Patent Publication Number: US-2009232425-A1

Title: Flexible Tubular Packaging Bag and Method and Apparatus for Making the Same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Application No. 097109315, filed on Mar. 17, 2008. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a flexible tubular packaging bag, more particularly to a flexible tubular packaging bag for sanitary products and a method and apparatus for making the same. 
     2. Description of the Related Art 
     Referring to  FIGS. 1 to 3 , a conventional flexible tubular packaging bag  1  for sanitary products is made by preparing a bag body  11  which is in the form of a flat sheet and which has an access opening  111 . Left and right sides of the bag body  11  are folded toward each other, as shown by the arrows in  FIG. 2 , through a folding device (not shown), and are sealed together through a sealing device (not shown) so as to form a tubular body  11 ′ having a sealing portion  112  that extends from a front end  114  to a rear end  113  thereof. Subsequently, the rear end  113  of the tubular body  11 ′ is sealed, the sanitary products (not shown) are disposed inside the tubular body  11 ′ through the front end  114  thereof, and the front end  114  is sealed. A resealable flap  12  is then adhered manually to the tubular body  11 ′ so as to close openably the access opening  111 . 
     In use, the resealable flap  12  is pulled open at one side so as to reveal the access opening  111 , and one of the sanitary products can be taken out from the tubular packaging bag  1 . The resealable flap  12  is resealed so as to close the access opening  111 , thereby preventing contamination of the remaining sanitary products in the tubular packaging bag  1 . Since the folding device is needed to fold the left and right sides of the flat sheet of the bag body  11  during manufacture of the tubular packaging bag  1 , the method for making the conventional flexible tubular packaging bag  1  is complicated. Further, the adhering operation of the resealable flap  12  is done manually, so that the production of the conventional tubular packaging bag  1  is not only slow, but the cost thereof is also increased. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of the present invention is to provide a method for making a flexible tubular packaging bag that has a resealable flap which can be adhered automatically to the flexible tubular packaging bag. 
     Another object of the present invention is to provide a system for making a flexible tubular packaging bag that has a resealable flap which can be adhered automatically to the flexible tubular packaging bag. 
     Still another object of the present invention is to provide a flexible tubular packaging bag having a resealable flap which can be adhered automatically to the flexible tubular packaging bag. 
     According to one aspect of this invention, an individual flexible tubular packaging bag for sanitary products comprises a flexible bag body and a resealable flap. The flexible bag body is made from a flexible seamless tubular body of a heat-weldable material by heat-sealing two opposite ends of the seamless tubular body. The flexible bag body defines a receiving space that is adapted to receive the sanitary products, and has an access opening in spatial communication with the receiving space. The resealable flap is connected to the flexible bag body, and seals openably the access opening. 
     According to another aspect of this invention, a method for making flexible tubular packaging bags for sanitary products comprises the steps of: (A) providing a strip of a flexible seamless tubular body of a heat-weldable material, the strip of the flexible seamless tubular body having a plurality of access openings spaced apart from each other and aligned along the length of the strip; (B) sealing openably and respectively the access openings with resealable flaps; (C) heat-sealing the seamless tubular body at a position between two adjacent ones of the resealable flaps so as to form a sealing portion therebetween; and (D) cutting the seamless tubular body along a cutting line between each two adjacent ones of the resealable flaps, thereby obtaining semi-finished individual flexible bag bodies, each of which has an open end, and a sealed end opposite to the open end and defined by the sealing portion. 
     According to still another aspect of this invention, a system for making flexible tubular packaging bags for sanitary products comprises a supplying roller, a conveying device, a label-adhering device, a sealing device, and a cutting device. The supplying roller holds a strip of a flexible seamless tubular body of a heat-weldable material. The strip of the flexible seamless tubular body has a plurality of access openings spaced apart from each other and aligned along the length of the strip. The conveying device is used to convey the strip of the seamless tubular body supplied by the supplying roller. The label-adhering device includes a roll of resealable flaps, and affixes each of the resealable flaps over a respective one of the access openings so as to seal openably the respective one of the access openings. The sealing device is disposed downstream of the label-adhering device, and heat-seals the strip of the seamless tubular body at a position between two adjacent ones of the resealable flaps so as to form a sealing portion therebetween. The cutting device is disposed downstream of the sealing device, and cuts the strip of the seamless tubular body along a cutting line between each two adjacent ones of the resealable flaps so as to form semi-finished individual flexible bag bodies, each of the which has an open end, and a sealed end opposite to the open end and defined by the sealing portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a conventional flexible tubular packaging bag; 
         FIG. 2  is a perspective view of a bag body used in the making of the conventional flexible tubular packaging bag; 
         FIG. 3  is another perspective view of the conventional flexible tubular packaging bag; 
         FIG. 4  is a perspective view of a flexible tubular packaging bag according to the preferred embodiment of the present invention; 
         FIG. 5  is a view similar to  FIG. 4 , but illustrating a resealable flap being pulled open to reveal an access opening; 
         FIG. 6  is another perspective view of the flexible tubular packaging bag of the present invention; 
         FIG. 7  is a flowchart, illustrating the steps involved in making the flexible tubular packaging bag of the present invention; 
         FIG. 8  is a schematic view of a system for making the flexible tubular packaging bag of the present invention; 
         FIG. 9  is a fragmentary schematic view of the preferred embodiment, illustrating a supplying roller supplying a strip of a flexible seamless tubular body; 
         FIG. 10  is a sectional view of the seamless tubular body; 
         FIG. 11  is a fragmentary schematic view of the preferred embodiment, illustrating how a resealable flap is attached to the seamless tubular body by a label-adhering device; 
         FIG. 12  is a fragmentary schematic view of the preferred embodiment, illustrating a punching device punching vent holes in the seamless tubular body; and 
         FIG. 13  is a fragmentary schematic view of the preferred embodiment, illustrating how a semi-finished individual flexible bag body is obtained. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 4 to 6 , an individual flexible tubular packaging bag  2  according to the preferred embodiment of the present invention is shown to comprise a flexible bag body  21  and a resealable flap  22 . In this embodiment, the tubular packaging bag  2  is adapted to contain sanitary products  5 , such as sanitary napkins, panty shields, or diapers, and may be made of plastic or aluminum foil. 
     The flexible bag body  21  is made from a flexible seamless tubular body  20  (see  FIG. 9 ) of a heat-weldable material by heat-sealing predetermined portions of the seamless tubular body  20 . The flexible bag body  21  defines a receiving space  211  that is adapted to receive the sanitary products  5 , and has an access opening  213  formed in a top face thereof and in spatial communication with the receiving space  211 , and two sealed ends  214  sealing opposite front and rear ends of the bag body  21 . 
     The resealable flap  22  is connected to the top face of the bag body  21 , and has an area larger than that of the access opening  213  so as to seal openably the same. The resealable flap  22  includes an adhesive portion  221  formed on a bottom side thereof and adhered to the top face of the bag body  21 , a pull tab  222  projecting forwardly from a front side of the resealable flap  22 , and two spaced-apart curved slits  223  proximate to a rear end thereof to define respectively two retaining portions  224 . The bag body  21  further includes two spaced-apart vent holes  215  proximate to the rear edge of the resealable flap  22  and in fluid communication with the receiving space  211 . The vent holes  215  permit communication between the receiving space  211  and the surrounding air. 
     To use the tubular packaging bag  2 , the resealable flap  22  is pulled upwardly and rearwardly through the pull tab  222  so as to expose the access opening  213 , thereby permitting access into the receiving space  211  and to the sanitary products  5 . The resealable flap  22  is prevented from separating from the bag body  21  through the retaining portions  224 , and is resealed to the bag body  21  after use so as to seal the access opening  213 , thereby preventing damping and contamination of the sanitary products  5  inside the receiving space  211 . 
       FIG. 7  illustrates a flowchart of a method for making the flexible tubular packaging bag  2  of the preferred embodiment. The method includes steps A to D.  FIG. 8  illustrates a system for making the flexible tubular packaging bag  2  of the preferred embodiment. The system includes a supplying roller  31 , a conveying device  32 , a label-adhering device  33 , a detector  34 , a punching device  35 , an image-forming device  36 , a sealing device  37 , and a cutting device  38 . 
     With reference to  FIG. 7 , in combination with  FIG. 8  and  FIGS. 9 to 13 , in step A, a strip of the flexible seamless tubular body  20  of a heat-weldable material is supplied by the supplying roller  31 . The strip of the seamless tubular body  20  has a plurality of the access openings  213  spaced apart from each other and aligned along the length of the strip. The strip of the seamless tubular body  20  is conveyed along a feed direction (I) by the conveying device  32 , which includes a plurality of spaced-apart pairs of feed rollers  321 . 
     Step B is carried out in cooperation with the label-adhering device  33  which is disposed downstream of the supplying roller  31 . The label-adhering device  33  includes a label-feeding wheel  331  for holding a roll of the resealable flaps  22 , and a label-applicator  332  disposed below the label-feeding wheel  331  and above the strip of the seamless tubular body  20 . Each resealable flap  22  is structured as described above with reference to  FIGS. 4 to 6 . The label-applicator  332  receives the resealable flaps  22  fed by the label-feeding wheel  331 , and affixes each of the resealable flaps  22  over a respective one of the access openings  213  when the strip of the seamless tubular body  20  is conveyed through the label-applicator  332  so as to seal openably the respective access opening  213 . 
     The detector  34  is disposed rearwardly of the label-adhering device  33  and two pairs of the feed rollers  321 . In this embodiment, the detector  34  employs an optical measurement method to detect a position of an adjacent one of the resealable flaps  22  passing therethrough and obtain a corresponding “detected value”. The detector  34  transmits the detected value to the punching device  35 , which is disposed downstream of the detector  34 , so as to effect punching of the strip of the seamless tubular body  20  with two spaced-apart vent holes  215  between each two adjacent ones of the resealable flaps  22  when the strip of the seamless tubular body  20  passes therethrough. Preferably, the vent holes  215  are provided proximate to the rear end of the corresponding resealable flap  22 . The detected value of the detector  34  is also transmitted to the image-forming device  36 , which is disposed downstream of the punching device  35 , so as to effect pressing of the top face of the corresponding resealable flap  22  and forming a letter, a number, or a pattern on the top face thereof when the seamless tubular body  20  passes therethrough. Air inside the seamless tubular body  20  is driven out via the vent holes  215  when the image-forming device  36  presses the corresponding resealable flap  22  so as to prevent bulging inside the seamless tubular body  20 . 
     Step C is carried out in cooperation with the sealing device  37  which is disposed downstream of the image-forming device  36  and one pair of the feed rollers  321 . The sealing device  37  has a heat knife  371  for heat-sealing the strip of the seamless tubular body  20  at a position between two adjacent ones of the resealable flaps  22  so as to form a sealing portion therebetween when the strip of the seamless tubular body  20  passes through the sealing device  37 . 
     Step D is carried out in cooperation with the cutting device  38  which is disposed downstream of the sealing device  37 . The cutting device  38  has a cutter  381  for cutting the strip of the seamless tubular body  20  along a cutting line between each two adjacent ones of the resealable flaps  22  when the seamless tubular body  20  passes through the cutting device  38 , thereby obtaining semi-finished individual flexible bag bodies  21 ′. Each of the flexible bag bodies  21 ′ has an open end  216 , and a sealed end  214  opposite to the open end  216  and defined by the sealing portion. Each flexible bag body  21 ′ is then sent to an operating device (not shown), where the sanitary products  5  (see  FIG. 4 ) can be disposed inside the flexible bag body  21 ′ via the open end  216 . Finally, the open end  216  is sealed through another sealing device (not shown) so as to form another sealed end  214 ′ (see  FIG. 4 ) which is opposite to the sealed end  214 , thereby forming the individual flexible tubular packaging bag  2  of the present invention. 
     Since the flexible bag body  21  is made from the flexible seamless tubular body  20 , in comparison with the making of the conventional flexible tubular packaging bag  1  (see  FIG. 1 ), there is no need to fold and seal together left and right sides of the seamless tubular body  20  so as to form the sealing portion  112  (see  FIG. 3 ), so that the method for making the flexible tubular packaging bag  2  of the present invention is simple. Further, through the presence of the label-adhering device  33 , the resealable flaps  22  can be adhered to the flexible bag body  21  through a fast and automatic process, thereby minimizing the production time and cost of the present invention. 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.