JP2007107017A - Film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film capable of preventing an insect, a larva of the insect or the like from invading into the inside of a package such as a cup-shaped container beforehand; and to provide a food-packaging method and a food packaged body using the film. <P>SOLUTION: Through holes for degassing, having 1-200 μm diameters are formed in a film 1 comprising a single-layer or multilayer heat-shrinkage film or the like of a polypropylene, a low-density polyethylene, an ethylene-vinyl acetate copolymer or the like over the whole area so as to have ≥500/cm<SP>2</SP>density. The film 1 in a roll shape is formed into a cylinder shape one by one and both the edge parts are heat-sealed. Two or more containers 13 storing a food such as dried noodles are transported into the inside of the cylindrical film 1 at a prescribed interval. The front and rear terminal parts of the film 1 covering the container 13 are cut to an adequate size and simultaneously heat-sealed by a heat-seal cutter 17, and the whole of the film 1 after the heat-sealing is heated and shrunk to package the container 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat-shrinkable film used for the outer packaging of food in containers.

  For example, instant foods in cups such as cup ramen, cup udon and cup fried noodles are usually stored in a cup-shaped container with a lid made of foamed polystyrene or paper, and the entire container is covered with a heat shrink film, This is done by heat shrinking the film.

  The heat-shrinkable film used at this time has a large number of minute through holes for deaeration during heat-shrinkage. In order to efficiently discharge the internal air to the outside, a hole diameter of 0. About several to several tens of through-holes of 5 mm to 2 mm are formed per one food package.

JP 47-017583 A

  However, as described above, the container is made of foamed polystyrene, paper, etc., and the lid is also simply fitted, so that the odor of food contained in the container is likely to leak to the outside. For this reason, there is a risk that small insects, insect larvae, etc. are attracted by the leaked odor and easily enter the inside of the film from the deaeration through hole of the exterior film.

  Accordingly, an object of the present invention is to provide a food packaging film that can prevent insects, insect larvae, and the like from entering the inside of a cup-shaped container package.

In order to solve the above-described problems, the invention according to claim 1 is a film for food packaging having heat shrinkability and used for the exterior of food in a container, and has 100 through-holes having a pore diameter of 1 μm to 400 μm. it is intended to provide a film characterized being formed in cm ² or more densities.

The invention according to claim 2, in the film of the invention according to claim 1, a pore diameter of the through hole is 1 m to 200 m, wherein the formation density of the through holes is 500 / cm ² or more It is said.

As described above, since the through hole having a hole diameter of 1 μm to 400 μm is formed at a density of 100 holes / cm ² or more in the film of the invention according to claim 1, the hole diameter of the through hole is 0.5 mm of the conventional hole diameter. Since it is smaller than ~ 2mm, it can prevent insects and insect larvae from entering the inside of the packaging of the container through this through-hole when used for the outer packaging of food in a container. A sufficient degassing effect can be ensured.

Further, considering only the deaeration performance, the formation density of the through-holes can be reduced as the hole diameter becomes larger. For example, if the through-hole has a hole diameter of about 200 μm to 400 μm, 100 holes / cm If it is formed at a density of about ^2, sufficient deaeration performance can be secured. However, since the smaller the hole diameter of the through-hole, the better the function of preventing insects and the like from entering, the number of through-holes having a hole diameter of 1 μm to 200 μm is particularly 500 / cm as in the film of the invention according to claim 2. It is desirable to form it at a density of ² or more. By adopting such a configuration, it is possible to more reliably prevent insects and insect larvae from entering while maintaining a sufficient deaeration effect.

  In particular, when the film of the invention according to claim 2 is used, since the through-hole diameter is very small as 1 μm to 200 μm, it is impossible to visually recognize these through-holes, and the presence of the through-holes Thus, the appearance of the food package is not impaired.

  An embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a perspective view of the film, FIG. 2 is a cross-sectional view of the film of FIG. 1, FIG. 3 is an explanatory view of the manufacturing process of the film of FIG. FIG. 5 is an explanatory view of the packaging process of the food in the container of FIG.

  First, in FIG. 1, 1 is a film for food packaging having a heat shrinkability, which is wound in a roll shape, and this film 1 is made of polypropylene, low density polyethylene, ethylene / vinyl acetate copolymer It is composed of a single layer such as a coalescence layer or a heat shrink film of these multilayers, and the thickness is 5 μm to 100 μm.

In this film 1, through holes 2 for deaeration having a hole diameter of 1 μm to 200 μm as shown in FIGS. 1 and 2 are formed at a density of 500 or more / cm ² over the entire surface. It is formed by an apparatus having a known configuration as described in Japanese Patent Publication No. 6-61858.

  This type of apparatus is basically configured as shown in FIG. 3, for example, in which 5 is a receiving roll in which a high-hardness polymer resin layer is coated on the surface of a metal roll, and 6 is on the surface. A diamond roll electrodeposited with a large number of synthetic diamonds having almost the same particle diameter, and a roll-shaped film 1 before opening is sandwiched between the receiving roll 5 and the diamond roll 6 while passing between the rolls 5 and 6. At the same time, the film 1 is passed between the rolls 5 and 7 while being sandwiched between the receiving roll 5 and the contact roll 7, and the film 1 is fed by the rotation of the feed roll 8.

  In this way, by sandwiching the film 1 between the receiving roll 5 and the diamond roll 6, the synthetic diamond on the surface of the diamond roll 6 is pressed against the film 1, and fine holes including a large number of non-through holes are formed in the film 1. It is formed.

  Further, in FIG. 3, 10 is a dielectric roll in which a large number of fine irregularities are formed, 11 is an electrode, and the film 1 in which fine holes including a large number of non-through holes are formed as described above. 10 and the electrode 11, and at this time, the film 1 is separated from the dielectric roll 10 by a predetermined gap length, and at the same time, the gap between the electrode 11 and the dielectric roll 10 and the electrode 11 is made zero. And an arc discharge is generated between the electrode 11 and the dielectric roll 10 so that the fine holes that are not penetrated through the film 1 are penetrated, and a large number of through holes 2 are formed over the entire surface of the film 1.

  At this time, it goes without saying that the diameter of the synthetic diamond to be electrodeposited on the diamond roll 6 and the discharge voltage of the arc discharge are set so that the diameter of the formed through-hole 2 is 1 μm to 200 μm.

  Next, as shown in FIG. 4, the food contained in the cup-shaped container 13 such as a cup ramen is packaged by the film 1 in which a large number of through-holes 2 are formed in this manner. A well-known pillow packaging apparatus is used, and the process is performed as shown in FIG.

  First, as shown in FIG. 5, a roll-shaped film 1 in which a large number of through-holes 2 are formed is successively drawn out and formed into a cylindrical shape by a former 15, and both edges of the cylindrical film 1 are heat-sealed. Is done. On the other hand, a plurality of containers 13 made of foamed polystyrene or the like that contains food such as dried noodles, powdered soup, and kayakaku and whose openings are closed by a lid are formed on the inner side of the tubular film 1 at predetermined intervals. It is conveyed in synchronization with the feed.

  Next, as shown in FIG. 5, the front and rear end portions of the film 1 covering the container 13 are cut into appropriate dimensions by the heat seal cutter 17 and simultaneously heat sealed, and then the entire film 1 is heated by blowing hot air or the like. The packaging of the container 13 by the food packaging body 18 made of the film 1 which is shrunk and has a large number of through holes 2 is completed. Here, when the film 1 is heated and shrunk, the air between the container 13 and the film 1 is discharged to the outside of the film 1 through the numerous through holes 2 in which the film 1 is formed.

In addition, as a suitable example in the packaging of such a cup ramen, the heat shrink film made of polypropylene having a thickness of 15 μm in which through holes 2 having a hole diameter of 1 μm to 80 μm are formed at a density of 1000 holes / cm ² or more on the film 1. Is preferably used.

By the way, when the hole diameter of the through-hole 2 is smaller than 1 μm, it is difficult to discharge the air between the film 1 and the container 13 through the through-hole 2 when the film 1 is heated and contracted, whereas the hole diameter of the through-hole 2 is more than 400 μm. If it is large, there is a disadvantage that insects and insect larvae easily enter the inside of the film 1 through the through holes 2. On the other hand, if the formation density of the through holes 2 is smaller than 100 holes / cm ² , it becomes impossible to obtain a sufficient degassing effect when the film 1 is heated and contracted in combination with the setting conditions of the hole diameter.

Furthermore, practically, that is, as a condition for production without causing a reduction in line speed on an actual food production line, the through hole 2 having a pore diameter of 3 μm to 200 μm has a formation density of 1000 holes / cm ² or more. It is preferable.

  Therefore, according to the above-described embodiment, since the hole diameter of the through-hole 2 is as small as 1 to 200 μm as compared with the conventional case, when used for the exterior of the food in a container, insects, insect larvae, etc. Further, it is possible to prevent the penetration of the through hole 2 from the outside, and the appearance is not impaired.

Furthermore, since the through holes 2 are formed at a density of 500 pieces / cm ² or more, it is possible to ensure a sufficient deaeration effect when the film 1 is heated and contracted, in combination with the setting conditions of the diameter of the through holes 2. The air can be prevented from remaining between the film 1 and the container 13.

  Further, as another embodiment of the present invention, the through-hole 2 may be formed not only on the entire surface of the film 1 but only in a band-like region along the longitudinal direction of the film 1 as shown in FIG. In this case, the belt-like region of the through-hole 2 is not limited to two places as shown in FIG. 6, and may be one place or three places or more.

  And when packaging a container by the film 1 which formed the through-hole 2 partially in this way, as shown by the dashed-dotted line in FIG. 7, the formation area of the through-hole 2 on each surface of the upper and lower surfaces and the side of the container It is desirable to package so that

  In this way, when the film 1 is heated and shrunk, the air between the upper and lower surfaces and the side surfaces of the container and the film 1 can be effectively discharged to the outside, and when the film 1 is printed, By performing printing on a portion other than the portion where the through hole 2 is formed, it is possible to perform good printing without causing the through hole 2 to interfere with printing.

In addition, in the said embodiment, although the through-hole 2 with a hole diameter of 1 micrometer-200 micrometers is formed by the density of 500 piece / cm < ² > or more, the hole diameter and formation density of the through-hole 2 are limited to such a range. However, if the pore diameter is in the range of 1 μm to 400 μm and the formation density is 100 / cm ² or more, the sufficient deaeration effect and insect repellent effect as described above can be ensured. For example, when the hole diameter of the through-hole 2 is relatively large as 200 μm to 400 μm, sufficient deaeration performance can be ensured even if the formation density of the through-holes 2 is set to about 100 holes / cm ² .

  Moreover, in the said embodiment, when forming the through-hole 2 of the film 1, the micropore containing a non-through-hole is formed by pressing an unprocessed film against the diamond roll 6 which electrodeposited the synthetic diamond on the surface. The through holes 2 having a diameter of 1 μm to 200 μm were formed by penetrating the non-through holes by arc discharge. However, when the through holes 2 can be obtained without arc discharge, it is not necessary to perform arc discharge.

  Further, instead of the synthetic diamond, other fine hard particles may be used, and the through holes 2 may be formed in the film 1 by a large number of fine needles.

  In particular, when the diameter of the through-hole 2 is set to a relatively large value of 200 μm to 400 μm, the through-hole 2 is reliably penetrated only by the needle-like body without using a hole-opening device having a diamond roll and an arc discharge portion. Since a hole can be formed, when forming the through-hole 2 with such a needle-like body, the existing packaging apparatus for packaging the container while forming the through-hole in the film can be easily improved by slightly improving the existing packaging apparatus. There is an effect that it can respond.

  Furthermore, in the above-described embodiment, the case of wrapping the cup ramen as an example has been described. However, examples suitable for applying the present invention are not limited to the cup ramen, and the material in which the odor of the contents easily leaks. It is desirable that the food be contained in a container.

It is a one part perspective view of one embodiment of this invention. It is a fragmentary sectional view same as the above. It is explanatory drawing of a one part manufacturing process same as the above. It is a perspective view of a packaging state same as the above. It is explanatory drawing of a packaging process same as the above. It is a one part perspective view of other embodiment of this invention. It is a perspective view of a packaging state same as the above.

Explanation of symbols

1 Film 2 Through-hole 13 Container

Claims (2)

In a film for food packaging that has heat shrinkability and is used for the exterior of food in containers,
A film characterized in that through-holes having a pore diameter of 1 μm to 400 μm are formed at a density of 100 holes / cm ² or more. ^2. The film according to claim 1, wherein the diameter of the through holes is 1 μm to 200 μm, and the formation density of the through holes is 500 / cm ² or more.

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