Abstract:
A cellular cushioning article is described. The cellular cushioning article may be used to wrap items such as fragile items needing protection during storage or shipping. The article includes a polymeric film including discrete first cells projecting from a major surface of the film. The first cells are arranged in rows parallel to each other, such that for two opposing polymeric films with the major surfaces facing each other, the total thickness of the two opposing polymeric films is less than twice the thickness of one polymeric film. The cellular cushioning article can be fan-folded into a stack occupying much less volume as compared to stacks formed by fan-folding known cellular cushioning articles.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/358,630, filed Jun. 25, 2010, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention disclosed herein relates to a packaging material, particularly a cellular cushioning article having an arrangement of inflated cells projecting from a major surface of the article. 
     BACKGROUND 
     Cellular cushioning articles are used for packaging, for example, for wrapping items needing protection when mailing, shipping or stored in a container, on a shelf, etc. One type of cellular cushioning article comprises a polymeric backing and a top layer partially in contact with the backing such that a layer of discrete hemispherical bubbles are formed across a major surface of the article. A cellular cushioning article of this type is known as Bubble Wrap® manufactured by Sealed Air Corp. Cellular cushioning articles comprising layers of discrete hemispherical bubbles are available in different configurations with respect to the diameters and heights of the bubbles, and generally provide more cushioning as bubble size increases. 
     SUMMARY 
     A cellular cushioning article is disclosed herein, the article comprising a polymeric film comprising first cells projecting from a major surface of the polymeric film, each first cell being surrounded by land area, wherein the first cells are arranged in rows substantially parallel to each other and substantially parallel to a length of the polymeric film, such that for two opposing polymeric films with the major surfaces facing each other, the total thickness of the two opposing polymeric films is less than twice the thickness of one polymeric film. The first cells may have any shape, for example, the first cells may be substantially hemispherical and have substantially the same diameter. 
     In some embodiments, the cellular cushioning article further comprises second cells projecting from the major surface and interspersed with the first cells in the rows comprising the first cells, wherein the second cells are substantially hemispherical and have substantially the same diameter, the diameter of the second cells being less than that of the first. Anywhere from a single second cell to as many as ten second cells may be disposed between adjacent first cells. 
     The cellular cushioning article may further comprise a plurality of fold zones comprising land area and being free of first cells. The fold zones extend across a width of the polymeric film, and are disposed between groups of the first cells. The cellular cushioning article may comprise two edge zones, each edge zone extending along an edge of the polymeric film and having a width of about two inches or less, the edge zones comprising land area and being free of first cells. The fold and/or edge zones may comprise second cells. 
     In general, the cellular cushioning article may be perforated across the width of the film. The cellular cushion article can be fan-folded to form a stack, and the stack can be disposed in a box or a bag. Stacks formed by fan-folding the cellular cushioning article disclosed herein can occupy much less volume as compared to stacks formed by fan-folding known cellular cushioning articles. 
     These and other aspects of the invention are described in the detailed description below. In no event should the above summary be construed as a limitation on the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention is further explained with reference to the following drawings which are intended to be merely illustrative and not limiting. The drawings are not necessarily to scale. 
         FIG. 1  shows a plan view of a known cellular cushioning article. 
         FIG. 2  shows a plan view of an exemplary cellular cushioning article disclosed herein. 
         FIG. 3   a  shows a cross-sectional view of the exemplary cellular cushioning article shown in  FIG. 2 . 
         FIG. 3   b  shows a cross-sectional view of two exemplary cellular cushioning articles shown in  FIG. 3   a , wherein the two articles are stacked such that inflated cells of each article face each other. 
         FIG. 3   c  shows a plan view of the two exemplary cellular cushioning articles shown in  FIG. 3   b.    
         FIGS. 4   a - 4   b ,  5   a - 5   b ,  6   a - 6   c ,  7   a - 7   c  and  8  show plan views of exemplary cellular cushioning articles disclosed herein. 
         FIG. 9  shows a cross-sectional view of a fan-folded cellular cushioning article. 
     
    
    
     DETAILED DESCRIPTION 
     Cellular cushioning articles have been known for many years, and many different types are available. One type of cellular cushioning article is illustrated in plan view in  FIG. 1  and comprises polymeric film  10  having hemispherical cells  12 , that protrude from a major surface of the film. Each cell is surrounded by land area  14 . The cells are arranged in a tight hexagonal configuration with little land area between the cells, relative to the diameter of the cells. For example, Bubble Wrap® is available with cells having a 3 cm diameter and less than 4 mm of land area between cells. These types of known cellular cushioning articles perform well, however, large quantities are extremely bulky to store when not in use. 
       FIG. 2  shows a plan view of an exemplary cellular cushioning article disclosed herein. Cellular cushioning article  20  comprises a polymeric film having a major surface, and first cells  22  protrude from the surface, each cell being surrounded by land area  24 . First cells  22  are arranged in rows substantially parallel to each other and substantially parallel to a length of the polymeric film. In this particular example, the cells are hemispherically shaped and have substantially the same diameter.  FIG. 3   a  shows a cross-sectional view of exemplary cellular cushioning article  20 . Top layer  26  is disposed on bottom layer  28  such that first cells  22  are formed between the layers. First cells  22  are discreet, substantially hemispherical cells having substantially the same diameter, and the cells are surrounded by land area  24 . The diameter of first cells  22  may be from about 0.20 to about 3 inches, preferably from about 1 to about 1.5. The land area between the first cells may be any distance relative to the diameter of the first cells, as long as the first cells nest as desired. Preferably, the diameter of first cells  22  may be from about 1 to about 1.5 inches with a land area between the first cells being from about 0.8 to about 2.5 inches. 
     It is to be understood that the cellular cushioning article disclosed herein may be formed in many different ways, and thus, the invention is not limited to articles constructed as shown in  FIG. 3   a . For example, the cellular cushioning article may comprise more than two layers, or the cells may not be formed from a layer of material. 
     Further, although first cells  22  are substantially hemispherical and have substantially the same diameter, the shapes and sizes of the first cells may be any shape or size, or combination of shapes and sizes, as long as two of the same articles can nest with each other. For example, the first cells may have hemispherical, oval, square, rectangular, triangular, hexagonal, polygonal or star shapes. For example,  FIG. 8  shows a plan view of an exemplary cellular cushioning article  95  comprising a polymeric film having a major surface, and first cells  96  protrude from the major surface, each cell being surrounded by land area  97 . First cells  96  have a rectangular shape and are arranged in rows substantially parallel to each other and substantially parallel to a length of the polymeric film. 
     In general, the cellular cushioning article of the invention can be characterized by the way in which the cells are arranged on a major surface of a polymeric film, in combination with the shapes and sizes of the cells. For two of the same cellular cushioning articles placed on top of one another, with the cells of each article facing each other, the cells “nest” with each other. Because of this nesting feature, the total thickness of the two nested articles can be less than the sum of the thicknesses for the two articles. 
       FIG. 3   b  shows a cross-sectional view of two exemplary cushioning articles  20  that are nested with each other to form stacked article  30 .  FIG. 3   c  shows the corresponding plan view of stacked article  30 , with cells  32  drawn in solid lines belonging to one of the articles  20 , and cells  34  drawn in dashed lines belonging to the other. 
     The cellular cushioning article of the invention may be perforated such that a long sheet of the article can be separated into shorter sheets.  FIG. 4   a  shows a plan view of exemplary cellular cushioning article  40  comprising first cells  41  protruding from a major surface of a polymeric film, each cell being surrounded by land area  42 . Article  40  is perforated across a width of the polymeric film as indicated by dashed lines  43 . 
     The first cells are generally arranged in a pattern, and the pattern may include periodic, repeating groups of cells as shown in  FIG. 4   b .  FIG. 4   b  shows a plan view of exemplary cushioning  45  comprising three groups of first cells  46   a - c  with corresponding land areas  47   a - c . Cellular cushioning article  45  comprises fold zones  49   a - b  each comprising a width of land area determined by measuring the distance between the first cells as shown in  FIG. 4   b  (the distance is measured substantially parallel to the rows). Fold zones  49   a - b  are free of first cells  46   a - c . In general, fold zones may be from about 0.15 to about 4.0 inches along the length of the polymeric film, and the fold zones may extend across a width of the polymeric film as shown in  FIG. 4   b . In general, fold zones separate first cells into groups. First cells  46   a - c  are arranged in groups that are substantially identical to each other. Cellular cushioning article  45  is perforated within the fold zones, across the width of the polymeric film, as shown by dashed lines  48 . 
       FIG. 5   a  shows a plan view of exemplary cushioning article  50  comprising first cells  51   a - b  arranged in identical groups (only portions of the groups are shown), with the first cells surrounded by land area  52   a - b . Fold zone  53  separates the groups of first cells. In this embodiment, cellular cushioning article has two edge zones  54   a - b  at each edge of the polymeric film. Fold zone  53  and edge zones  54   a - b  are free of first cells  52   a - b .  FIG. 5   b  shows a plan view of exemplary cushioning article  55  comprising cellular cushioning article  50  that is perforated across the width of the polymeric film as indicated by dashed line  56 . In general, edge zones have a width of about 1 inch or less. 
     The cellular cushioning article may comprise more than one type of cell projecting from the major surface of the polymeric film.  FIG. 6   a  shows a plan view of exemplary cushioning article  60  comprising first cells  61  and second cells  62 . Both first and second cells have substantially hemispherical shapes. The first cells have substantially the same diameter, and the second cells have substantially the same diameter, and the diameter of the second cells is less than that of the first. Second cells  62  are interspersed with first cells  61  in the rows comprising the first cells. Land area  63  is between the first and second cells. Cellular cushioning article  60  also comprises edge zones  64   a - b.    
     Anywhere from 1 to 10 cells smaller than the first cells may be grouped together to form second cells. Preferably, there are 3, 5 or 7 cells grouped together to form second cells.  FIG. 6   b  shows an embodiment in which cellular cushioning article  65  comprises first cells  66  and three small cells form second cells  67 . Land area  68  is between the first and second cells. Cellular cushioning article  65  also comprises edge zones  69   a - b.    
       FIG. 6   c  shows an embodiment in which cellular cushioning article  70  comprises first cells  71  and seven small cells form second cells  72 . Land area  73  is between the first and second cells. Cellular cushioning article  70  also comprises edge zones  74   a - b.    
     The cellular cushioning article may comprise a nestable pattern in which the second cells have the same diameter as the first cells, but have less height relative to the first cells. 
       FIG. 7   a  is a plan view of another embodiment of the cellular cushioning article disclosed herein. Cellular cushioning article  75  comprises first cells  76   a - b  and second cells  77   a - b  interspersed with the first cells as shown. The first and second cells are arranged in identical groups (only portions of the groups are shown), with the first and second cells surrounded by land area  78   a - b . Fold zone  79  separates the groups of first and second cells. In this embodiment, cellular cushioning article has two edge zones  81   a - b  at each edge of the polymeric film. Fold zone  79  and edge zones  81   a - b  are free of first cells  76   a - b . In this embodiment, fold zone  79  comprises third cells arranged in columns  80   a - b . The third cells may or may not be the same as the cells that form the second cells  77   a - b .  FIG. 7   b  shows a plan view of exemplary cushioning article  85  comprising cellular cushioning article  75  that is perforated across the width of the polymeric film as indicated by dashed line  86 . 
     The cellular cushioning article disclosed herein may comprise fourth cells disposed in rows in edge zones.  FIG. 7   c  shows a plan view of exemplary cushioning article  90  comprising cellular cushioning article  85  having rows of fourth cells  91   a - b  arranged in edge zones  81   a - b , respectively. The fourth cells may or may not be the same as the cells that form the second cells  77   a - b  or the third cells in columns  80   a - b.    
     The embodiment shown in  FIG. 7   c  can be described as follows: A cellular cushioning article comprising: a polymeric film comprising first cells projecting from a major surface of the polymeric film, each first cell being surrounded by land area, wherein the first cells are arranged in rows substantially parallel to each other and substantially parallel to a length of the polymeric film, such that for two opposing polymeric films with the major surfaces facing each other, the total thickness of the two opposing polymeric films is less than twice the thickness of one polymeric film; a plurality of fold zones comprising land area and being free of first cells, the fold zones being from about 0.15 to about 4.0 inches along the length of the polymeric film and extending across a width of the polymeric film, wherein the first cells are arranged in groups substantially identical to each other and separated from each other by a fold zone; two edge zones, each edge zone extending along an edge of the polymeric film and having a width of about 2 inches or less, the edge zones comprising land area and being free of first cells; and second cells projecting from the major surface, wherein the second cells are substantially hemispherical and have substantially the same diameter, the diameter of the second cells being less than that of the first, wherein the second cells are arranged in columns in the fold zones and rows in the edge zones, and the polymeric film is perforated in the fold zones across the width of the polymeric film. 
     The cellular cushioning article disclosed herein may be fan-folded into a stack with the major surfaces facing each other, and the stack is disposed in a box or a bag.  FIG. 9  is a cross-sectional view of cellular cushioning article  101  fan-folded to form stack  100 . The cellular cushioning article comprises first cells  102  with land area  103 . 
     EXAMPLES 
     A cushion wrap article or roll with a plurality of multi-size bubbles for cushioning, wherein the bubbles are arranged in a pattern to provide reduced volume when folded. The lower bubbles nest with the larger bubbles when folded. A fan-folded option and a machine direction fold option are described. An improved bubble pattern for edge and perforation zones to reduce loss of cushioning at the edges is described. 
     This example illustrates an exemplary cellular cushioning article fan-folded into a stack wherein the volume of the stack is at least 30% less than that of a stack formed from a standard cellular cushioning article. A standard 25 foot roll of ½″ size bubble cushion wrap ( FIG. 1  with first cells having a height of about ½ inch) was modified to allow nesting when fan-folded. The nesting pattern was achieved by deflating a bubble pattern in each sheet that allowed nesting when folded face to face. The cushion wrap was fan folded nesting the deflated bubble pattern with the inflated bubble pattern on the opposite sheet. The resulting fan-folded stacked sheets occupied significantly less space then a standard 25 foot roll of ½″ bubble cushion wrap. The height of the fan-folded stack was 6½″ for the nestable pattern vs. 10½″ for the standard ½″ bubble cushion wrap. The nestable fan-folded sample had 38% less volume than the standard ½″ bubble fan-folded. 
     A 100 foot roll of standard 3/16″ bubble cushion wrap was fan-folded and placed in a box (12½″×12½″×12½″). Currently a standard 100 foot roll of 3/16″ cushion wrap is sold in a boxed configuration (roll placed inside a 15″×12⅜″×13½″ box). The fan-folded cushion wrap in a box is ˜22% smaller than the current roll in a box. 
     Several box designs were evaluated for dispensing performance of the fan-folded cushion wrap. A larger slot width performed better for the larger ½″ size bubble. This allows the folded sheet to more easily be pulled out when the box is full. 
     The smaller 3/16″ bubble was also evaluated for dispensability in a 2′ and 8″ width slot. Both slot widths dispensed the smaller bubble size although the 8″ width was preferred when the box was full. 
     A length of standard ½″ size Bubble Wrap® (from Sealed Air Corp.) was also modified to allow nesting, when folded length-wise, with the bubbles facing each other. The nesting pattern was achieved by deflating bubbles. The folded length of nested cushioning article was rolled up. The resulting folded roll was significantly smaller than the same length roll of standard ½″ cushion wrap. 
     Improved edge and perforation protection is illustrated by the following example. Current cushion wrap, in particular larger size bubbles such as ½″ bubble, damages or deflates bubbles with the perforation and slitting process. The perforation process currently deflates approximately 1 row every 11 rows of bubbles for ½″ bubble cushion wrap. In addition, the slitting process to convert wide master rolls to a 12″ width roll will deflate approximately ½ to 1 row of bubbles on each side. A further improvement to the cushion wrap would incorporate a unique bubble pattern to minimize the amount of deflated bubbles that currently occur during the perforation and slitting process by including a smaller size bubble pattern at the perforation and slitting locations. An example of this bubble pattern is in  FIG. 7   c.