Patent Publication Number: US-2023133660-A1

Title: Film processing device, bag manufacturing device, method for processing film, and method for manufacturing bag

Description:
TECHNICAL FIELD 
     The present invention relates to a film processing device, a bag manufacturing device, a method for processing a film, and a method for manufacturing a bag. 
     BACKGROUND ART 
     A technique for forming a tab for unsealing a bag has been known. For example, Patent Literature 1 discloses a technique in which a cutting device that forms a tab in a film of a bag base material includes, in addition to a cutting blade and a receiver base, a spacer member that is disposed between a first film and a second film. This prevents, when forming a tab in the first film, the tab from being extended to the second film due to passing through of the cutting blade and reliably forms a so-called half-cut. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 2018-176437 A 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, since the cutting blade in the technique described in Patent Literature 1 comes into contact with the spacer member, the cutting blade is easily worn. Further, processing includes many steps and is complicated. Furthermore, in order to interpose the spacer member between films, a cut for a tab is required to be formed prior to forming a seal region around the tab. Thus, the cut may be fusion-bonded due to heat of heat sealing during forming the seal region. 
     Accordingly, an object of the invention is to provide a film processing device, a bag manufacturing device, a method for processing a film, and a method for manufacturing a bag, which are able to reduce abrasion of a cutting blade when forming a half-cut in a film and to improve manufacturing efficiency by simplifying steps of processing. 
     Means for Solving the Problems 
     
         
         
           
             [1] A film processing device including: a first cutting blade and a first receiver base that are opposed to each other with a film including at least two layers interposed therebetween, and are configured to move toward and away from each other; and a first distance adjuster that adjusts, without being in contact with the film, a minimum distance between the first cutting blade and the first receiver base. 
             [2] The film processing device according to [1], further including: a second cutting blade and a second receiver base that are opposed to each other with the film interposed therebetween at a position that is different from a position where the first cutting blade and the first receiver base face each other, and are configured to move toward and away from each other; and a second distance adjuster that adjusts, without being in contact with the film, a minimum distance between the second cutting blade and the second receiver base, in which the second cutting blade and the second receiver base are arranged invertedly from the first cutting blade and the first receiver base with respect to the film. 
             [3] The film processing device according to [2], in which, when the first cutting blade and the first receiver base have moved toward each other to a minimum distance and the second cutting blade and the second receiver base have moved toward each other to a minimum distance, the first cutting blade and the second cutting blade overlap with each other in a thickness direction of the film. 
             [4] The film processing device according to [3], in which the film has a first surface and a second surface that are overlapped with each other, with a tearing strip and a base strip of a zipper tape interposed between the first surface and the second surface, the minimum distance between the first cutting blade and the first receiver base is adjusted in such a manner as to cut the first surface, the tearing strip, and the base strip, and not to cut the second surface, and the minimum distance between the second cutting blade and the second receiver base is adjusted in such a manner as to cut the second surface and the base strip, and not to cut the first surface and the tearing strip. 
             [5] The film processing device according to [4], in which the film further has a third surface and a fourth surface that are folded in between the first surface and the second surface, the tearing strip and the base strip are interposed between the first surface and the third surface, the minimum distance between the first cutting blade and the first receiver base is adjusted in such a manner as to cut the first surface, the tearing strip, the base strip, and the third surface, and not to cut the fourth surface and the second surface, and the minimum distance between the second cutting blade and the second receiver base is adjusted in such a manner as to cut the second surface, the fourth surface, the third surface, and the base strip, and not to cut the first surface and the tearing strip. 
             [6] The film processing device according to any one of [2] to [5], in which the first cutting blade and the second receiver base are attached to a common drive mechanism that is included in the first distance adjuster and in the second distance adjuster, and the first receiver base and the second cutting blade are supported by a table that is included in the first distance adjuster and in the second distance adjuster, the table being on an opposite side of the drive mechanism with the film interposed therebetween. 
             [7] A bag manufacturing device including the film processing device according to any one of [1] to [6], the bag manufacturing device further including a sealing device that forms a seal portion having a surrounding shape where the film is sealed, in a portion of the bag, in which the first cutting blade and the first receiver base form a tab in a region surrounded by the seal portion. 
             [8] A bag manufacturing device including the film processing device according to [5], the bag manufacturing device further including a sealing device that forms a seal portion where the first surface and the third surface are sealed to each other, in a portion of the bag, in which the first cutting blade and the first receiver base form a tab in the seal portion. 
             [9] A method for processing a film, the method including forming a first cut in a film including at least two layers by using a first cutting blade and a first receiver base, the first cutting blade and the first receiver base being opposed to each other with the film interposed therebetween, in which a minimum distance between the first cutting blade and the first receiver base is adjusted by a first distance adjuster which is not in contact with the film. 
             [10] The method for processing the film according to [9], further including forming a second cut in the film from a side opposite to the first cut by using a second cutting blade and a second receiver base, the second cutting blade and the second receiver base being opposed to each other with the film interposed therebetween at a position that is different from a position where the first cutting blade and the first receiver base face each other, in which a minimum distance between the second cutting blade and the second receiver base is adjusted by a second distance adjuster which is not in contact with the film. 
             [11] The method for processing the film according to [10], in which the first cut and the second cut overlap with each other in a thickness direction of the film. 
             [12] The method for processing the film according to [11], in which the film has a first surface and a second surface that are overlapped with each other, with a tearing strip and a base strip of a zipper tape interposed between the first surface and the second surface, the first cut is formed in the first surface, the tearing strip, and the base strip, and is not formed in the second surface, and the second cut is formed in the second surface and the base strip, and is not formed in the first surface and the tearing strip. 
             [13] The method for processing the film according to [12], in which the film further has a third surface and a fourth surface that are folded in between the first surface and the second surface, the tearing strip and the base strip are interposed between the first surface and the third surface, the first cut is formed in the first surface, the tearing strip, the base strip, and the third surface, and is not formed in the fourth surface and the second surface, and the second cut is formed in the second surface, the fourth surface, the third surface, and the base strip, and is not formed in the first surface and the tearing strip. 
             [14] The method for processing the film according to any one of [10] to [13], in which the first cutting blade and the second receiver base are attached to a common drive mechanism that is included in the first distance adjuster and in the second distance adjuster, and the first cut and the second cut are formed by reciprocating motion of the common drive mechanism. 
             [15] A method for manufacturing a bag including the steps of the method for processing the film according to any one of [9] to [14], the method for manufacturing the bag further including: forming a tab by means of the first cut in the bag; and forming a seal portion where the film is sealed in a region surrounding the tab. 
             [16 ] A method for manufacturing a bag including the steps of the method for processing the film according to [13], the method for manufacturing the bag further including forming a seal portion where the first surface and the third surface are sealed in a portion of the bag, in which a tab is formed by means of the first cut in the seal portion. 
           
         
       
    
     According to the above-described configurations, the minimum distance between the cutting blade and the receiver base is adjusted by the distance adjuster that is not in contact with the film. This makes it possible to reduce abrasion of the cutting blade when forming a half-cut in the film and to improve manufacturing efficiency by simplifying steps of processing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram illustrating a schematic configuration of a film processing device according to a first exemplary embodiment of the invention. 
         FIG.  2    is an arrow view taken along a line II-II of  FIG.  1   . 
         FIG.  3    is a partial plan view of a bag to be manufactured using a film which has been processed in the first exemplary embodiment of the invention. 
         FIG.  4    is a cross-sectional view taken along a line IV-IV of  FIG.  3   . 
         FIG.  5    is a diagram illustrating a schematic configuration of a film processing device according to a second exemplary embodiment of the invention. 
         FIG.  6    is a partial cross-sectional view of a bag to be manufactured using a film which has been processed in the second exemplary embodiment of the invention. 
         FIG.  7    is a diagram illustrating a schematic configuration of a film processing device according to a third exemplary embodiment of the invention. 
         FIG.  8    is a partial cross-sectional view of a bag to be manufactured using a film which has been processed in the third exemplary embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENT(S) 
     The following describes preferred exemplary embodiments of the invention in detail with reference to the accompanying drawings. It is to be noted that, in the specification and the accompanying drawings, components that have substantially the same functional configuration are indicated by the same codes, and thus redundant description thereof is omitted. 
     First Exemplary Embodiment 
       FIG.  1    is a diagram illustrating a schematic configuration of a film processing device according to a first exemplary embodiment of the invention.  FIG.  2    is an arrow view taken along a line II-II of  FIG.  1   . In the illustrated example, a processing device  1 A includes: a cutting blade  3 A and a receiver base  4 A opposed to each other with a film  2  interposed therebetween; a drive mechanism  5  to which the cutting blade  3 A is attached via a holder  51 ; an arm  6  that supports the drive mechanism  5 ; a post  7  that supports the support arm  6 ; and a table  8  that supports the post  7  and the receiver base  4 A. The cutting blade  3 A and the receiver base  4 A move toward and away from each other by reciprocating motion of the drive mechanism  5  within a predetermined range of movement in a vertical direction with the arm  6  as a fulcrum. 
     Here, a minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A, i.e., a distance between a tip of the cutting blade  3 A and a surface of the receiver base  4 A when the cutting blade  3 A is closest to the receiver base  4 A, is variable by means of a shim  52  interposed between the cutting blade  3 A and the holder  51 . That is, in the exemplary embodiment, the drive mechanism  5  including the holder  51  and the shim  52 , the arm  6 , the post  7 , and the table  8  configure a distance adjuster that adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A. As illustrated in  FIG.  2   , the distance adjuster is C-shaped in cross section as a whole, and thus is not in contact with the film  2 . 
     In the exemplary embodiment, the film  2  has two surfaces  2 A and  2 B that are overlapped with each other, with a tearing strip  21  and a base strip  22  of a zipper tape interposed between the surfaces  2 A and  2 B. The processing device  1 A adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A in such a manner as to cut the surface  2 A, the tearing strip  21 , and the base strip  22 , and not to cut the surface  2 B. Specifically, the minimum distance d 1  corresponds to a thickness of the surface  2 B. This allows the processing device  1 A to form a cut (half-cut) that is obtained by cutting only some of the layers of a multi-layer structure in which the film  2 , the tearing strip  21 , and the base strip  22  are overlapped with each other. 
       FIG.  3    is a partial plan view of a bag to be manufactured using a film which has been processed in the first exemplary embodiment of the invention.  FIG.  4    is a cross-sectional view taken along a line IV-IV of  FIG.  3   . A cross-sectional direction of  FIG.  4    is the same as that of  FIG.  1   ; however,  FIG.  4    illustrates an unbonded portion as a space. In the illustrated example, a sealing device which is provided separately from the processing device  1 A seals the surfaces  2 A and  2 B of the film  2  to each other at a side seal portion  23  and a surrounding seal portion  24 . As illustrated in the figure, a portion of the side seal portion  23  and the surrounding seal portion  24  form a seal portion having a surrounding shape. The processing device  1 A forms a tab by means of a cut  25 A in a region surrounded by the side seal portion  23  and the surrounding seal portion  24 . In this case, either the forming of the side seal portion  23  and the surrounding seal portion  24  or the forming of the tab by means of the cut  25 A may be performed first; however, it is preferable that the forming of the seal portions be performed first in order to prevent fusion-bonding of the cut due to heat of heat sealing, as described below. 
     As illustrated in (a) of  FIG.  4   , the cut  25 A passes through the surface  2 A, the tearing strip  21 , and the base strip  22 . Thus, as illustrated in (b) of  FIG.  4   , a user is able to lift the above-described three layers from a surface  2 A side using the tab formed by means of the cut  25 A as a starting point. When the user holds and pulls the tab, as illustrated in (c) of  FIG.  4   , the base strip  22  breaks at the surrounding seal portion  24 , and only the surface  2 A is torn along the tearing strip  21 , thereby unsealing the bag. Such a bag is described in, for example, Japanese Unexamined Patent Application Publication No. 2019-051963, and thus further detailed description of the bag is omitted. 
     According to the first exemplary embodiment of the invention described above, the distance adjuster that is not in contact with the film  2  adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A. The distance adjuster is disposed in such a manner as not to be in contact with the film  2 . The cutting blade thus does not come into contact with the distance adjuster unlike a case of interposing a spacer member as a distance adjuster between films, for example. Accordingly, it is possible to reduce abrasion of the cutting blade and to improve manufacturing efficiency by simplifying steps of processing. Further, the distance adjuster does not come into contact with the film  2 , which makes it possible to form the cut by the processing device  1 A after a seal region as illustrated in  FIG.  3    is formed by heat sealing, for example. This prevents fusion-bonding of the cut due to the heat of the heat sealing. 
     In the example described above, the drive mechanism  5  disposed on a cutting blade  3 A side, the arm  6 , the post  7 , and the table  8  configure the distance adjuster; however, the distance adjuster may not necessarily include portions referred to as arm, post, and table. Regardless of a specific shape of a member, a C-shaped, box-shaped, or portal-shaped frame that supports the cutting blade  3 A and the receiver base  4 A and is disposed to surround the film  2  as a whole may be used as the distance adjuster according to an exemplary embodiment of the invention. Although the shim  52  is exemplified as a component included in the distance adjuster for varying the distance, the distance may also be varied by using various methods available as a linear position adjuster such as a ball screw. The drive mechanism  5  may not necessarily be disposed on the cutting blade  3 A side, and may be disposed on a receiver base  4 A side, for example. 
     Second Exemplary Embodiment 
       FIG.  5    is a diagram illustrating a schematic configuration of a film processing device according to a second exemplary embodiment of the invention. The configuration of the exemplary embodiment is similar to that of the above-described first exemplary embodiment except for the following points, and thus redundant and detailed description thereof is omitted. In the illustrated example, a processing device  1 B includes, in addition to the cutting blade  3 A, the receiver base  4 A, the drive mechanism  5 , the arm  6 , the post  7 , and the table  8  described above, a cutting blade  3 B and a receiver base  4 B opposed to each other with the film  2  interposed therebetween. The cutting blade  3 B and the receiver base  4 B face each other at a position different from a position where the cutting blade  3 A and the receiver base  4 A face each other. The cutting blade  3 B and the receiver base  4 B are arranged invertedly from the cutting blade  3 A and the receiver base  4 A with respect to the film  2 . Thus, in the exemplary embodiment, the cutting blade  3 B is supported by the table  8  via a holder  81 , and the receiver base  4 B is attached to the drive mechanism  5 . In other words, the cutting blade  3 A and the receiver base  4 A move toward and away from each other by the reciprocating motion of the cutting blade  3 A by the drive mechanism  5 , whereas the cutting blade  3 B and the receiver base  4 B move toward and away from each other by the reciprocating motion of the receiver base  4 B by the drive mechanism  5 . 
     Here, a minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B, i.e., a distance between a tip of the cutting blade  3 B and a surface of the receiver base  4 B when the cutting blade  3 B is closest to the receiver base  4 B, is variable by means of a shim  82  interposed between the cutting blade  3 B and the holder  81 . That is, in the exemplary embodiment, the drive mechanism  5 , the arm  6 , the post  7 , and the table  8  including the holder  81  and the shim  82  configure a distance adjuster that adjusts the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B. In the exemplary embodiment, the first distance adjuster that adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A and the second distance adjuster that adjusts the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B include the followings in common: a body part of the drive mechanism  5 ; the arm  6 ; the post  7 ; and a body part of the table  8 . As with the example of  FIG.  2   , the first distance adjuster and the second distance adjuster are each C-shaped in cross section as a whole, and thus are not in contact with the film  2 . 
     In the exemplary embodiment, the film  2  has the surfaces  2 A and  2 B similar to those of the first exemplary embodiment, and the tearing strip  21  and the base strip  22  are interposed between the surfaces  2 A and  2 B. The processing device  1 B adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A in such a manner as to cut the surface  2 A, the tearing strip  21 , and the base strip  22 , and not to cut the surface  2 B, as with the first exemplary embodiment. In contrast, the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B is adjusted in such a manner as to cut the surface  2 B and the base strip  22 , and not to cut the surface  2 A and the tearing strip  21 . Specifically, the minimum distance d 2  corresponds to a thickness obtained by adding respective thicknesses of the surface  2 A and the tearing strip  21 . Thus, in the exemplary embodiment, a first cut formed from the surface  2 A side using the cutting blade  3 A and the receiver base  4 A, and a second cut formed from a side opposite to the first cut using the cutting blade  3 B and the receiver base  4 B are formed substantially simultaneously by reciprocating motion of the common drive mechanism  5 . 
     In a case where the minimum distance d 1  and the minimum distance d 2  are adjusted as described above, the cutting blade  3 A and the cutting blade  3 B overlap with each other in a thickness direction of the film  2  when the cutting blade  3 A and the receiver base  4 A have moved toward each other to the minimum distance and the cutting blade  3 B and the receiver base  4 B have moved toward each other to the minimum distance as illustrated in  FIG.  5   . In this case, the multi-layer structure in which the film  2 , the tearing strip  21 , and the base strip  22  are overlapped with each other has at least one layer which is cut by both the cutting blade  3 A and the cutting blade  3 B. In the exemplary embodiment, the base strip  22  is cut by both the cutting blades  3 A and  3 B. 
       FIG.  6    is a partial cross-sectional view of a bag to be manufactured using a film which has been processed in the second exemplary embodiment of the invention. A cross-sectional direction of  FIG.  6    is the same as that of  FIG.  5   ; however,  FIG.  6    illustrates an unbonded portion as a space. In the exemplary embodiment, the processing device  1 B forms the cut  25 A from the surface  2 A side and a cut  25 B from a surface  2 B side. The cut  25 A is provided as a tab for unsealing. As illustrated in (a) of  FIG.  6   , the cut  25 A passes through the surface  2 A, the tearing strip  21 , and the base strip  22 . Thus, as illustrated in (b) of  FIG.  6   , the user is able to lift the above-described three layers from the surface  2 A side using the tab formed by means of the cut  25 A as a starting point. When the user holds and pulls the tab, the cut  25 B separates the tearing strip  21  from the base strip  22 , and only the surface  2 A is torn along the tearing strip  21 , thereby unsealing the bag. The bag unsealing structure according to the exemplary embodiment is mostly similar to that of the first exemplary embodiment described above; however, the cut  25 B makes it unnecessary to break the base strip  22  and allows the bag to be unsealed with less force. 
     According to the second exemplary embodiment of the invention described above, the distance adjuster that is not in contact with the film  2  adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A and the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B. In the exemplary embodiment also, the distance adjuster is disposed in such a manner as not to be in contact with the film  2 . This makes it possible to reduce abrasion of the cutting blade, and prevents fusion-bonding of the cut due to the heat of the heat sealing. The modifications described above for the first distance adjuster that adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A are similarly applicable to the second distance adjuster that adjusts the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B. 
     Third Exemplary Embodiment 
       FIG.  7    is a diagram illustrating a schematic configuration of a film processing device according to a third exemplary embodiment of the invention. The exemplary embodiment is similar to the above-described second exemplary embodiment except for a configuration of the film  2  and a set value of the minimum distance d 1  in the processing device  1  B, and thus redundant and detailed description thereof is omitted. In the illustrated example, a bag formed by using the film  2  has a so-called side gusset structure. Specifically, the film  2  has two surfaces  2 A and  2 B overlapped with each other to configure a front surface and a back surface of the bag, and two surfaces  2 C and  2 D provided by folding a side portion of the bag. In a portion where the cuts  25 A and  25 B are formed by the processing device  1 B, the surfaces  2 A,  2 C,  2 D, and  2 B are overlapped in this order. 
     In the exemplary embodiment, the processing device  1 B adjusts the minimum distance d 1  between the cutting blade  3 A and the receiver base  4 A in such a manner as to cut the surface  2 A, the tearing strip  21 , the base strip  22 , and the surface  2 C, and not to cut the surface  2 D and the surface  2 B. Specifically, the minimum distance d 1  corresponds to a thickness obtained by adding respective thicknesses of the surface  2 D and the surface  2 B. In contrast, the minimum distance d 2  between the cutting blade  3 B and the receiver base  4 B is adjusted in such a manner as to cut the surface  2 B, the surface  2 D, the surface  2 C, and the base strip  22 , and not to cut the surface  2 A and the tearing strip  21 . Specifically, the minimum distance d 2  corresponds to a thickness obtained by adding respective thicknesses of the surface  2 A and the tearing strip  21 . Thus, the processing device  1 B is able to form the cut  25 A from the surface  2 A side and the cut  25 B from the surface  2 B side. The cut  25 A is provided as a tab for unsealing, and the cut  25 B facilitates the unsealing as described above. 
       FIG.  8    is a partial cross-sectional view of a bag to be manufactured using a film which has been processed in the third exemplary embodiment of the invention. A cross-sectional direction of  FIG.  8    is the same as that of  FIG.  7   ; however,  FIG.  8    illustrates an unbonded portion as a space. A bag unsealing structure illustrated in (a) of  FIG.  8    and (b) of  FIG.  8    is mostly similar to that of the second exemplary embodiment, but differs from second exemplary embodiment in that the bag has the side gusset structure. In a case where the surfaces  2 C and  2 D folded in the side gusset structure are not bonded to each other as illustrated in the figure, it may be difficult to perform unsealing using the tab as a starting point if the cut  25 A passes through to the surface  2 B side. Accordingly, the configuration according to the exemplary embodiment in which the cutting blade  3 A forms the tab as a half-cut may be advantageous. Other advantages and modifications of the exemplary embodiment are similar to those of the second exemplary embodiment described above. 
     The bag according to the exemplary embodiment may be manufactured as with the example described above referring to  FIG.  3    by surrounding a region where the tab is to be formed by means of the cut  25 A by the side seal portion  23  and the surrounding seal portion  24 . Alternatively, the bag according to the exemplary embodiment may be manufactured by forming a seal portion where the surfaces  2 A and  2 C of the film  2  are sealed to each other in a portion of the bag including a position where the tab is to be formed, and then forming the cut  25 A as the tab and the cut  25 B in the seal portion by a processing device  1 C. 
     Preferred exemplary embodiments of the invention have been described above in detail with reference to the accompanying drawings, but the invention is not limited to such exemplary embodiments. It is apparent that a person having ordinary skill in the art of the invention can arrive at various alterations and modifications within the scope of the technical idea recited in the appended claims, and it is understood that such alterations and modifications naturally fall within the technical scope of the invention.