JP2003081329A - Shrink packaging member and packaging method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shrink packaging member in which a film is closely and properly adhered to a packaged item even if the item is a soft material such as a cooked bread, its outer appearance is superior and an easy seal opening characteristic is attained. SOLUTION: A packaged item 1 is stored in a cylindrical film 2 composed of a thermal shrinkage film. Opening ends 4a, 4b are sealed and concurrently a through-pass hole 6 sealing the circumferential edge is formed near the opening end 4a, hot air or the like is applied to make a heat shrinkage of the film 2 and the film is closely contacted with it to attain a packaged item 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shrink package, in which an object to be packaged such as food is covered with a heat-shrinkable film and then the film is heat-shrinked to be brought into close contact with the object to be packed. Regarding packaging method.

[0002]

2. Description of the Related Art In general, breads sold in supermarkets and convenience stores are manufactured and packaged in large quantities by manufacturers and supplied to stores. Therefore, as a packaging form, a packaged body in which items to be packaged such as breads are stored in a cylindrical transparent film and then the open ends on both sides are sealed by heat sealing is general.

However, in the case of the above package, since the film is not in close contact with the package, the package moves due to vibration during transportation. There is no problem if the items to be packaged are sweet breads such as bean bread, but in the case of so-called cooked bread where croquette, yakisoba, salad and other side dishes are sandwiched between cut rolls and two breads, There are problems in appearance such as spilled food outside and stains on the inner surface of the film and bread with the sauces used for the food. Therefore, in such cooking pan packaging, the film should be attached to the cooking pan to some extent,
It is necessary to keep the sandwiched state of the side dish.

Examples of the method for wrapping the film in close contact with the object to be packaged include stretch wrapping and shrink wrapping.

Stretch wrapping is a method in which a stretch film is used and at least the bottom surface of the article to be wrapped is wrapped so that the film can be overlapped. Therefore, the stretch wrapping basically stretches the film to wrap the object to be packaged, so that excessive tightening force is applied to the object to be packaged and the object to be packaged is a very soft and weak body such as a cooking pan. Had a bad appearance due to crushed bread and delicatessen, and could significantly deteriorate the soft texture of the bread itself. Therefore, it is extremely difficult to finely adjust the tightening force by the machine, and automation is difficult.

In stretch packaging, the film is folded back on the bottom surface of the cooking pan and taped with an adhesive tape or heat-sealed on a hot plate. In addition, when opening, the film at the folded back part or the part that is in close contact with the object to be packaged will be broken, making it difficult to open (low ease of opening), and the risk that the side dishes will pop out with the force of breaking the film. There is also.

On the other hand, the shrink wrapping is a method in which the object to be packaged is primarily packaged with a heat-shrinkable film, and then the film is heated and contracted by hot air or the like so as to be brought into close contact with the object to be packaged. It is a widely used packaging method because it can be automated. The method, the tightening force to the object to be packaged by the shrinkage force of the film generated during heat shrinkage, the packing margin ratio in the pre-wrapping body before heat shrinkage (margin of the film with respect to the maximum circumference of the object to be packaged in a predetermined direction). It can be adjusted by changing the ratio of dimensions), and is a packaging method suitable for soft items such as bread.

However, the conventional shrink packaging is
The packaged object is stored in a heat-shrinkable film that is tubular, bag-shaped, or folded in half, and the film is shrunk after the open end is sealed by heat sealing, so the film adheres to the entire packaged object. However, like the stretch wrapping, there is a problem that it is difficult to open. Especially when the item to be packaged is very soft and weak like a cooking pan,
When pulling and tearing the film adhered to the object to be packaged, the object to be packaged may be crushed.

Further, in shrink wrapping, since numerous degassing holes are provided in the film in order to remove the air inside when the film is heat-shrinked, when the food is directly packaged, there is a problem in the hygienic condition after the packaging. There is.

As described above, there are various problems in the conventional packaging method for bringing the film into close contact with the article to be packaged, and normally, the manual packaging is generally performed. However, even by manual packaging, it is inevitable that a certain amount of tightening force is generated when the film is wrapped around the object to be packaged, and the packaging work efficiency is poor, so it is not suitable for large-scale packaging. Further, as in the stretch wrapping, the hand-wrapped body has a problem that the folded portion of the film is taped or heat-sealed, so that there is a problem in the easy-opening property, and there is a risk that the side dish will pop out when opening.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide easy-opening property in shrink packaging that can be automated, and further to prevent contamination of the packaged product after packaging, and particularly Even if the package is a soft body such as cooking bread, the shrink package can be easily opened without affecting the object to be packaged, and further, the shrink package that solves the problem of hygiene after packaging, and To provide a packaging method.

[0012]

A first object of the present invention is a shrink wrapping body obtained by covering an object to be packaged with a heat-shrinkable film, sealing and sealing the opening end, and then heat-shrinking the film. A shrink wrapping body is provided in the vicinity of the seal portion, which has a through hole penetrating two or more films and having a peripheral edge portion sealed and sealed.

In the shrink package of the present invention, it is preferable that the shrink package has deaeration holes sealed by a label attached to the film from the outside and the package is a soft body.

A second aspect of the present invention is to store an article to be packaged in a tubular heat-shrinkable film and seal the open end of the tubular film at the same time, or after that, to seal the sealed portion. At the same time, two or more films are partially sealed in the vicinity, and at the same time, a cut is made in the sealed region to form a through hole having a peripheral edge sealed and sealed, and the entire film is heated to cause heat shrinkage. The shrink wrapping method is characterized in that the shrink wrapping is performed by closely contacting the article to be wrapped.

In the shrink wrapping method of the present invention, it is preferable that the cylindrical film is provided with deaeration holes in advance, and after the film is thermally shrunk, a label is attached to seal the deaeration holes. .

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The shrink wrapping body of the present invention is characterized by having a through hole with a peripheral edge sealed and sealed in the vicinity of the seal portion at the opening end, and the through hole serves as a knob portion at the time of opening. , Can be opened easily. In addition, the through-hole is provided in the sealing area at the same time when the object to be packaged is accommodated in the tubular film and the opening end is sealed or after sealing the two or more films partially. It can be easily formed by making a notch.

Hereinafter, the shrink wrapping body and the wrapping method of the present invention will be described in detail with reference to embodiments.

FIG. 1 is a diagram showing the steps of an embodiment of the shrink wrapping method of the present invention. In the figure, 1 is an article to be wrapped (cooking pan), 2 is a tubular film, 3 is a seal portion, 4
a and 4b are open ends, 5a and 5b are seal parts of the open ends 4a and 4b, 6 is a through hole, 7 is a seal part of a peripheral portion of the through hole 6, 8 is a package, 9 is a deaeration hole, and 10 is a label. Is. Each step will be described below.

In the present invention, as shown in FIG. 1 (a), first, the article to be packaged 1 is housed in the tubular film 2 made of a heat-shrinkable film. FIG. 1 (a) shows a conventional pillow packaging method in which a sheet-shaped film is folded from both sides and the ends of the pieces are sealed to form a tubular film 2 and the article to be packaged 1 is wrapped. However, the tubular film 2 may be, for example, one formed by inflation molding, or one in which two films are overlapped and sealed at a pair of opposing end portions (two sealing portions 3). In addition, as shown in FIG. 1A, it is preferable to arrange the seal portion 3 on the bottom surface of the article to be packaged 1 or on the side surface of the article to be packaged 1 in order to improve the appearance after packaging.

Heat-shrinkable fill used in the present invention
The heat shrinkage is low at 80 to 160 ° C
Both are preferably 20% or more in the width direction. In addition, this
Here, the heat shrinkage is defined as a 100 mm square film sample
It can be freely placed in an air oven type thermostat set to the temperature of
After heat-shrinking for 10 minutes, it can be vertically and horizontally
Determine the amount of heat shrinkage of the film in the (width) direction, and measure the size before shrinkage.
It is the value expressed as a percentage of the value divided by. Also, similarly
The heat shrinkage stress is measured according to ASTM D2838.
In the temperature range of 80-160 ℃
And preferably 400 g in both the longitudinal and transverse directions of the film
/ Mm²Or less, more preferably 300 g / mm²Below,
And preferably 250 g / mm²Below, preferably 20
0 g / mm ²It is the following.

The resin constituting the heat-shrinkable film used in the present invention is not particularly limited as long as it is a thermoplastic resin. For example, high-pressure process low-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer ( Linear low-density polyethylene, ultra-low-density polyethylene, and other soft resins with a crystallinity of 30% or less by the X-ray method, such as those polymerized with a Ziegler catalyst, and usually a single-site catalyst is used. Polymerized), polypropylene resins (homopolymers and copolymers with at least one α-olefin such as ethylene and butene), polybutene resins (homopolymers and ethylene or propylene). At least one α such as
Copolymers with olefins, etc.), poly-4-methylpentene resins, crystalline 1,2-polybutadiene, soft polymers consisting of α-olefin copolymers different from the above ethylene-α-olefin copolymers, ethylene-acetic acid Vinyl copolymers, ethylene-aliphatic unsaturated carboxylic acid copolymers, ethylene-aliphatic unsaturated carboxylic acid ester copolymers, block copolymers of vinyl aromatic hydrocarbons and conjugated dienes and their double bonds Derivatives such as at least partially hydrogenated, ethylene-vinyl alcohol copolymers, polyamide resins, polyester resins, and modified polymers thereof (acid-modified, ionized, etc.) and the like can be mentioned. Or a blended resin in which one or more resins are mixed, or mainly composed of these resins (including 50% by weight or more), A blended resin in which other resins are mixed can be used.

The heat-shrinkable film used in the present invention may be one which has been crosslinked by irradiation with ionizing radiation, preferably an electron beam, and the one which is crosslinked by irradiation is effective in terms of easy opening. is there. Further, the heat-shrinkable film may be a single layer or a multi-layer, and at least 1
Anti-fog agent, plasticizer, antioxidant, UV absorber, in one layer
Lubricants, colorants, surfactants, anti-blocking agents, inorganic fillers, tackifiers, etc. can be included, and corona treatment, plasma treatment, and various coating treatments can be performed.

The thickness of the heat-shrinkable film used in the present invention is usually 5 to 100 μm for shrink packaging, but it is preferably 5 to 5 from the viewpoint of resource saving and waste reduction. The thickness is 50 μm, more preferably 5 to 30 μm.

In the present invention, the packaging margin ratio (the ratio of the margin dimension of the film 2 to the maximum circumference of the packaging object 1 in a predetermined direction) when the packaging object 1 is housed in the tubular film 2 is Preferably, the lengthwise direction (L
Direction) and 0 to 30%, and in the width direction (direction orthogonal to the lengthwise direction, C direction), 3 to 25%.
Desirably, it is 5 to 20% in the L direction and 5 to 20% in the C direction, and when the perimeter of the object to be packaged 1 in the L and C directions is the same, both are adjusted in the range of 0 to 20%. Preferably.

Next, as shown in FIG. 1B, the open ends 4a and 4b of the tubular film 2 are sealed and sealed. In the present embodiment, the step of sealing the open ends 4a and 4b after storing the object to be packaged 1 in the tubular film 2 cut into a predetermined length has been described. Accommodates the object to be packaged 1 while forming a long heat-shrinkable film into a tubular shape, and melt-seals the open ends 4a and 4b with a fusing blade (they are heat-sealed at the same time when the open ends 4a and 4b are cut and formed). )In some cases.

In the present invention, the through hole 6 is formed before the tubular film 2 is thermally contracted. The through-hole 6 penetrates two or more films (two in the case other than the seal part 3 and may be substantially three or more in the seal part 3) forming the tubular film 2 and has a peripheral edge sealed. It is sealed. That is, the internal air does not escape from the through hole 6 when the tubular film 2 is thermally contracted. 1 in FIG.
The sectional view of the through-hole 6 vicinity of (b) is shown.

The positions of the through holes 6 are the open ends 4a, 4
It is near one of the seal portions 5a and 5b (5a in FIG. 1B) of b, and the peripheral edge seal portion 7 of the through hole 6 and the seal portion 5a of the opening end 3a may be in contact with each other.

Further, the through-hole 6 can be formed by simultaneously sealing the opening ends 4a and 4b, or at the same time, by partially sealing two or more films and at the same time making a cut in the sealing region. It can be easily formed. Specifically, it can be preferably formed by bringing a hot blade, which is usually used for fusing and sealing, into contact with the film. Therefore, the above-mentioned open ends 4a, 4
In the case of an automatic shrink wrapping machine that cuts and forms b and seals and seals, a hot blade is attached in the vicinity of the fusing blade that cuts, forms, and seals the open end 4a.
The through hole 6 can be formed at the same time as the cutting of 4b and the sealing.

The size of the through hole 6 according to the present invention is preferably 1/15 to 1/2 of the bag width of the tubular film 2, and more preferably 1 when a straight cut is made. It is / 10 to 1/3.

In the present invention, the seal portions 3, 5a,
The sealing of 5b and 7 can be performed by fusing sealing, heat sealing, impulse sealing, ultrasonic sealing or the like.

Next, the open ends 4a, 4b of the tubular film 2
The tubular film 2 is heat-shrinked by applying hot air, steam or the like to the preliminary package having the through-holes 6 sealed and sealed, and the tubular film 2 is brought into close contact with the object to be packaged 1 and the shrink package 8 of the present invention [Fig. 1 (c)] is obtained.

At this time, since the peripheral portion of the through hole 6 is sealed, it does not come into close contact with the article to be packaged 1 due to heat shrinkage, and the peripheral portion seal portion 7 forms the package 8 as shown in FIG. 1 (c). It will be in a more protruding state. Therefore, when opening the package 8, the package 8 can be easily opened by pinching and pulling the protruding portion as a knob.

When performing shrink wrapping normally,
A deaeration hole for removing the air inside is formed in the film. Also in the present invention, as shown in FIGS. 1 (a) and 1 (b), the degassing holes 9 are formed in advance in the tubular film 2, and the labels 10 are attached after the heat shrinkage so that the degassing holes 9 are formed. It is possible to prevent the contamination of the object to be packaged 1 after packaging by sealing. The number of the deaeration holes 9 is not particularly limited, but in consideration of the sticking operation of the label 10, the smaller number is preferable, and the number is preferably one. Also, the size of the degassing hole 9,
The shape is preferably a circle having a diameter of 2 to 5 mm. still,
As the label 10, the product name, the manufacturing date, the expiration date,
It is sufficient to use a product label that displays prices and the like.

Examples of the method of forming the degassing holes 9 include a method of forming a melt hole with a laser or a hot needle, a method of mechanically forming with a needle, a method of punching, and the like. The method of forming a melt hole is preferable because the film does not tear from the pores 9.

Examples of automatic packaging machines and semi-automatic packaging machines for carrying out the shrink packaging method of the present invention include L-type packaging machines and pillow packaging machines.

[0036]

Example As a heat-shrinkable film, both surface layers are linear low-density polyethylene (comonomer: hexene-1, density:
0.913 g / cm ³ ) 90% by weight and high-pressure low density polyethylene (density: 0.924 g / cm ³ ) 10% by weight mixed resin, and the core layer is different from the above linear low density polyethylene (comonomer: Hexen-1, density: 0.9
28 g / cm ³ ) 75 wt% and high-pressure low density polyethylene (density: 0.924 g / cm ³ ) 25 wt% mixed resin 3 layers (thickness ratio of each layer = 15: 70: 1)
5) having a thickness of 11 μm and subjected to a crosslinking treatment was used. The degree of cross-linking treatment was expressed as a gel fraction, and the sample was extracted for 12 hours in boiling p-xylene, and the proportion of the insoluble portion was 21% by weight expressed by the following formula.

Gel fraction (% by weight) = (sample weight after extraction / sample weight before extraction) × 100

The heat shrinkage ratio of the heat shrinkable film is 140% at 83 ° C. in the longitudinal direction and 81% in the transverse direction. The heat shrinkage stress at 120 ° C. is 190 g in the longitudinal direction.
/ Mm ² , and the lateral direction was 200 g / mm ² .

A cooking roll having a length of 210 mm as a product to be packaged was cut in the longitudinal direction (L direction) and sandwiched with fried noodles to prepare a cooking roll. L of the cooking roll
The outer circumference (maximum) in the direction (C direction) orthogonal to the direction is 205
It was mm.

A diameter of about 3 m is applied to the heat shrinkable film with a hot needle.
m deaeration holes are provided, and then the cooking roll pan is wrapped while forming the seal portion 3 by heat sealing by the pillow packaging method as shown in FIG. 1 (a), and the open ends 5a, 5b are melted and sealed by a sealing device. Sealed by
A prepack was formed. At this time, a hot blade having a blade width of 15 mm is provided in the vicinity of the fusing blade that seals and seals one opening end 5a. 6 was formed. The temperature of the fusing blade and the hot blade was 220 ° C.

In the above-mentioned preliminary package, the packaging margin ratio for the cooking roll bread is 20% in the L direction and 18% in the C direction.
Met.

The above pre-packaged body is subjected to a hot air tunnel of 900 mm in length controlled at 140 ° C. and passed for 5 seconds to heat-shrink the heat-shrinkable film, and then a product label is attached to the deaeration hole, The deaeration hole was sealed to obtain a shrink package.

The obtained package body has a proper film adhesion to the cooking roll pan, the cooking roll pan does not move in the package body, and the roll pan and the side dish are not fastened with the film. Since the portion where the mark was formed was projected from the package, the film could be easily peeled off by pinching and pulling, and the opening property was excellent.

[0044]

As described above, since the shrink wrapping body of the present invention has the through hole having the peripheral edge sealed and sealed, the portion to be packaged is affected by pinching and pulling this portion. It can be easily opened without affecting. The through hole can be formed by adding a simple structure to the conventional automatic shrink wrapping machine. further,
Even if a deaeration hole is provided in the film to remove air when the film is heat-shrinked, the deaeration hole can be sealed by using a product label, etc., so that contamination of the packaged item after packaging can be easily prevented. can do.

Therefore, according to the present invention, since the easy-opening property is realized in the shrink wrapping and contamination of the packaged item after the wrapping is prevented, the use of the shrink wrapping is expanded, and the automatic wrapping is performed in each use. The efficiency of can be improved. In particular, even when the object to be packaged is a soft body such as a cooking pan, it is possible to provide a package which has an excellent appearance, is easy to open, and is hygienic.

[Brief description of drawings]

FIG. 1 is a process drawing showing an embodiment of a shrink wrapping method of the present invention.

FIG. 2 is a cross-sectional view in the vicinity of a through hole in the preliminary packaging body of FIG.

[Explanation of symbols]

1 Items to be packaged 2 tubular film 3, 5a, 5b, 7 Seal part 4a, 4b Open end 6 through holes 8 packaging 9 Degassing holes 10 labels

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Claims (5)

[Claims] 1. A shrink wrapping body obtained by covering an object to be packaged with a heat-shrinkable film, sealing and sealing the open end, and then heat-shrinking the film, wherein two or more sheets are provided in the vicinity of the seal portion. A shrink wrapping body having a through hole penetrating the film and having a peripheral edge sealed and sealed. 2. The shrink wrapping body according to claim 1, which has deaeration holes sealed by a label attached to the film from the outside. 3. The shrink package according to claim 1, wherein the object to be packaged is a soft body. 4. A tubular heat-shrinkable film containing an object to be packaged, and simultaneously sealing or sealing the open end of the tubular film, or thereafter, two or more films in the vicinity of the sealing portion. Is partially sealed, and at the same time, a cut is made in the sealed area to form a through hole having a peripheral edge sealed and sealed, and further, the entire film is heated to cause heat shrinkage to be brought into close contact with an object to be packaged. A shrink wrapping method characterized by the above. 5. The shrink wrapping method according to claim 4, wherein a deaeration hole is provided in advance in the tubular film, and a label is attached after the film is thermally shrunk to seal the deaeration hole.