Abstract:
A bag for containing produce and the like which comprises a central section and two end sections. The end sections they each comprise sections of thermoplastic sheeting, sealed together to provide a pair of facing bag walls defining a bag interior. The central section of the bag comprises at least one plastic mesh sheet. The central section defines a pair of facing, peripherally sealed walls, at least one of the walls comprising the plastic mesh sheet to further define the bag interior.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    In Recchia U.S. application Ser. No. 09/481,211, a bag is provided which is suitable for the storage of onions and other products, where a high degree of open ventilation is necessary or desired, while such a bag may be made on an automated process line from rolls of plastic material.  
           [0002]    This bag has one wall which is substantially a plastic sheet, while the other wall is primarily made of a mesh of plastic. A header portion is provided at one end from a folded end of the plastic sheeting of the bag, to provide a small section where opposed, opening-free plastic sheeting is provided on both sides.  
           [0003]    By this invention, a similar bag is disclosed which has a mesh window and exhibits the advantage of providing a large degree of air ventilation to its contents, while at the same time the bag may be formed and filled on conventional bag-making equipment that is presently available.  
         DESCRIPTION OF THE INVENTION  
         [0004]    By this invention, a bag is provided for containing produce and the like. The bag comprises a solid-wall, first thermoplastic sheet and a second mesh sheet, which sheets are sealed along opposed side edges to define a bag interior. The bag also defines a first transverse seal line between the first thermoplastic sheet and the mesh sheet. The first transverse seal line is spaced from the ends of the bag, and extends across the width of the bag.  
           [0005]    A first end of the bag comprises the first thermoplastic sheet, which sheet is folded over to define a pair of wall portions, with one of the wall portions typically ending adjacent to the first transverse seal line where it is sealed to the mesh sheet. Thus, the mesh sheet is spaced from the one bag end, which bag end is defined by folded portions of the first thermoplastic sheet.  
           [0006]    A second transverse seal line is positioned between a second thermoplastic sheet and the mesh sheet, the second seal line being adjacent to the end of the mesh sheet which is opposed to the first seal line. The second seal line also extends across the width of the bag.  
           [0007]    The first thermoplastic sheet extends from the first end of the bag, along the mesh sheet, and beyond the opposed end of the mesh sheet, to lie against the second thermoplastic sheet, to optionally permit formation of a third transverse closure seal between the first and second thermoplastic sheets, which third transverse seal is typically spaced from the mesh sheet. Alternatively, the bag may be gathered together near second seal line  30  with a bunching member such as a wire tie, hog ring, or the like to provide closure.  
           [0008]    Thus, a bag is provided having solid plastic sheet ends, and a central portion which comprises at least one wall having mesh sheet, and the other wall comprising a portion of said first thermoplastic sheet.  
           [0009]    Such a bag, having exclusively solid plastic sheeting ends which are spaced from a central mesh wall, can be both manufactured and filled on conventional bag forming and filling machinery, such as Lockwood Mfg. Co. or Volmpack Machines.  
           [0010]    Also, a third thermoplastic sheet may be joined to the first sheet and the mesh sheet by the first seal line. The third sheet is typically positioned inside of the mesh sheet, while the first sheet is positioned outside of the mesh sheet in the area adjacent to the seal line. This third sheet can provide added plastic material to strengthen the bonding strength of the seal line between the mesh sheet and the first sheet, to make it possible for the bag to carry a substantial weight of onions or other produce, or materials such as ice. The third sheet is typically substantially smaller than the first sheet or the second sheet.  
           [0011]    Thus, a bag is provided which can carry a large mesh sidewall portion for extra high ventilation of the contents of the bag. Also, the bag can be manufactured by conventional, retrofitted form and fill machines out of rolls of plastic sheeting and the mesh material, preferably making use of the particular heat seal die disclosed in the above cited patent application Ser. No. 09/481,211. 
       
    
    
     DESCRIPTION OF DRAWINGS  
       [0012]    [0012]FIG. 1 is a perspective view of the bag of this invention.  
         [0013]    [0013]FIG. 2 is a longitudinal sectional view of the bag of FIG. 1, shown along lines  2 - 2  of FIG. 1, with the filled, sealed bag shown in broken lines. 
     
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS  
       [0014]    Referring to the drawings, a bag  10  is shown having a plastic mesh sheet  12  as part of its sidewall. Plastic mesh sheet  12  is sealed at its side edges  14  to corresponding side edges of a first thermoplastic sheet  16  to define bag interior  18 . The mesh sheet may be of woven or nonwoven type.  
         [0015]    Bag  10  also defines a first transverse seal line  20  between first thermoplastic sheet  16  and mesh sheet  12 , with seal line  20  being spaced from the respective ends  22 ,  24  of bag  10 , and positioned at or near the respective ends  13 , 17  of mesh sheet  12  and first thermoplastic sheet  16 . First seal  20  extends across substantially the entire width of bag  10  to define a sidewall comprising a portion  26  of first sheet  16 , connected to mesh sheet  12 . First sheet  16  is folded over at end  22  so that first sheet portion  26  is continuous and integral with the remainder of first thermoplastic sheet  16 , so that first thermoplastic sheet  16  and mesh sheet  14  together form a complete portion of bag  10  having a closeable interior  18 , as particularly shown in FIG. 2. The bottom portion of bag  10  is formed by wall portion  26 , facing another wall portion  28  of the first sheet  16 . Thus, because of this foldover structure of first sheet  16 , first seal line  20  is spaced from the one bag end  22 , as well as the other bag end  24 .  
         [0016]    A second transverse seal line  30  is provided between a second thermoplastic sheet  32  adjacent to the end  34  of mesh sheet  12 , which is opposed to first seal line  20 . Second seal line  30  also extends across the width of bag  10 , so that second thermoplastic sheet  32  forms an extension of the bag wall which comprises mesh sheet  12 , as particularly shown in FIG. 2.  
         [0017]    First thermoplastic sheet  16  extends beyond opposed end  34  of mesh sheet  14  and also second seal line  30 , so that an end portion  36  of first thermoplastic sheet  16  can lie against second thermoplastic sheet  32 , forming an end portion of the bag which comprises a pair of aperture-free thermoplastic sheets. Thus, the bag ofthis invention may comprise a closed bag, sealed on three sides but with an open upper end  40 . Such a bag may be filled with onions  42  or any other desired item. Then, the bag may be gathered into a bunched-up neck  43 , by a wire tie, hog ring, or the like as indicated by arrows  45  for bag closure, as shown in the broken line portion of FIG. 2. Alternatively, a third transverse seal  44  may be imposed as shown between second sheet  32  and sheet portion  36  to form a strong seal line. Either way, the contents of bag  10  are sealed, but with a large source for air exchange being provided by the area of mesh sheet  12 , so that the contents of the bag, although sealed, may remain well ventilated.  
         [0018]    Additionally, a third thermoplastic sheet  46  may be added within bag  10 , inside and in contact with mesh sheet  12 . The third thermoplastic sheet  46  may participate in the formation of first heat seal  20  as desired, to provide more plastic material to the heat seal, surrounding the strands of the mesh sheet  12  to provide greater strength to seal line  20 . Third sheet  46  can be seen to be much smaller than first sheet  16  or second sheet  32 , being typically no larger than is desirable for convenient placement of the third sheet for strengthening seal line  20  by providing plastic to the seal. The mesh sheet  12  is preferably sandwiched at seal line  20  between third sheet  46  and thermoplastic sheet portion  26 . Then, after bag  10  has been filled, third seal line  44  may be formed in a conventional manner between second sheet  32  and sheet portion  36  at the upper bag end, or a bunching member  45  such as a hog ring is used.  
         [0019]    Mesh sheet  12  is made, as is conventional, of crossing plastic strands which adhere to each other at junction points. The particular crossing strands preferably comprise one set of parallel strands  50  that are perpendicular to the side edges  14  of bag  10 . The reason for this is that the bag of this invention may be made on a suitably modified conventional form and fill machine currently known to the art. Strands  50  prevent stretching of the mesh sheet on the process line. The bag materials start as sheets of plastic and mesh on rolls. The rolls are advanced in the direction of parallel strands  50  along the process line, with first thermoplastic sheet  16  having one side rolled up to form folded sheet portion  26 . Then, first and second seal lines  20 ,  30  are formed on the advancing sheeting, with second sheet  32  being also advanced on a continuous basis from a roller. Third sheet  46  may also be similarly advanced from a roller on a continuous basis when used, so that the assembly shown in FIG. 2 with first and second seal lines  20 ,  30  is formed, with continuous advancement in the direction of strands  50 . The side heat seals  14  may be added at another station, either before or after the first and second seals  20 ,  30 . The product  42  may be inserted into each bag after formation of the side seals  20 ,  30 , and the third seal line  48  may then be formed or a hog ring applied, providing a sealed bag with high ventilation.  
         [0020]    If desired a second mesh wall may be placed opposite to mesh sheet  12  in the first thermoplastic sheet  16 , to provide a second window for the bag, with the bag being manufactured in otherwise similar manner.  
         [0021]    Examples of mesh sheeting which may be used for purposes of this invention comprise a variety of commercially available plastic mesh materials, or metal strand mesh if desired. Typically the mesh sheet and the first, second and third sheets may be made of polyethylene or the like. For example, the mesh material may comprise CLAF® cross-laminated fiber material. A preferred mesh for sheet  12  comprises three sets of nonwoven parallel strands, angularly spaced from each other by 60 degrees, and secured together at common junction points.  
         [0022]    Any portion of thermoplastic sheets  16  and  32  may carry printing, so that the bag may be identified on both sides.  
         [0023]    Thus, a bag is provided having high ventilation characteristics, which bag can be produced on conventional form and fill machinery with relatively small modification, for automated manufacture and filling, having ends made of abutting plastic sheeting walls.  
         [0024]    The above has been offered for illustrative purposes only, and is not intended to limit the scope of the invention of this application, which is as defined in the claims below.