Patent Publication Number: US-RE42240-E

Title: Inflatable, cushioning, bubble wrap product having multiple, interconnected, bubble structures

Description:
This is a continuation of Ser. No. 09/717,782, filed Nov. 21, 2000, now U.S. Pat. No. 6,410,119. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to an inflatable, cushioning, bubble wrap product. 
     This invention relates particularly to a bubble wrap product which has the bubbles formed in individual inflatable strips. The individual inflatable strips extend laterally across the width of a sheet of film material, and each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway. The interconnected passageway is smaller in size and in internal volume that the bubble chambers but is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers. 
     This invention relates particularly to a bubble wrap product in which each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal lines which have an undulating configuration free of corner shapes which could concentrate stresses. 
     Webs of plastic film which are constructed to permit the production of patterns of air filled envelopes, cushions and pillows have (in the past ten years or so) been used extensively for cushioning objects to be transported in containers. 
     The thin webs incorporate two thin sheets of plastic film and are inexpensive, tough, resilient and recyclable. 
     Inflated pillow packagings which are created from these webs of plastic film are used for void-fill packaging to replace products such as crumpled paper or polyethylene peanuts and for protective packaging to replace molded or extruded forms. 
     U.S. Pat. Nos. 5,454,642; 5,651,237; 5,755,328; 4,017,351; and 5,824,392 disclose methods, apparatus, and webs of plastic film used for making strips of inflated pillow packaging of this general kind. Each of these U.S. patents is incorporated by reference in this application. 
     Co-pending applications Ser. No. 09/207,129 filed Dec. 8, 1998, now U.S. Pat. No. 6,116,000, Ser. No. 09/439,552 filed Nov. 12, 1999, now U.S. Pat. No. 6,209,286, and Ser. No. 09/638,843, filed Aug. 14, 2000, also disclose methods, apparatus and webs of plastic film of this general kind. Each of these three co-pending applications is assigned to the same assignee as the assignee of this application. Each of these three co-pending applications is incorporated in this application by reference. 
     It is a primary object of the present invention to construct a web of two sheets of film material in a pattern of seal lines which enables an inflatable, conformable, cushioning, multiple bubble strip, packaging product to be produced which has significant functional and economic advantages over existing bubble packaging. 
     It is a related object to construct an inflatable packaging product which enables inflated bubble chambers to be large enough so that only a single layer of inflated packaging product can provide the necessary cushioning for many objects. 
     It is a related object to construct an inflatable packaging product in which substantially all of the area of the packaging product is available for inflation to provide cushioning. 
     It is a related object to construct an inflatable packaging product which is highly conformable to provide effective cushioning at all angles of possible shock loads on the object being shipped. 
     It is a related object to construct an inflatable packaging product in which the seal lines for inflatable bubble structures have an undulating configuration free of corner shapes or sharp bends which could concentrate stresses. 
     It is a related object to construct an inflatable packaging product having a plurality of individual inflatable strips of multiple bubble cushioning structures which extend laterally across the longitudinal length a web of inflated film material and in which each bubble chamber in an individual inflatable strip is interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers but which is sufficiently large to enable air volume and pressure in one inflated bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the inflatable strip of interconnected bubble chambers. 
     SUMMARY OF THE PRESENT INVENTION 
     An inflatable, conformable, cushioning, multiple bubble strip, packaging product is constructed for interposing between and engagement with both the interior surfaces of a shipping container and the outer surfaces of one or more objects packaged within the shipping container. The inflatable packaging product is constructed, when inflated, to reduce or to eliminate the transfer of shock load from the shipping container to the objects packaged within the shipping container. 
     The packaging product comprises a first sheet of film material and a second sheet of film material. The sheets have substantially equal lengths and substantially equal widths. The sheets are joined together as a web in a pattern of seal lines. 
     The pattern of seal lines form an inflation channel which extends linearly along the length of the sheets for receiving pressurized air from an outlet end of an inflation tube. 
     The pattern of seal lines also form a plurality of individual inflatable strips of multiple bubble cushioning structures which extend laterally from the inflation channel. 
     Each individual inflatable strip has a plurality of bubble chambers with each bubble chamber interconnected to an adjacent bubble chamber by an interconnecting passageway which is smaller in size and internal volume than the bubble chambers but which is sufficiently large to enable air volume and pressure in one inflatable bubble chamber to be transmitted to adjacent bubble chambers for distributing a shock load on one bubble chamber along the entire length of the individual inflatable strip of interconnected bubble chambers. 
     Each individual inflatable strip of multiple bubble cushioning structures has an entrance port connecting the first bubble chamber in the strip to the inflation channel for receiving pressurized air at the inflation station to inflate all of the bubble chambers in the individual inflatable strip. 
     The entrance port is configured to permit the entrance port to be sealed by a line seal formed across the entrance port by a heated sealing element at a sealing station as the web of film material is continuously and uninterruptedly transported through the sealing station after the bubble chambers have been inflated at the inflation station. 
     Each individual inflatable strip is defined between two laterally extending spaced apart peripheral seal lines of the pattern. The peripheral seal lines have an undulating configuration free of corner shapes or sharp bends which could concentrate stresses. 
     The peripheral seal lines have a generally sinusoidal configuration as viewed from above the web formed by the two sheets. 
     In a preferred embodiment of the present invention the bubble chambers in one individual inflatable strip are laterally offset with respect to the bubble chambers in an immediately adjacent individual inflatable strip so that a bubble chamber in one inflatable strip is opposite an interconnecting passageway in an immediately adjacent inflatable strip. 
     In a preferred embodiment of the present invention a peripheral seal line on one side of a first inflatable strip is also a peripheral seal line for a second individual inflatable strip which is immediately adjacent said one side of the first inflatable strip. 
     In the present invention the bubble chambers can be made sufficiently large so that only a single layer of the inflated packaging product can provide the necessary cushioning for many objects. 
     In one embodiment of the present invention the inflation channel extends along one side edge of the web, and each individual inflatable strip extends across substantially the entire width of the web. 
     In another embodiment of the present invention the inflation channel extends along a center portion of the web, and the individual inflatable strips extend laterally outwardly from the central inflation channel toward the peripheral side edges of the web. 
     Inflatable packaging products which incorporate the features described above and which function as described above comprise additional objects of the invention. 
    
    
     
       Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings, which by way of illustration, show preferred embodiments of the present invention and the principles thereof and what are now considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. 
       BRIEF DESCRIPTION OF THE DRAWING VIEWS 
         FIG. 1  is an isometric view showing a bubble wrap product constructed in accordance with one embodiment of the invention.  FIG. 1  shows a patterned web of the bubble wrap product in the process of being inflated and sealed. The patterned web is taken off of a storage roll and then advanced through a machine. The machine inflates bubble chambers of the patterned web at an inflation station and then seals the air in the inflated bubble chambers at a sealing station. 
         FIG. 2  is a top plan view of a portion of the uninflated web shown in FIG.  1 . 
         FIG. 3  is a plan view like  FIG. 2  but showing a packaging product constructed in accordance with another embodiment of the present invention. In  FIG. 3  the inflation channel extends through the center portion of the web while in  FIG. 2  the inflation channel extends along one side portion of the web. 
         FIG. 4  is a view like  FIG. 2  but showing a packaging product having bubble chambers which are smaller in size than those of FIG.  2 . 
         FIG. 5  is a view like  FIG. 3  but showing a packaging product having smaller size bubble chambers. 
         FIG. 6  is an isometric view showing how the inflated packaging product (see the inflated product shown in the lower part of  FIG. 1 ) is used to envelope and cushion an object to be shipped within a shipping container. In  FIG. 6  the object to be shipped is a generally rectangular shaped object.  FIG. 6  shows how the construction of the inflated packaging product of the present invention is readily conformable to wrap around all surfaces of the rectangular object, including the corner areas of the object, to provide cushioning against shock loads imposed at any angle on the outer shipping container.  FIG. 6  also shows how the shape, size and volumes of the inflated bubble chambers are large enough so that a single layer of the packaging product can provide the necessary cushioning for the object to be shipped. 
         FIG. 7  is an isometric view like  FIG. 6  but showing the inflated packaging product of the present invention can be wrapped about a cup to cushion the cup for shipment within the outside container. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is an isometric view showing a bubble wrap product  11  constructed in accordance with one embodiment of the present invention. 
       FIG. 1  shows a patterned web of the bubble wrap product  11  in the process of being inflated and sealed. 
     As illustrated in  FIG. 1  the uninflated patterned web of the bubble wrap product  11  is stored on a storage roller  13  and is looped over guide rollers  15  and  17  as the web  11  is advanced, in the direction indicated by the block arrow  18 , to and through a machine  19 . 
     The machine  19  inflates bubble cushioning structures and interconnecting passageways with pressurized air at an inflation station and seals the pressurized air within the bubble chambers and the interconnecting passageways at a sealing station (as will be described in more detail below). 
     In the preferred embodiments of the present invention the bubble wrap product  11  is constructed so that the inflation and sealing can be accomplished as the web  11  is moved continuously, without interruption or intermittent stopping, through the machine  19  during a production run. This will also be described in more detail below. 
     The lower part of  FIG. 1  shows the web  11  in its inflated form and ready for use as a cushioning packaging product. 
     In the inflated form individual inflated strips  21  extend laterally across the width of the web  11 . 
     Each individual inflated strip  21  comprises a series of inflated bubble chambers  23  with each bubble chamber  23  interconnected to an adjacent bubble chamber  23  by an interconnecting passageway  25 . 
     The interconnecting passageways  25  are smaller in size and internal volume than the bubble chambers  23 , but the passageways  25  are sufficiently large to enable air volume and pressure in one inflated bubble chamber  23  to be transmitted to adjacent bubble chambers  23  for distributing a shock load (imposed on or near one bubble chamber  23 ) along the entire length of the individual strip  21  of interconnected bubble chambers  23 . 
     The interconnecting passageways  25  also function to facilitate bending or creasing of the packaging product  11  by folding or bending along a line passing through the passageways  23  at any one of a number of varied angles. This function will be better understood with reference to  FIGS. 6 and 7  described in more detail below. This function enables the packaging product  11  to be highly conformable to enable and to cushion the object being shipped, as also will become more apparent from a review of  FIGS. 6 and 7 . 
     A seal line  27  produced by the inflating and sealing machine  19  (see the bottom part of  FIG. 1 ) closes one end (the right hand end as viewed in  FIG. 1 ) of each inflated strip  21 . 
     The length of the inflated packaging product to be used for any particular application can be determined either by cutting across the inflated web  11  or by detaching along preformed perforation lines (not shown in FIG.  1 ). 
     The seal line  27  is formed by the inflating and sealing machine  19 , but the seal line pattern on the upper part of the web  11  shown in  FIG. 1  is preformed either by a pressing machine or by a continuous roller mechanism. 
     Pattern forming machines of these kinds are disclosed in several of the U.S. patents which are incorporated by reference in this application. 
     The web  11  is formed of a first sheet of film material and a second sheet of film material with both sheets having substantially equal lengths and substantially widths. 
     The first and second sheet can be separate sheets or can be a single sheet that is folded over to provide the two sheets. 
     The two sheets are joined together in a web by the pattern of seal lines shown in the top part of FIG.  1 . 
     The pattern of seal lines shown in the top part of  FIG. 1  form an inflation channel  31  which extends linearly along the length of web  11 . 
     In the particular embodiment of the packaging product  11  shown in  FIG. 1 , the inflation channel  31  extends along one side edge portion of the web  11 . 
     In the embodiment shown in  FIG. 3 , the inflation channel  31  extends linearly along a center portion of the web  11 . 
     The inflation channel  31  is defined between spaced apart seal lines  33  and  35 . 
     The seal line  33  is opened at spaced intervals to provide outlet ports  37 . The outlet ports  37  function to permit a certain amount of the inflation pressure in the inflation channel  31  to be vented to atmosphere. 
     In addition, the air that exits from the outlet ports  37  can be sensed by a pressure transducer (as described in application Ser. No. 09/638,843 now U.S. Pat. No. 6,659,150 incorporated by reference in this application) to allow for accurate position sensing of the individual inflatable strips  21  as these strips move through the machine  19 . This sensing of escaping air through the outlet ports  37  can be used as signals for counting the number of strips inflated in a particular run through the machine and can also be used to stop the movement of the web  18  through the machine, after one production run of a selected number of inflated strips, at a position which is the right position to start a subsequent production run of a selected number of inflated strips  21 . 
     The seal line  35  is open at intervals to provide entrance ports  41 . The entrance ports  41  permit pressurized air from the inflation channel  31  to enter the individual inflatable strips  21  for inflating the bubble chambers  23  and interconnecting passageways  25  (as described above). 
     Each individual and inflatable strip  21  is defined between two laterally extending seal lines  43 . 
     In the preferred embodiments of the invention shown in  FIGS. 1-7  each laterally extending seal line  43  serves as a common boundary between two immediately adjacent inflatable strips  21  so that the only area of the inflatable portion of the web  11  which cannot be inflated and used for cushioning is the very small area of the seal lines  43  themselves. 
     As can best be seen by viewing the lower part of  FIG. 1 , the bubble chambers  23  of one individual inflatable strip  21  are offset laterally with respect to the bubble chambers  23  of an immediately adjacent individual inflatable strip  21 . A bubble chamber  23  in one strip is directly opposite a passageway  25  of an immediately adjacent inflatable strip  21 . 
     The seal line  27  shown in the lower part of  FIG. 1  is formed across the inlet ports  41  at the sealing station of the machine  19  as the web  11  is transported continuously and without interruption through the sealing station and through the machine  19 . 
     The machine  19  shown in  FIG. 1  is the same as the machine illustrated and described in detail in co-pending application Ser. No. 09/638,843 now U.S. Pat. No. 6,659,150 filed Aug. 14, 2000, entitled “Methods and Apparatus for Inflating and Sealing Pillows in Packaging”, Andrew Perkins, Oliver M. Reyes, Phillip Borchard, and Nicholas P. De Luca, inventors, assigned to the same assignee as the assignee of this application and incorporated by reference in this application. 
     A short summary of the parts of that machine as shown in  FIG. 1  of the drawings in this application will now be described. 
     The machine  19  includes a first set of film transport rollers  51 , a second set of film transport rollers  53  and a drive mechanism, including a drive belt  55 , for driving the film transport rollers  51  and  53 . 
     An outlet bulb  57  of an inflation tube  59  is positioned within the inflation channel  31  and introduces air under pressure into the inflation channel for inflating the individual inflatable strips  21  by causing pressurized air to flow through the entrance ports  41 . 
     The outlet ports  37  which are opposite certain ones of the entrance ports  41  serve to regulate the level of the air pressure within the inflation channel  31  (as described in more detail in co-pending application Ser. No. 09/638,843 now U.S. Pat. No. 6,659,150 incorporated by reference in this application). 
     The seal line  27  is formed across the entrance ports  41  as the strip of the film which contains the entrance ports  41  is passed through a sealing station. The film is engaged with a sealing wheel  61  on one side of the film  11  and is engaged with a heated sealing element on the other side of the film. The heated sealing element includes a fabric covered, electrically heated Nicrom wire. 
     A slitting station (not shown in  FIG. 1  but described in application Ser. No. 09/638,843 now U.S. Pat. No. 6,659,150) slits the inflation channel  31  to permit the web  11  to pass over the inflation tube  59  after the seal line  27  has been formed by the machine  19 . 
     The pressure of the inflation air can range from ½ pounds per square inch gauge to 10 pounds per square inch gauge. 
     The material of the two sheets making up the web  11  can be low density polyethylene or can be high density polyethylene. The thickness of the web  11  can be one mil to ten mils. 
     The height of an inflated bubble chamber  23  can be from ¼ inch to 9 inches. 
     The configuration of each seal line  43 , as viewed from above in  FIG. 1 , is, in the preferred embodiments of the present invention, a wavy, undulating, curved configuration without corners or sharp bends that could concentrate stresses. 
     In a specific embodiment as illustrated in  FIGS. 1-7  of the drawings, the configuration of a seal line  43  is generally sinusoidal, as viewed from directly above. 
     The center line of each individual inflatable strip  21  preferably extends orthogonally across the width of the web  11 , but the center line could be itself a wavy configuration and could extend at some angle other than directly orthogonal. 
       FIG. 2  is an enlarged top plan view of a web  11  having the line pattern structure shown in the top part of FIG.  1 . 
       FIG. 3  is a plan view like  FIG. 2  but shows a packaging product constructed in accordance with another embodiment of the present invention. In  FIG. 3  the inflation channel  31  extends through the center portion of the web  11 . 
     In  FIG. 2  the inflation channel  11  extends along one side portion of the web  11 . 
     The embodiment of the patterned web  11  shown in  FIG. 3  is inflated and sealed by an apparatus and method described in detail in co-pending application Ser. No. 09/439,552 filed Nov. 12, 1999 now U.S. Pat. No. 6,209,286, and titled “Machine and Method for Manufacturing a Continuous Production of Pneumatically Filled Inflatable Packaging Pillows”, Andrew Perkins, Nicholas P. De Luca, and Phillip Borchard, inventors, and assigned to the same assignee as the assignee of this application, and incorporated by reference in this application. 
     In the embodiment shown in  FIG. 3 , two seal lines  27  are formed alongside the inflation channel  31  and across the inlet ports  41 . 
       FIG. 4  is a view like  FIG. 2  but showing a packaging product having bubble chambers which are smaller in size than those of FIG.  2 . 
       FIG. 5  is a view like  FIG. 3  but showing a packaging product having smaller size bubble chambers than FIG.  3 . 
       FIG. 6  is an isometric view showing how the inflated packaging product  11  of the present invention is used to cushion a generally rectangular shaped object  71  within a shipping container  73 . 
       FIG. 6  shows how the individual bubble chambers  23  are effectively engaged with all outer surfaces of the object  71  to envelope the object  71  within the conformable inflated packaging product  11 . 
     As noted above, the interconnecting passageways  25  in particular are readily foldable and bendable along lines as needed to facilitate conforming of the inflated packaging product  11  to the particular object being shipped. The construction of the individual inflatable strips which permits a certain amount of bending or compressing of some parts of the inflated strip (by transferring pressurized air to other parts of the inflated strip) also facilitates conformation of the packaging product to the configuration of the object being shipped. 
     The conformability of the packaging product (the ability to wrap all surfaces of the object, including corner areas of the object) provides cushioning against shock loads imposed at any angle on the outer shipping container  11 . 
       FIG. 6  also shows how the shape, size and volumes of the inflated bubble chambers  23  are large enough so that a single layer of the packaging product  11  can provide necessary cushioning for the object to be shipped. 
       FIG. 7  is an isometric view like  FIG. 6  but shows the inflated packaging product  11  wrapped about a cup  75  to cushion the cup for shipment within the outer container  73 . 
     While we have illustrated and described the preferred embodiments of our invention, it is to be understood that these are capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.