JP2018122460A - Manufacturing method of square bottom bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for stably and further securely manufacturing a square bottom bag having a good appearance and not being provided with excess horizontal reinforcements on a surface, and having excellent appearance on assembly without strain of the cylindrical body shape before square bottom formation.SOLUTION: A square bottom bag is manufactured continuously or intermittently by placing base paper 100 of a square bottom bag on a carrier machine and transporting it thereon at a prescribed transportation speed in the longitudinal direction while forming right-and-left gussets 13 on both end parts of a front surface 11 and a rear face 12 which are opposed to each other and folding a bottom part to give a square bottom 14. In a vertical reinforcement formation process A, a secondary horizontal reinforcement formation process D2 in which a secondary horizontal reinforcement 142L perpendicular to the transportation direction is formed in advance only in a width direction range excluding a range corresponding to the front surface 11 is conducted, and in a folding process C, a correction process F in which a contact correction body 3 is brought into a surface contact with the folded rear face from the above at a correction speed which is regulated and set to conduct a correction transportation is conducted.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method of manufacturing a square bottom bag in which a square bottom is formed on each lower side of the front and back surfaces of the gusseted paper bag, and in particular, a handbag is attached to each upper side of the front and back surfaces of the gusseted paper bag. The present invention relates to a method for manufacturing a square bottom bag including a square paper bag with a handbag, in which a square bottom is folded.

  Conventionally, regarding a corner bottom bag creasing device for attaching a crease when folding a corner bottom portion of a paper bag, a side tube is glued to form a paper tube that opens front and rear, and the paper tube is conveyed to perform a bottom folding process. A first streaked blade that engraves a fold line of the fold flap near the bottom opening of the paper tube in the middle of the conveyance, and a fold flap on the surface side of the paper tube in parallel with the fold line In a corner bottom bag creasing device provided with a second braided blade for engraving a folding line for turning it over, a blade holder for assembling the first and second braided blades is provided. A hard receiving portion is provided below the holder for abutting the first and second braided blades with the paper tube interposed therebetween, and a concave groove corresponding to the first braided blade is formed in the receiving portion. The flexible rubber material to be mounted in the concave groove and the first streaked bush The paper tube is fastened with a card, and the crease line of the folding flap is engraved on the front and back of the paper tube, and the paper tube is fastened with a receiving portion and the second braided blade. The thing which engraved the folding line only on the surface side is disclosed (refer patent document 1). According to this apparatus, the first braided blade is bitten into the rubber material provided in the concave groove of the receiving portion, and the crease line of the folding flap is engraved on the front and back of the paper tube. On the other hand, the second braided blade for putting the folding line of the front folding flap is completed by engraving the folding line for folding the front folding flap only on the surface paper of the paper tube by abutting against the hard receiving part. It is said that no streak marks are left on one side of the paper bag.

  In addition, the present invention relates to a scoring device that forms a folding line for folding and forming a square bottom on a bag sheet, and a folding line for folding a folding line for folding one side of the paper tube at the corner bottom into the bag sheet before folding. A creasing device for a square-bottom bag making machine having an attaching roller portion is disclosed (see Patent Document 2). In this apparatus, the fold-backing roller portion includes a pair of rollers for inserting a crease that forms a valley fold on one side of the bag sheet formed into a cylindrical shape, and a gusset on the other side of the cylindrical shape after molding. Each roller pair is composed of a plurality of flanges attached to the shaft with axial separation and a scoring blade on one side of the roller pair on the other side. The blade receivers that receive the creasing blades are configured so as to be spanned and fixed in the axial direction on the outer peripheral portions of the flanges constituting the rollers. According to this apparatus, the capacity | capacitance of the folding | returning creasing roller in a creasing apparatus can be made light, and this can be moved and replaced | exchanged easily.

Japanese Patent Laid-Open No. 08-090687 JP 2011-152882 A

Here, in the bag making of the square bottom bag by this type of folding, it is necessary to form a horizontal stripe at a portion corresponding to the folding line of the square bottom when the front and back surfaces are folded. That is, when forming the square base, as shown in FIG. 4 and FIG. 20 of the above-mentioned document 1, the front and back surfaces are folded and formed into a cylindrical body, and two perpendicular to both sides and parallel to the lower side are formed. The lateral stripes of each are valley-folded and mountain-folded, and the sides are opened to form a square bottom.

In the manufacturing process of the square bottom bag, when the first and second horizontal stripes are formed after the front and back surfaces are folded into a cylindrical body, the parallel horizontal stripes aligned with each other can be formed. The horizontal streak (second lateral streak) enters the surface (for example, the surface shown in FIG. 20C of Patent Document 1) after folding, and the appearance of the surface is lacking.

In this regard, a technique for forming the second horizontal stripe only on one surface even after the front and back surfaces are folded back as in the above-mentioned document 1 is affected by various conditions such as paper quality and paper thickness. It lacks stability.

On the other hand, the formation of the second horizontal stripe on the surface range can be avoided by partially forming only the second horizontal stripe in the unfolded state as in the above-mentioned document 2. However, there may be a case where the cylindrical shape is distorted when the cylindrical body is formed due to a difference in the stiffness of the paper depending on the folding direction or a partial difference in folding resistance due to the folding of the upper side. When such a cylindrical shape distortion occurs, an actual fold line is formed with a second streak line different from the previously formed second horizontal streak. In other words, double second horizontal stripes appear when assembled, resulting in lack of appearance during assembly.
The cylindrical shape distortion is, for example, as shown in FIG. 5 in a state where a slight shift occurs at the overlapping position of the gusset fold sides of the front and back surfaces, or in order to eliminate such a shift. This is a state where both sides of the cylindrical body are made non-parallel by distorting the folded side of one side of the tube. Such a state is particularly likely to occur when the cylinder is folded by a folding blade by an automatic folding machine while continuously transporting the cylinder.

Therefore, in the present invention, a square bottom bag excellent in appearance without forming extra lateral streaks on the surface is more reliably manufactured with stability, and there is no distortion of the cylindrical shape before the formation of the square bottom. It is an object of the present invention to provide a method for producing a square-bottom bag that is excellent in appearance at the time of assembly without causing double second horizontal stripes to appear on the back surface when assembled.

  In order to solve the above problems, the following technical means (1) to (4) are taken. It should be noted that the numeral strings, alphabets, or numeral strings including the alphabets that follow the following terms are reference symbols given for convenience in order to refer to the corresponding components of the embodiments in the drawings, and identify the concept or form. It is not intended to be limited.

(1) The manufacturing method of the square bottom bag of the present invention is as follows:
While the base paper 100 of the bottom bag is continuously placed and conveyed in the vertical direction by the conveying device 2 at a predetermined conveying speed 2 V, left and right gussets 13 are formed on both sides of the front surface 11 and the back surface 12 facing each other and the lower portion A method for producing a square bottom bag, in which a square bottom bag having a square bottom 14 folded therein is produced continuously or intermittently,
“Vertical stripe forming step A” for forming vertical stripes 13L to be gussets 13 at corresponding positions in the width direction;
“Gusset folding step B” for forming the gusset 13 by folding the longitudinal bars 13L inward in the width direction;
The back surface 12 after the gusset folding process B is folded back onto the front surface 11 to form the tube bag 101, and the edge 121 of the back surface of the folding destination is bonded to the gusset 13 formed on the edge 111 of the surface. "When,
A “horizontal streak forming step D” in which the horizontal streaks 141L perpendicular to the transport direction are superimposed on the corresponding positions of the corner bottoms at the positions corresponding to the horizontal folding lines for forming the corner bottoms 14 on the tube bag 101 after the folding process C. When,
Comprising a step of forming a square base 14 by folding the horizontal stripe and bonding the square base 14 to form a square base,
In each of the above steps,
At the time of the vertical streak forming step A (before and after the vertical streak forming step A) and before the turning back step C, the second horizontal streak 142L perpendicular to the conveying direction, which becomes a valley fold line after square bottom forming, is formed on the surface 11. The “second lateral streak forming step D2” is formed in advance only in the width direction range corresponding to the back surface 12 and the width direction range of the gusset 13 adjacent to the left and right side portions of the back surface, excluding the width direction range corresponding to Done
In the folding process C, a “correcting process F” is performed in which the contact correcting body 3 is brought into surface contact from the upper side and corrected and conveyed at a correction speed 3 V adjusted and set with respect to the folded back surface.
Then, in the correction step F, while being placed and transported at the predetermined transport speed 2V, the upper surface of the back surface 12 that has been folded back is folded back by being transported in contact with the top at a correction speed 3V different from the transport speed 2V. Adjusting the position and correcting the misalignment of the folded corner portion 101C to be within a specified range;
Further, in the correction step F, the surface contact range (effective length of surface contact in the transport direction) of the contact corrector includes a length in the transport direction from the folded back portion of the back surface to the end of the bottom fold portion. And

  If it is the above, by carrying out surface contact with the entire vertical direction (length in the conveyance direction) of the folded back surface, the flat surface correction of the back surface is performed on the entire back surface, and the back surface during the folding process It is possible to reliably adjust the folding position of the back surface while avoiding distortion. It is further preferable that the contact correcting body in the surface contact range is in surface contact with the back surface in a state where the contact correction body is stretched with a predetermined tension or more. In the embodiments described later, by adding a tension roll to the downstream side in the transport direction, a predetermined tension is applied to the contact correction body, so that contact correction to the entire length in the transport direction on the back surface is reliably performed.

  In addition, in the unfolded base paper 100 before the front and back surfaces are folded, the second horizontal streaks 142L are first formed in advance in a part (equivalent range of the back surface 12) in the width direction, so that the surface 11 has an extra area. It is possible to keep the appearance of the surface without forming the second horizontal streak. Further, when the second horizontal streak 142L is pre-formed, the second horizontal streak 142L and the valley fold line at the time of actual square bottom formation are displaced due to the distortion of the cylindrical shape after the folding process. By correcting, the parallelism with the first lateral streak at the time of forming the bottom is surely removed, so that the deviation between the second lateral streak 142L and the valley fold line at the time of the actual formation of the bottom is eliminated.

(2) Moreover, the manufacturing method of the square bottom bag of this invention is as follows.
Each process consisting of at least the vertical line forming process, the gusset folding process, the second horizontal line forming process, the folding process, the horizontal line forming process, and the square bottom forming process as a first process set. After going
Each step consisting of the vertical streak forming step, the gusset folding step, the second horizontal streak forming step, the folding step and the correcting step, the horizontal streak forming step, and the square bottom forming step is a second step. A method of manufacturing a square bottom bag as a set,
The contact correction body is driven by a drive mechanism different from the drive mechanism of the transporter,
Furthermore, it has a variable adjuster that variably adjusts the speed difference between the transport speed of the transport machine and the correction speed of the contact correction body to a predetermined adjustment value,
In the correction step in the second step set,
The variable adjuster is positive or negative based on the amount of positional deviation between the corner at the upper edge of the back edge and the corner at the upper edge of the front edge in the folding process (that is, the amount of deviation AD of the mouth corner). It is preferable that the adjustment value is set and the driving force of the drive mechanism of the contact correction body is controlled based on the set adjustment value.

  In the case of the above manufacturing method, the bonding position of the back surface 12 is folded in accordance with the speed difference between the bottom feed speed (transport speed 2V) and the top speed of the contact correction body (correction speed 3V). Adjustment is made at the corner portion 101C. By adjusting only the bonding position of the back surface 12 with the contact correction body 3 that is in surface contact with the entire back surface 12, there is no distortion on the side of the cylinder, and a cylindrical shape in which both sides are parallel to each other is formed. Can do. In particular, if the contact correction body is driven by a drive mechanism different from the drive mechanism of the transport machine and is provided with the above variable adjuster, the speed is adjusted by another drive mechanism and variable adjuster. By performing independent driving, fine adjustment is possible.

  In the correction step, the surface contact range of the contact correction body includes a length in the conveyance direction from the folded back portion of the back surface to the bottom fold end. Accordingly, the entire surface in the vertical direction of the back surface is brought into surface contact and transported, and the surface correction of the entire back surface can be reliably performed. It is further preferable that the contact correcting body in the surface contact range is in surface contact with the back surface in a state where the contact correction body is stretched with a predetermined tension or more. In an embodiment described later, by adding a tension roll on the downstream side in the transport direction, a predetermined tension is applied to the contact correction body, so that the contact correction to the entire back surface is reliably performed.

  (3) It is preferable that the correction contact surface of the contact correction body in the correction process of any one of the manufacturing methods has a sliding angle of a contact load of 500 kgf between the contact correction bodies having a measurement surface of 60 mm square exceeds 31.0 °. However, the slip angle is a friction test using a tilt method based on JISP8147, and is a value according to the test condition of a weight contact load of 500 kgf between contact correction bodies having a measurement surface of 60 mm square.

  The above is based on the result of measuring the slip angle of the same sample of the contact correction body by the slip angle tester, and those having a slip angle exceeding 31.0 ° are good for those having a slip angle of 31.0 ° or less. It was confirmed that excellent contact correction was achieved in the folding process and the correction process of this manufacturing method.

  (4) In the second horizontal streak forming step of any one of the above manufacturing methods, the horizontal streak forming knife is pressed within a predetermined discontinuous range, and an upper presser portion for preventing lifting is provided on the upstream side or the downstream side of the horizontal streak forming knife. It is preferable that the lifted piece formed at the time of forming the horizontal stripe is brought into upper contact with the upper pressing portion to restrict the lifting.

By taking the above-mentioned means, in the present invention, a square bottom bag excellent in appearance without forming extra transverse streaks on the surface is more reliably produced with stability, and the cylinder before the corner bottom formation There is no distortion of the body shape, no double second horizontal streaks appear on the back when assembled, and a method for producing a square-bottom bag excellent in appearance during assembly is provided.

Explanatory drawing of each state of a base paper, a cylinder, or a square bottom bag by the process of the manufacturing method of the square bottom bag of Example 1. Side view outline figure of manufacturing apparatus of square bottom bag of Example 1 Side view explanatory drawing of the structure around the correction | amendment apparatus 3 in the manufacturing apparatus of the square bottom bag of Example 1. FIG. Plan view explanatory drawing of the structure of the conveying machine 2 in the manufacturing apparatus of the square bottom bag of Example 1. FIG. The figure which shows the some example of a state which the gap | deviation produced in the mouth folding corner | angular part of the cylinder after a folding process Explanatory drawing of each state of a base paper, a cylinder, or a square bottom bag by the process of the manufacturing method of the square bottom bag of Example 2. Explanatory drawing of the conventional manufacturing process which shows the process in which the shift | offset | difference of a corner fold corner part generate | occur | produces.

  The present invention basically forms a cylindrical bag having a gusset while conveying a base paper whose front and back surfaces are arranged in the width direction in the vertical direction at a predetermined conveyance speed of 2 V, and further folds and forms the square bottom. This is a manufacturing method for manufacturing a square bottom bag continuously or intermittently. In particular, the right and left gussets 13 are formed on both sides of the front surface 11 and the back surface 12 facing each other while the base paper 100 of the square bottom bag is continuously placed and transported in the vertical direction by the transport device 2 at a predetermined transport speed 2V. In addition, a square bottom bag manufacturing method for continuously or intermittently manufacturing a square bottom bag in which a bottom 14 is folded at the lower portion, wherein the second lateral stripes are formed in the unfolded state before the front and back surfaces are folded. When the back surface is folded, the entire length in the conveyance direction of the back surface is adjusted by surface contact to correct the misalignment of the mouth folded corner of the tube bag.

  As shown in FIG. 1, the square bottom bag to be manufactured is in a folded state in which left and right gussets 13 are formed on both sides of the front surface 11 and the back surface 12 facing each other and a square bottom 14 is folded at the lower portion. By assembling so that the square bottom 14 becomes the bottom surface, the front surface 11 and the back surface 23 are in a standing state. However, the horizontal surface is not formed in the surface 11 in the assembled state, and only the second horizontal wire 122L formed in advance appears in the surface on the back surface 12 in the assembled state, which is different from the second horizontal line 122L. Lines are not formed. Further, as shown in FIG. 1, the upper part of the bag mouth according to the manufacturing method of the square-bottom bag of Example 1 is formed with a mouth folded part 15 that is folded inward. In addition to this form, the form of Example 2 in which a string-like handbag 16 is through-bonded to the mouthfold 15 as shown in FIG.

As the basic steps of the manufacturing method according to the first embodiment of the present invention, the following steps shown in FIG. 1 are performed while carrying by the carrier 2 (FIGS. 2 and 4).
“Folder folding step P” for horizontally folding the mouth fold 15 along the upstream edge in the transport direction of the base paper 100
"Vertical line forming step A" for forming vertical lines 13L to be gussets 13 at corresponding positions in the width direction
-The second horizontal streak 142L perpendicular to the conveying direction, which is a valley fold line after square bottom forming, at the time of the vertical streak forming step A (simultaneously with or before and after step A) and before the following folding step C, “Second lateral streak forming step D2 which is preliminarily formed only in the width direction range corresponding to the back surface 12 except the width direction range corresponding to the front surface 11 and the width direction range of the gusset 13 adjacent to the left and right side portions of the back surface. ”
A “gusset folding process B” in which the vertical stripes 13L are folded inward in the width direction to form the gusset 13
The back surface 12 after the gusset folding process B is folded back onto the front surface 11 to form the tube bag 101, and the edge 121 on the back surface of the folding destination is bonded to the gusset 13 formed on the edge 111 of the front surface. C ”
In the folding process C (at the same time as or before and after the process C), the correction body F is corrected and conveyed by bringing the contact correction body 3 into surface contact from above at the correction speed 3V adjusted and set on the folded back surface.
-The horizontal streaks 141L perpendicular to the conveying direction are formed on the tube bag 101 after the folding step C at the position corresponding to the horizontal fold line for forming the corner bottom 14, and overlapped with the corresponding position on the corner bottom. ”
・ Fold the horizontal stripes to fold the bottom 14 and bond it.
Hereafter, each process and the apparatus structure for implementing this are explained in full detail.

(Vertical line forming step A, second horizontal line forming step D2, gusset folding step B)
The vertical streak forming step A is a step of forming the vertical streaks 13L to be gussets 13 at corresponding positions in the width direction. Specifically, the vertical stripe 13L is formed by two parallel first vertical stripes 131L in the same direction as the transport direction and a single line formed in the same direction as the transport direction between the two first vertical bars 131L. It consists of a total of three parallel push rules consisting of the second vertical bars 132L. In the gusset folding process B, the folds are folded along the first vertical bars 131L and the valleys are folded along the second vertical bars 132L, whereby the gusset 13 having an M-shaped cross section is formed. As corresponding positions in the width direction of the unfolded base paper 100, three vertical streaks 13L (131L, 132L) are formed in parallel at three positions on the left and right sides of the surface. All of the first vertical bars 131L and the second vertical bars 132L are accurately parallel folding lines, and the second horizontal bars 142L in the second horizontal bar forming step D2 described later are the first vertical bars 131L and the second vertical bars. An accurate perpendicular fold line is formed for each of 132L.

(Folding process C)
In the folding process C, the back surface 12 after the gusset folding process B is folded on the front surface 11 to form the tube bag 101, and the edge 121 on the back surface of the folding destination is attached to the gusset 13 formed on the front edge 111. It is a process of combining. Thus, the present invention is characterized in that the following correction process F is performed during the folding process C.

(Correction process F)
The correction process F adjusts the folding position with respect to the front surface 11 of the folded back surface 12 by carrying the upper surface at a correction speed 3V different from the conveyance speed 2V while being placed and conveyed at the predetermined conveyance speed 2V. In this step, the misalignment of the folded corner portion 101C is corrected to be within a specified range. In particular, in the embodiment, in the folding process B, the “contact correction body 3” that is annularly arranged with a predetermined length in the width direction is applied to the folded back surface from above at an adjusted correction speed 3V. It is assumed that correction conveyance is performed by bringing the surface into contact.

  The contact correction body 3 is driven by a drive mechanism different from the drive mechanism of the transport machine, and the transport speed 2V difference of the drive mechanism of the contact correction body is variably adjusted to a predetermined adjustment value with respect to the drive mechanism of the transport machine. The variable adjuster 35 is provided. Here, the surface contact range of the contact correction body 3 (the range of the double-headed arrow shown in FIG. 3) is the length of the conveyance direction length from the folded back portion of the back surface to the end of the bottom fold portion (FIG. 1C). The vertical length of the cylindrical body 101 indicated by the horizontal parallel lines 101) is included. Further, the variable adjuster 35 is set with a positive or negative adjustment value based on the misalignment amount AD of the fold corner, and controls the driving force of the drive mechanism of the contact correction body based on the set adjustment value. However, the misalignment amount AD of the folded corner portion means a distance between the corner portion of the upper edge of the back surface and the corner portion of the upper edge of the surface after the folding process as shown in each drawing of FIG. In the manufacture of the square bottom bag, in order to maintain the quality of the product, a prescribed range regarding the amount of deviation AD is set in advance. FIG. 5A shows that the back fold angle portion 102C is the front fold angle. This shows that the shift is excessively lower than the portion 101C, and the shift amount AD exceeds the specified range. 5 (b) and 5 (c) show that the back corner fold corner portion 102C is slightly displaced downward and upward from the front surface corner fold corner portion 101C, respectively, and the deviation amount AD is defined in both cases. Indicates a state that does not exceed the range.

  The bonding position of the back surface 12 is adjusted by the fold corner portion 101C according to the speed difference between the bottom feed speed (transport speed 2V) and the top speed of the contact correction body (correction speed 3V). It becomes. By correcting the bonding position of the back surface with the entire length in the conveyance direction of the surface by the surface contact body having a predetermined sliding angle and a predetermined surface contact range, the side of the cylinder body is not distorted, and both sides are mutually connected. It can be set as a parallel cylinder shape.

(Second transverse line forming step D2)
The second horizontal streak forming step D2 is a step in which the formation of the second horizontal streaks 142L is first performed in advance (in a corresponding range of the back surface 12) in the width direction in the unfolded base paper 100 before the front and back surfaces are folded. is there. At the time of the vertical streak forming step A (at the same time as or before and after step A) and before the following folding step C, the vertical streak 13L is a vertical fold line after square bottom forming and perpendicular to the conveying direction. The vertical second horizontal streaks 142L are preliminarily provided only in the width direction range corresponding to the back surface 12 excluding the width direction range 11W corresponding to the front surface 11 and the width direction range of the half piece of the gusset 13 adjacent to the left and right side portions of the back surface. Form. No second lateral streak is formed within the range of the non-formed width NLW. Thereby, it is possible to maintain the appearance of the surface without forming an extra second horizontal stripe in the surface area of the surface 11. Further, when the second horizontal streak 142L is pre-formed, the second horizontal streak 142L and the valley fold line at the time of actual square bottom formation are displaced due to the distortion of the cylindrical shape after the folding process. By correcting, the parallelism with the first lateral streak at the time of forming the bottom is surely removed, so that the deviation between the second lateral streak 142L and the valley fold line at the time of the actual formation of the bottom is eliminated.

(Variable adjuster 35)
The manufacturing apparatus of the present invention includes a conveyor 2 that intermittently or continuously conveys a cylindrical base paper, and a surface contact range that includes a length in the conveyance direction from the folded back portion of the folded back surface to the bottom folded portion. A contact correcting body 3 having a fold line, a fold line forming machine 4 which is disposed above the transport space of the transport machine 2 and intermittently inserts knives for various fold lines, and a transport section of the transport machine 2. And a folding machine 5 that folds and forms the base paper conveyed by an upright blade, and a folding machine 6 that forms a square bottom.

  In the embodiment, the hand strap attaching machine 7 for attaching the hand strap to the mouth portion of the cylindrical body, and the horizontal streak forming knife are pressed in a predetermined non-continuous range, and are used to prevent the streak from being raised upstream or downstream of the horizontal streak forming knife. The contact presser is driven by the upper presser 8 and a drive mechanism different from the drive mechanism of the transport machine, and the difference in transport speed 2V of the drive mechanism of the contact corrector is set to a predetermined adjustment value with respect to the drive mechanism of the transport machine. And a variable adjuster 35 (not shown) for variable adjustment.

  In the variable adjuster 35, a positive or negative adjustment value is set based on the misalignment amount AD (see FIG. 5) of the fold corner, and the drive of the drive mechanism of the contact correction body 3 is driven based on the set adjustment value. It controls the speed. Fine adjustment is possible by independent driving at a speed set with an adjustment value by another drive mechanism.

(Contact correction body 3)
The correction contact range of the contact correction body 3 has a length in the conveyance direction including from the upper end opening of the cylindrical body to the cutting opening before forming the bottom corner, and the entire correction contact range is stretched by a predetermined tension. As a result, the surface contact area 3EL for surface contact correction including the length 1AL in the conveyance direction from the upper end opening of the cylindrical body to the cutting opening before the bottom of the bottom is formed is in surface contact with a predetermined friction force. ing.

(Upper presser part 8)
The upper presser portion 8 is a blade body that presses the horizontal streak forming knife in a predetermined non-continuous range in the second horizontal streak forming step, and is disposed on the upstream side or the downstream side of the horizontal streak forming knife. It functions as a press-up portion for preventing the lift-up piece from coming into contact with the upper press-up portion and restricting the lift-up piece.

(Problems of conventional manufacturing methods)
Hereinafter, problems of the conventional manufacturing method will be described. The bottom of the paper bag base paper that is an existing technology only on the back side (the surface that can be seen from the front of the paper bag when folded in the appearance of the paper bag is the front side, and the side that can be seen from the bottom fold is the back side) When performing bottom second creasing (horizontal creasing) for molding, even if using the technology and mechanism applied to flat base paper on the machine, or flat base paper that has been subjected to scoring by pre-processing using a punching machine However, it is difficult to stably produce paper bags because there is no technique for aligning the horizontal streaks processed on the back of the paper bag base paper on the machine.

  Further, in an existing sheet-fed bag making machine, a method of gusseting into an M-shape and pasting the back surface of the bag to the adhesive margin on the front side minimizes the error of the folded corner portion of the paper bag as shown in FIG. Therefore, the cylindrical finish was distorted (tapered). Therefore, when the basis weight of the base paper is small as shown in FIG. 7 (D ′), the folded back surface is shifted to the downstream side, and when the basis weight of the base paper is large as shown in FIG. 7 (D ″). There was a tendency for the folded back surface to shift upstream. That is, since the resistance at the time of folding varies depending on the basis weight of the base paper, it is necessary to adjust and set the folding angle of the folding blade in the folding process each time depending on the paper quality and folding shape. This significantly lowered the precision of bottom molding and the efficiency of manufacturing, and this was a fatal defect in the bag-making without surface streaking due to this horizontal streaking.

  In addition, even when processing the triangular broken line formed on the gusset portion in the bottom molding at the same time as the bottom second line (bottom line) for bottom molding, the accuracy error in the actual bottom molding (thickness of the paper bag base paper) Because of this, it causes double fold lines during automatic bag making (triangular lines that are crooked and the broken lines in the machine molding during automatic bag making do not completely match), which causes defective products. It could not be used practically, and the existing scoring device alone could not produce a stable and efficient bag without surface streaks.

  In addition, in the horizontal creasing process on the machine, if it is only a creasing process, it is possible to adopt the existing technology. In order to make it fold down after bonding, the specification is such that a creasing blade is installed on the bottom surface of the bag making machine and a scoring blade receiver is installed on the top surface. In this specification, the base paper for the paper bag is lifted (crimped to the blade receiver) during the horizontal creasing process, and it collides with the transport roll or transport belt immediately after that, or the base paper is distorted or clogged. There was a case.

  In addition, since horizontal scoring on the machine is technically difficult for stable production, either horizontal scoring by pre-processing is performed, and it is manufactured on the machine while ignoring the decrease in yield, or manually. There was only a low-efficiency production method of how to manufacture paper bags.

(Function and effect)
In response to the above problems, according to the manufacturing method of the present invention, the accurate parallel formation of the first and second lateral stripes and the formation of the cylindrical bag (backside reverse bonding), which are the problems of the conventional method of manufacturing a square bottom bag, At the same time, the displacement of the mouth portion can be eliminated simultaneously with the deformation of the cylindrical bag shape. That is, even when the folding position of the back surface is adjusted at the corner of the mouth, the entire back surface is contact-corrected by the contact correction body 3 having a predetermined correction speed of 3V, so that both sides of the tube bag are kept parallel to form the bottom of the corner. At that time, the trough was accurately folded along the same line as the second lateral streak formed in advance.

  Furthermore, an automatic square-bottom bag making machine for sheet-fed bags can make it possible to stably and efficiently produce a “surface-free line-free bag” on a bag making machine from plain paper 100. It was. In addition, it is possible to realize an efficient work that secures workability by minimizing machine elements without using a complicated or multi-stage machine structure.

(About the contact correction body 3 and the correction device)
In this manufacturing apparatus, the gusset 13 is formed in an M shape in the width direction of the paper bag base paper on the transport device 2, and immediately after the back surface of the paper bag is bonded to the adhesive margin on the front side of the paper bag, The contact correction body 3 for correcting the alignment position is brought into surface contact. This contact correction body 3 advances at a belt at an arbitrary correction speed (for example, with an accuracy of 0.1 mm) by differential driving typified by servo control, and is predetermined on the back surface of the paper bag that is placed and transported on the transport device 2. It consists of a conveyor belt that makes contact with the above contact pressure. The surface contact range of the contact correction body 3 includes a conveyance direction length H from the folded back portion of the folded back surface to the bottom fold end, and a contact load of 500 kgf between the contact correction bodies having a measurement surface of 60 mm square. The angle is set to exceed 31.0 °.

The setting of the sliding angle (setting that the sliding angle of the contact load of 500 kgf between the contact correction bodies having a measurement surface of 60 mm square exceeds 31.0 °) is based on the friction test result of the tilt method based on JISP8147. Specifically, in order to obtain a preferable set value of the slip angle, a plurality of samples having a contact load of 500 kgf and a measurement surface of 60 mm × 60 mm are overlapped, and based on JISP8147 using a slip angle measuring device manufactured by The Pack Co., Ltd. A friction test using the tilt method was performed, and the angle at which the samples began to slide (slip angle) was measured in each sample combination. As a sample of the conveyance belt of the contact correction body 3 to be brought into surface contact, a sample 1 made of T-10 made by Mitsuboshi Belting Co., Ltd., 30 mm wide, a sample 2 made of XVV-2237 made by Habasit Japan Co., Ltd., 25 mm wide, and A relative sample 3 made of oil-based offset printing solid (lower gloss craft 100 kgf / m ² ) was prepared. The combination of samples 1 (combination pattern a), the combination of samples 2 (combination pattern b), the combination of sample 1 and relative sample 3 (combination pattern c), and the combination of sample 2 and relative sample 3 The slip angle was measured for each of the four types of combination patterns a to d including (combination pattern d). The measurement test is performed in accordance with the friction test using the tilt method of JISP8147. The test condition is a weight contact load of 500 kgf between the contact correction bodies having a measurement surface of 60 mm square, and the slip is increased by gradually increasing the angle of the inclined plate. The starting angle, i.e. the sliding angle, was measured. As a result, the average slip angle was 31.0 ° for the combination pattern a, 54.0 ° for the combination pattern b, 41.2 ° for the combination pattern c, and 47.0 ° for the combination pattern d. Further, when the parallel strains on both sides of the cylindrical body when the samples 1 and 2 were used as the material of the contact correction body 3 were measured, the average parallel strain rate of the sample 1 was 1.30% at n = 100. , N = 100, the average parallel strain rate of Sample 2 was 0.40%. From this, it is a slip angle exceeding the slip angle of 31.0 degree in the contact load 500kgf of the contact correction bodies of the measurement surface 60mm square of the sample 1 at least, Furthermore, the contact correction of the measurement surface 60mm square of the sample 1 at least. It is necessary that the slip angle at the body-to-body contact load of 500 kgf exceeds 31.0 °, and the slip angle at the contact load of 500 kgf for the lower glossy craft paper 100 kgf / m ² (relative sample 3) exceeds 41.2 °. It is judged that there is. Desirably, the sliding angle at a contact load of 500 kgf between contact correction bodies having a measurement surface of 60 mm square of sample 2 is 54.0 ° or more, and contact with lower gloss kraft paper 100 kgf / m ² (relative sample 3). It is determined that the slip angle at a load of 500 kgf is preferably 47.0 ° or more.

  Further, as shown in FIG. 3, the correction device including the contact correction body 3 includes, in addition to the contact correction body 3 including the annular belt body 30, seven contact rolls 31 arranged in parallel, and an upstream side. A downstream tension roll 32 that is arranged to float on the downstream side of the seventh abutment roll as viewed, and a pair of upstream and downstream upper tensions that are disposed obliquely above the seven abutment rolls 31. A roll 33, a servo motor 34 disposed above them, and a variable adjuster 35 for controlling the driving force of the servo motor 34 are provided. In the present embodiment, effective surface contact correction is performed over a range between the lower ends of the frontmost contact roll 31 and the rearmost contact roll 31 among the seven contact rolls 31. For this reason, the distance between the lower end of the foremost contact roll 31 and the rearmost contact roll 31 is the effective length of the surface contact range 3EL (FIG. 3).

  Among these, the variable adjuster 35 drives the servo motor 34 by controlling the correction speed with another drive mechanism for the contact correcting body with respect to the drive mechanism of the transport device. Specifically, the difference between the conveyance speed 2V of the conveyance device 2 and the correction speed 3V of the contact correction body 3 is used as an adjustment value, and the distance of the folded state of the fold corner portions 101C and 102C shown in FIG. And a setting mechanism for manually or automatically setting the adjustment value to a predetermined value of plus or minus. The variable adjuster 35 set with the adjustment value by the setting mechanism controls the driving force of the drive mechanism of the contact correction body based on the set adjustment value.

Of the seven abutment rolls 31, the distance between the axes of the first abutment roll 31 on the most upstream side and the seventh abutment roll 31 on the most downstream side is determined by the contact correcting body 3 in the flow direction of the paper bag. The length is set so as to exceed the length from the fold-folded portion side to the bottom end side, and is in a tensioned state in which a predetermined tension or more is applied so as not to loosen.
The contact correction body 3 has a length that extends from the mouth fold side to the bottom end side in the flow direction of the paper bag, and has a static friction resistance based on a slip angle of a predetermined value or more, thereby correcting the entire back surface in the flow direction. It is a specification that can be performed gently and reliably. For this reason, the correction capability is demonstrated on the entire back surface, and correction of the bonding position of the paper bag (reduction of the misalignment amount AD or elimination of misalignment of the folded corner) is achieved without causing defects such as wrinkles. Yes.

  With the function of the correction device, it is possible to perform the position (register) alignment of the horizontal stripes while maintaining the accuracy of the gusset molding and the bonding molding of the paper bag, and the accuracy of the bottom molding is also maintained.

  The bottom second creasing (horizontal creasing) device for bottom molding is placed upstream in the flow direction from the vertical creasing mechanism for gusset molding, and creasing is performed with the base paper for the paper bag completely flat. This makes it possible to achieve both stable horizontal creasing and conveyance.

  The horizontal creasing process is the front side of the back of the bag, half of the gusset on the back side, the glue margin part that bonds the front and back sides, and half of the glue margin side of the gusset on the front side in the width direction of the paper bag base paper Only the horizontal line of the bottom second rebar for bottom molding is creasing. At this time, the crease for the gusset portion at the time of bottom molding is not performed. Also, the creasing on the back side in the lateral creasing process is a paper pressing guide or rotary type to prevent the base paper from lifting up, as the creasing blade and blade rest are installed in the direction of the valley fold when the paper bag is bonded. The rope is installed to prevent distortion and clogging of the base paper during transportation, and realizes stable transportation.

  Since the bottom 1 streak for bottom molding is the basis of bottom molding, the second streak is in the state of a gusset before the bottom molding and the cylindrical shape after the lamination, as in the case of the existing single-wafer bag making machine. This is done at a position different from the horizontal line.

  By using the above-mentioned correction device for the bonding position by the contact correction body and measures for preventing the floating of the base paper when the horizontal line is attached, stable conveyance and accurate position (registration) alignment of the horizontal line are possible. It is possible to perform a mechanism (performed with two axes) for performing horizontal stripes on the side and the back side at once, and it is possible to reduce the complexity of work related to mold change and adjustment. It was.

  In addition, with the above-described correction device for the bonding position by the contact correcting body and the measure for preventing the base paper from being lifted at the time of the horizontal streak, the base paper 100 that has been subjected to creasing processing by a punching machine or the like can be stably conveyed and the position of the horizontal streak (registered) This makes it possible to realize a stable and efficient automatic bag making of a bag without surface streaking without distinguishing between the on-machine creasing and the creasing base paper by the pre-processing.

(Operation of manufacturing equipment)
In the present invention, the mouth portion is folded by the main cylinder, transferred to the reverse drum, and the second creasing for forming the square bottom is performed by the horizontal creasing blade before the vertical creasing roll.

  The horizontal screed blade is composed of a first blade and a second blade configured on one axis. The first blade forms the front and back gussets on the back of the paper bag, and the second blade forms the adhesive margin and the back. Do creasing to half the gusset. The horizontal barbing shaft is driven by a single servo control separately from the machine main body, and has a mechanism capable of processing the bar at an arbitrary position.

  In addition, the horizontal streak blade has a structure with a dedicated holder and receiving rubber according to the finished shape of the paper bag. The back side of the front side folds when the paper bag base paper is viewed from the machine, and the glue margin side folds down. Perform horizontal creasing so that

  Further, the base paper for the paper bag is pressed against the receiving rubber by the horizontal streaking blade, and the paper floats up on the back side. As the paper floats up, the paper collides with the transport roll immediately after it, causing bending or transport distortion. To prevent this, a paper presser (guide) 8 is provided, and the base paper for the paper bag is always placed under the transport roll. Measures to pass. The same effect can be obtained with a rotary rope or flat belt according to the paper pressing guide.

  Immediately after passing through the vertical streaking roll, synthetic glue is applied to the end of the back side of the paper bag base paper by a spray gun in parallel with the machine flow direction. After that, the paper bag base paper is nip-fed by the lower belt and the upper belt for conveyance, and while passing through this section, the front side of the paper bag surface is formed along the molding plate, and both sides of the paper bag are molded along the gusset molding plate. The base paper is folded along the vertical lines so that both ends of the paper are Z-shaped. This section is called the first molded part.

  Immediately after passing through the first forming part, folding creases are attached to the front surface and the gusset folds by means of three gusset press rolls on the left and right.

  After passing through the gusset roll, the paste margin side is folded according to the folding guide while supporting the back surface and the paste margin folding position along the molding plate while being nip-fed by the lower belt and the upper belt 28 as in the first molding. The folding posture is maintained by pressing the adhesive margin. The back side is folded in the direction of the glue margin according to the folding guide with a delay, and the glue margin and the end of the back surface are bonded by the synthetic glue applied before the first molding, and the bonding posture is held by the glue margin presser It enters a correction device equipped with a single servo motor.

  The servomotor of the correction device 6 can be rotated at an arbitrary speed with respect to the machine speed and is equipped with an upper belt having a high friction coefficient. The surface contact area 3EL of the contact corrector 3 in contact with the upper belt paper bag base paper has a length over the entire length of the conveying direction length 1AL with respect to the flow direction of the paper bag. The surface contact range 3EL of the contact corrector 3 refers to the length in the conveyance direction of the effective range of surface contact. For example, in the embodiment shown in FIG. 3, the distance between the foremost part and the last part among the plurality of contact rolls 31 is the surface contact range 3EL. Before the glue is dried and the margin and the back edge are completely bonded, the correction device is moved at a variable speed, and the position (register) of the horizontal stripes attached by the paper bag bonding portion and the horizontal stripes is accurately adjusted. The correction by the correction device can be adjusted only by changing the rotation speed of the upper belt within ± 10% regardless of whether it is manual operation by push button operation or automatic operation using a separate device such as image processing. Yes.

  The paper bag base paper in which the lateral stripes are aligned by the correction device is pressure-bonded to the adhesive margin and the adhesive surface at the end of the back surface by the cylinder press roll immediately thereafter, and is then conveyed to the bottom molding unit.

  In FIG. 6, the state of the processed goods (base paper 100, cylinder 101, square bottom bag 102) of each process by the manufacturing method of Example 2 of this invention is shown. In Example 2, it replaces with the mouth part folding process P of Example 1, and comprises the handbag formation process P1 which makes the string-like handbag 16 penetrate and adhere to the mouth folding part 15. FIG. The handbag forming step is a state in which the string-like handbag 16 is passed through two places within the fold line of the mouthfold section 15, the mouthfold section 15 is folded and the end of the handbag 16 is accommodated in the mouthfold section 15. Glue with. As a result, the mouth-folding portion 15 is in a state in which the end portion of the handbag 16 is accommodated therein, and the thickness is partially increased by the internal accommodation. Thereby, in Example 2, the square bottom bag having the string-like handbag 16 is formed, but in particular, the processed body of the base paper 100 having a portion having a different thickness at the mouth as in Example 2. In the folding process, a deviation AD exceeding the specified value is likely to occur at the corner of the mouth fold due to distortion in the thickness direction, and wrinkles are likely to occur on the folded back surface. Therefore, the correction process using the contact correcting body 3 of the present invention Becomes effective. In addition, other manufacturing methods, manufacturing apparatuses, and formation modes of the components that are not specified are the same as those in the first embodiment.

  In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made as appropriate without departing from the spirit of the present invention, such as combining the elements of each part of the embodiments or extracting or replacing each element. Further, the shape of each component is not limited to the description of the embodiments or those shown in the drawings, and the shape of each element can be changed.

DESCRIPTION OF SYMBOLS 100 Base paper 101 Cylinder body 101C, 102C Folding corner part 102 Square bottom bag 11 Front surface 111, 121 Edge 12 Back surface 13 Machi 131L, 132L Longitudinal line 14 Corner bottom 141L First horizontal line 142L Second horizontal line 15 Folding part 1AL Conveyance direction Length 2 Conveyor 3 Contact correction body 3EL Surface contact range 4 Folding line forming machine 5 Folding machine 6 Folding machine 8 Upper presser part A Vertical stripe forming process AD Displacement amount at the corner of the mouth fold B Machi folding process C Folding process D Transverse process D Formation process D2 Second lateral line formation process E Square bottom forming process F Correction process P Opening process

Claims (4)

While the base paper of the square bottom bag is placed and conveyed in the vertical direction at a predetermined conveyance speed by the conveyor, left and right gussets are formed on both sides of the front and back surfaces, and the square bottom is folded at the bottom. A method for producing a square-bottom bag that continuously or intermittently produces a square-bottom bag that is placed and conveyed in a vertical direction at a predetermined conveyance speed by a conveyer,
A vertical streak forming step of forming a vertical streak as a gusset at a corresponding position in the width direction;
A gusset folding step of folding the longitudinal stripes inward in the width direction to form gussets;
A folding step of folding the back surface after the gusset folding process on the surface to form a cylindrical bag, and bonding the edge of the back surface of the folding destination to the gusset formed on the edge of the surface;
A horizontal streak forming step of superimposing a horizontal streak perpendicular to the transport direction on a corresponding position of the bottom of the corner at a position corresponding to the folding line for forming the bottom of the tube after the folding process;
Folding the horizontal streak to fold the bottom of the corner to form and adhere to the bottom forming step, and further comprising the steps,
During the vertical streak forming process and before the folding process, the back and left and right sides of the back surface, excluding the range corresponding to the front surface, the second horizontal streaks perpendicular to the conveying direction, which becomes the valley fold line after the square bottom molding Performing the second horizontal streak forming step to pre-form in the width direction range of the gusset half adjacent to the side part,
During the folding process, a correction process is performed in which the contact correction body is brought into surface contact from the top at a correction speed adjusted and set with respect to the folded back surface, and is corrected and conveyed.
In the correction step, the entire back surface is adjusted with respect to the front surface by transporting the upper surface at a correction speed different from the transport speed while being placed and transported at the predetermined transport speed. To correct the deviation to be within the specified range.
In the correction step, the surface contact range of the contact correction body includes a length in the conveying direction from the folded back portion of the back surface to the bottom folded portion end. Each process consisting of the vertical stripe forming process, the gusset folding process, the second horizontal stripe forming process, the folding process, the horizontal stripe forming process, and the square bottom forming process is performed as a first process set. After that, each process consisting of the vertical stripe forming process, the gusset folding process, the second horizontal stripe forming process, the folding process and the correcting process, the horizontal stripe forming process, and the square bottom forming process. A method of manufacturing a square bottom bag as a second process set,
The contact correction body is driven by a drive mechanism different from the drive mechanism of the transporter,
Furthermore, it has a variable adjuster that variably adjusts the speed difference between the transport speed of the transport machine and the correction speed of the contact correction body to a predetermined adjustment value,
In the correction step in the second step set,
In the variable adjuster, a positive or negative adjustment value is set based on the amount of deviation between the corner of the upper edge of the back surface and the corner of the upper edge of the front surface in the folding process, and the adjusted value is set to the adjusted value. The manufacturing method of the square bottom bag of Claim 1 which controls the drive force of the drive mechanism of a contact correction body based on.   The correction contact surface of the contact correction body in the correction process is a friction test using an inclination method based on JISP8147, and the slip angle in the test condition of the weight contact load 500 kgf between the contact correction bodies having a measurement surface of 60 mm square is 31.0 °. The manufacturing method of the square bottom bag of Claim 1 or 2 exceeding.   In the second horizontal streak forming step, the horizontal streak forming knife is pressed within a predetermined non-continuous range, and an upper presser for preventing lifting is formed on the upstream side or the downstream side of the horizontal streak forming knife. The manufacturing method of the square bottom bag of any one of Claim 1, 2, or 3 which regulates a lift by contacting a piece upwards in an upper pressing part.

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