Abstract:
A process for packing flexible articles in a flexible bag ( 10 ) wherein said flexible bag ( 10 ) is sealed at its top panel ( 11 ) after introduction of said flexible articles leaving attached at least one flap ( 12 ) protruding from said top panel ( 11 ) of said flexible bag ( 10 ), said flap ( 12 ) comprises a grip area ( 14 ) and a grip area perimeter ( 15 ), characterized in that said flexible bag ( 10 ) is pre-made before said introduction of said flexible articles through an area corresponding to said top panel ( 11 ), a handle element ( 13 ) is shaped from said flap ( 12 ), said handle element ( 13 ) comprising a handle element perimeter ( 16 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a process for packing absorbent articles in a pre-made flexible bag and subsequently creating a handle element on-line.  
         DESCRIPTION OF THE PRIOR ART  
         [0002]    Flexible bags are widely used to pack many different types of consumer products. For instance, disposable diapers are typically packed in plastic bags. The resultant bags are generally cumbersome and difficult to carry. In order to facilitate consumer handling, handle elements are disposed on the outer surface of the flexible bags. It has been customary to provide separate handle elements of cardboard, moulded plastic or other suitable materials that are glued, stapled or heat welded to the bag. U.S. Pat. No. 4,252,269 teaches a bag of polymeric plastic material that has an opening at one end and a gusset at the opposite end. Within the gusset, a handle is welded to the front and rear panels of the bag along a fold line. In U.S. Pat. No. 4,539,705, the handle strip is inserted in the gusset during production of the bag and the ends of the handle strip are sealed to the adjacent wall panels of the bag by a heat seal. U.S. Pat. No. 5,054,619 refers to an easy open flexible bag containing one or more stacks of flexible articles that comprises a longitudinally oriented carrying handle, which is formed independently of the bag. These handle elements are not entirely satisfactory for all purposes and are often impractical in terms of material utilisation, wastage of raw materials, complexity of process steps, stacking and packaging, and effectiveness in that the handle element can tear away from the carrier bag and expose the contents.  
           [0003]    Nevertheless, some bags have been specifically designed with integral handle elements. U.S. Pat. No. 5,026,173 describes a plastic bag having a side panel with a carry grip area in which a carry strip portion is located. The carry strip portion is formed between carry grip apertures or easily breakable weakening lines. The carry strip is coplanar with the side panel of the plastic bag and does not require seals of any kind. Protective and reinforcement strips are provided underneath the carry grip apertures in order to protect the contents of the plastic bag from external contamination. GB 1 575 921 teaches a bag provided with a carrier handle means where the handle is not located in loose flap members protruding from a sealed top panel, but in a flap participating in the wrapping of the articles. The products are first packaged in the bag, the flap portion is then folded over the top side of the products and thereafter the other flap portion is folded down along the vertical side of the bag and adhesively attached to this side. U.S. Pat. No. 4,913,693 provides a bag that includes a side-to-side continuous handle, which is formed from pieces of material that make up the sidewalls of the bag and a closed top formed from a separate piece of material. DE 2 051 833 describes a means of producing a package for hygienic articles comprising two strips of plastic, one wider than the other. The preferred production method consists of first forming a tube around the articles to be packed, then welding transversely to separate the tubes or packages while at the same time cutting the packages successively from one another. The resultant package may contain a handle and a tear-off opening. The handle lies between the welding seam used to seal the package shut and an additional seam, which is present for stability purposes.  
           [0004]    The above prior art, however, does not teach a process for packing absorbent articles in a pre-made flexible bag by introducing the absorbent articles through an area corresponding to the top panel of the bag and by subsequently creating a handle element on-line from the excess trim material protruding from the top panel. Excess trim material is usually included in a bag design to account for variations in the height of the products to be packed and to allow for sealing variations. The exploitation of this excess trim material according to the present invention leads to such benefits as excellent material utilisation and a reduction in raw material wastage. The advantage of the pre-made bag lies in the flexibility that it offers to both suppliers, packagers and manufacturers. There is no tying effect and therefore no need exists for the combination of an on-line packaging and bag manufacturing step as described in the prior art document DE 2 051 833. The complexity of the manufacturing phase is thus greatly reduced. Furthermore, with the aid of suitable reinforcements and effective sealing techniques, a strong handle element mounting can be formed which results in improved consumer confidence.  
         OBJECT AND SUMMARY OF THE INVENTION  
         [0005]    It is an object of the present invention to provide a process for packing absorbent articles in a pre-made flexible bag by introducing the absorbent articles through an area corresponding to the top panel of the bag and by subsequently creating a handle element on-line from the excess trim material protruding from the top panel. A further object of the present invention is to provide a strong handle element mounting using suitable reinforcements and effective sealing techniques.  
           [0006]    In accordance with the objects of the invention, a pre-made flexible bag for flexible articles is provided. Flexible articles are introduced into the flexible bag through an area corresponding to the top panel, which is subsequently sealed at its top panel. At least one flap protruding from the top panel is left attached. The flap comprises a grip area and a grip area perimeter. The flexible bag is pre-made before the introduction of the flexible articles and a handle element is shaped from the flap protruding from the top panel, the handle element comprising a handle element perimeter. The preferred embodiment comprises two flaps. The handle element comprises a seal running along the handle element perimeter. In order to allow fingers or hands to wrap around the handle, a grip area is formed. The reinforced handle element can comprise flaps that are sealed together in the entire area of the handle element except for the grip area or the flaps are further reinforced at the handle element perimeter or the flaps comprise a seal surrounding the grip area perimeter or the flaps comprise a seal abutting the entire grip area perimeter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    While the specification concludes with claims particularly pointing out and distinctly claiming the invention, it is believed that the invention will be better understood from the foregoing description in conjunction with the accompanying drawings in which:  
         [0008]    [0008]FIG. 1 is a front view of a pre-made flexible bag comprising a handle element made on-line.  
         [0009]    [0009]FIG. 2 is a front view of the various design configurations existing for the handle element of the pre-made flexible bag.  
         [0010]    [0010]FIG. 3 shows six different embodiments of sealing design configurations that are suitable for the handle element of the pre-made flexible bag. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]    As used herein, the term “pre-made” refers to a bag in which the front, back, top, bottom and side panels are all interconnected. As used herein, the term “grip area” describes the area designed for gripping that is either cut, punched or scored out. As used herein, the term “grip area perimeter” represents the edge of the grip area. As used herein, the term “handle element perimeter” represents the edge of the handle element.  
         [0012]    [0012]FIG. 1 shows a pre-made flexible bag  10  comprising flexible articles. The flexible articles may comprise disposable absorbent diapers, sanitary articles, incontinence pads or briefs, bandages and the like. The flexible articles are typically compressed to between 20 and 70 percent of their uncompressed volume and may be oriented either with all their waist features directed upwards towards the top panel  11  of the flexible bag  10  or with all their waist features directed downwards towards the bottom panel of the flexible bag  10  or the flexible articles may be alternated. The flexible bag  10  is preferably made from conventional flexible polymer such as polyethylene or oriented polypropylene and the film caliper ranges from 30 to 120 micrometers. The flexible bag  10  comprises a top panel  11 , a bottom panel, a front panel, a back panel and a pair of side panels, which are all interconnected according to means known in the art.  
         [0013]    Typically, the pre-made flexible bag  10  to be used for containing the flexible articles is supplied either on wickets or on rolls, wickets being preferred. The flexible bag  10  is sealed at its top panel  11  after introduction of the flexible articles, leaving attached at least one flap  12 , which protrudes from the top panel  11  of the flexible bag  10 . The preferred embodiment comprises two flaps  12 . These flaps  12  represent excess trim material. A handle element  13  is then shaped from the flaps  12 , and comprises a handle element perimeter  16 . The handle element  13  can combine both curved and straight portions as is depicted in FIG. 2. Furthermore, the base of the handle element  13  can lie along a portion of the top panel  11  as is visible in embodiments (1), (2) and (4) of FIG. 2 or the base of the handle element  13  can run along the entire length of the top panel  11  as is visible in embodiment (3) of FIG. 2. The formation of the handle element  13  is preferentially carried out during or shortly after the top panel  11  has been sealed. The key features of the handle element  13  are the grip area  14 , the grip area perimeter  15  and the handle element perimeter  16 . The grip area  14  can be formed on-line by either cutting, punching or scoring out the desired shape, which is suitable for gripping by the end user, namely the consumer. Alternatively, grip holes can be cut, punched or scored out of the flaps  12 . Several grip holes, preferably three or four, may be present and they can also be pre-made at the bag suppliers. The grip area perimeter  15  and the handle element perimeter  16  follow the contours of the selected shapes for the grip area  14  and the handle element  13 , respectively.  
         [0014]    Various sealing embodiments exist in order to reinforce the handle element  13  and support the weight of the flexible bag  10 . With a film caliper ranging from 50 to 70 micrometers, the handle element  13  is capable of sustaining bag loads ranging from 2.5 to 4 kilograms without causing deformation or failure when being carried by the end user, namely the consumer. It is preferred that the base of the handle element  13  run along the entire length of the top panel  11  (for example, refer to embodiment (3) in FIG. 2) such that the handle element  13  can better support the bag load and lead to improved stability.  
         [0015]    [0015]FIG. 3 shows six different embodiments of sealing design configurations that are suitable for the handle element  13 . For each of the embodiments described below, the base of the handle element  13  comprises a seal  17 , which is either the complete seal  17  or a portion of the seal  17  arising from the closure of the top panel  11  of the flexible bag  10 . In the first embodiment, a seal  17  runs along the handle element perimeter  16 . In the second embodiment, the flaps  12  are sealed together in the entire area of the handle element  13  except for the grip area  14 . In the third embodiment, the flaps  12  are further reinforced a the handle element perimeter  16 . In fact, the third embodiment comprises the first embodiment and further comprises seals  17  that are located in the corners lying closest to the seal  17  of the base of the handle element  13  and the seal  17  running along the side of the handle element perimeter  16 . It is feasible to place approximately one to three seals  17  per corner, the form of the seals  17  being either straight or curved. The fourth embodiment comprises the first embodiment plus a seal  17  surrounding the grip area perimeter  15 . The seal  17  is preferably located a distance ranging from 5 to 25 millimeters from the grip area perimeter  15  and typically the seal  17  follows the contours of the shape selected for the grip area  14 . The fifth embodiment similarly comprises the first embodiment plus a seal  17  abutting the entire grip area perimeter  15 . The sixth embodiment, similar to the third embodiment, further comprises reinforcements at the handle element perimeter  16 . More specifically, the sixth embodiment comprises both the first and fifth embodiments plus diagonal seals  17  that extend from a location on the seal  17  running along the outermost part of the handle element perimeter  16  to a location on the seal  17  of the base of the handle element  13 . The seals  17  in all cases preferably range from three to four millimeters in width although any width is possible.  
         [0016]    The sealing can be performed using conventional heat sealing techniques or alternatively, techniques such as ultrasound, crimping or pressure bonding can be employed. Heat sealing techniques tend to weaken the flaps  12  in the immediate vicinity of the sealed area due to the concentration of heat along the seal  17 . In contrast, the other techniques rely less on heat and more on pressure and thus do not weaken adversely the flaps  12 . It is also possible to vary the sealing pattern. Rather than having a single line comprising the sealing pattern, which is typical of the current heat sealing techniques, a pattern with alternating bonded zones and unbonded zones can be formed. The sealing pattern can comprise crosses, dashed lines, v-shapes, u-shapes, inverted shapes, to cite but a few of the many possibilities existing. The effect of the pattern results in an improved distribution of heat over a wider area and consequently, a stronger supporting film around the seals  17 .