JPH08198320A - Easy to open laminated packaging material - Google Patents

Abstract

PURPOSE: To simultaneously accomplish an accurate unsealability and sufficient content protective properties by a method wherein in a packaging material made of a laminated material, at least one perforation cut line is formed in at least one layer of the laminated material, and the length of an uncut part on the cut line is specified. CONSTITUTION: A packaging material 10 formed by a dry lamination method is composed of a biaxially oriented polyester 1, an aluminum foil 2, and an unoriented polypropylene 3. The packaging material 10 is moved with the condensing irradiation with a carbon dioxide gas laser, whereby a 100μϕ diameter cut line 4 to be unsealed is formed only in the polyester in a perforation line form, At this time, the length of an uncut part 4' of the perforation line is specified to 0.02-0.2mm by adjusting an interval of a repeated laser generation. Next, packaging materials 10 are made into a bag by three-side sealing so that the cut lines are matched on the top and rear sides, and a notch is formed. Thereafter, water is poured into the bag, and the bag is sealed 11 in the upper part. The cut line 4 is spaced approximately 20mm from the upper end of the pouch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily openable laminated packaging material capable of achieving both accurate opening property and sufficient content protection property.

[0002]

2. Description of the Related Art Today, by using laminated packaging materials, packaging materials excellent in content protection such as strength, gas barrier property and water vapor barrier property are being developed one after another. There is a demand for a packaging material that brings difficulties and has both strength / barrier and easy opening property.

Various techniques have already been proposed for the easy-opening property of the above-mentioned laminated packaging material. Among them, as a method for providing the unsealing property along a predetermined predetermined direction, laser processing is used. There is a technique of providing a linear kerf in a part of the packaging material. As an easily openable processing technique using a laser, for example, US Pat. No. 3,790,74 is used.
No. 4 discloses a technique in which only a part of the laminated packaging material is half-cut by irradiation with a laser beam so as to have an unsealing property along a kerf. In addition, the actual Kaisho 60-1106
No. 29 discloses a technique in which only a specific layer of a laminated film is processed by using a carbon dioxide gas laser so as to have an opening property along a kerf. As the form of this processing line, a continuous line or a perforated line can be selected.

[0004]

In the above-mentioned prior art, in the case of continuous wire processing, the strength of the packaging material itself (content protection property) is provided by continuously providing a kerf in at least one specific layer. ) Is liable to decrease. On the other hand, in the case of perforation processing, since there is a non-notched portion, the strength of the packaging material can be maintained to some extent, but on the other hand, the cut line at opening is likely to come off the perforation (predetermined cut line), so pull Can be extremely difficult to remove.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in order to achieve accurate openability and sufficient content protection at the same time, in a packaging material made of a laminated material, At least one perforated cut line is formed in at least one layer of the laminated material, and the length of the non-cut portion on the cut line is 0.02 to 0.2 mm.
The present invention provides an easy-open laminated packaging material characterized by:

The "easy-open property" in the present invention means
It has the significance that both the force required for tearing when opening the packaging material is small and that it can be opened accurately along the perforation line (as a result, it is easier to take out the contents). The emphasis is on the accurate openability of the latter.

For the easily openable laminated packaging material of the present invention, conventionally known papers, polymer films, aluminum foils, vapor deposition films of inorganic oxides and composites thereof can be used. Method or dry lamination method.

As a method for forming perforated cutout lines,
Pulsed laser irradiation can be used.
A carbon dioxide gas laser, a YAG laser, a semiconductor laser, an argon ion laser, or the like can be used as the type of laser and is not particularly limited, but the packaging material needs to have absorption of a laser oscillation wavelength in order to form a cut line. Therefore, the carbon dioxide gas laser is particularly preferably used. It is possible to provide the same effect with other lasers by providing the laser light absorption layer by printing or coating. Further, the position and depth of the notch line can be arbitrarily selected depending on the structure of the laminated material, the position of the laser light absorption layer, and the intensity of the laser to be irradiated, and either straight line or curved line is possible.

The laminated structure of the easily-openable laminated packaging material of the present invention and the layer forming the notch line can be arbitrarily determined according to the presence or absence of absorption of laser light in the packaging material and the position of the laser light absorption layer. For example, a method of notching only the polyester layer in the layer structure of (polyester / aluminum foil / polypropylene) using the absorption difference of the carbon dioxide laser into the packaging material,
An example is a method of notching only the polyester layer in the (polyester / polyethylene) layer structure. In this case, a wavelength of 10.6μ of carbon dioxide laser light is easily absorbed selectively by polyester, most of it is reflected by aluminum foil, and most of it is transmitted by polyethylene. Is possible. Note that the above layer structure is an example of the present invention and is not necessarily limited to these.

The size of the perforated notch line is such that the length of the non-notched portion is 0.02 to 0.2 mm, more preferably 0.05 to 0.1 mm. If the length of the non-notched portion is less than 0.02 mm, the strength of the packaging material becomes weak, and the tear strength, drop strength, etc. (content protection property) of the packaging bag are significantly reduced. On the other hand, if it is longer than 0.2 mm, the actual opening line is likely to come off the notch line during tearing, which is not suitable.

In the process of forming the perforated cut lines, the interval between the perforations (notched portion and non-notched portion) is controlled by controlling the number of laser pulse oscillations and the interval according to the relative moving speed of the packaging material. It is possible to use a laser that can be controlled and that can perform on / off control on the order of microseconds.

[0012]

In the easily openable laminated packaging material of the present invention, the size of the perforated cutout line is defined within a predetermined range, and a non-cutout portion of a predetermined length is secured at the lower limit of the range, so that the packaging material The overall strength is reinforced, and the length of the non-notched portion is limited at the upper limit of the range, and the tear line easily breaks along the notch line at the time of tearing.

[0013]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited to the examples below.

A packaging material 10 having the following specifications as shown in FIGS. 1A and 1B was prepared by using a dry lamination method which is a conventionally known method. This packaging material 10 comprises biaxially stretched polyester 1 (12 μm) and aluminum foil 2 (7
μm) and unstretched polypropylene 3 (60 μm).

A carbon dioxide laser with an oscillating wavelength of 10.6 μ (DIAMOND64 manufactured by Coherent Inc., USA) is focused and irradiated with a pulse width of 10 μ seconds, the packaging material is moved at a speed of 60 m / min, and only polyester is opened with a diameter of 100 μφ. The notch line 4 for the perforation was provided in a perforated shape. At this time, the repetition oscillation interval was adjusted to 1 to 10 kHz, and the length l of the non-notched portion 4'of the perforation was adjusted to 0 (continuous line) to 0.5 mm.

Next, the packaging material 10 was bag-formed by a three-way seal with 130 mm × 170 mm so that the cut lines were aligned with each other on the front and back sides and a notch was provided, and then 200 g of water was added to seal the upper part (heat sealing with number 11). Parts are shown),
The notch line 4 was made to come 20 mm from the upper part of the pouch.

When 100 bags of each of the pouches were torn from the cut line 4, the number of bags in which the cut portion came off the cut line 4 was counted. 120cm for 100 pouch bags
From the height of, 3 with the last heat-sealed surface facing down
A drop test was performed up to 0 times, and the average bag breakage rate was calculated by the following formula. Table 1 shows the results.

Average bag breakage rate = (number of samples broken bag) / (number of times required to break the bag (30 times if the bag was not broken within 30 times)) Table 1 Perforation non-notched portion Tearability Width of average bag breakage rate (mm) (Number of bags out of cut line) Example 1 0.05 0/100 0.02 Example 2 0.1 0/100 0.01 Comparison Example 1 0 (continuous line) 0/100 0.13 Comparative example 2 0.01 15/100 0.10 Comparative example 3 0.5 32/100 0.01

[0019]

As described in detail above, according to the easily openable laminated packaging material of the present invention, at least one perforated notch is provided in at least one layer of the laminated material in the packaging material made of the laminated material. Since a line is formed and the length of the non-cutout portion on the cutout line is set to 0.02 to 0.2 mm, it is possible to achieve accurate openability and sufficient content protection at the same time. .

[Brief description of drawings]

1A and 1B show an embodiment of the present invention.

Claims (3)

[Claims] 1. A packaging material comprising a laminated material, wherein at least one layer of the laminated material is formed with at least one perforated cut line, and the length of the non-cut portion on the cut line is An easily openable laminated packaging material, which has a thickness of 0.02 to 0.2 mm. 2. The easily openable laminated packaging material according to claim 1, wherein the notch line is formed by laser irradiation of pulse oscillation. 3. The length of the non-cutout portion on the cutout line is 0.05.
The easily-openable laminated packaging material according to claim 1, wherein the laminated packaging material has a thickness of 0.1 mm.