entrance end to 180 degrees near the exit end, wherein the twist angle is formed by the intersection between a first plane containing the central chassis and a second plane containing the contoured surface and may be measured in a twist angle plane section transverse to the twist axis for any location along the twist axis, wherein said folding plow has a transition corner intersecting an inner edge and outer edge of said folding plow, wherein said transition corner has an inner transition point and an outer transition point, wherein said inner transition point and said outer transition point have an angular offset in the longitudinal direction, wherein the twist angle plane section is oriented at an angle with respect to the twist angle axis, thereby forming an angular offset distance such that the portion of the flap near the central chassis begins to fold prior to the remaining portion of the flap; wherein the flap-folding conveyor moves the central chassis along the inner edge of the folding plow and the flap slides against the contoured surface from the entrance end to the exit end, such that the flap folds around the central chassis near the inner edge. 2. The folding system of claim 1, wherein the twist angle increases approximately linearly along the twist axis. 3. The folding system of claim 1, wherein the twist angle plane section is oriented at an angle approximately in the range of 30 to 60 degrees with respect to the twist angle axis. 4. The folding system of claim 1, wherein the folding plows further include an elongated, flat surface positioned near the entrance end and in-line with the contoured surface such that the flap-folding conveyor moves the absorbent article as the flap slides along the flat surface before the flap engages the contoured surface, and wherein the flat surface includes a chamfered inner edge that transitions into the inner edge of the contoured surface. 5. The folding system of claim 4, wherein the chamfered inner edge has a chamfer size approximately in the range of 5 to 25 millimeters and a chamfer angle approximately in the range of 10 to 60 degrees with respect to the first plane containing the central chassis. 6. The folding system of claim 1, wherein the folding plow further includes a throat region near the exit end and having an inner corner, wherein the radius of the inner corner is approximately in the range of 2 to 10 millimeters. 7. The folding system of claim 1, further comprising at least one blower positioned near the flap-folding conveyor and generating a gas flow impinging upon the absorbent article, thereby helping to hold the flap against the folding plow. 8. The folding system of claim 7, further comprising a plurality of blowers positioned near the conveyor and generating a positive pressure profile impinging upon the absorbent article, thereby helping to hold the flap against the folding plow. 9. The folding system of claim 7, wherein the gas flow is primarily composed of air. 10. The folding system of claim 7, further comprising: a transfer conveyor for moving each absorbent article to the flap-folding conveyor, the transfer conveyor including: a moving belt having a multiplicity of perforations; a stationary back plate supporting the moving belt and in fluid communication with a vacuum source, the back plate having a plurality of spaced-apart slots arranged in a row near an outer edge of the moving belt such that the perforations of the moving belt and the flap of each absorbent article passes over the slots, wherein each slot is oriented at a slot angle with respect to the longitudinal direction; and a transfer roll for moving each absorbent article from the continuous moving web to the transfer conveyor; whereby vacuum is progressively communicated through the slots and the perforations to the flap in an outwardly direction from the central chassis, thereby smoothing the transfer of each pad from the transfer roll to the transfer conveyor. 11. The folding system of claim 10, wherein the slot angle is approximately in the range of 30 to 60 degrees. 12. The folding system of claim 10, further comprising a slip-and-cut device positioned near the transfer conveyor, wherein the slip-and-cut device forms a release tape with an adhesive applied thereto for each absorbent article and attaches the release tape to the flap of the absorbent article as the absorbent article is moved by the transfer conveyor. 13. The folding system of claim 1, further comprising: a cylindrical, phase-driven, rotary knife having a drum surface disposed around a hub, the rotary knife including: at least one knife having the shape of the absorbent article and positioned on the drum surface; and a recess in the drum surface positioned within an area defined by each knife; and a compression roller in rolling engagement with the rotary knife; wherein the continuous moving web passes between the rotary knife and the compression roller such that the central chassis of each absorbent article locates into the recess as the knife cuts each absorbent article from the moving web, thereby equalizing the tension in the longitudinal direction of the moving web across the width of the moving web near the rotary knife. 14. The folding system of claim 13, wherein the rotary knife further includes a recess insert that removably attaches to the inside of the recess, such that the depth of the recess may be adjustable. 15. The folding system of claim 1, further comprising a bonding roll positioned near the exit end of the folding plow and near the flap-folding conveyor such that each absorbent article moves off of the folding plow and is compressed within a gap between the flap-folding conveyor and the bonding roll, wherein the flap-folding conveyor is driven at a conveying velocity in the longitudinal direction, and wherein the bonding roll is rotatably driven such that a tangential velocity of the bonding roll is in approximately the same direction as the conveying velocity near the gap, and the tangential velocity is greater than the conveying velocity. 16. The folding system of claim 15, wherein the tangential velocity of the bonding roll is approximately 7 to 15% greater than the conveying velocity of the flap-folding conveyor. 17. The folding system of claim 1 for folding a first flap and a second flap extending from opposite sides of the central chassis, wherein the folding system includes an operator side folding plow spaced apart from a driver side folding plow, such that the first flap slides on the operator side folding plow and the second flap slides on the driver side folding plow, and the first and second flaps fold around the central chassis.