Abstract:
A plastic pharmacy purchase bag is disclosed having a seamless perimeter defined by a tubular member folded at a first closed end, and an open end including means for closing the receptacle after use. The plastic tubular member comprises integrally formed walls that terminate in a base at said closed end with the edges of the walls cooperating to form a sealed relationship. An outer surface of the receptacle includes indicia printed thereon.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part and claims priority from U.S. application Ser. No. 11/063,058, filed Feb. 22, 2005, which is a continuation of U.S. application Ser. No. 10/423,427 filed Apr. 25, 2003, the contents of both of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    Pharmacy prescriptions have traditionally been packaged in opaque white paper bags for purposes of privacy and for costs. These paper bags create enormous waste and the cost of paper products have made these bags more expensive than ever. Further, paper bags can tear or rip easily, particularly when wet, and do not have a reliable method of sealing. Therefore, the contents of the bag can become lost or spilled, leading to a loss of privacy and possible damage to the product. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention overcomes the shortcomings of the prior art in providing a seamless pharmacy purchase bag formed of a copolymer plastic material shaped without any longitudinal seams or crevasses. The plastic bag is preferably extruded in its open configuration to provide an opaque bag that is continuous and seamless circumferentially along its inner surface and is resilient. A first preferred embodiment comprises a bag made from a copolymer comprising ethylene and propylene that is heated to approximately 200° C. and then extruded into its final shape at a pressure of 450 Bar. The resultant bag is approximately 0.0015 inches thick and is opaque, pliable, and resilient. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is an elevated perspective view of a preferred embodiment of the present invention; 
           [0005]      FIG. 2  is a bottom view of the embodiment of  FIG. 1 ; 
           [0006]      FIG. 3  is a step diagram of the method for making the present invention; and 
           [0007]      FIG. 4   a - f  is a sequence of stages illustrating the method of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0008]      FIG. 1  illustrates a first preferred embodiment of a pharmacy bag  100  of the present invention having a generally open-ended columnar structure comprising a base  110 , a front wall  115 , a rear wall  120 , and two side walls  125  with a crease  130  in the side walls  125  and a crease  135  in the front wall for collapsing the bag into a planar configuration prior to use. The four walls are integrally formed without a seam such that there is a continuous and uniform construction throughout and across the four walls. That is, the bag  100  is created as a tubular construction rather than a folded sheet, and thus there are no seams extending longitudinally along the bag&#39;s walls. Each wall is formed of a common uninterrupted thickness, and the thickness of the base  110  may preferably be consistent with the thickness of the four walls. 
         [0009]    Closure means is preferably provided along an outer surface of at least one of the front and rear walls  115 , 120  along an upper edge. Closure means may comprise a twist-tie member (not shown) adhesively secured to the outer wall that allows the upper portion of the bag to be folded closed and secured using the flexible twist-tie member. Alternatively, an adhesive strip  140  may be included along the outer surface for securing a first folded edge of the bag  100  to an opposite folded edge in a closed and folded configuration thereby preventing the bag from unfolding and opening inadvertently. Other closure means exist in the art such as interlocking groove and tab members on the interior of opposing walls (such as those found on popular plastic sandwich bags), an envelope type overlapping adhesive configuration, and many others that may be employed without deviating from the scope of the present invention. 
         [0010]    The bag  100  of the present invention preferably is formed of a copolymer material comprising ethylene and propylene. Pellets of the plastics are melted into a working composite mixture at about two hundred degrees Celsius (200° C.), along with some additive agents for coloring purposes. This heated molten compound is placed in a die where an extrusion process forms an open-ended tubular bag ( FIG. 4   a ) as the compound flows into the gaps between the extruding member and the die. The extrusion process may take place at a controlled pressure of 450 Bar. This process creates an open-ended tubular member with a seamless perimeter that is not present in paper bags formed from flat sheets. After the extruded tubular member is formed, folds and creases that convert the tubular member into a rectangular shaped collapsible parallelepiped that folds into a flattened configuration are formed ( FIGS. 4   c - e ). This step is preferably done in an automated setting wherein a machine is utilized to create the folds and creases. The bottom of the bag ( FIG. 2 ) is closed and sealed with a heat-press at an edge  172  of the tubular member ( FIG. 4   f ) to ensure that there can be no leakage through the bottom of the bag. 
         [0011]    In an optional step, the tubular member is subjected to a printing step ( FIG. 4   b ) in which printing  150  is applied on an outer surface or surfaces to include advertising for the pharmacy, as well as possibly identifying the manufacture or the customer, present ordering information, or the like. The printing  150  is preferably carried out by a Gravure process whereby engraved plates or cylinders include an inverse image of the final indicia, and the plates or cylinders are inked and brought in contact with the outer surface of the tubular member to leave a remnant impression. This process permits high-speed printing of many units rapidly before each individual tubular member is formed into a bag. 
         [0012]    The tubular member of the extruded copolymer plastic composition is formed into a bag by a sheet folding machine that folds a bottom end  110  of the tubular member into a closed configuration using either a heat-applying press or adhesively clamping the bottom edges of the plastic walls. The thus-closed end cooperates with the seamless integral wall configuration to prevent the contents of the bag from exiting through the junctures at the bottom and sides of the bag  100 . The uninterrupted and uniform thickness of the walls  115 ,  120 ,  125  are approximately 0.0015 inches thick, and this thickness provides adequate strength and coverage in the event of weak spots or unexpected thinning of the bag while preserving the flexibility and resiliency of the bag necessary to fold and stack the articles in confined spaces. 
         [0013]    The finished bag  100  is preferably four and one half to five inches tall and two and one half inches wide with a three inch bottom gusset in the open or inflated configuration, but may vary in size. The tolerance on the thickness is approximately five to ten percent. The bag can preferably be folded along vertical creases, and along traverse creases adjacent the base, to contract into a flat, compact pocket-size configuration prior to use. 
         [0014]      FIG. 3  illustrates the steps for manufacturing a preferred embodiment of the present invention. Step  200  represents the acquisition of the various copolymer constituents used to make the present invention. Upon acquiring the constituents, step  210  corresponds to the mixing and heating of the constituents into a workable composition that can be formed in an extrusion process. The extruding process and cooling step (step  220 ) follows, where the composition is formed into a tubular member with a seamless, uniform perimeter. In step  230 , the tubular member is folded and creased using a sheet folding machine into a rectangular configuration with creases that cause the tubular member to fold into a bag-shaped configuration. In addition, the bottom end of the bag is sealed closed using heat or adhesive to form a fluid-tight seal to prevent leakage through the bottom of the bag. After the bag has been formed and cooled, the final step  240  calls for the printing of various graphics and information, including instruction, on the outside of the bag. The final printing step is preferably accomplished with a Gravure process that allows rapid printing of many bags. 
         [0015]    The description above is illustrative only, and is intended to provide the inventor&#39;s best mode of making and using the invention. However, it will be apparent to one of ordinary skill in the art that the present invention can be practiced outside of the present description. Thus, the disclosure should be viewed as illustrative only, with the scope of the invention limited only by the language of the claims presented below.