Apparatus and method for forming absorbent cores

Abstract

Several variations of core formation techniques and machines to produced cores are disclosed, including a large and small discrete core, formed on a screen and combined; a large and small continuous core, formed on a web; and two and three-dimensional cores, formed on a screen, and core formation on a non-woven web.

1 - 20 . (canceled) 
     
     
         21 . An absorbent core forming system comprising:
 a first core-forming drum configured to form a first core;   a second core-forming drum configured to form a second core;   an absorbent material introduction unit positioned adjacent each of the first core-forming drum and the second core-forming drum and configured to apply an absorbent material thereon for forming the first and second cores;   a web introduction unit positioned adjacent to the first core-forming drum and/or the second core-forming drum and configured to introduce a non-woven web to the first core-forming drum and/or the second core-forming drum, with the absorbent material applied onto the non-woven web;   a first debulking unit configured to debulk the first core;   a second debulking unit configured to debulk the second core positioned downstream from the first debulking unit; and   a means for combining the debulked first core and the debulked second core to form an assembled absorbent core.   
     
     
         22 . The system of  claim 21  wherein at least one of the first debulking unit and the second debulking unit comprises a calendar unit configured to mechanically compress the first core and/or the second core. 
     
     
         23 . The system of  claim 21  wherein the means for combining the debulked first core and the debulked second core comprises a conveyor on which the first core and the second core are translated. 
     
     
         24 . The system of  claim 23  wherein the means for combining the debulked first core and the debulked second core further comprises one or more accelerator units configured to accelerate a speed of at least one of the first core and the second core to move at a same speed as the other of the first core and the second core moving on the conveyor. 
     
     
         25 . The system of  claim 21  wherein the absorbent material comprises a super absorbent polymer (SAP) or a mixture of fluff and SAP. 
     
     
         26 . The system of  claim 25  wherein at least one of the first core-forming drum and the second core-forming drum comprises a discrete pocket formed therein in which the SAP or mixture of fluff and SAP is applied, so as to form a discrete core in the discrete pocket. 
     
     
         27 . The system of  claim 25  wherein at least one of the first core-forming drum and the second core-forming drum comprises a continuous pocket formed therein in which the SAP or mixture of fluff and SAP is applied, so as to form a continuous core material in the continuous pocket; and
 wherein the system further comprises a knife configured to cut the continuous core material, after debulking thereof, to form discrete cores. 
 
     
     
         28 . The system of  claim 25  further comprising a third absorbent material introduction unit positioned adjacent one or more of the first core-forming drum and the second core-forming drum and configured to apply fluff onto the SAP or mixture of fluff and SAP. 
     
     
         29 . The system of  claim 21  wherein the web introduction unit is positioned adjacent to the first core-forming drum and configured to introduce the non-woven web thereon; and
 wherein the system further comprises:
 a tissue applicator unit positioned adjacent to the second core-forming drum and configured to:
 apply a base tissue layer to the second core-forming drum such that the absorbent material is applied onto the base tissue layer; and 
 apply an upper tissue layer to the second core after the second core has been removed from the second core-forming drum, with the base tissue layer and top tissue layer wrapping the second core; and 
 
 a knife station configured to cut the upper and lower tissue layers, so as to form a discrete wrapped second core. 
 
 
     
     
         30 . A method of forming an absorbent core comprising:
 forming a first core on a first core-forming drum;   debulking the first core at a first debulking unit;   forming a second core on a second core-forming drum;   debulking the second core at a second debulking unit that is separate from the first debulking unit; and   combining the debulked first core and the debulked second core to form an assembled absorbent core;   wherein forming the first core and/or forming the second core further comprises introducing a non-woven web to the first core-forming drum and/or the second core-forming drum and applying an absorbent material onto the non-woven web, the absorbent material comprising super absorbent polymer (SAP) or a combination of fluff and SAP.   
     
     
         31 . The method of  claim 30  wherein debulking the first core and debulking the second core comprises calendaring the first core and the second core to mechanically compress the first core and the second core. 
     
     
         32 . The method of  claim 30  wherein, in combining the debulked first core and the debulked second core, the method comprises:
 after debulking the first core, depositing the first core onto a running web; 
 conveying the running web and the first core toward the second core-forming drum; and 
 after debulking the second core, depositing the second core onto the first core. 
 
     
     
         33 . The method of  claim 32  further comprising:
 receiving the second core at a core acceleration unit; 
 accelerating the second core with the core acceleration unit; and 
 depositing the second core from the core acceleration unit onto the first core, with the core acceleration unit functioning to adjust a speed of the second core to align the second core with the first core. 
 
     
     
         34 . The method of  claim 30  wherein at least one of said first and said second cores are formed as a continuous core web, said continuous core web cut by a knife to form discrete cores. 
     
     
         35 . The method of  claim 30  wherein the first core is formed by applying the absorbent material onto the non-woven web and the second core is formed without the non-woven web, and wherein forming the second core comprises:
 applying a base tissue layer to the second core-forming drum; 
 applying the SAP or combination of fluff and SAP onto the base tissue layer; and 
 applying an upper tissue layer to the second core after the second core has been removed from the second core-forming drum, with the base tissue layer and top tissue layer wrapping the second core. 
 
     
     
         36 . The method of  claim 35  further comprising cutting the upper and base tissue layers via a knife station, so as to form a discrete wrapped second core. 
     
     
         37 . The method of  claim 36  wherein combining the debulked first core and the debulked second core comprises:
 depositing the discrete wrapped second core onto the debulked first core; 
 depositing the discrete wrapped second core and the debulked first core onto a poly layer; and 
 compressing the discrete wrapped second core and the debulked first core via a compression unit, to form the assembled absorbent core. 
 
     
     
         38 . An absorbent core forming system comprising:
 material supply units configured to provide absorbent core material;   a first core-forming drum positioned to receive absorbent core material from one of the material supply units and configured to form a first core;   a second core-forming drum positioned to receive absorbent core material from one of the material supply units and configured to form a second core;   a web introduction unit positioned adjacent to the first core-forming drum and/or the second core-forming drum and configured to introduce a non-woven web to the first core-forming drum and/or the second core-forming drum, with the absorbent core material applied onto the non-woven web;   a first debulking unit positioned adjacent the first core-forming drum and configured to debulk the first core;   a second debulking unit positioned adjacent the second core-forming drum configured to debulk the second core and that is separate from the first debulking unit; and   a means for combining the debulked first core and the debulked second core to form an assembled absorbent core;   wherein the first debulking unit and second debulking unit interact with the first core-forming drum and second core-forming drum, respectively, to compress the first core and the second core.   
     
     
         39 . The system of  claim 38  wherein at least one of the first core-forming drum and the second core-forming drum comprises a discrete pocket formed therein in which the absorbent core material is applied, so as to form a discrete core in the discrete pocket. 
     
     
         40 . The system of  claim 38  wherein at least one of the first core-forming drum and the second core-forming drum comprises a continuous pocket formed therein in which the absorbent core material is applied, so as to form a continuous core material in the continuous pocket; and
 wherein the system further comprises a knife configured to cut the continuous core material, after debulking thereof, to form discrete cores.