Patent Publication Number: US-2007098308-A1

Title: Bag for crushing objects

Description:
I. BACKGROUND OF THE INVENTION  
      The present invention relates to containers used in crushing or otherwise reducing medicine from pill or tablet form to powder form and methods to manufacture such containers. More particularly, it relates to plastic bags used to contain the medicine during the crushing process and a method to manufacture such plastic bags.  
      It is widely known that many people have difficultly swallowing a pill or tablet regardless of size. As a result, such people often crush pills into a powder to make the medicine easier to take. Once crushed the user may mix the powdered medicine with a liquid, food, or another substance to make the medicine easier to take, or the user may simply consume the powder directly. Although crushing a pill may render medicine easier to ingest, it has disadvantages including losing or contaminating a portion of the dose while crushing the pill To avoid losing or contaminating the medicine while crushing a pill, users often place the pill between two layers of material such as cloth, paper, or plastic before crushing it. For example, the two layers of material can be the sides of a plastic bag. Once the pill is positioned between layers of material, the user may crush the pill by using a hard object to apply pressure to the surface of the pill until the pill breaks into pieces. The user continues applying pressure until the pill is pulverized into sufficiently small granules. Such methods for crushing pills typically cause the user to lose a portion of the pill. For example, some of the pill may be embedded in the layers of material used to contain the pill or lodged in the corner of the plastic bag or other container. During the process of crushing the pill, it may also get contaminated with dirt, bacteria, or other undesirable substances introduced by the material used to contain the pill, the objects used to apply the pressure, or the objects used to retrieve the crushed pill from the materials used to contain the pill. Additional disadvantages include possible injury during the crushing process, and other possible physical hazards stemming from pieces of the crushed object acting as a projectile,  
      A conventional method of crushing one or more pills involves positioning the pill inside a polyethylene bag having an open end and walls of the same size and shape. When using such a bag to contain a pill for crushing, a portion of the crushed pill typically lodges in the lower corners of the bag and remains difficult to retrieve without significant additional effort. A portion of the crushed pill also adheres to the interior surfaces of the walls of the bag, for example, because of a small static charge that is typically present on the surface of a plastic bag or that can be generated by the crushing process As a result, the entire dose of the pill may not be available for ingestion.  
     II. SUMMARY OF THE INVENTION  
      The inventor has developed a bag that addresses the disadvantages described above and minimizes the amount of medicine lost or contaminated when crushing a pill. A bag according to the convention has a front wall and a back wall as depicted in  FIG. 4 . Each wall has a first side edge, a second side edge, a top edge, and a bottom edge. The respective bottom edges, first side edges, and second side edges of the front and back walls are connected to create an interior region. Although the front and back walls of a bag according to the invention can be made from various plastic materials, low density polyethylene (LDPE) is suitable and approved by the FDA for containing food and medicine. The walls are preferably at least 6 mil thick to withstand without failing the forces applied during crushing. However, any thickness of the bag walls that withstands the forces applied during crushing is sufficient. The seal at the bottom of the bag defines an angle α inside the bag interior of greater than 90° and less than 180° with each of the side edges of the bag. Increasing the angle α beyond 90° reduces the amount of crushed, powdered material that may remain lodged in the bag during dispensing. A preferred minimum angle α is 120°. This bottom seal can be curved with the concave side facing the top (open end of the bag) as shown in  FIG. 4 . Alternatively, the bottom seal may be defined as a series of two or more connected linear segments (not illustrated) arranged so that the angle α on each side of the bag is greater than 90° and less than 180° and all angles between any two connected segments is also greater than 90° and less than 180°.  
      The bag according to the invention may also incorporate several additional features that facilitate its use. For example, to maximize the proportion of crushed material that can be extracted reliably from the bag, the walls may be made with a material that includes an additive or interior coating that minimizes static charge, reduces friction between the interior walls and the contents of the bag or both. Such anti-static and anti-friction additives are commercially available and known. The free top edge of the back wall may extend beyond the free top edge of the front wall to form a lip that makes the bag easier to open by providing a part of the bag that the user can grasp easily when the bag is closed. This lip may also include a gripper portion defined by features on the interior, exterior, or both surfaces of the lip (or the front and/or back walls near the opening) to assist further the user in opening the bag. For example, gripper portion is illustrated in  FIG. 4  as one or more gripper lines that protrude from the exterior surface of the lip and extend approximately parallel to the top edge of the back wall. Alternatively, the gripper portion may be a texture that is embossed or printed upon the interior and/or exterior surfaces of the lip (or the front and/or back walls of the bag if no lip is present). Placing the gripper portion on the exterior of the bag allows the crushed material to be poured from the bag across the lip without obstruction. To assist in aligning, registering, or orienting the bag in a pill crushing device, the bottom edge of the bag may extend beyond the bottom seal and away from the open top edge of the bag as depicted in  FIG. 4  to form a flat bottom edge. The bag may also include relatively wide sealed seams that extend along at least portions of the first and second side edges. A preferred width of 0.125 inches or more causes the bag to open more readily when the user grasps the sides of the bag and squeezes them together. These seams also increase the strength of the sides of the bag to prevent bursting when pressure is applied to crush a pill. A bag according to the invention may also include an indicator mark to permit a quick visual identification of the unsealed edge of the bag. For example, the indicator mark may be an integrally extruded line of material near the open end of the bag (which may be colored) as depicted in  FIG. 4 . Alternatively, the indicator mark may be pressed or printed near the top edge of either wall. Either of these two types of indicator marks may further ease the opening of the bag when the user squeezes the sides of the open end of the bag together.  
      The foregoing general description and the following detailed description are exemplary and explanatory only and do not restrict the claims directed to the invention. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and together with the description, serve to explain the principles of the invention.  
    
    
     III. BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic diagram of an extrusion system used to make a bag according to the invention,  
       FIG. 2  is a perspective view from above of an die assembly suitable for making a bag according to the invention with the system shown in  FIG. 1 .  
       FIG. 3  is a perspective view of a representative section of material taken from a tubular film extruded through the die assembly of  FIG. 2 .  
       FIG. 4  is a frontal perspective view of a first embodiment of a bag according to the invention.  
       FIG. 5  Is a schematic cross-sectional view of the bag illustrated in  FIG. 4  taken along lines  5 - 5 .  
       FIG. 6  is a schematic frontal perspective view of a tubular film extruded from the extrusion die assembly of  FIG. 2  after it has been cut longitudinally and folded into a J-shaped configuration and depicting one method of making side seams on the bag of  FIG. 4 .  
       FIG. 7  is a perspective view of the tubular film illustrated in  FIG. 6  depicting one method of making the curved bottom seal on the bag of  FIG. 4 .  
    
    
     IV. DETAILED DESCRIPTION OF THE INVENTION  
      This application refers in detail below to the exemplary embodiments of the bag according to the invention, which are illustrated in the accompanying drawings. Wherever possible, the application uses the same reference numbers throughout the drawings to refer to the same or similar items,  
       FIG. 1  schematically illustrates a system suitable for manufacturing bags according to the invention. Raw material such as FDA-approved, food-grade, LDPE resin is fed into the intake  10  of an extrusion machine  11 , which melts the raw material and extrudes it through a die assembly  12  to create a tubular film  30 . After exiting the die assembly  12 , the tubular film  30  is cooled, for example, by the blower  17  and rolled onto a spool  18 . Die assembly  12  shown in  FIG. 2  is configured to include one or more notches  40  so that the tubular film  30 , shown in  FIG. 3 , includes one or more longitudinal ridges  31  (e.g., two ridges are illustrated in  FIG. 1 ), which eventually constitute gripper  51  on the finished bag. Additionally, a secondary extrusion head  14  to add a strip  32  to the tubular film  30  (or ridges  31  or any other feature appropriately applied longitudinally on tubular film  30 ). The strip  32  is made of a thermoplastic material compatible with the bag walls (preferably colored LDPE) in that it is capable of binding to or melting into the material used to form the tubular film  31 . Eventually, strip  32  constitutes the indicator mark  52  shown in  FIG. 4  on the finished bag.  
       FIG. 2  is a perspective view from above of the die assembly  12  that is suitable for making a bag according to the invention with the system shown in  FIG. 1 . The melted raw material from the extrusion machine in  FIG. 1  is forced between the inner plate  20  and the outer plate  21  of die assembly  12 . Longitudinal channels  40  protrude substantially radially outward on outer plate  21  form ridges  31  on the exterior surface of tubular film  30 . Channels (not illustrated) that are similar to channels  40  may be added (or substituted for channels  40  on outer plate  21 ) to protrude substantially radially inward on inner plate  20  to form ridges on the inner surface of tubular film  30 . Die assembly  12  also includes an aperture  22  that permits pressurized air (or some other gas as required) to be injected into the interior of the tubular film  30  as it exits the die assembly  12 . Injecting air or gas through aperture  22  helps to maintain the thickness of the walls of tubular film  30  and the generally circular cylindrical shape of tubular film  30 .  
       FIG. 3  is a perspective view of a representative section of material taken from the tubular film  30  extruded through the die assembly  12  of  FIG. 2 .  FIG. 3  illustrates the tubular film  30  including ridges  31 , which constitute gripper  51  in the finished bag  50 .  FIG. 3  also illustrates the strip  32 , which constitutes the indicator mark  52  on the finished bag. Also shown in  FIG. 3  is cut line  33 , which represents the line along which tubular film  30  is longitudinally cut to define the top edges of the finished bag.  
       FIG. 4  is a frontal perspective view of an embodiment of a bag  50  according to the invention. The bag  50  includes a back wall  58  and a front wall  59  that are joined by the side seals  56  along side edges  60  and  61  and the bottom seal  62  near bottom edge  57  to define an interior with an opening  54 , which is located at the top of the bag  50  shown in  FIG. 4 . Back wall  58  extends farther from the bottom seal  62  than the front wall  59  to define a lip  53  extending beyond the top edge  55  of front wall  59 . The lip  53  provides the user a convenient handling point for identifying the open end  54 , opening the bag  50 , and orienting the opening  54  of the bag  50 . The front wall  59  and back wall  58  are sufficiently thick (at least about 5 mil and preferably at least about 6 mil) to enable the walls to withstand the forces applied when a user crushes a pill or other object in the interior of the bag  50 . The thickness of the front and back walls also facilitates opening the bag  50  along substantially its entire length when opening  54  is opened. In turn, opening the bag along its entire length increases the likelihood that the user will be able to dispense substantially all the crushed material from the interior of the bag.  
      As shown in  FIG. 4 , seals  56  are relatively wide seams along the first side edge  60  and the second side edge  61 . The use of wide seals, while not strictly necessary, further enhances the user&#39;s ability to open bag  50  along substantially its entire length. These wide seals also enhance the bag&#39;s ability to withstand pressures applied while crushing a pill. Seals  56  are preferably at least about 0.125 inch wide.  
      The bottom seal  62  illustrated in  FIG. 4  intersects with each of side edges  60  and  61  and defines a vertex at each intersection. The angles a defined by these vertices (or “corners”) is greater than 90° and less than 180° (with a preferred angle of at least 120°), to minimize the tendency of crushed material to lodge in these “corners” of the interior of bag  50 . While seal  62  is substantially continuously curved between these corners, other geometries for seal  62  are acceptable. For example, seal  62  may be formed as a series of two or more connected linear segments (not illustrated) arranged so that the angles α are greater than 90° and less than 180° and all angles defined by the vertices formed by any two connected linear segments are also greater than 90° and less than 180°. A curved seal  62 , as shown, is preferred because it minimizes the number of vertices formed along the seal  62 , which therefore also minimizes the amount of crushed material that lodges in such vertices.  
      Gripper  51  is illustrated on the exterior surface of lip  53  allowing easy handling and opening of the bag. The gripper  51  provides tactile feedback and improve friction between the user&#39;s fingers and the lip, which assists the user in opening the bag. While gripper  51  is shown in the exterior surface of the lip  53  on the back wall  58 , it may also be located on the interior surface of the lip  53 , the interior surface of the front wall  59 , the exterior surface of the front wall  59 , or any combination of all four surfaces. The gripper is illustrated as two parallel lines, which originated as ridges  31  in the manufacturing process. While the number of ridges  31  affects the functional effectiveness of gripper  51 , it is possible for any number of ridges  31  to serve as a gripper. Alternatively, the geometry of the gripper  51  need not be as shown in  FIG. 4 . For example, gripper  51  may be a series of dots, dashes, or some other shape different from the substantially parallel ridges  31  shown. Additionally, the gripper may be added to bag  50  via a variety of methods other than the direct extrusion of ridges  31  on tubular film  30  described in connection with  FIGS. 1-3 . For example, the gripper may be added by a separate extrusion head like secondary extrusion head  14  or by a type of printing process that deposits and binds material on the surface of the bag in the appropriate locations.  
      The bag shown in  FIG. 4  also includes the optional indicator mark  52  that is positioned near opening  54 . The indicator mark may be imprinted on a surface of the front wall  59  or back wall  58  or incorporated as additional thermoplastic material that is incorporated into (e.g., by being integrally extruded) or onto (e.g., by being separately extruded) one of these surfaces. The indicator mark  52  (e.g., a colored line that is substantially parallel to the edge defining the open end of the bag) provides a visual cue that further aids the user in identifying the opening  54  of the bag  50 . The indicator mark  52  if formed of additional material rather than being imprinted on the bag  50  also provides a tactile cue and adds stiffness to the portion of front wall  59  near opening  54 . This added stiffness enhances the ease with which the user can open bag  50  to dispense crushed material inside bag  50 . The thickness added by an extruded version of indicator mark  52  increases the ease of producing a sufficiently wide opening when side edges  60  and  61  are squeezed toward each other.  
      The bag  50  shown also includes a bottom  57  edge, which is typically closed if bag  50  is formed using the system described above. However, bottom edge  57  need not be closed. To assist in aligning, registering, or orienting the bag in a pill crushing device, the bottom edge  57  may extend in a direction away from the opening  54  and beyond the bottom seal  62  to form a flat bottom edge as depicted in  FIG. 4 . However, the geometry of bottom edge  57  could be altered as desired to match geometry of a pill crushing device. For example, the bottom edge  57  could have a shape (not illustrated) that is concave downward (with reference to  FIG. 4 ). Such a shape could mate with a complementary mounting surface in a pill crushing device to ensure precise registration of the bag in the device by tending to cause the bag to center itself on the complementary mounting surface. The shape of bottom edge  57  may also be altered to create a desired aesthetic effect.  
       FIG. 5  is a schematic cross-sectional view of the bag  50  illustrated in  FIG. 4  taken along lines  5 - 5 . The figure illustrates aspects of the gripper  51 , an indicator mark  52  made of added material rather than being imprinted, and lip  53 .  
       FIG. 6  is a schematic frontal perspective view of a tubular film  30  extruded from the extrusion die assembly of  FIG. 2  after it has been cut longitudinally along cut line  33  and folded into a J-shaped configuration.  FIG. 6  further illustrates the manner in which wide seals  56  shown in  FIG. 4  are made as heat seams  70  that are spaced apart with desired spacing W (measured from center to center of adjacent sealed portions of the tubing  30 ). When tubular film  30  is cut along cut line  33  and folded into the J-shape shown in  FIG. 6 , the fold at the bottom of the film defines the front wall  59  and back wall  58 . The fold is located such that the edge  63  of back wall  58  is farther from the fold than the edge  64  of front wall  59  to define a back wall  58  that is taller than front wall  59 . The difference in height between back wall  58  and front wall  59  defines the height of the lip  53 . Also shown in  FIG. 6  are gripper  51  and indicator mark  52 .  
       FIG. 7  is a perspective view of the J-shaped film  30  illustrated in  FIG. 6  depicting a method of making the curved bottom seal  62  shown on the bag  50  illustrated in  FIG. 4 . Heat seams  80  are formed as shown to bind front wall  59  to the back wall  58  and close the what will become the bottom of bag  50  shown in  FIG. 4 . Cut lines  82 , also separated by spacing W, are preferably located to coincide with the vertical (as shown in  FIG. 6 ) centerline of heat seams  70 . The J-shaped film  30  is cut along cut lines  82  to form the individual bags. Heat seams  80  may be formed in the J-shaped film  30  before or after the J-shaped film  30  is cut along cut lines  82 . However, it is preferred to form heat seams  80  before the cutting operation because it is easier to precisely register the J-shaped film  30  in the heat sealing machine than to register individual bags.  
      It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of a bag according to the invention and methods of making such a bag that are described above without departing from the scope or spirit of the invention. Therefore, other embodiments of the invention will be apparent to those skilled in the art from their consideration of the specification and practice of the invention disclosed above. The applicant intends that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.