Method and apparatus for making flexible articles having elastic-like behavior with visually distinct regions

Abstract

A method of forming flexible bags from a continuous web is disclosed. The method includes introducing a continuous web of sheet material and passing it through a process whereby the flexible bag is formed having elastic-like behavior. The continuous web is processed into a continuous web having at least two regions that are visually distinct. A sheet material is introduced having one portion of the sheet material overlapping another portion of the sheet material. The sheet material is formed into a strainable network. The strainable network includes a plurality of first regions and a plurality of second regions. The first regions are substantially un-deformed and the second regions are formed into disengageable pleat elements. As the overlapped portions of the sheet material are formed they engage each other at the pleat elements. The pleat elements of each overlapped portion become engaged within each other and resist disengagement because of the frictional forces of the sheet material. The overlapped portions of the sheet material are separated using a disengaging means so that the overlapped portions become disengaged and are separated from each other while riding on the disengaging means. The disengaging means is in the form of either air knife, static opening bar, dynamic opening bar, or suction means, and any combinations thereof.

1 . A method of making an article having elastic-like behavior comprising the steps of: 
 Introducing a sheet material having at least one overlapped portion;    Forming said overlapped portion of sheet material into a strainable network including a plurality of first regions and a plurality of second regions, said first regions being substantially un-deformed and said second regions being formed into disengagable pleat elements; and    Disengaging said pleat elements using a disengaging means:    
   
   
       2 . The method of making an article according to  claim 1 , wherein said disengaging means is selected from the group consisting of air knife, static opening bar, dynamic opening bar, and suction means, and any combinations thereof.  
   
   
       3 . The method of making an article according to  claim 1 , further comprising the step of overlapping one portion of sheet material over another portion of sheet material.  
   
   
       4 . The method of making an article according to  claim 2 , further comprising the step of separating said overlapped portions of said sheet material using said disengaging means.  
   
   
       5 . The method of making an article according to  claim 2 , wherein said dynamic opening bar comprises at least one first set of rollers and said pleat elements are disengaged from each other while at least one portion of said sheet material rides over an opposite outer segment of at least one roller.  
   
   
       6 . The method of making an article according to  claim 5 , wherein said dynamic opening bar includes an end cap.  
   
   
       7 . The method of making an article according to  claim 5 , wherein said dynamic opening bar is wholly surrounded by said overlapped portions of said sheet material.  
   
   
       8 . The method of making an article according to  claim 5 , wherein said dynamic opening bar comprises a second set of rollers and said pleat elements remain engaged as said sheet material passes between a first set of rollers and thereafter said pleat elements are disengaged while at least a portion of said sheet material is riding over at least one opposite outer segment of a second set of rollers.  
   
   
       9 . The method of making an article according to  claim 1 , wherein said disengaging step further comprising riding said sheet material on said disengaging means.  
   
   
       10 . The method of making an article according to  claim 2 , wherein the step of forming further comprises forming said pleat elements as said sheet material passes between a pair of forming rollers, at least one forming roller having toothed regions and grooved regions.  
   
   
       11 . The method of making an article according to  claim 2 , wherein said disengaging step further comprises the step of applying a vacuum to at least one overlapped portion of said sheet material.  
   
   
       12 . The method of making an article according to  claim 1 , further comprising the step of winding said sheet material onto a roll.  
   
   
       13 . The method of making an article according to  claim 1 , further comprising the step of incorporating a closure means into said sheet material.  
   
   
       14 . The method of making an article according to  claim 1 , further comprising the step of unwinding a continuous web of sheet material from a roll.  
   
   
       15 . The method of making an article according to  claim 1 , further comprising the steps of extruding a raw plastic material and converting the extruded plastic material into a continuous web of sheet material.  
   
   
       16 . The method of making an article according to  claim 1 , further comprising the step of forming flexible bags from said sheet material.  
   
   
       17 . The method of making an article according to  claim 16 , further comprising the step of sealing at least one edge of said flexible bag, and severing said sheet material across a width thereof at said sealed edge to separate said sheet material into individual flexible bags.  
   
   
       18 . The method of making an article according to  claim 16 , further comprising the step of sealing at least one edge of said flexible bag, and perforating said sheet material across a width thereof at said sealed edge.  
   
   
       19 . The method of making an article according to  claim 18 , further comprising the step of interleaving said individual flexible bags.  
   
   
       20 . A method of making an article having elastic-like behavior comprising the steps of: 
 Introducing at least one sheet material having at least one overlapped portion;    Forming said overlapped portion of sheet material into at least one region of disengagable pleat elements; and disengaging said pleat elements using a disengaging means selected from the group consisting of air knife, static opening bar, dynamic opening bar, and suction means, and any combinations thereof.