Abstract:
Plastic film bags, commonly used for storing and/or transporting various products and things, and methods of manufacturing the plastic film transport bags are disclosed. A transport bag includes a double-walled rear panel integral formed with a double-walled front panel. A lower terminal edge of the double-walled rear panel is integral with a lower terminal edge of the double-walled front panel. Accordingly, the double-walled front and rear panels define a continuous compartment extending between the front wall and the rear wall.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    The present application claims priority to U.S. Provisional Patent Application Serial No. 60/324,856, filed Sep. 26, 2001, the entire contents of which are incorporated herein by reference. 
     
    
     
       BACKGROUND  
         [0002]    1. Technical Field  
           [0003]    The present disclosure is directed to plastic film bags commonly used for storing and/or transporting various products and things and, more particularly to an improved plastic film bag having an opening which is selectively closeable and leakproof. The present disclosure is also directed to a method of manufacturing the plastic film bags disclosed herein.  
           [0004]    2. Background of Related Art  
           [0005]    Plastic film bags are manufactured and are very commonly used for holding and storing various types of items ranging from industrial and manufacturing items to edible goods and medical specimens. Such bags are generally made by joining thin plastic film panels to one another so as to form the bag. The bags themselves typically range in size and holding capacity depending on the particular intended use. One type of plastic film bag which is today commonly used is initially in an open condition for placing or receiving a product or item therein and is, thereafter, easily selectively closeable. It is desirable that the closure seal be generally secure after a product has been placed therein and the bag closed. Accordingly, when desired, the bag can be opened, generally by cutting or tearing at serration or score lines, for gaining access to the product retained therein.  
           [0006]    In general, the typical plastic film bag includes a front and a rear plastic wall, made from a single layer of plastic film, joined together so as to form a bag having a bottom, side edges and an opening between the top edges of the walls. An adhesive strip is provided on the inside surface of one of the walls and extends linearly near the top edges from side edge to side edge. A release liner is provided extending the full width of the bag from side edge to side edge but is partially notched at its longitudinal ends for creating a shortened longitudinal portion which is placed within the bag between the front and rear walls and over the adhesive strip. Typically, the surface of the release linear which is to contact the adhesive strip is coated with a layer of silicone in order to prevent the release liner from sticking to the adhesive strip. By pulling the release liner out from between the front and rear walls, the adhesive strip is exposed to the inside surface of the other wall for thereby adhering or attaching together the front and rear walls along the bag opening and for closing the bag. The adhesive strip is made of an adhesive which is selected to be sufficiently tacky in order to prevent easy separation of the front wall from the rear wall and in order to prevent loss of the contents of the bag retained therein.  
           [0007]    As mentioned above, as is typically the case with such bags, the walls of the bag are each made from a single layer of plastic film. As such, puncture or penetration through the single layer of the bag is relatively easy thus resulting in the potential for relatively easy undesired escape of the contents of the bag therefrom. Accordingly, the need exists for a plastic film bag which reduces the incidents of loss of the contents of the bag therefrom.  
         SUMMARY  
         [0008]    The present disclosure is directed to plastic film bags commonly used for storing and/or transporting various products and things. The present disclosure is also directed to methods of manufacturing the plastic film transport bags disclosed herein.  
           [0009]    In an embodiment, the transport bag includes a double-walled rear panel integral with a double-walled front panel. The double-walled rear panel includes an inner and outer layer. Preferably each of the inner and outer layers of the double-walled rear panel has an upper terminal edge, a lower terminal edge, and a pair of side terminal edges. The double-walled rear panel has a length. The upper terminal edges of the inner and outer layers of the rear panel are joined to one another.  
           [0010]    The transport bag further includes a double-walled front panel. The double-walled front panel has an inner and an outer layer. Each of the inner and outer layers of the double-walled front panel has an upper terminal edge, a lower terminal edge, and a pair of side terminal edges. The double-walled front panel preferably has a length which is less than the length of the front panel. The upper terminal edges of the inner and outer layer of the front panel are joined together.  
           [0011]    Preferably, the lower terminal edge of the inner layer of the rear panel is integral with the lower terminal edge of the inner layer of the front panel and the lower terminal edge of the outer layer of the rear panel is integral with the lower terminal edge of the outer layer of the front panel. Accordingly, the inner and outer layers define a compartment therebetween and the front and rear panels define a pocket therebetween.  
           [0012]    Preferably, the side terminal edges of the rear panel and the side terminal edges of the front panel are joined to one another. The side terminal edges of the inner and outer layer of the rear panel are joined to one another and the side terminal edges of the inner and outer layer of the front panel are joined to one another.  
           [0013]    Preferably, the inner and outer layers of the front panel are joined together at a distance spaced from the upper terminal edge thereof. More preferably, the inner and outer layers of the front panel are joined together at a distance of about three-eights of an inch from the upper terminal edge thereof.  
           [0014]    Preferably, the transport bag further includes a strip of adhesive applied to the inner layer of the rear panel extending across a width of the bag. More preferably, the transport bag further includes a release liner releasably disposed over the strip of adhesive applied to the inner layer of the rear panel.  
           [0015]    It is envisioned that the strip of adhesive can be applied to the inner layer of the rear panel at a location in registration with the location of where the inner and outer layers of the front panel are joined.  
           [0016]    In one embodiment, it is envisioned that the transport bag includes adhesive tape affixed to the inner layer of the rear panel at a location in proximity to the upper terminal edge thereof. In another embodiment, it is envisioned that the transport bag includes adhesive tape affixed to the outer layer of the front panel at a location spaced a distance from the upper terminal edge thereof. Preferably, the adhesive tape is affixed to the outer layer of the front panel at a distance of about one-half an inch from where the inner and outer layers of the front panel are joined together.  
           [0017]    It is envisioned that the transport bag can be constructed from a polymeric material selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyvinylchloride and vinyl acetate.  
           [0018]    A preferred method of manufacturing the transport bag disclosed herein includes the steps of providing a lower and an upper elongate strip of polymeric material, the upper and lower elongate strips each including a proximal terminal edge and a distal terminal edge, laying the upper elongate strip atop the lower elongate strip, joining the distal terminal edge of the upper elongate strip to the distal terminal edge of the lower elongate strip, joining the proximal terminal edge of the upper elongate strip to the proximal terminal edge of the lower elongate strip, wherein the upper and lower elongate strips are joined at a distance spaced from their proximal terminal edges, applying a longitudinal bead of adhesive to an upper surface of the upper elongate strip, applying a release liner atop the longitudinal bead of adhesive strip, folding the upper and lower elongate strips at a location such that the proximal terminal edges thereof are spaced a distance from the distal terminal edges thereof, and feeding the folded elongate strip through a hot cut off blade to simultaneously transversely cut and seal the folded elongate strip.  
           [0019]    Preferably, the upper and lower elongate strips are joined at a distance spaced about three-eights of an inch from the proximal terminal edges thereof.  
           [0020]    The method further includes the step of affixing an adhesive tape longitudinally along the upper surface of the upper elongate strip. Preferably, the adhesive tape is affixed to the upper surface of the elongate upper strip in close proximity to the distal terminal edge of the elongate upper and lower strips.  
           [0021]    Alternatively, the method includes the step of affixing the adhesive tape longitudinally along a lower surface of the lower elongate strip. Preferably, the adhesive tape is affixed to the lower surface of the elongate lower strip at a distance of about one-half an inch from the joined proximal terminal edges of the upper and lower strips.  
           [0022]    These and other objects will be more clearly illustrated below by the description of the drawings and the detailed description of the preferred embodiments. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    Other objects and features of the present disclosure will become apparent from the following detailed description considered in connection with the accompanying drawings. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the disclosure.  
         [0024]    [0024]FIG. 1 is a perspective view of a double walled transport bag in accordance with the present disclosure;  
         [0025]    [0025]FIG. 2 is a front elevational view of the double walled transport bag of FIG. 1;  
         [0026]    [0026]FIG. 3 is a cross-sectional side elevational view of the double walled transport bag taken along line  3 - 3  of FIG. 2; and  
         [0027]    FIGS.  4 - 7  illustrate a method of production of the double walled transport bag shown in FIG. 1.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0028]    Preferred embodiments of the presently disclosed double walled transport bag will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical elements. Referring to FIGS.  1 - 3 , a double walled transport bag is shown generally as reference numeral  100 . Although bag  100  offers significant advantages and will be described in detail for use with medical specimens and samples, it will be understood that the bag is applicable for use in, for example, transporting money, checks, bonds, stocks, food stamps, jewelry and other such items. In addition, it is envisioned that bag  100  offers significant advantages in storing and maintaining perishable goods therein.  
         [0029]    In accordance with the present disclosure, bag  100  is preferably formed from a medium-weight durable plastic such as polyethylene, polypropylene, polyethylene terephthalate, polyvinylchloride, vinyl acetate or other similar plastic materials. It is preferred that bag  100  have a material thickness of about 0.002 mils or heavier.  
         [0030]    As seen in FIGS.  1 - 3 , and in particular in FIG. 3, bag  100  includes an inner layer  102  and an outer layer  104  joined thereto. In particular, inner and outer layers  102 ,  104  of bag  100  are folded over onto one another to define a double-layered front panel  106 , a double-layered rear panel  108  and an inner and outer bottom terminal edge  110   a ,  110   b , respectively. It is envisioned that inner and outer layers  102 ,  104  are folded over at a location such that rear panel  108  has a length which is greater than front panel  106 . Preferably, rear panel  108  has a length which is about two inches greater than the length of front panel  106 .  
         [0031]    Preferably, as best seen in FIG. 3, inner layer  102  and outer later  104  of rear panel  108  are joined to one another along an upper terminal edge  112  thereof by a seal  130  extending across the entire width of bag  100 . Further, inner layer  102  and outer layer  104  of front panel  106  are joined to one another by a seal  132  preferably extending across an entire width of bag  100 . Preferably, seal  132  is spaced a transverse distance from an upper terminal edge  114  of front panel  106 , most preferably, seal  132  is spaced about three-eights of an inch from upper terminal edge  114 .  
         [0032]    Turning back to FIGS. 1 and 2, bag  100  includes side weld lines  134  extending from terminal edge  112  of rear panel  108  through bottom terminal edges  110   a ,  110   b  of bag  100 . Preferably, side weld lines  134  are substantially close to right and left side terminal edges  116 ,  118 , respectively, of bag  100 . It is contemplated that front and rear panels  106 ,  108  can be joined together along their terminal side edges  116 ,  118  by heat welding or fusing methods which are well known in the art. Accordingly, a pocket “P” (as seen in FIG. 3) is defined in bag  100  when front panel  106  is joined to rear panel  108 . Moreover, in accordance with the present disclosure, an interior compartment “C” (as seen in FIG. 3) is defined between inner and outer layers  102 ,  104 . Interior compartment “C” is preferably continuous from rear panel  108 , around bottom terminal edges  110   a ,  110   b , through to front panel  106 .  
         [0033]    Preferably, bag  100  includes a strip of adhesive tape  136  affixed to rear panel  108  in close proximity to upper terminal edge  112  disposed on the same side as front panel  106 . Adhesive tape  136  preferably extends across the entire width of bag  100 , and more preferably between side-weld lines  134 . Accordingly, when the upper portion of rear panel  108  is folded over front panel  106 , adhesive tape  136  effectively closes pocket “P” by adhering the upper portion of rear panel  108  against outer layer  104  of front panel  106 . Alternatively, adhesive tape  136   a  (as seen in FIG. 3) can be affixed to outer layer  104  of front panel  106  at a location spaced a distance from upper terminal edge  114  of front panel  106 . Preferably, adhesive tape  136   a  is affixed to front panel  106 , adhesive tape  136  is spaced a distance of about one-half an inch below seal  132 .  
         [0034]    Bag  100  includes a strip of adhesive  138  affixed to rear panel  108  at a distance from upper terminal edge  112  between inner and outer layers  102 ,  104  of front panel  106 , substantially equal to the location of seal  132 . Preferably, adhesive strip  138  extends across the entire width of bag  100  and, more preferably, between side-weld lines  134 . It is contemplated that adhesive strip  138  is a single bead of hot melt adhesive. A release liner  140  is releasably affixed to adhesive strip  138  in order to prevent adhesive strip  138  from prematurely contacting inner layer  102  of front panel  106 .  
         [0035]    Turning now to FIGS.  4 - 7 , a method of manufacturing bag  100 , in accordance with the present disclosure will be described. As seen in FIG. 4, two elongate strips of polymeric material, namely, a lower strip  202  and an upper strip  204 , are laid atop one another to create a double wall of polymeric material. Each strip  202 ,  204  includes a proximal terminal edge  206  and a distal terminal edge  208 . Preferably, distal terminal edge  208  of each strip  202 ,  204  is joined to one another along the entire length thereof using known sealing techniques to form a sealed distal terminal edge  210 . In addition, either prior to, simultaneous with or subsequent to the joining of distal terminal edges  208 , each strip  202 ,  204  is permanently fused to one another along proximal terminal edges  206  to form a fused proximal terminal edge  212 . Preferably, fused proximal terminal edge  212  is spaced a distance from proximal terminal edges  206  and, more preferably, spaced three-eights of an inch from proximal terminal edges  206 . It is contemplated that proximal terminal edges  206  are preferably fused together by means of a hot seal or by other techniques known in the art.  
         [0036]    As seen in FIG. 5, a strip of adhesive tape  214  is preferably longitudinally affixed to either lower or upper strip  202 ,  204 . Preferably, adhesive tape  214  is spaced a distance from sealed distal terminal edge  210  and, more preferably spaced about one-half an inch from sealed distal terminal edge  210 .  
         [0037]    Next, as seen in FIG. 6, joined lower and upper strips  202 ,  204  are folded along a longitudinal fold line “F” to define a long side  216  and a short side  218 . Preferably, when short side  218  is folded along fold line “F”, on top of long side  216 , proximal terminal edges  206  are spaced a distance from sealed distal terminal edge  210 . It is contemplated that proximal terminal edges  206  are spaced a distance of about two inches from sealed distal terminal edge  210 .  
         [0038]    Prior to completely folding short side  218  over onto long side  216 , a single bead of hot melt adhesive  220  is applied, together with a strip of release liner  222 , longitudinally along long side  216  of upper strip  204 . Preferably, hot melt adhesive  220  is applied at a location along the surface of long side  216  which is three-eights of an inch below where proximal terminal edges  206  rest against long side  216 . This results in the creation of the “press to close” closure of interior compartment “C” of bag  100 . While a hot melt adhesive  220  is preferred, it is envisioned that any type of adhesive may be used.  
         [0039]    As seen in FIG. 7, the folded and joined lower and upper strips  202 ,  204  is passed through or fed through a hot cut off blade which both transversely cuts and seals the sides of each bag  100 , along dashed lines “X”, thereby completing production.  
         [0040]    Although the subject disclosure has been described with respect to preferred embodiments, it will be readily apparent to those having ordinary skill in the art to which it appertains that changes and modifications may be made thereto without departing from the spirit or scope of the subject disclosure.