Methods and Apparatuses for Folding Absorbent Articles

Abstract

The present disclosure relates systems and methods for folding absorbent articles advancing in a converting line. The folding processes and apparatuses herein may be configured with tucker blades that are configured to maximize the period of time wherein the leading edges of the tucker blades move at maximum speeds during the folding process.

What is claimed is: 
     
         1 . A method for folding absorbent articles, the method comprising the steps of:
 conveying an absorbent article at a first speed, S1, in a first direction on a first carrier to define an article transport plane, wherein the absorbent article includes a first surface and a second surface opposite the first surface, wherein the absorbent article includes a first end and a second end, and wherein the absorbent article includes a first end region and a second end region, and a central region located between the first and second end regions;   advancing the first end region past a nip defined between the first carrier and a second carrier;   rotating a tucker blade, wherein the tucker blade includes a first surface and a second surface opposite the first surface, and wherein the tucker blade includes a leading edge and a trailing edge, wherein the leading edge and the trailing edge move through the article transport plane at the nip as the tucker blade rotates;   contacting the first surface of the absorbent article with the leading edge of the tucker blade thereby creating a fold line across the central region of the absorbent article;   redirecting the central region of the absorbent article in a second direction into the nip with the leading edge of the tucker blade;   maintaining contact between the fold line and the leading edge of the tucker blade for a total time period, Ttot, while portions of the leading edge contacting the fold line move at speeds, Smax, of at least 0.8*S1 for a time period, Tmax, of at least 0.5*Ttot; and   conveying the folded absorbent article in the second direction between the first carrier and the second carrier away from the article transport plane.   
     
     
         2 . The method of  claim 1 , further comprising the step of: cutting the absorbent article from a continuous length of absorbent articles, wherein the absorbent article includes a pitch length, PL, defined by a distance in the machine direction between the first end and the second end. 
     
     
         3 . The method of  claim 2 , further comprising the step of: advancing the continuous length of absorbent articles absorbent articles at a line speed, SL, in a machine direction, wherein SL is less than S1. 
     
     
         4 . The method of  claim 1 , further comprising the step of folding, n, absorbent articles with one full revolution of the tucker blade, wherein n is greater than one. 
     
     
         5 . The method of  claim 5 , wherein n is 2. 
     
     
         6 . The method of  claim 1 , wherein the first carrier comprises a belt conveyor. 
     
     
         7 . The method of  claim 1 , wherein the second carrier comprises a belt conveyor. 
     
     
         8 . The method of  claim 1 , wherein the absorbent article comprises a diaper, and wherein the first end region comprises a front waist region, and wherein the second end region comprises a rear waist region. 
     
     
         9 . The method of  claim 1 , wherein the first surface of the absorbent article comprises a wearer facing surface. 
     
     
         10 . The method of  claim 1 , wherein Smax is at least 0.95*S1, and Tmax is at least 0.7*Tot. 
     
     
         11 . The method of  claim 1 , wherein Smax is S1, and Tmax is at least 0.9*Tot. 
     
     
         12 . A method for folding absorbent articles, the method comprising the steps of:
 advancing a continuous length of absorbent articles absorbent articles at a line speed, SL, in a machine direction;   cutting the continuous length of absorbent articles into discrete absorbent articles, wherein each discrete absorbent article includes a first surface and a second surface opposite the first surface, wherein each discrete absorbent article includes a first end region and a second end region, and a central region located between the first and second end regions, and wherein each discrete absorbent article includes a first end and a second end, and a having a pitch length, PL, defined by a distance in the machine direction between the first end and the second end;   conveying each discrete absorbent article at a first speed, S1, in a first direction on a first carrier to define an article transport plane, wherein S1 is greater than SL;   advancing the first end and the first end region of each discrete absorbent article past a nip defined between the first carrier and a second carrier;   rotating a tucker blade through the article transport plane at the nip as the tucker blade rotates;   contacting the first surface of a discrete absorbent article with a leading edge of the tucker blade thereby creating a fold line across the central region of the discrete absorbent article;   redirecting the central region of the absorbent article in a second direction into the nip with the leading edge of the tucker blade; and   maintaining contact between the fold line and the leading edge of the tucker blade for a total time period, Tot, while portions of the leading edge contacting the fold line move at speeds, Smax, of at least 0.8*S1 for a time period, Tmax, of at least 0.5*Ttot; and   conveying the folded absorbent article in the second direction away from the article transport plane.   
     
     
         13 . The method of  claim 12 , wherein Smax is at least 0.95*S1, and Tmax is at least 0.7*Tot. 
     
     
         14 . The method of  claim 12 , wherein Smax is S1, and Tmax is at least 0.9*Tot. 
     
     
         15 . The method of  claim 12 , further comprising the step of folding more than one discrete absorbent article with one full revolution of the tucker blade. 
     
     
         16 . The method of  claim 12 , wherein the step of conveying the folded absorbent article further comprises conveying the folded absorbent article in the second direction between the first carrier and the second carrier. 
     
     
         17 . The method of  claim 12 , wherein the first carrier comprises a belt conveyor, and wherein the second carrier comprises a belt conveyor. 
     
     
         18 . The method of  claim 12 , wherein the absorbent article comprises a diaper, and wherein the first end region comprises a front waist region, and wherein the second end region comprises a rear waist region, and wherein the first surface of the absorbent article comprises a topsheet. 
     
     
         19 . An apparatus for folding absorbent articles, the apparatus comprising:
 a knife adapted to cut discrete absorbent articles from a continuous length of absorbent articles advancing in a machine direction at a line speed, SL;   a first carrier adapted to convey an absorbent article in a first direction and a second direction at a first speed, S1;   a second carrier adjacent the first carrier to define a nip extending in the second direction;   a tucker blade including a leading edge, wherein the leading edge moves through the article transport plane at the nip as the tucker blade rotates; and   a motor adapted to rotate the tucker blade so as to maintain contact between the absorbent article and the leading edge of the tucker blade for a total time period, Ttot, while portions of the leading edge contacting the absorbent article move at speeds, Smax, of at least 0.8*S1 for a time period, Tmax, of at least 0.5*Ttot.   
     
     
         20 . The apparatus of  claim 19 , wherein the first speed S1 is greater than the line speed SL.