JP4942086B2 - Method for producing packaging bag for maintaining freshness of fruits and vegetables and packaging bag for maintaining freshness of fruits and vegetables manufactured by the same method - Google Patents

Description

  The present invention relates to a method for producing a packaging bag suitable for maintaining the freshness of fruits and vegetables, and a packaging bag produced by the method.

  Conventionally, there is a packaging bag formed from a biaxially stretched polypropylene film (hereinafter also referred to as “OPP film”) that is excellent in economic efficiency, transparency, heat-weldability, and appearance.

  And in such a packaging bag, the gas permeability is too low, it becomes an excessively low oxygen and high carbon dioxide state, and the quality deterioration tends to proceed rapidly, so generally the upper part of the bag is left unsealed, Alternatively, it is lightly folded and taped.

In addition, there is a type in which fine holes are formed in the packaging bag to suppress the gas permeability (for example, see Patent Documents 1 and 2).
JP-A-2-85181 Japanese Patent Laid-Open No. 6-22686

  However, if the packaging bag is not sealed, the original freshness maintaining effect is not exhibited, and there is a problem that the freshness is lowered in a very short time.

  Further, a packaging bag in which fine holes are formed after sealing is expensive because an operation step for forming fine holes is required.

  The present invention has been made in view of such circumstances, and even when fruits and vegetables are sealed, the oxygen and carbon dioxide concentrations in the bag can be maintained at suitable values, while being excellent in economy. The manufacturing method of a packaging bag provided with the property, transparency, heat-welding property, and appearance, and the packaging bag manufactured by the same method are provided.

In order to solve the above-mentioned problem, in the method for producing a packaging bag for maintaining freshness of fruits and vegetables according to the present invention, it has a thickness of 8 to 30 μm and an oxygen permeability at 20 ° C. of 1000 to 3750 cc / m ² · day · atm A first roll obtained by winding a biaxially stretched polypropylene film and an unstretched polypropylene film having a thickness of 20 to 40 μm and an oxygen permeability at 20 ° C. of 1500 to 6000 cc / m ² · day · atm. This is a method for producing a freshness-maintaining packaging bag for fruits and vegetables, in which a biaxially stretched polypropylene film and an unstretched polypropylene film are fused by heat while cutting a biaxially stretched polypropylene film and an unstretched polypropylene film. Te, a biaxially oriented polypropylene film drawn out from the first roll, and a non-oriented polypropylene film drawn from said second roll, the overlapping step of overlapping while conveying respectively, superimposed Fi The arm, while feeding in a predetermined direction, and a bottom portion forming step of sealing with hot blown along a same predetermined direction, in a direction intersecting the forming direction of the bottom portion formed by the bottom forming step, the biaxially oriented A bag forming step in which a hot blade is brought into contact from the polypropylene film side, and the biaxially stretched polypropylene film melted while being thermally melted is entangled with the unstretched polypropylene film to form a side portion by sealing the film. And so on.

  The following points are also characteristic.

Prior Kisoko portion forming step, 3 50 welded end portions while fusing at a temperature of ± 5 ° C., in the bag forming process, welded end portions while fusing at a temperature of 3 80 ± 5 ° C. thing.

Before the Kisoko portion forming step, the tension of the biaxially oriented polypropylene film drawn out from the first roll is greater than the tension of the non-stretched polypropylene film drawn out from the second roll.

Furthermore, in the packaging bag for freshness preservation of fruit and vegetables which concerns on this invention, it decided to manufacture with the manufacturing method of the packaging bag for freshness preservation of fruit and vegetables of any one of Claims 1-3 .

The method for producing a packaging bag for maintaining freshness of fruits and vegetables according to claim 1, wherein the biaxially oriented polypropylene has a thickness of 8 to 30 µm and an oxygen permeability at 20 ° C of 1000 to 3750 cc / m ² · day · atm. A first roll wound with a film and a second roll wound with an unstretched polypropylene film having a thickness of 20 to 40 μm and an oxygen permeability at 20 ° C. of 1500 to 6000 cc / m ² · day · atm A roll and a biaxially stretched polypropylene film and a non-stretched polypropylene film while thermally fusing the ends thereof to produce a packaging bag for maintaining freshness of fruits and vegetables , transportable and biaxially oriented polypropylene film drawn out from the roll, and a non-stretched polypropylene film drawn from said second roll, the overlapping step of overlapping while conveying respectively, the superposed film, in a predetermined direction And while, the contact with the bottom forming step of sealing with hot blown along a same predetermined direction, in a direction intersecting the forming direction of the bottom portion formed by the bottom forming step, a heat blade from the biaxially oriented polypropylene film side The biaxially stretched polypropylene film melted while being thermally melted is entangled with the unstretched polypropylene film and sealed to form a side portion, and a bag forming step for making the film into a bag shape. , One side can be an OPP film with economy, transparency, heat-weldability and appearance, the other side can be a CPP film with good gas permeability, and even if the packaging bag is sealed, A packaging bag for maintaining the freshness of fruits and vegetables that can maintain the freshness of the fruits and vegetables stored therein can be manufactured.

In the manufacturing method of the fruits or vegetables Freshness packaging bag according to claim 2, in the bottom portion forming step, welding the blown while ends at a temperature of 3 50 ± 5 ° C., in a bag forming step, 3 80 ± 5 ℃ of temperature fusing welded to the ends while Runode, can be welded without distortion and different OPP film and the CPP film melting point.

Moreover, in the manufacturing method of the packaging bag for freshness preservation of fruit and vegetables of Claim 3 , in the bottom part formation process, the tension | tensile_strength of the unstretched polypropylene film pulled out from the 2nd roll is biaxially stretched | drawn out from the 1st roll. Since the tension is lower than that of the polypropylene film, the OPP film and the CPP film having different melting points can be further welded without distortion.

Furthermore, in the packaging bag for freshness maintenance of the fruits and vegetables of Claim 4 , since it manufactures with the manufacturing method of the packaging bag of any one of Claims 1-3, even if a packaging bag is sealed, inside It can be set as the packaging bag for freshness preservation of the fruits and vegetables which can maintain the freshness of the fruits and vegetables stored in the container.

  In the method for manufacturing a packaging bag according to the present invention, the biaxially stretched polypropylene film pulled out from the first roll and the unstretched polypropylene film pulled out from the second roll are overlapped with each other while being transported. The bottom forming step of sealing the film while conveying the film in a predetermined direction and heat-treating along the predetermined direction, and the side sealed and heat-treated in the direction intersecting the forming direction of the bottom formed in the bottom forming step Forming a portion and forming a film into a bag shape.

  That is, in the present invention, the OPP film wound around the first roll and the CPP film wound around the second roll are transported and overlapped with each other with different tensions. Crossing the bottom forming process in which the film is transported in a predetermined direction and the heated hot blade is brought into contact with the predetermined direction and sealed while thermally fusing, and the forming direction of the bottom formed in the bottom forming process A hot blade heated in the direction, sealed while thermally fusing to form a side part, and a side part forming step for making the film into a bag shape, and transporting and storing the formed packaging bag on a conveyor Like to do.

  Therefore, an OPP film having a different melting point and a CPP film can be thermally welded into a bag shape, and a packaging bag that can maintain the freshness of fruits and vegetables stored therein even when the packaging bag is sealed. It can be manufactured continuously in a series of process flows.

  Here, when the heated hot blade is brought into contact with the stacked films and thermally melted, it is preferable that the film having a low melting point is thermally melted while the hot blade is brought into contact with the film from the high melting point side. Specifically, it may be blown by contacting a hot blade from the side of the OPP film having a high melting point.

  According to such a thermal fusing method, biaxially stretched polypropylene (hereinafter referred to as OPP) melted at the end of the OPP film at the moment of fusing with a hot blade, is also blown with the hot blade. Since it can be entangled with the end portion of the CPP film, the end portions of the stacked films can be welded without distortion, and the strength of the welded portion can be made sufficient.

  The temperature of the hot blade is such that the film wound on the first roll and the film wound on the second roll are superposed and thermally fused to form a bag, and the first roll and the first roll When the roll of 2 is an OPP film, the temperature is lower than the temperature when the laminated film is thermally fused with a hot blade, and when the first roll and the second roll are CPP films, It is preferable to set the temperature higher than the temperature at which the film is thermally fused with a hot blade.

  More specifically, it is set to 350 ± 5 ° C. in the bottom forming step and 380 ± 5 ° C. in the side forming step, so that the welded portion obtained by thermally fusing the stacked films can be efficiently packaged. Can be manufactured.

  In the bottom forming step, the tension of the unstretched polypropylene film drawn from the second roll is adjusted to be smaller than the tension of the biaxially stretched polypropylene film drawn from the first roll.

  Since this CPP film has the property that it is easier to stretch than the OPP film, if the same tension as the OPP film is applied to the CPP film, the CPP film will shrink when released from the tension, and the manufactured packaging bag It will be warped.

  Therefore, by setting the tension applied to the film in advance to be CPP film <OPP film, the shrinkage of the CPP film that occurs when released from the tension can be made equivalent to that of the OPP film. Can be prevented.

  Here, the tension applied to each film is preferably about CPP film: OPP film = 1: 2. By setting it as such tension | tensile_strength, it can be set as a moderate shrinkage | contraction and the curvature of the manufactured packaging bag can be prevented, making the welding part which carried out the heat fusing good state.

Further, it is desirable that the OPP film and the CPP film can transmit a predetermined amount of oxygen. That is, for the OPP film, the oxygen permeability at 20 ° C. is 1000 to 3750 cc / m ² · day · atm, more preferably 1200 to 1800 cc / m ² · day · atm, and for the CPP film, 20 ° C. oxygen permeability ^{1500~6000cc / m 2 · day · atm} , more preferably those which are 2000~5000cc / m ² · day · atm good at.

  By using a film having oxygen permeability such as these, a packaging bag that can keep the freshness of vegetables and fruits good can be made.

  Also, since the thickness of the film affects the processability when making a packaging bag, it is 8-30 μm for an OPP film, preferably 10-25 μm, more preferably 15-25 μm. For example, 20-40 μm, preferably 20-30 μm, more preferably 20-25 μm.

  By using a film having such a thickness, a packaging bag that can maintain good freshness of vegetables and fruits can be produced.

  In addition, because fruits and vegetables such as vegetables and fruits have different breathing rates and deterioration rates depending on the variety, harvest time, production area, distribution conditions, storage conditions, and sales conditions, for example, the thickness of the film can be reduced for vegetable packaging bags and fruits. You may make it change with a packaging bag.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a flow showing a manufacturing process of an embodiment according to the present invention. In the method for manufacturing a packaging bag according to the present invention, the tension adjusting step (step S1), the overlapping step (step S2), the bottom portion forming step (step S3), the side portion forming step (step S4), the conveying step (step S5), Bag making is performed through six processes including a storage process (step S6).

  FIG. 2 is an explanatory view schematically showing a bag making machine A for producing a packaging bag according to the present invention. The bag making machine A is provided with a first roll 11 wound with an OPP film 19 and a second roll 12 wound with a CPP film 20, and the OPP film 19 drawn from the rolls 11 and 12, The packaging bag 18 is manufactured in a so-called two-by-one manner by superposing the CPP film 20 and thermally fusing it. In the following, description will be given in order along the flow shown in FIG.

[Tension adjustment process]
First, in the tension adjusting step, a predetermined tension is applied to the OPP film 19 and the CPP film 20 drawn out from the rolls 11 and 12, so that the bag 18 is not warped when the bag is made ( Step S1).

  The OPP film 19 pulled out from the first roll 11 includes a first guide roller 30, a second guide roller 31, and a first tension roller 13 disposed below the first and second guide rollers 30, 31. , Respectively.

  The first tension roller 13 is a moving pulley-like roller that can move in the vertical direction. The tension of the first tension roller 13 is pushed downward by a tension adjusting device (not shown) to apply tension to the OPP film 19. I try to put it on.

  On the other hand, similarly to the first roll, the CPP film 20 drawn from the second roll 12 is below the third guide roller 32, the fourth guide roller 33, and the third and fourth guide rollers 32, 33. Are respectively wound around the second tension roller 14 disposed on the belt.

  The second tension roller 14 is also a moving pulley-like roller that can move in the vertical direction. By pressing the shaft of the second tension roller 14 downward by a tension adjusting device (not shown), the CPP film 20 The tension is applied to the.

  Here, the tension applied to the CPP film 20 by the second tension roller is about one half of the tension applied to the OPP film by the first tension roller 13. However, it is a matter of course that these tensions are appropriately adjusted according to the temperature of the film and the humidity during production.

  Thereby, the difference in shrinkage caused by the difference in the film material is corrected to prevent warping of the packaging bag after bag making.

  The tension rollers 13 and 14 can weaken the tension by moving the shaft upward.

  In this embodiment, the tension is adjusted by one guide roller and one tension roller for one film, but the present invention is not limited to this, and the buffer area of the film during the flow operation Therefore, more guide rollers and a plurality of tension rollers may be provided.

[Stacking process]
Next, the OPP film 19 and the CPP film 20 that have undergone the tension adjustment process are conveyed to the overlapping process. In this overlapping step, the films are overlapped with each other while maintaining the tension applied thereto to form a double film 21. (Step S2).

  That is, the OPP film 19 that has passed through the second guide roller 31 is wound around the fifth guide roller 34, the CPP film 20 that has passed through the fourth guide roller 33 is wound around the sixth guide roller 35, and the other film is applied to one film. Are brought into contact with each other to form a double film 21.

  A seventh guide roller 36 and a pressing roller 37 are disposed downstream of the fourth guide roller 33 and the sixth guide roller 35, and a gap between the seventh guide roller 36 and the pressing roller 37 is provided. By sandwiching the double film 21, the tension of the film is maintained.

  Therefore, the double film 21 can be formed while maintaining the tension applied to each film in the tension adjusting step.

[Bottom forming process]
Next, a bottom portion forming step is performed in which the substantially central portion in the width direction of the double film 21 formed in the overlapping step is continuously melted to form the bottom portion 41 (step S3).

  FIG. 3 shows a state in which the double film 21 is viewed from the front in the bottom forming step, and the temperature is set to 350 ± 5 ° C. at the substantially central portion in the width direction of the double film 21 indicated by the symbol B in the figure. At the same time, the bottom forming hot blade 15 was brought into contact with and melted, and at the same time, the end of the OPP film 19 and the end of the CPP film 20 were welded along the length direction of the double film 21. A bottom 41 is formed. In FIG. 3, white arrows indicate the direction in which the double film 21 flows.

  Here, the bottom forming hot blade 15 may be anything that is generally used as a hot blade for bag making, and is particularly limited as long as the end portion can be welded while cutting the double film 21. It is not something.

(Side formation process)
Next, the double film 21 in which the bottom portion 41 is formed in the bottom portion forming step is thermally cut in the width direction to form a side portion to form a bag (step S4).

  In this side portion forming step, as shown in FIG. 2, a side portion forming hot blade 16 that can be moved up and down at predetermined time intervals on the upper portion of a roll conveyor 17 in which a plurality of rolls are arranged in parallel. The double film 21 that has undergone the bottom forming process is passed through the gap between the roll conveyor 17 and the side forming hot blade 16, and the side forming hot blade 16 is moved up and down at a predetermined time interval. When the sheet is moved downward, the double film 21 is brought into contact with the double film 21 to be melted and melted to form a side portion 42 in a direction intersecting with the bottom portion 41 as shown by a broken line in FIG. I am doing so. In addition, the white arrow in FIG. 4 indicates the direction in which the double film 21 flows.

  The time interval of the vertical movement of the side forming hot blade 16 can be adjusted as appropriate according to the size of the packaging bag 18 to be manufactured.By increasing the time interval of the vertical movement, the internal volume is increased. By shortening the time interval, the packaging bag 18 having a small internal volume can be manufactured.

  Here, the side forming hot blade 16 is brought into contact from the film side having the high melting point of the double film 21, that is, from the OPP film 19 side in this embodiment.

  That is, first, the OPP film 19 having a high melting point is melted and cut, and the melted OPP film 19 is entangled with the CPP film 20 so that an enlarged sectional view of the welded portion of the side portion 42 shown in FIG. As described above, the seal ball 43 is formed on the side portion 42. Therefore, when the sealing balls 43 are cooled and solidified, the side portions 42 having sufficient strength can be formed while the packaging bag 18 is composed of the OPP film 19 and the CPP film 20 having different melting points.

  If the CPP film 20 having a low melting point is first brought into contact with the side forming hot blade 16, excessive heat is applied to the CPP film 20 at the fusing portion, as shown in FIG. 5 (b). Further, there is a possibility that a cracking phenomenon occurs in the root portion of the seal ball 43, and a blocking phenomenon occurs in which the strength of the side portion 42 becomes extremely weak.

  If this blocking phenomenon occurs, a hole is formed in the packaging bag 18 from the crack 44 where the film has become thin, or tearing occurs when fruits and vegetables are stored in the packaging bag 18, which is not preferable.

  Therefore, in order to prevent the blocking phenomenon, it is preferable that the side forming hot blade 16 is first brought into contact with the OPP film 19 having a high melting point.

  Further, the temperature of the side forming hot blade 16 is adjusted to 380 ± 5 ° C. Accordingly, the seal balls 43 that can maintain sufficient strength can be formed on the side portions 42, and the packaging bag 18 can be efficiently manufactured.

[Transport process]
Next, a transporting process is performed in which the packaging bag 18 formed in the side part forming process is placed on the roll conveyor 17 and transported to the storage part 6 provided at the terminal part of the roll conveyor 17 (step S5). ).

  Here, as shown in FIG. 2, the packaging bag 18 on the roll conveyor 17 is placed so that the CPP film 20 side contacts the roll conveyor 17.

  Therefore, since the CPP film 20 with good slipping property comes into contact with the rotating roll conveyor 17, the packaging bag 18 can be smoothly conveyed up to the storage unit 6.

  In the side part forming step, the CPP film 20 side of the double film 21 is faced down, and the side part forming hot blade 16 is contacted from the OPP film side without the need to invert the formed packaging bag 18. Since it can be transported as it is by the roll conveyor 17 in this transport process, the labor required for reversal can be reduced, and the production cost can be reduced.

[Storage process]
And the storage process which piles up the packaging bag 18 sent through the conveyance process and stores it in the storage part 6 is performed (step S6).

  In this storage step, the packaging bag 18 may be stored in the storage unit 6 manually, or a bundle of the packaging bags 18 may be mechanically formed and stored in the storage unit 6.

  As shown in FIG. 6, the packaging bag 18 stored in this manner is composed of an OPP film 19 and a CPP film 20, and a welded bottom portion 41 and side portions 42 and 42, and an opening 45 formed in the upper portion. And a bag body.

  Note that the manufacturing method of the packaging bag 18 according to the present invention and the packaging bag 18 manufactured by the method have been described so far with reference to the drawings, but can be appropriately changed without departing from the concept of the present invention. Needless to say.

  For example, in this embodiment, the bottom portion 41 is formed by fusing the substantially central portion in the width direction of the double film 21, and the side forming hot blade 16 contacts the double film 21 once in the subsequent side portion forming step. Although the manufacturing method by what is called two picking which can obtain the two packaging bags 18 by this was demonstrated, it is not limited to this, It can apply also to the manufacturing method by one picking.

  Further, in the bottom forming step, the bottom forming hot blade 15 is continuously brought into contact with the double film 21 to form the bottom 41. However, the present invention is not limited to this, and is similar to the side forming hot blade 16. The bottom 41 may be formed by heat welding using the above method.

  Further, the packaging bag 18 manufactured in the present embodiment is a substantially rectangular bag body, but is not limited to this, and the substantially trapezoidal bag body and the side portion 42 also serve as the bottom portion 41. It may be triangular. As an example, the packaging bag 18 having these shapes may be provided with a plurality of side-forming hot blades 16 in a substantially eight-letter shape, or by changing the angle with respect to the flow direction of the double film 21. Can be manufactured.

  Next, a description will be given of a test in which a gas analysis was performed using the thus produced packaging bag 18 according to the present invention when the fruits and vegetables were stored and stored in the packaging bag 18.

[Measurement of oxygen permeability of each film]
First, prior to the fruit and vegetable test, the oxygen permeability of the OPP film and the CPP film was measured. This test was conducted according to JIS K 7126 B method at 20 ° C. and humidity 80%.

表１にも示すように、OPPフィルム及びCPPフィルムともに、フィルムの厚みが薄くなるにしたがって、酸素透過性が高くなる傾向が見られた。また、OPPフィルムとCPPフィルムとを比較すると、同じ厚みのフィルムであれば、CPPフィルムはOPPフィルムに比して酸素透過性が高いことが示された。

As shown in Table 1, both the OPP film and the CPP film tended to have higher oxygen permeability as the film thickness decreased. Further, when the OPP film and the CPP film were compared, it was shown that the CPP film had higher oxygen permeability than the OPP film if the film had the same thickness.

  About the packaging bag formed based on these data, the result of actually storing fruits and vegetables and measuring the internal gas concentration is shown below.

[Komatsuna preservation test 1]
Seven kinds of packaging bags with different film materials and thicknesses are formed, and the mustard vegetables are stored in each packaging bag and stored at a predetermined temperature. The amount of oxygen and carbon dioxide in the packaging bags, and the freshness of the appearance of the mustard vegetables A test was performed for changes over time. Seven types of packaging bags formed to be used for this test are as follows. The “handkerchief fold” described in each pattern of the packaging bag described below refers to a state where the opening portion of the bag is folded and locked.

  Pattern (1) packaging bag: Two OPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. However, the upper part was left open.

  Pattern (2) packaging bag: Two OPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42, 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. However, the upper part was folded into a handkerchief.

  Pattern (3) packaging bag: Two CPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (4) packaging bag: OPP film with a thickness of 25μm and CPP film with a thickness of 20μm are stacked to form the bottom 41 and side portions 42 and 42 by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Packaging bag of pattern (5): OPP film with a thickness of 25μm and CPP film with a thickness of 25μm are overlapped, and the bottom 41 and side portions 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18, the upper opening 45 of the upper part was thermally welded to be in a sealed state.

  Pattern (6) packaging bag: OPP film with a thickness of 25μm and CPP film with a thickness of 30μm are overlapped, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (7) packaging bag: Two OPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Then, the change over time in the gas concentration (%) of Komatsuna was measured under the condition of room temperature of 15 ° C., and the change over time in the freshness of Komatsuna under the condition of room temperature of 15 ° C. was investigated over a maximum of 8 days. In this test, the thickness of the OPP film was fixed at 25 μm, which is currently widely used as a packaging bag for Komatsuna, and data was collected by changing the thickness of the CPP film. This includes the intention to reduce the manufacturing cost of the packaging bag according to the present invention by using a commonly used material as much as possible. These results are shown in Tables 2 and 3.

表２及び表３から分かるように、OPPフィルムとOPPフィルム、または、CPPフィルムとCPPフィルムを組み合わせて形成した両面同素材の包装袋よりも、OPPフィルムとCPPフィルムを組み合わせて形成した包装袋の方が良好な結果が得られた。

As can be seen from Table 2 and Table 3, the packaging bag formed by combining the OPP film and the CPP film rather than the OPP film and the OPP film or the packaging bag of the same material formed by combining the CPP film and the CPP film. Better results were obtained.

  That is, while the thickness of the OPP film is fixed to 25 μm for the reasons described above, the oxygen permeability decreases as the thickness of the CPP film increases, so that the oxygen concentration in the packaging bag decreases and the carbon dioxide concentration increases. It was suggested that the progress of yellowing was suppressed.

  Further, when paying attention to the packaging bag of the pattern (7) sealed with the double-sided OPP film, the oxygen concentration on the eighth day was substantially the same as the oxygen concentration on the eighth day of the pattern (6). Odor was observed due to the high carbon concentration.

[Komatsuna preservation test 2]
Next, based on the result of the Komatsuna preservation test 1, the Komatsuna preservation test 2 was conducted in order to optimize the gas environment in the packaging bag.

  As shown in Tables 2 and 3, when the test was conducted with one side fixed to a 25 μm thick OPP film in Komatsuna preservation test 1, when a 30 μm thick CPP film was applied to the other side, 15 Odor generation was confirmed by storage at 8 ° C. for 8 days. Therefore, it was shown that the generation of a strange odor can be avoided by reducing the thickness of the CPP film to 25 μm or 20 μm. However, the oxygen concentration in the packaging bag is considerably lower than that at the start of the test, and there is a risk that the fruits and vegetables may generate an odor by performing anaerobic breathing.

  Therefore, in order to obtain an optimum gas environment that maintains quality and does not cause anaerobic breathing, in this Komatsuna preservation test 2, the thickness of the OPP film was changed and examined. The following seven types of packaging bags were formed for use in this test.

  Pattern (1) packaging bag: Two OPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. However, the upper part was a handkerchief fold.

  Pattern (2) packaging bag: OPP film with a thickness of 15μm and CPP film with a thickness of 20μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (3) packaging bag: OPP film with a thickness of 15μm and CPP film with a thickness of 25μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (4) packaging bag: OPP film with a thickness of 20μm and CPP film with a thickness of 20μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (5) packaging bag: OPP film with a thickness of 20μm and CPP film with a thickness of 25μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (6) packaging bag: OPP film with a thickness of 25μm and CPP film with a thickness of 20μm are overlapped, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (7) packaging bag: OPP film with a thickness of 25μm and CPP film with a thickness of 25μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  And the change with time of the gas concentration (%) of Komatsuna was measured over a maximum of 8 days under the condition of room temperature of 15 ° C. The results are shown in Table 4.

表４からも分かるように、OPPフィルムの厚みが薄くなるほど、包装袋内の酸素濃度は高くなり二酸化炭素濃度は低くなった。厚み15μｍのOPPフィルムと厚み20μｍのCPPフィルムとを貼り合わせた最もガス透過度の高いと考えられる包装袋では、十分な酸素濃度の低下は認められなかった。

As can be seen from Table 4, the thinner the OPP film, the higher the oxygen concentration in the packaging bag and the lower the carbon dioxide concentration. In the packaging bag considered to have the highest gas permeability, which is a laminate of a 15 μm thick OPP film and a 20 μm thick CPP film, a sufficient decrease in oxygen concentration was not observed.

  Also, a 15 μm thick OPP film and a 25 μm thick CPP film, a 20 μm thick OPP film and a 20 μm thick CPP film, a 20 μm thick OPP film and a 25 μm thick CPP film, or a 25 μm thick OPP film and a 20 μm thick CPP film. In combination with pineapple, yellowing and off-flavour were suppressed and freshness was maintained.

[Komatsuna preservation test 3]
Form the packaging bags of patterns (1) to (7) of the above-mentioned Komatsuna preservation test 1 and store the Komatsuna in each packaging bag, and change with time in the gas concentration (%) of the Komatsuna at room temperature of 25 ° C. And the time course of appearance freshness of Komatsuna was investigated under the condition of room temperature of 25 ° C. These results are shown in Tables 5 and 6.

表５及び表６から分かるように、保存温度を25℃とした場合であっても、OPPフィルムとOPPフィルム、または、CPPフィルムとCPPフィルムを組み合わせて形成した両面同素材の包装袋よりも、OPPフィルムとCPPフィルムを組み合わせて形成した包装袋の方が良好な結果が得られた。

As can be seen from Table 5 and Table 6, even when the storage temperature is 25 ° C., rather than a double-sided packaging bag of the same material formed by combining OPP film and OPP film, or CPP film and CPP film, Better results were obtained with packaging bags formed by combining OPP and CPP films.

  In addition, the same tendency as in Komatsuna preservation test 1 was observed, and as the thickness of the CPP film increased, the oxygen permeability decreased, so the oxygen concentration in the packaging bag decreased and the carbon dioxide concentration increased, resulting in yellowing. It was suggested that the progression of the is suppressed.

  Further, focusing on the packaging bag of the pattern (3) sealed with the double-sided CPP film, the oxygen concentration on the 6th day was substantially the same as the oxygen concentration on the 6th day of the pattern (4). Due to the low carbon concentration, slightly yellowing was observed compared to pattern (4).

  Focusing on the packaging bag with the pattern (5) sealed with a 20 μm thick OPP film and a 25 μm thick CPP film, the oxygen concentration on the 6th day is almost the same as the pattern (5) in the komatsuna preservation test 1 However, due to the high storage temperature, generation of off-flavors was observed.

[Komatsuna preservation test 4]
Next, based on the results of the above-mentioned Komatsuna preservation tests 1 to 3, tests were conducted on the reproducibility of changes in the gas environment in the packaging bag. In addition, we also examined whether the OPP film alone can maintain freshness. The following 10 types of packaging bags were formed for use in this test.

  Pattern (1) packaging bag: Two OPP films with a thickness of 25μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. However, the upper part was a handkerchief fold.

  Pattern (2) packaging bag: OPP film with a thickness of 20μm and CPP film with a thickness of 20μm are stacked, and the bottom 41 and side portions 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (3) packaging bag: OPP film with a thickness of 20μm and CPP film with a thickness of 25μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (4) packaging bag: OPP film with a thickness of 20μm and CPP film with a thickness of 30μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (5) packaging bag: OPP film with a thickness of 15 μm and CPP film with a thickness of 25 μm are stacked, and the bottom 41 and side portions 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (6) packaging bag: OPP film with a thickness of 25μm and CPP film with a thickness of 25μm are stacked, and the bottom 41 and sides 42 and 42 are formed by heat welding. A 380 mm packaging bag 18 was formed. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (7) packaging bag: Two OPP films with a thickness of 15μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (8) packaging bag: Two OPP films with a thickness of 20μm are stacked, the bottom 41 and sides 42 and 42 are formed by heat welding, the inner dimensions are 230mm in width and 380mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (9) packaging bag: Two OPP films with a thickness of 25 μm are stacked, and the bottom 41 and side portions 42 and 42 are formed by heat welding, and the actual inner dimensions are 230 mm in width and 380 mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (10) packaging bag: Two 20-μm thick CPP films are stacked, bottom 41 and sides 42 and 42 are formed by thermal welding, and the actual inner dimensions are 230mm in width and 380mm in height. Was molded. Then, after the komatsuna was stored in the packaging bag 18 formed in each pattern, the upper opening 45 was thermally welded to be in a sealed state.

  Then, the change over time in the gas concentration (%) of Japanese mustard spinach was measured under conditions of room temperature of 15 ° C., and the change over time in the freshness of Japanese mustard spinach under the conditions of room temperature of 15 ° C. was investigated over a maximum of 9 days. The results are shown in Tables 7 and 8.

これらの結果から分かるように、厚み15μｍのOPPフィルムで形成した包装袋や、厚み20μｍのOPPフィルムで形成した包装袋、厚み25μｍのOPPフィルムで形成した包装袋では、異臭の発生が認められ、品質の低下が確認された。これは、保存３日目以降に包装袋内部の酸素濃度が急激に低下したためであると考えられる。

As can be seen from these results, in the packaging bag formed with the OPP film with a thickness of 15 μm, the packaging bag formed with the OPP film with a thickness of 20 μm, and the packaging bag formed with the OPP film with a thickness of 25 μm, the generation of off-flavor was observed, A decline in quality was confirmed. This is considered to be because the oxygen concentration inside the packaging bag suddenly decreased after the third storage day.

  Next, when considering a packaging bag formed by combining an OPP film and a CPP film, if the thickness of the OPP film is constant, the thicker the CPP film, the greater the concentration of oxygen in the packaging bag over time. Tended to decrease.

  Similarly, if the thickness of the CPP film is constant, the oxygen concentration in the packaging bag tends to decrease with the passage of days as the thickness of the OPP film increases.

  From these results, the combinations considered to be suitable for maintaining the freshness of Komatsuna, as suggested by the test results in Table 4, are a 15 μm thick OPP film, a 25 μm thick CPP film, and a 20 μm thick OPP film. It has been shown that packaging bags formed of 20 μm thick CPP film, 20 μm thick OPP film and 25 μm thick CPP film, 25 μm thick OPP film and 20 μm thick CPP film give good results.

  However, since the respiration rate varies depending on various factors even for the same fruits and vegetables, it is necessary to appropriately examine the combination of films.

[Leaf onion preservation test]
Form five types of packaging bags with different film materials and thickness, store leaf onions in each packaging bag and store them at a predetermined temperature, oxygen and carbon dioxide content in the packaging bags, and appearance of leaf onions Tests were conducted for changes in freshness over time. Five types of packaging bags formed to be used in this test are as follows.

  Pattern (1) packaging bag: Two OPP films with a thickness of 25μm are stacked, and the bottom 41 and sides 42, 42 are partially (spot-like) heat-sealed. A 600 mm packaging bag 18 was formed. Then, after the leaf leek was accommodated in the packaging bag 18, the upper opening 45 was partially (spot-like) heat welded to make it unsealed.

  Pattern (2) packaging bag: Two OPP films with a thickness of 20μm are stacked on top of each other, and the bottom 41 and sides 42, 42 are formed by heat welding. Was molded. Then, after the leaf leek was accommodated in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (3) packaging bag: A 20 μm thick OPP film is layered with a 30 μm thick polyethylene film (hereinafter also referred to as PE film), and the bottom 41 and the side portions 42 and 42 are formed by heat welding. A packaging bag 18 having a horizontal width of 80 mm and a height of 600 mm was formed. Then, after the leaf leek was accommodated in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (4) packaging bag: A 20μm thick OPP film and a 20μm thick CPP film are overlapped to form the bottom 41 and side portions 42 and 42 by heat welding. The packaging bag 18 was formed. Then, after the leaf leek was accommodated in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  Pattern (5) packaging bag: Two CPP films with a thickness of 20μm are stacked on top of each other, and the bottom 41 and sides 42, 42 are formed by thermal welding, and the actual inner dimensions are 80mm in width and 600mm in height. Was molded. Then, after the leaf leek was accommodated in the packaging bag 18, the upper opening 45 was thermally welded to be in a sealed state.

  And while measuring the time-dependent change of the gas concentration (%) of a leaf leek on condition of room temperature 15 degreeC, the time-dependent change of the appearance freshness of a leaf leek was investigated over a maximum of seven days on condition of room temperature 15 degreeC. . These results are shown in Tables 9 and 10.

表９及び表10から分かるように、OPPフィルムとOPPフィルム、または、CPPフィルムとCPPフィルムを組み合わせて形成した両面同素材の包装袋よりも、異種のフィルムの組み合わせ（OPPフィルムとCPPフィルム、または、OPPフィルムとPEフィルム）を組み合わせて形成した包装袋の方が良好な結果が得られた。

As can be seen from Table 9 and Table 10, a combination of different types of films (OPP film and CPP film, or OPP film and OPP film, or a double-sided packaging material made of CPP film and CPP film) , OPP film and PE film) were combined to give better results.

  That is, according to Table 10, a remarkable difference in appearance freshness was recognized on the 7th day after storage, and patterns (3) and (4) maintained the best freshness, but pattern (2) had a strange odor. Some degradation was observed in both freshness and freshness.

  Furthermore, when comparing patterns (3) and (4), which showed the best results, the transparency of CPP film is higher than that of PE film, and the visibility of contents is improved due to the nature of the packaging bag. Therefore, CPP film was considered to be more useful to improve consumers' willingness to purchase.

  From these results, the packaging bag suitable for suppressing the yellowing and off-flavor generation of leaf leek and maintaining freshness is a combination of 15-20 μm OPP film and 20-25 μm CPP film. It was suggested.

  Finally, the description of each embodiment described above is an example of the present invention, and the present invention is not limited to the above-described embodiment. For this reason, it is a matter of course that various modifications can be made in accordance with the design and the like as long as they do not depart from the technical idea according to the present invention other than the embodiments described above.

  For example, in the embodiment described in the present specification, the test is performed as a packaging bag used for Japanese mustard spinach and leaf leek, but the present invention is not limited to this and may be used for all vegetables and fruits. At this time, the thickness of the OPP film and the CPP film can be changed according to the variety of vegetables and fruits stored in the packaging bag, the production area, the harvest time, etc. The thickness of the film may be changed between a summer packaging bag for storing the harvested vegetables and a winter packaging bag for storing the vegetables harvested in winter.

It is the flow which showed the process of the manufacturing method of the packaging bag which concerns on this invention. It is explanatory drawing which showed the bag making machine for manufacturing the packaging bag which concerns on this invention. It is explanatory drawing which showed the double film in a bottom part formation process. It is explanatory drawing which showed the double film in a side part formation process. It is an expanded sectional view of the side part formed in the side part formation process. It is explanatory drawing which shows the packaging bag manufactured with the manufacturing method of the packaging bag which concerns on this invention.

Explanation of symbols

11 First roll
12 Second roll
18 Packaging bag
19 Biaxially oriented polypropylene film
20 Unstretched polypropylene film
S2 Overlay process
S3 Bottom forming process
S4 Side forming process

Claims (4)

A first roll wound with a biaxially stretched polypropylene film having a thickness of 8 to 30 μm and an oxygen permeability at 20 ° C. of 1000 to 3750 cc / m ² · day · atm, and a thickness of 20 to 40 μm Then, using a second roll wound with an unstretched polypropylene film having an oxygen permeability at 20 ° C. of 1500 to 6000 cc / m ² · day · atm, heat the biaxially stretched polypropylene film and the unstretched polypropylene film. It is a method for producing a freshness-maintaining packaging bag for fruits and vegetables that is made by fusing the ends while fusing .
A biaxially oriented polypropylene film drawn out from the first roll, and a non-oriented polypropylene film drawn from said second roll, the overlapping step of overlapping while conveying respectively,
A bottom forming step of sealing the film while transporting the stacked films in a predetermined direction while thermally fusing along the predetermined direction;
In the direction crossing the forming direction of the bottom formed in the bottom forming step, a hot blade is brought into contact with the biaxially stretched polypropylene film side, and the biaxially stretched polypropylene film melted while thermally fusing is applied to the unstretched polypropylene film. A bag forming process in which a film is formed into a bag shape by entangled and sealed to form a side part,
A method for producing a packaging bag for maintaining freshness of fruits and vegetables . In the bottom portion forming step, the ends are welded while fusing at a temperature of 3 50 ± 5 ° C.,
In the bag forming process, 3 80 manufacturing method of vegetables and fruits Freshness packaging bag according to claim 1, the ends while fusing at a temperature of ± 5 ℃ characterized welded to Rukoto. In the bottom portion forming step, the tension of the biaxially oriented polypropylene film drawn out from the first roll, according to claim 1, wherein greater than the tension of the non-stretched polypropylene film drawn out from the second roll Of manufacturing packaging bags for maintaining freshness of fruits and vegetables . Claim 1-3 fruits or vegetables Freshness packaging bag manufactured by the manufacturing method of the fruits or vegetables Freshness packaging bag of any one.

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