Packaging that can release pressure

Abstract

The present invention relates to a package capable of relieving pressure built up inside. The package includes a container portion configured to contain a product and a flexible film portion having at least one pressure-relief design on an outer surface of the portion, the pressure-relief design comprising at least two identical or different patterns of indentations interlocked together, forming three or more intersections of the patterns, with at least one pattern forming a closed shape. The present invention also relates to a pressure-relief design for a flexible film, the pressure-relief design comprising at least two identical or different patterns of marks interlocked together, forming three or more intersections of the patterns, with at least one pattern forming a closed shape. [Selected figure] Figure 3

Description

[Technical Field]

[0001] This technology relates to packaging materials that can release pressure. [Background technology]

[0002] Special packaging, such as sealed food packaging that can be sterilized by pasteurization or sterilization methods, then frozen or refrigerated, and heated in a microwave oven, is currently gaining popularity. However, because this packaging is sealed, it requires pre-opening, cutting, or puncturing before heating in a microwave oven to release the pressure and steam generated inside the packaging to the outside. Such actions cause the food inside to lose moisture and nutrients, making the food look unappetizing and inconvenient for the user.

[0003] Therefore, there are efforts to develop packaging that can automatically release the pressure or steam formed inside by using various techniques, such as the use of valves that are fitted into the packaging after it has been perforated. This requires adjustments to the machinery used in the manufacturing process to install the valves, which increases manufacturing costs. When a weakened sealing area is created to make it easy to open by coating the sealing mark of the packaging with a chemical to block it or by using peelable tape, when pressure is formed inside the packaging, the sealing mark area tears, creating a release point for pressure and steam. However, when using such methods, the size of the pressure and steam release point is usually large, so food or water may spill out of the packaging and contaminate the microwave.

[0004] Another technique developed for use with film packaging to automatically release pressure and steam involves using laser power to reduce the thickness within a certain design area of ​​the outer layer film's surface by forming lines, holes, or various designs through perforation. When the food is heated and high-pressure steam is formed, the laser-perforated notches are pressed and torn. Such a method is easy to implement and requires only lower manufacturing costs than the aforementioned method.

[0005] Examples of literature disclosing packaging that is subjected to laser application to create a pressure-releasing design are as follows:

[0006] U.S. Patent Application Publication 2015 / 210463(A1) discloses a laminated film packaging comprising an inner film made of thermoplastic resin that can be heat-sealed and laminated to an outer film including a brittle cutout created by laser to remove a portion of the outer film. The laser cutout may be a variety of patterns, such as a straight line 150 μm wide and 40 mm long. The brittle cutout has a Young's modulus of less than 2.0 GPa. As pressure is generated inside the packaging during heating, many small vents are formed in the brittle cutout.

[0007] U.S. Patent No. 9505543(B2) discloses the manufacture of sealed packaging, such as freezer-safe and microwave-safe packaging containing food products. Such packaging has a pressure-relieving system formed by a CO2 laser, which may be a linear pattern or other patterns such as circles, ellipses, triangles, or squares. The span of the laser pattern is from 1% to 50% of the size of the inner region span, which has a film thickness remaining after laser application of approximately 5 to 25 μm.

[0008] U.S. Patent Application Publication 2008 / 260917(A1) discloses a heat-sealable composite film comprising a base layer which is a polymer base layer having a first surface and a second surface disposed on the base layer to form a barrier layer. The base layer has perforations for pressure release having a diameter of about 0.05 to 1.5 mm. These perforations may be made using laser perforation, hot needle perforation, or gas flame perforation. Perforations disclosed in this document include, for example, V-shaped, U-shaped, T-shaped, I-shaped, and X-shaped.

[0009] However, the pressure-relieving designs fabricated using the lasers disclosed in the above-mentioned literature still have several drawbacks. For example, in the case of closed-shaped laser designs such as circles, triangles, or squares, if the number or size of the laser cuts is very small, the pressure and steam cannot be released in a timely manner, resulting in delamination of the laminated film, damage to the packaging, or contamination of the food contained in the packaging. Also, in the case of open-shaped laser designs such as V-shapes, I-shapes, or X-shapes, widespread tearing can occur, meaning that the tearing of the packaging can spread from the edges of the laser cuts, resulting in the aforementioned drawbacks. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] U.S. Patent Application Publication No. 2015 / 210463 [Patent Document 2] U.S. Patent No. 9505543 [Patent Document 3] U.S. Patent Application Publication No. 2008 / 260917 [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, an object of the present invention is to provide a packaging having a pressure release design that can effectively and automatically release the pressure formed inside, i.e., a pressure release point that can be formed, allowing for timely release of water vapor pressure, without damaging the packaging, and without causing widespread tearing of the pressure release design. More specifically, the present invention provides a sealed packaging that can be used as a vacuum packaging that can be subsequently frozen or refrigerated and heated in a microwave oven, can be sterilized by pasteurization or sterilization methods, and has a pressure release design that is automatically formed when heated.

[0012] Another object of the present invention is to provide a pressure-relieving design for a flexible film to be applied to packaging, in particular to provide a sealed packaging that can be later frozen or refrigerated and heated in a microwave oven, and is sterilized by pasteurization or sterilization. [Means for solving the problem]

[0013] A first embodiment of the present invention relates to a packaging body capable of releasing internally formed pressure. The packaging body comprises a container portion formed for housing a product and a flexible film portion having at least one pressure-releasing design on its outer surface, wherein the pressure-releasing design comprises at least two identical or different patterned notches (scores) combined together, forming three or more intersections of the patterns, and at least one of the patterns being a closed shape.

[0014] A second embodiment of the present invention relates to a pressure-relieving design for a flexible film, characterized in that the pressure-relieving design comprises at least two identical or different patterned notches that are combined together, forming three or more intersections of the patterns, and at least one of the patterns being a closed-shaped pattern. [Effects of the Invention]

[0015] The package having a pressure release design according to the present invention can be used easily and conveniently because it can automatically release pressure and steam. Therefore, the package does not require pre-opening, cutting, or perforating to create a pressure release opening before heating in a microwave oven. Also, delamination of the package does not occur when the package is made of laminated films. The sealing mark area or other areas do not rupture. A wide range of tearing of the pressure release design does not occur while the package is in use, for example, while being heated in a microwave oven. The user can be ensured that the contents in the package, such as food, retain their nutritional value and cleanliness, and the food inside the package is not contaminated. Also, the food does not lose too much water. Therefore, the food retains its original taste and visual appeal, for example, it has a soft texture, does not dry out or become hard, and looks like freshly cooked food.

Brief Description of the Drawings

[0016] [Figure 1] FIG. showing a tray-shaped package and a sealing portion according to an exemplary embodiment of the present invention. [Figure 2] [Figure 3] FIG. showing a package which is a vertically placed bag according to an exemplary embodiment of the present invention. [Figure 4] [Figure 5] FIG. showing an example of a pressure release design according to the present invention. FIG. showing examples of various positional arrangements of the pressure release design on the package according to the present invention.

Modes for Carrying Out the Invention

[0017] Any aspect shown in the present invention shall be construed to include its application to other aspects of the present invention unless otherwise indicated.

[0018] Scientific and technical terms used in this specification shall have the definitions understood by those skilled in the art unless otherwise defined.

[0019] Throughout this invention, the term “about” is used to indicate that any value shown or presented herein may vary or deviate. Such variation or deviation may result from errors in the equipment or methods used to determine this value.

[0020] The terms “consist of,” “equip,” “have,” and “include” are open-ended verbs. For example, any way of “consisting of,” “equiping,” “having,” or “include” one or more components or steps is not limited to just one or more components or steps, but also includes components or steps that are not mentioned.

[0021] Any tools, equipment, methods, materials, or chemicals referred to herein mean tools, equipment, methods, materials, or chemicals that are commonly used or practiced by those skilled in the art, unless otherwise indicated.

[0022] All disclosed components and / or methods, as well as the claims of the present invention, include embodiments of the present invention obtained from any acts, practices, modifications, or alterations made to the elements without attempting to deviate significantly from the present invention, even if not specifically indicated in the claims, and are intended to obtain objects having characteristics, usefulness, and effects similar to embodiments of the present invention in the view of a person skilled in the art. Accordingly, objects equivalent to or similar to embodiments of the present invention, including any minor modifications or alterations that are obvious to a person skilled in the art, should also be considered to be within the spirit, scope, and concept of the present invention.

[0023] (definition) The term “pressure release,” as used herein, means an embodiment of packaging that, upon receiving heating or any force that generates pressure inside the packaging, can create an automatic release mechanism for the pressure, air, and / or steam formed inside, as well as an embodiment of packaging that can control the pressure so that it is within a suitable range as calculated or determined in advance.

[0024] The term "flexible film," as used herein, refers to a plastic film that has expansion properties when heated and / or subjected to forces including pressure, as well as advantageous properties such as strength, and the ability to prevent gas permeation, support printing, and be heat-sealed. Therefore, the packaging is suitable for applications such as lamination processes for creating flexible packaging.

[0025] The term “closed shape,” as used herein, means a shape having a clear boundary or area defined by straight lines and / or curves connecting at the ends that form a perimeter surrounding a closed area. Examples of closed shapes according to the present invention include circles, semicircles, ellipses, semi-ellipses, pointed-end ellipses, pointed-end semi-ellipses, and polygons such as triangles, squares, pentagons, hexagons, etc.

[0026] The term "open shape," as used herein, means a shape having an indistinct boundary or area defined by straight lines and / or curves that do not connect at the ends. Examples of open shapes according to the present invention include straight lines, crosses, asterisks, curves, wavy lines, V-shapes, T-shapes, and the like.

[0027] Next, the present invention will be described in more detail with reference to exemplary experiments and accompanying drawings, but this is not intended to limit the scope of the invention.

[0028] The packaging according to the present invention may take on different forms commonly used in the market, such as a centrally sealed bag, which is a bag sealed in the middle; a three-side sealed bag, which is a bag having three sealed sides and one open side for filling with products that are sealed after the products are filled; a vertically oriented bag, which is similar to a three-side sealed bag except that the bottom is folded (referred to herein as the "folded part") so that the bag can stand upright; or a packaging that is a container for holding products and is sealed with a flexible film.

[0029] Figures 1 to 3 show exemplary embodiments of the packaging according to the present invention.

[0030] Figure 1 shows a package comprising a container portion 1, which is a tray for storing products such as food or snacks; a sealing portion 2, which is a flexible film portion for sealing the container portion 1; and a pressure-relieving design 3 formed on the outer surface of the sealing portion 2. In addition to the tray-like embodiment, the container portion 1 can also be formed by molding plastic or any material to obtain other non-limiting shapes such as a plate, box, bowl, or glass.

[0031] Figure 2 shows a packaging body which is a vertically oriented bag made of flexible film for storing the product and for which a pressure-relieving design 3 is provided on the outer surface of the bag.

[0032] Figure 3 shows a packaging body that contains a product and is sealed in the middle, a centrally sealed bag made of flexible film, and the outer surface of this bag has a pressure release design 3.

[0033] According to the present invention, pressure relief design 3 comprises at least two identical or different patterned notches, which are combined together such that at least one of the patterns is a closed-shaped pattern, and three or more pattern intersections are formed, as shown in Figure 4 illustrating preferred examples of pressure relief designs 4.1 to 4.8 according to the present invention.

[0034] In a preferred embodiment of the present invention, the pressure-relieving design 3 is formed by at least two identical or different closed-shape pattern notches that are combined together. For example, the closed-shape patterns may be selected from the group consisting of circles, semicircles, ellipses, semi-ellipses, pointed ellipses, pointed semi-ellipses, polygons, or combinations thereof, as shown in designs 4.1, 4.2, and 4.8 of Figure 4.

[0035] In another preferred embodiment of the present invention, the pressure relief design 3 is formed by at least one closed-shaped pattern and at least one open-shaped pattern notch that are combined together. For example, the open-shaped pattern may be selected from the group consisting of straight lines, crosses, asterisks, curves, wavy lines, V-shapes, T-shapes, or combinations thereof, as shown in designs 4.3, 4.4, 4.5, 4.6, and 4.7 of Figure 4.

[0036] In certain embodiments of the present invention, the pressure relief design 3 may be formed of notches in a pattern of at least two circles or ellipses or pointed ellipses that are combined together to form pattern intersections and create 3 to 17 pressure relief points.

[0037] In another specific embodiment of the present invention, the pressure relief design 3 may be formed of notches of at least one circular, elliptical, or pointed elliptical pattern combined with a cross pattern to form pattern intersections and create 3 to 17 pressure relief points.

[0038] The pressure release design 3 may be provided at one, two, or more locations on the outer surface of the sealing portion or on either side of the flexible film portion.

[0039] According to the present invention, the pressure-relieving design 3 should have a widest diameter that is 7 to 100%, preferably 10 to 100%, of the widest diameter of the flexible film portion. In a preferred embodiment, the pattern notches have a depth that does not perforate the thickness of the flexible film portion and have a depth that starts from the outer surface of the flexible film portion within a range of 20 to 75% of the thickness of the flexible film portion.

[0040] According to the present invention, the patterned notches can be formed on the surface of the flexible film portion by using a laser. The laser is selected from a fiber laser or a CO2 laser, preferably a CO2 laser.

[0041] In certain aspects of the present invention, the patterned notches are formed by using a CO2 laser having a wavelength ranging from 300 to 17,000 nm, preferably from 9,300 to 10,700 nm, a laser power ranging from 1 to 30 watts, preferably from 10 to 20 watts, and a laser scanning speed ranging from 6 to 720 m / min, preferably from 10 to 100 m / min.

[0042] A preferred example of the flexible film portion according to the present invention is a laminated film comprising an inner layer film which is a layer that comes into contact with the product contained in the packaging, and an outer layer film which is laminated onto the inner layer film on the side surface that does not come into contact with the product.

[0043] As an example, the inner layer film is made from polyolefin, preferably low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene homopolymer, polypropylene copolymer, or a combination thereof. The outer layer film is made from polyamide, preferably biaxially-oriented polyamide (BOPA), or polyester, preferably biaxially-oriented polyethylene terephthalate (BOPET).

[0044] The inner layer film should have a thickness in the range of 40 to 100 μm, preferably in the range of 40 to 80 μm. The outer layer film should have a thickness in the range of 12 to 25 μm, preferably in the range of 12 to 15 μm.

[0045] The pressure-relieving design according to the present invention may be formed by using a CO2 laser on the outer layer film side to form the pattern notches, and the thickness of the remaining laminated film in the pattern notch area after using the CO2 laser is in the range of 30 to 75 μm.

[0046] The packaging according to the present invention is suitable for use as a sealed packaging or a heat-resistant sealed packaging for use in a microwave oven in vacuum packaging of products, and / or as a packaging that can be sterilized by pasteurization or sterilization, and / or as a packaging that can be used in a refrigerated or frozen state.

[0047] A second embodiment of the present invention also relates to a pressure-relieving design for a flexible film having the above-described characteristics.

[0048] (experiment) (Sample packaging) The method for forming sample packaging used in pressure release efficiency tests and various applications may be carried out in several ways depending on the nature of the sample packaging being tested. The following are illustrative details.

[0049] If the tested packaging is a centrally sealed bag, a sample film comprising a 15 μm thick nylon outer layer film and a 60-80 μm thick linear low-density polyethylene (LLDPE) inner layer film is subjected to laser application generated by a CO2 laser marker to form pressure-relieving designs of different sizes and shapes on the outer surface of the film. The film is inspected to ensure there are no leaks. The film with the pressure-relieving designs is then formed as a bag packaging. A sponge containing 50 ml of water is placed inside the bag. The bag containing the sponge is then heated to seal it.

[0050] If the tested packaging is a vertically oriented bag and a three-side sealed bag, a sample film comprising a nylon outer layer film with a thickness of 15 μm and an LLDPE inner layer film with a thickness of 60-80 μm undergoes a forming process to produce a bag. The bag is then subjected to laser application generated by a CO2 laser marker to form pressure-relieving designs of different sizes and shapes on the outer surface of the bag. The bag is inspected to ensure there are no leaks. A sponge containing 50 ml of water is placed inside the bag. The bag containing the sponge is then heated to seal it.

[0051] If the tested packaging is a tray with a sealing section made of flexible film featuring a pressure-relieving design, a sample film comprising a 15 μm thick nylon outer layer film and a 60-80 μm thick LLDPE inner layer film is subjected to laser application generated by a CO2 laser marker to form pressure-relieving designs of different sizes and shapes on the outer surface of the film. The film is inspected to ensure there are no leaks. The film with the pressure-relieving design is then heated to seal it as a lid for a packaging tray containing a sponge with 50 ml of water inside, using a Multivac tray sealer T100 at a sealing temperature of 190°C and a pressure of 1 bar for 3 seconds.

[0052] Numerous sample packages, prepared on top of 10 to 30 samples, are inspected for leaks using a Keyence VHX-5000 microscope at 200x magnification, the thickness of the remaining laminated film after laser application is measured, and pressure release is tested by heating in a Panasonic NE-1753 microwave oven at 1300 watts for 60 seconds.

[0053] (Evaluation of the pressure release efficiency of the packaging) The three important factors to consider when evaluating pressure release efficiency are as follows: 1. Pressure release of the packaging: The test results are classified into two sections using the following criteria. - "Good pressure release" means that the packaging forms a pressure release point and can release water vapor pressure in a timely manner, which can be seen from the appearance of the packaging, for example, the bag or seal remains sealed as it was before heating (the results are reported as the ratio of the number of packaging with good pressure release to the total number of packaging tested). - "Poor pressure release" refers to a situation where the packaging can form pressure release points, but the increasing pressure inside the packaging cannot be released in a timely manner, or the pressure release points formed are too small, resulting in excessive pressure acting on the packaging that cannot be released in a timely manner. Therefore, the film is further stretched so that delamination or widespread tearing can occur in the area of ​​the pressure release design or in any other area of ​​the packaging. 2. Delamination: The laminated film is examined to see if the bonded films separate from each other after heating in a microwave oven (the results are reported as the ratio of packages exhibiting delamination to the total number of packages tested). 3. Extensive tearing: Tearing should be considered to extend further beyond the edge of the pressure-relieving design.

[0054] (Study on the influence of different patterns on pressure release efficiency) The tests were conducted using the method described above. In this experiment, the centrally sealed bag packaging was formed with a film having pressure-relief designs at one and two positions on the outer surface. The pressure-relief designs had a widest diameter of 12 mm and had different shapes: a circle, a cross, an asterisk formed by three intersecting lines, and an asterisk formed by four intersecting lines. The thickness of the remaining laminated film within the patterned area remaining after laser application was similar, and this was approximately 40 μm. The results are shown in Table 1.

[0055] [Table 1]

[0056] Tests revealed that bags with one location of pressure-release design were able to release pressure, but delamination occurred. In particular, pressure-release designs formed by notches of a pattern consisting of two intersecting straight lines (crosses) caused widespread tearing from the edges of the pressure-release design and explosion of the bag while heating in the microwave. On the other hand, other pressure-release designs did not have widespread tearing or explosion problems.

[0057] Next, further experiments were conducted using a centrally sealed bag packaging made of film with two pressure-relieving designs positioned at the same center, separated from each other along the longitudinal direction. The widest part had a diameter of 12 mm, and the thickness of the remaining laminated film after laser application was approximately 40 μm. The results showed that increasing the number of pressure-relieving designs allowed the bag to release internal pressure more effectively, as more pressure-relieving points were present, and delamination was reduced in all pressure-relieving designs. However, while increasing the number of pressure-relieving designs improves pressure-relieving efficiency and reduces delamination, it does not eliminate delamination completely, or at least reduces it to an acceptable level.

[0058] To increase pressure release efficiency and solve the delamination problem, further experiments were conducted on a 20×15cm sheet with a 4.5cm folded section, where two positions of the pressure release design were arranged so that they were separated from each other along the longitudinal direction at the same center. 2 The experiment was conducted using a vertically positioned bag. The diameter of the widest part of the pressure relief design at both positions was 20 mm. The results are shown in Table 2.

[0059] [Table 2]

[0060] Experiments revealed that increasing the size of the pressure-relieving design allows the bag packaging to release pressure more effectively, and that there is no delamination when a larger pressure-relieving area is created by increasing the size of the pressure-relieving design.

[0061] However, the pressure-relieving design formed by the intersecting straight lines of the pattern in Table 2 has tears extending from the ends of the straight lines, which can tear the bag packaging if the pressure is not released in a timely manner.

[0062] (Pressure relief design according to the present invention) To address the problems of insufficient timely pressure release, the aforementioned delamination issues, and widespread tearing, the pressure release design was modified to consist of a closed pattern and more pattern intersections, as illustrated by the pressure release design in Figure 4, designs 4.1 to 4.4. In this experiment, a 20 × 15 cm pattern with a 4.5 cm fold was used. 2 Vertically positioned bags were used, and each bag had a different pressure release design at one position. The results of the pressure release efficiency test are shown in Table 3.

[0063] [Table 3]

[0064] Experiments revealed that the pressure-relief designs formed by pattern notches of combined closed shapes (circles and pointed ellipses) according to designs 4.1 and 4.2, and the pressure-relief designs formed by pattern notches of combined closed shapes (circles and pointed ellipses) with open shapes (crosses) according to designs 4.3 and 4.4, were able to solve the problem of widespread tearing. Furthermore, increasing the number of pattern intersections in the pressure-relief design increased the number of pressure-relief locations, resulting in better pressure relief with no widespread tearing and delamination, or only 10% delamination. In addition, the bag packaging shown in Table 3 exhibits good pressure-relief efficiency despite having only one pressure-relief design, which is advantageous in terms of manufacturing cost and a more easily controllable manufacturing process compared to using lasers to form pressure-relief designs at multiple locations. Furthermore, in terms of user safety, since the locations where pressure release points are formed have high-temperature steam pressure coming through them, a greater number of pressure release designs further increases the risk of users being exposed to high-temperature steam while using the packaging.

[0065] (Research on the effect of the number of pattern crossovers on pressure release efficiency) Further experiments were conducted to study the effect of pattern intersections forming pressure relief points in different pressure relief designs of the present invention on relative exemplary designs. Central-sealed bags with the pressure relief designs shown in Figure 4, designs 4.5 to 4.7, and comparative examples, designs with two partially overlapping circular notches, were used. The size of the pressure relief design was 10–15% of the maximum length of the bag packaging. The results of the pressure relief efficiency tests are shown in Table 4.

[0066] [Table 4]

[0067] Table 4 shows that, compared to a comparative example of two partially overlapping circles with only two pattern intersections resulting in 20% delamination, a pressure-relief design with intersections formed at three or more pressure-relief points (designs 4.5 to 4.7) allows the bag to effectively release pressure without delamination and spreading problems.

[0068] (Research on the effect of pattern intersections forming pressure release points on pressure release efficiency) Further research into the pattern intersection locations that form pressure release points was conducted by studying the pressure release designs according to designs 4.4, 4.5, and 4.8 in Figure 4. The results are shown below in Table 5.

[0069] [Table 5]

[0070] The study shows that in the case of pressure release design 4.4, pressure release points are simply formed at the intersections of a pattern in which two circles or pointed ellipses are formed and a pattern in which at least one straight line intersects each other. In other words, pressure release points were formed at positions 2, 3, 4, and 5. These positions where pressure release points are formed are pattern intersection positions, and the thickness of the remaining laminated film after laser application is lower than that of other pattern intersection positions. For example, in design 4.4, the positions where pressure release points are formed have similar laminated film thicknesses ranging from 49 to 57 μm (positions 2, 3, 4, and 5), while the position where no pressure release points are formed (position 1) has a considerably larger film thickness than the other intersection positions. When pressure is formed inside the bag while it is being heated in the microwave, the intersection positions with lower film thickness (lower strength) expand, and pressure release points are formed to release pressure and steam from the bag. Therefore, the remaining pressure inside the bag is not sufficient to create a remaining intersection (position 1) with a greater film thickness that expands to form a pressure release point. Also, when pressure is generated inside the bag and gives a similar film thickness within the patterned notch area, the linear notches of the pattern help to distribute the tension in the intersection area, so increasing the number of linear notches in the pattern at intersections promotes the formation of pressure release points. Thus, pressure release points can be formed more easily and efficiently.

[0071] Similarly, in the pressure release design 4.5, the pressure release points are formed only at intersections 1, 2, and 3.

[0072] For pressure relief design 4.8, where there is no increase in the number of notches in a pattern that is a straight line or a cross at the intersection, the pressure relief points are formed randomly, that is, pressure relief points can be formed at any position among positions 1 to 6 at intersections 1 to 6. Therefore, the formation of pressure relief points is random and cannot be controlled.

[0073] (Research on the effects of laser application conditions and the remaining film thickness after laser application) The experiment involved a 20 x 15 cm sample with a 4.5 cm folding section. 2 This was carried out by applying a laser to a vertically positioned bag to form pressure-relieving designs 4.2 and 4.4. Laser application conditions, such as laser power and laser scanning speed, which affect the laser marking time and the thickness of the remaining laminated film after laser application in the patterned area, were adjusted. The results are shown in Table 6.

[0074] [Table 6]

[0075] From experiments, it was found that for pressure release design 4.2, the appropriate laser application conditions that yield good pressure release without causing delamination and widespread tearing are a laser power of 16 watts and a laser scanning speed of 30 m / min, which gives the remaining laminated film thickness in the patterned notched area after laser application to a range of 30 to 50 μm.

[0076] For pressure release design 4.4, suitable laser application conditions that provide good pressure release without causing delamination and widespread tearing are a laser power of 16 watts and a laser scanning speed of 66 m / min that give the remaining laminated film thickness after laser application in the patterned notch area in the range of 35 to 45 μm, a laser power of 16 watts and a laser scanning speed of 72 m / min that give the remaining laminated film thickness after laser application in the patterned notch area in the range of 45 to 55 μm, and a laser power of 16 watts and a laser scanning speed of 78 m / min that give the remaining laminated film thickness after laser application in the patterned notch area in the range of 65 to 70 μm.

[0077] The results described above demonstrate that the pressure-relieving design according to the present invention provides water vapor and gas barrier properties similar to, or not significantly different from, those of an untreated film, even when the thickness of the remaining laminated film after laser application is large. Therefore, laser application conditions can be adopted that provide a shorter marking time and a thicker remaining laminated film after laser application, making it more suitable for use. Accordingly, the packaging may be used to store food without affecting the shelf life of the food inside the packaging.

[0078] Furthermore, by testing bags with pressure-relieving design 4.4 and comparing them to laminated film bags not subjected to laser application, the water vapor transmission rate (WVTR) was determined according to ASTM F1249 at 37.8°C and 90% relative humidity, and the oxygen transmission rate (OTR) was determined according to ASTM D3985 at 23°C and 0% relative humidity. The results showed that bags with pressure-relieving design 4.4 had a water vapor transmission rate of 3.78 g / m³. 2 .day, and oxygen permeability of 66.5 cc / m³ 2 Bags that have undergone laser treatment have a water vapor transmission rate of 4.39 g / m³. 2 .day, and oxygen permeability of 52.4 cc / m³ 2 It was found to have .day. The results show that the water vapor and oxygen permeability of the laminated film bag that was laser-treated to form the pressure-relieving design according to the present invention did not differ significantly from that of the bag that was not laser-treated, indicating that the bag retains good barrier properties.

[0079] (Research on the effect of size on pressure relief design) The experiment involved 10 × 10 cm pressure relief designs of different sizes. 2 The tests were conducted using centrally sealed bags (excluding the sealing area). The size of the pressure-relieving design was calculated as a percentage of the diameter of the widest part of the design, based on the maximum length of the bag packaging. The results are shown in Table 7.

[0080] [Table 7]

[0081] From the results, it was found that an appropriate pressure relief design that enables very low delamination (10% or less) and good pressure relief without extensive tearing is a pressure relief design in which the diameter of the widest part is 7% or more. The pressure relief design that shows the best results without delamination or extensive tearing is a pressure relief design in which the diameter of the widest part is within the range of 10 to 100% based on the maximum length of the bag package.

[0082] Next, further experiments on the effect of the size of the pressure relief design on the pressure relief efficiency were carried out using vertical bags of 20×15 cm 2 having different sizes of pressure relief designs 4.3 and 4.4 and various remaining film thicknesses after laser application. The results are shown in Table 8.

[0083]

Table 8

[0084] From Table 8, it can be seen that appropriate sizes of the pressure relief design and the remaining film thickness after laser application give good pressure relief efficiency with no delamination and extensive tearing, or a very low rate of delamination and extensive tearing.

[0085] (Research on the position of the pressure relief design on the surface of the package) The experiment was carried out using center-sealed bags and three-side-sealed bags having the pressure relief design 4.4 at different positions on the bag package, as shown in Fig. 5, and the diameter of the widest part of the pressure relief design was 10% with respect to the maximum length of the bag package. The results are shown in Table 9. [[ID=​​​​​​​​​ Table 9 shows that the pressure relief design can be located anywhere on various bag packaging materials without affecting pressure relief efficiency or causing delamination and widespread tearing problems.

[0088] (Research on the use of packaging materials as vacuum-packed products) The experiment was conducted using a centrally sealed bag with a pressure-releasing design 4.4 containing a sponge with 50 ml of water inside, as described above. During the sealing step, the air inside the bag was removed to simulate a vacuum-sealed state. The bag samples were then kept at room temperature for 6 months before testing their ability to release pressure by heating in a microwave oven.

[0089] The results show that the bag packaging having the pressure release design 4.4 according to the present invention can be used as a vacuum packaging because the bag packaging can still maintain a vacuum state after being stored at room temperature, and when heated in a microwave oven, the pressure can be effectively released without delamination and widespread tearing.

[0090] (Research on using packaging materials as vacuum-sealed packaging materials subject to sterilization) The experiment was conducted using a centrally sealed bag with a pressure-releasing design 4.4 containing a sponge with 50 ml of water inside, as described above. During the sealing step, the air inside the bag was removed to simulate a vacuum packaging state. The bag samples were then sterilized at 90°C for 25 minutes in a water-spray pressurized retort (KM Grand Pack Co., Ltd, KM-P60SS-E). The sterilized vacuum bag packaging was kept at room temperature for two weeks before testing its ability to release pressure by heating in a microwave oven.

[0091] The results show that the bag packaging having the pressure-releasing design 4.4 according to the present invention can be used as a vacuum packaging because the bag packaging can still maintain a sealed vacuum state after sterilization and storage at room temperature, and can be sterilized and, when heated in a microwave oven, can effectively release pressure without delamination and widespread tearing.

[0092] (Research on using packaging materials as vacuum-sealed packages that are sterilized and stored in a frozen state) The experiment was conducted using a centrally sealed bag with a pressure-releasing design 4.4 containing a sponge with 50 ml of water inside, as described above. During the sealing step, the air inside the bag was removed to simulate a vacuum packaging state. The bag samples were then sterilized at 90°C for 25 minutes in a water-spray overpressure retort. The bag packaging was then kept frozen at -18°C for two weeks before testing its ability to release pressure by heating in a microwave oven.

[0093] The results show that the bag packaging having the pressure-releasing design 4.4 according to the present invention can be used as a vacuum packaging because the bag packaging can still maintain a sealed vacuum state after sterilization and frozen storage (-18°C), and can be sterilized and, when heated in a microwave oven, can effectively release pressure without delamination and widespread tearing.

[0094] (Best Mode of the Invention) The best mode of this invention is as described in the detailed description of the invention.

Claims

1. A container section formed for storing the product, A flexible film portion comprising a flexible film portion having at least one pressure-relieving design on its outer surface, In a packaging body that can release the pressure formed inside, The pressure relief design comprises at least two identical or different patterned notches that are combined together, and three or more intersections of the patterns are formed. The pressure relief design is formed by the notches of at least one closed-shaped pattern and at least one open-shaped pattern that are combined together. The pressure-relieving design has a widest portion dimension that ranges from 15% to 100% of the widest portion dimension of the flexible film portion. The notches in the pattern are formed on the surface of the flexible film portion by using a laser. The flexible film portion is a laminated film comprising an inner layer film which is a layer that comes into contact with the product contained in the packaging, and an outer layer film which is laminated on the inner layer film on a side that does not come into contact with the product. The laminated film has the pressure-relieving design formed by using a laser on the side surface of the outer layer film to form the notches of the pattern, and the thickness of the remaining laminated film in the notched area of ​​the pattern after the laser is used is in the range of 50 μm to 75 μm. A packaging body characterized by the following features.

2. The packaging according to claim 1, wherein the closed shape pattern is selected from the group consisting of circles, semicircles, ellipses, semi-ellipses, pointed ellipses, pointed semi-ellipses, polygons, or combinations thereof.

3. The packaging according to claim 1, wherein the open shape pattern is selected from the group consisting of straight lines, crosses, asterisks, curves, wavy lines, V-shapes, T-shapes, or combinations thereof.

4. The packaging according to any one of claims 1 to 3, wherein the pressure relief design is formed by the notches of the pattern of at least one circle, ellipse, or pointed ellipse combined with the cross pattern, such that the intersection of the pattern is formed and 3 to 17 pressure relief points are created.

5. The packaging according to any one of claims 1 to 4, wherein the notches in the pattern have a depth that does not perforate the thickness of the flexible film portion.

6. The packaging according to claim 5, wherein the notches of the pattern have a depth starting from the outer surface of the flexible film portion, within a range of 20% to 75% of the thickness of the flexible film portion.

7. The aforementioned laser is a fiber laser or CO2 laser. ２ A laser is selected, preferably CO ２ The packaging body according to claim 1, wherein it is a laser.

8. The notches of the pattern have wavelengths ranging from 300 nm to 17,000 nm, or from 9,300 nm to 10,700 nm, laser power ranging from 1 watt to 30 watts, or from 10 watts to 20 watts, and laser scanning speeds ranging from 6 m / min to 720 m / min, or from 10 m / min to 100 m / min. ２ A packaging body according to claim 1 or 7, formed by using a laser.

9. The packaging according to claim 1, wherein the inner layer film is made of polyolefin, or low-density polyethylene, or linear low-density polyethylene, or high-density polyethylene, or polypropylene homopolymer, or polypropylene copolymer, or a combination thereof.

10. The packaging according to claim 1, wherein the outer layer film is made of polyamide, or biaxially oriented polyamide (BOPA), or polyester, or biaxially oriented polyethylene terephthalate (BOPET).

11. The packaging according to claim 1 or 9, wherein the inner layer film has a thickness in the range of 40 μm to 100 μm, or in the range of 40 μm to 80 μm.

12. The packaging according to claim 1 or 10, wherein the outer layer film has a thickness in the range of 12 μm to 25 μm, or in the range of 12 μm to 15 μm.

13. A sealed package according to any one of claims 1 to 12.

14. The packaging body according to claim 13, wherein the bag is made of a flexible film and has the pressure-relieving design on the outer surface of the bag.

15. The packaging according to claim 13, comprising a tray-shaped container portion and a sealing portion made of a flexible film, wherein the sealing portion has the pressure-relieving design on its outer surface.

16. A packaging body according to claim 13 or 14 for vacuum packing a product.

17. The packaging according to any one of claims 13 to 16, wherein the packaging can be sterilized by pasteurization or sterilization.

18. A packaging body according to any one of claims 13 to 17, which can be used in a refrigerated or frozen state.

19. In a pressure-relieving design for a flexible film, the pressure-relieving design comprises at least two identical or different patterns of notches combined together, and three or more intersections of the patterns are formed. The pressure relief design is formed by the notches of at least one closed-shaped pattern and at least one open-shaped pattern that are combined together. The pressure-relieving design has a widest portion dimension that ranges from 15% to 100% of the widest portion dimension of the flexible film. The notches in the pattern are formed on the surface of the flexible film by using a laser. The aforementioned flexible film is a laminated film for making a packaging body, The laminated film comprises an inner layer film which is a layer that comes into contact with the product contained in the packaging, and an outer layer film which is laminated on the inner layer film on a side that does not come into contact with the product. The pressure relief design is formed by using a laser on the side surface of the outer layer film to form the notches of the pattern, and the thickness of the remaining laminated film in the notched area of ​​the pattern after the laser treatment is in the range of 50 μm to 75 μm. A pressure-relieving design characterized by the following features.

20. The pressure relief design according to claim 19, wherein the closed shape pattern is selected from the group consisting of circles, semicircles, ellipses, semi-ellipses, pointed ellipses, pointed semi-ellipses, polygons, or combinations thereof.

21. The pressure relief design according to claim 19, wherein the open shape pattern is selected from the group consisting of straight lines, crosses, asterisks, curves, wavy lines, V-shapes, T-shapes, or combinations thereof.

22. The pressure relief design according to any one of claims 19 to 21, wherein the intersection of the patterns is formed and the notches of the pattern are formed in combination with the cross pattern, such that the intersection of the patterns is formed and 3 to 17 pressure relief points are created.

23. The pressure relief design according to any one of claims 19 to 22, wherein the notches in the pattern have a depth that does not perforate the thickness of the flexible film.

24. The pressure relief design according to claim 23, wherein the notches of the pattern have a depth starting from the surface of the flexible film within a range of 20% to 75% of the thickness of the flexible film.

25. The aforementioned laser is a fiber laser or CO2 laser. ２ Selected from lasers, specifically CO ２ A laser is selected for the pressure relief design according to claim 19.

26. The notches of the pattern have wavelengths ranging from 300 nm to 17,000 nm, or from 9,300 nm to 10,700 nm, laser power ranging from 1 watt to 30 watts, or from 10 watts to 20 watts, and laser scanning speeds ranging from 6 m / min to 720 m / min, or from 10 m / min to 100 m / min. ２ A pressure relief design according to claim 19 or 25, formed by using a laser.

27. The pressure relief design according to claim 19, wherein the inner layer film is made of polyolefin, or low-density polyethylene, or linear low-density polyethylene, or high-density polyethylene, or polypropylene homopolymer, or polypropylene copolymer, or a combination thereof.

28. The pressure relief design according to claim 19, wherein the outer layer film is made of polyamide, or biaxially oriented polyamide (BOPA), or polyester, or biaxially oriented polyethylene terephthalate (BOPET).

29. The pressure relief design according to claim 19 or 27, wherein the inner layer film has a thickness in the range of 40 μm to 100 μm, or in the range of 40 μm to 80 μm.

30. The pressure relief design according to claim 19 or 28, wherein the outer layer film has a thickness in the range of 12 μm to 25 μm, or in the range of 12 μm to 15 μm.

31. A pressure relief design according to any one of claims 19 to 30 for use with a sealed package.

32. The pressure-relieving design according to claim 31, wherein the sealed packaging body is a bag made of flexible film, and the outer surface of the bag has the pressure-relieving design.

33. The pressure-relieving design according to claim 31, wherein the sealed packaging comprises a tray-shaped container portion and a sealing portion which is the flexible film, the sealing portion having the pressure-relieving design on its outer surface.

34. The pressure-relieving design according to claim 31 or 32, wherein the sealed packaging is used for vacuum packing of a product.

35. The pressure-relieving design according to any one of claims 31 to 34, wherein the sealed packaging can be sterilized by pasteurization or sterilization.

36. The pressure-relieving design according to any one of claims 31 to 35, wherein the sealed packaging can be used in a refrigerated or frozen state.

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