Abstract:
A continuous roll of plastic bags are joined “mouth to mouth” and “bottom to bottom”. The bags are separated by sealed seams and perforations at their bottoms and by non-coinciding perforated lines at their mouths. The non-coinciding perforated lines may be sinusoidal inverses of each other in one embodiment.

Description:
BACKGROUND OF INVENTION  
         [0001]    The present invention relates to packaging bags which are stored and dispensed in rolls.  
           [0002]    Rolls of packaging bags which are generally mounted on a dispenser permits the user to tear off a bag, one at time, along a straight perforated line. By this method, the user is subjected to normal and frequent problems such as identifying which end of the bag is the opening; once the opening is finally located, the user experiences the added problem of separating the two layers of this material at the opening; once the bag is opened, the user then needs to close the opening after filling the bag with the desired items by using a fastener device such as a twist tie, strap or similar gadget.  
           [0003]    These fasteners are obtained from separate container which are often empty or not readily available in the areas where the bags are dispensed  
           [0004]    In U.S. Pat. No. 5,617,627 issued to Tenneco Packaging on Mar. 18, 1997, easy open thermoplastic bags are disclosed which are dispensed from a roll. The bags are manufactured from a flattened tube of thermoplastic material which may be distinctively severed along independently phase shifted sinusoidal oscillating paths down the centre of the collapsed tube. However, in this patent, a single bag cannot be conveniently torn off the roll as each segment of the roll is composed of two bags. Therefore, after a single segment has been severed, it must then be severed again into two separate bags.  
           [0005]    In U.S. Pat. No. 5,246,110 issued to Greyvenstein on Sep. 21, 1993, there is shown thermoplastic bags having an open mouth side which defines projecting tie parts that can be readily tied by hand. Although this bag has an easily identifiable opening end, it does not permit easy separation of the two layers of material at the opening. Therefore, there is a need in the art for a plastic bag roll which provides bags which are easy to open, the open end of which is easy to identify and which provides for projecting tie parts.  
           [0006]    Therefore, there is a need in the art for a plastic bag roll which provides bags which are easy to open, the open end of which is easy to identify and which provides for projecting tie parts.  
         SUMMARY OF INVENTION  
         [0007]    This invention provides a plastic bag roll which permits a user to tear off a bag, identify the opening, open and fill the bag and close the opening more easily than with the prior art, while still dispensing packaging bags by permitting the user to tear off a bag, one at a time, from the dispenser. The unevenness of the opening will permit the user to easily identify the opening. The wave design of the opening produces two singleprotruding edges. This allows for easy separation by pulling the protruding singleedges of the opening. In addition, the design of the opening of the bag with its two protruding edges, permits the user to tie the bag closed without resorting to the use of additional fastening devices.  
           [0008]    In the prior art, these bags are dispensed in a roll with a straight line perforation and one parallel seam establishing the outside boundaries of each bag. The user has to pull the bag off, one at a time, identify the opening and separate the two layers of the material at the opening which are generally stuck together and, when the bag is filled, to search for a fastener to secure the opening.  
           [0009]    These disadvantages can be overcome by separating the bags with a waveperforation for the two connected and consecutive openings. The corresponding bottoms of the bags are separated by two parallel straight seams or heat seals with a perforated straight line which is preferably equidistant between these two seams.  
           [0010]    The wave-shaped design of the opening permits the user to identify the opening of the bag once torn off the roll while the protruding edges of the opening allows the bag to be opened easily. The protruding edges can be used to tie the opening once the bag is filled, thus eliminating the need to provide other closing devices and the dispenser to contain these closing devices. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]    An embodiment of the present invention will now be described with reference to the enclosed drawings in which:  
         [0012]    [0012]FIG. 1 shows a plastic bag roll showing a single bag which may be separated from the roll.  
         [0013]    [0013]FIG. 2 shows a view of the plastic bag roll showing closed end seam (first separator) and the open end seam (second separator) of the roll.  
         [0014]    [0014]FIGS. 2A and 2B show alternative configurations of the perforated separators.  
         [0015]    [0015]FIG. 3 is a view of a single plastic bag severed from the roll.  
         [0016]    [0016]FIG. 4 is a view of a full single plastic bag with the open end tied off.  
         [0017]    [0017]FIG. 5 shows an alternative embodiment of the present invention.  
         [0018]    [0018]FIG. 6 shows an alternative embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0019]    The plastic bag roll of the present invention may be comprised of a flattened tube of thermoplastic material which is divided into a plurality of plastic bags by a series of first and second separators. The first separator is a straight perforated line ( 4 ) which has a seam ( 3 ) on either side of it. The seam ( 3 ) is created by bonding the top and bottom layers of the tube together to seal the tube. The seam ( 3 ) becomes the closed bottom end of the bag once separated from the roll. The second separator comprises two perforated lines; one through each of the top and bottom layers of the flattened tube. The two perforated lines do not coincide. The two separators are aligned substantially across the flattened tube such that the individual bags created by tearing the roll apart at the separators are joined “mouth to mouth” and “bottom to bottom”. Preferably, the two perforated lines are sinusoidal, or substantially sinusoidal, and intersect at least once. More preferably, the first perforated line ( 5 ) is the sinusoidal inverse of the second perforated line ( 6 ), as is shown in the Figures, creating an uneven opening having protruding lobes ( 7 ) of material. These lobes ( 7 ) may be used to tie the bag closed once it is filled as is shown in FIG. 4.  
         [0020]    The present invention includes variations in sizes of the bag, types of pliable soft material, color of the material, shapes of the bag and other design features. In addition, the uneven opening of the bag can have a variation of different shapes providing the protruding edges are uneven enough to allow for the separation of the opening of the bag easily. Consequently, the shape of the perforated lines, and consequently the shape of the protrusions ( 7 ) may vary without compromising its design purpose. Alternative configurations of the perforated lines are shown in FIGS. 2A and 2B. Tearing off a bag from a roll suspended on a dispenser adds to the efficiency but is not entirely necessary.  
         [0021]    In an alternative embodiment, as shown in FIGS. 5 and 6, a roll ( 100 ) of plastic bags ( 102 ) is divided by separators ( 104 ) such that the mouth ( 106 ) of individual bags is one lateral edge of the roll. In this embodiment, the roll is not a flattened tube but is a single sheet folded over onto itself. The roll may be formed from a flattened tube where one lateral edge has been cut. The lateral edge which has been cut and which forms the bag openings comprises an upper edge ( 108 ) and a lower edge ( 110 ). The two edges ( 108 ,  110 ) do not coincide and are preferably sinusoidal shaped and overlapped in the same manner as the perforated lines described above.  
         [0022]    Each separator comprises a pair of parallel sealed seams ( 112 ) separated by a perforation ( 114 ). An individual bag ( 102 ) is separated from the roll ( 100 ) by tearing the perforated line ( 114 ). The bottom ( 116 ) of the bag may be gusseted if desired.  
         [0023]    As will be apparent to those skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.