WO2020263196A2

WO2020263196A2 - Multi-compartment packaging capable of releasing pressure

Info

Publication number: WO2020263196A2
Application number: PCT/TH2020/000042
Authority: WO
Inventors: Ittiporn ARDPRU; Juthamas MAHAJAROENSIRI; Buncherd NGAMNAWAKUL; Adisak VORAKUNPINIJ
Original assignee: Scg Packaging Public Company Limited
Priority date: 2019-06-25
Filing date: 2020-06-23
Publication date: 2020-12-30
Also published as: WO2020263196A3

Abstract

The present invention provides a multi-compartment packaging comprising a pouch made of a flexible film material and sealed on all of its edges, thereby defining an interior chamber for containing foodstuffs; one or a plurality of first sealing lines for dividing the interior chamber into two or more compartments; and at least one pressure releasing means provided to one of the compartments; characterized in that each of the first sealing lines comprises at least one through- hole formed along the sealing line, thereby allowing pressure and steam generated upon heating the foodstuffs to be transferred between the compartments. The food packaging may further comprise one second sealing line for further dividing the interior chamber into multiple compartments. In some embodiments, the second sealing line may serve as an easily peelable sealing line which opens when the pressure in the packaging reaches a certain value.

Description

MULTI COMPARTMENT PACKAGING CAPABLE OF RELEASING PRESSURE FIELD OF THE INVENTION

The present invention relates to a multi-compartment packaging. In particular, the present invention relates to a multi-compartment packaging capable of releasing pressure.

BACKGROUND ART

A microwavable food packaging is generally designed to be hermetically sealed, in order to prevent microorganisms, oxygen or water vapour in the air from entering the packaging, and so, prevent food contamination and spoilage. While this type of food packaging provides convenience to various users and consumers, it often causes undesirable mixing when two or more types of foodstuffs or food components are filled within the same packaging and heated in a microwave oven. It is also inconvenient to the users and consumers if different types of the foodstuffs are to be packed and heated separately. Furthermore, the users and consumers are required to pre-open ₍cut, tear-open or pierce₎ the food packaging before heating or cooking in the microwave oven, so as to prevent building up of over-pressure and steam generated within the packages. However, the need to pre-open (cut, tear-open or pierce) the food packages causes losses of water contents and nutritional values from the foodstuffs, resulting in unappetizing foods.

There are numerous packaging and packages in the art that are provided with two or more compartments for containing different foodstuffs and at the same time, capable of releasing pressure from the packaging.

JP2004284604 (A) discloses a packaging bag having a laminated film structure with its compartment being divided into two chambers for packing liquid food and dry food. In particular, the packaging bag is divided into two chambers by an easily-peelable heat-bonded portion with a seal strength of 10 to 20 N/l 5 mm. The heat-bonded portion is opened by steam pressure generated during heating in a microwave oven, results in a mixing of liquid food with the dry food. An increasing of heat generates steam pressure inside the package, results in an opening of pressure releasing hole in a wing- like folding part of the film and that pressure releasing hole is designed to locate on the sealing line of such wing-like folding part. JP6130813 ₍B2₎ discloses a stand-up type flexible packaging having a sealing line ₍or preferably a V shape-like sealing line) at the centre of the packaging for dividing the interior of the packaging into a lower and an upper chamber. The sealing line is opened by pressure which builds up when heating the foods in a microwave oven (or a conventional oven₎, which then allows the foods contained in the lower and upper chambers to mix. The packaging also comprises a plurality of lateral openings along the sealing line, thereby enabling the steam and pressure to be released from the packaging. The packaging further comprises a guide line for permitting easy opening of the packaging. The packaging, in some embodiments, may also be provided with a base in form of a tray in which disposable spoons and forks may be arranged and positioned.

W02006/ 136825 ₍ Ab discloses a design of a packaging bag with two or more compartments, so that different food components are kept separate from one another prior to cooking. The packaging bag is divided into two or more compartments by using an easily peelable sealing line or strip When this type of packaging bag is heated in a microwave oven, the sealing line is peeled off when a pressure is reached, thereby enabling the food components contained in the compartments to mix together and be cooked together. The self- venting mechanism may be added on film scoring at an inner layer film where there is no adhesive layer attached to the outer layer film or an attachment of a pressure releasing valve, etc.

To overcome the issues mentioned in the foregoing, there remains a need to introduce and provide an improved packaging. The improved packaging comprises multiple compartments divided by sealing lines formed via a sealing method. The improved packaging also comprises through- holes or openings that allow pressure and steam to be transferred between the compartments during heating in a microwave oven. The improved packaging further comprises automatic pressure and steam releasing means, hence eliminating the need to pre- open the packaging before heating in the microwave oven.

By providing the improved packaging mentioned in the foregoing, it then allows different types of foodstuffs or food components (such as dry foodstuffs, wet/liquid foodstuffs, or both) to be contained in the same packaging. The improved packaging can also be used in a wide range of applications, and it can provide time- savings with good tasty as it can be used to heat multiple types of foodstuffs at the same time. SUMMARY OF THE INVENTION

The present invention provides a food packaging comprising a pouch made of a flexible film material and sealed on all of its edges, thereby defining an interior chamber for containing foodstuffs; one or a plurality of first sealing lines for dividing the interior chamber into two or more compartments; and at least one pressure releasing means provided to one of the compartments; characterized in that each of the first sealing lines comprises at least one through- hole formed along the sealing line, thereby allowing the compartments of the interior chamber to communicate with each other. By providing at least one through- hole along the first sealing line, it also allows pressure and steam generated upon heating the foodstuffs to be transferred between the compartments.

The aforementioned food packaging may further comprise one second sealing line for further dividing the interior chamber into multiple compartments. The second sealing line may also serve as an easily peelable sealing line which opens when the pressure in the packaging reaches a certain value, in order to allow the foodstuffs contained in the compartments (i.e. the compartments that are separated by the second sealing line) to mix together.

The present invention is advantageous in that:

• The packaging can be used to pack, fill or contain various types of foodstuffs or food components in separate compartments and as desired, thereby preventing unappetizing foods and undesirable mixing of foodstuffs prior to heating or cooking

• The packaging can be used in a wide range of applications, as it enables the foodstuffs (such as sausages/meatballs with dipping sauce, or meats with vegetables and gravy sauce) to mix together when being heated or cooked in the microwave oven. The packaging also enables the foodstuffs (such as dumplings and steamed buns, or meat and vegetables/ffuits) to be contained and remained in separate compartments, even after they have been heated or cooked in the microwave oven

• Size and number of the compartments of the packaging can be customized according to the types of foodstuffs

• The packaging is convenient and easy to be used, because it is able to automatically release the pressure and steam during heating or cooking in the microwave oven. It is not required to pre-open (cut, tear- open or pierce) the packaging before heating or cooking in the microwave oven, to avoid building up of the steam and pressure generated in the packaging during the heating or cooking, which may cause the packaging to explode

• The packaging can be used as a hermetically sealed packaging and/or as a frozen or chilled packaging and/or as a vacuum packaging and/or as a pasteurized or sterilized packaging, before it is heated in the microwave oven; and

• It provides a convenience and time- savings, because it is easy to heat the foodstuffs contained in the packaging for consumption onsite or at the premises. It also enables various foodstuffs to be heated or cooked in the packaging simultaneously.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Figure 1 illustrates a three-side sealed pouch comprising a sealing line at the centre of the packaging for dividing an interior space of the packaging, according to the present invention.

Figure 2 illustrates pouches having the various configurations of the first sealing line, according to the present invention.

Figure 3 illustrates pouches providing with various types of pressure releasing means, according to the present invention.

Figure 4 illustrates pouches providing with various types of pressure releasing means, according to the present invention.

DETAILED DESCRIPTION

Any aspects stated herein shall include modification to other aspects of the present invention unless otherwise specified.

Technical terms and other scientific terms used herein are defined to be understood by a person having ordinary skill in the art unless otherwise specified.

As used herein, the terms xonsist(s) of, "comprise/sr, "contain(s)" and "include(s)_” are open- ended verbs. For example, any method onsistcs) of', "comprise(s)", "contain(s)ⁿ or ' include(s)" one or more components, or one or more steps, which are not limited to one component or step or more steps and components but also include to components or steps that have not been defined herein.

As used herein, tools, equipment, methods, materials or any chemicals mentioned herein, unless otherwise specified shall mean tools, equipment, methods, materials or chemicals used or generally operated by a person having ordinary skill in the art.

The disclosed components and/or methods and the claims of the present invention intend to include all aspects of the present invention obtained from actions, operations, modifications or changes of any factors without experiments, which significantly differ from the present invention; to obtain a qualified and useful article, and to provide results similar to the aspects of the present invention according to the view of the person having ordinary skill in the art even they are not explicitly defined in the claims. Therefore, the substitution or things similar to the aspects of the present invention including any small modifications or changes which can be apparent to the person having ordinary skill in the art should be considered to be within the spirit, scope and idea of the present invention.

“As used herein, the term“sealing line” may refer to a“first sealing line”, or a_“second sealing line_” The first and second types of sealing lines are sealing lines for dividing the interior chamber of the packaging into several compartments. The first sealing line is a sealing line comprising at least one through- hole formed along the sealing line, while the second sealing line is an easily peelable sealing line which forms a weakened sealing area along the sealing line or portions of the sealing line.

As used herein, the term“sealed edge” refers to a sealing line along the edge of the packaging.

As used herein, the term“ opening” may refer to a type of opening. In one embodiment, it may refer to the through- hole formed along the first sealing line. In another embodiment, it may refer to the opening created by the second sealing line when it is peeled off or opened due to the result of an increase of steam pressure inside the packaging during the heating or cooking process.

As used herein, the term“through-hole” or“through-holes_” refer to the opening or openings formed along the first sealing line. As used herein, the term“easily peelable sealing line” refers to weakened sealing area on the sealing line. When heating the foodstuffs contained in the packaging in a microwave oven, the pressure and steam created inside the packaging will cause the weakened sealing area to open as an opening.

As used herein, the term flexible film” refers to film suitable to be used as a lamination for making flexible packaging. The flexible film may comprise stretching properties when being exposed to heat and/or force including pressure. The flexible film may also comprise other advantageous properties such as strength, ability to prevent gas permeation, printability and heat sealing ability.

As used herein, the term 'pressure release" refers to the characteristics of the packaging that enable a release mechanism to automatically vent out pressure, air and/or steam inside the packaging once the packaging being exposed to heat or any force causes pressure to increase inside the packaging. It also refers to the characteristics of the packaging to control the pressure inside the packaging so that the pressure is maintained at a pre determined level.

As used herein, the term“pressure releasing means_” refers to the pressure releasing mechanism provided to the packaging. It is used for releasing pressure or for the steam to vent out of the packaging automatically, when the pressure inside the packaging exceeds the resistance of the film. For example, the pressure releasing means that may be used in the present invention may be a weakened sealing pattern, a film scoring pattern, an incomplete sealing pattern, a wing- like protrusion, a pressure releasing valve or a film scoring pattern with chemical coating.

The description of the present invention will be described in more details as follows:

In accordance with one embodiment of the present invention, there is provided a food packaging comprising a pouch made of a flexible film material and sealed on all of its edges, thereby defining an interior chamber for containing foodstuffs; one or a plurality of first sealing lines for dividing the interior chamber into two or more compartments; and at least one pressure releasing means provided to one of the compartments; characterised in that each of the first sealing lines comprises at least one through- hole formed along the sealing line, thereby allowing the compartments of the interior chamber to communicate with each other, and also allowing pressure and steam generated upon heating the foodstuffs to be transferred between the compartments

As illustrated in Figure 1, the packaging of the present invention may be a pouch made from a flexible laminated film material 20 or more preferably a three- side seal bag 30. Accordingly, the space confined within the sealed edges of the pouch or bag 30 may define an interior chamber for containing foodstuffs. The packaging may also comprise a first sealing line

40 at the centre of the packaging, as illustrated in Figure 1, thereby dividing the interior chamber of the packaging into two compartments 10. These compartments 10 may each be used to contain similar types or different types of foodstuffs. Additionally, although the first sealing line 40 is located at the centre of the packaging in Figure 1 , it should be appreciated that the first sealing line 40 need not be located at the centre of the packaging. It should also be appreciated that more than first sealing line 40 may be provided to the packaging, thereby dividing the interior chamber of the packaging into more than two compartments 10.

The aforementioned first sealing line 40 may comprise at least one through-hole 50 formed along the sealing line 40, as shown in Figure 1. When a user or a consumer heats or cooks the foodstuffs contained in the packaging, water vapour or steam may be generated from the heating process, thereby contributing the build-up of pressure in each of the compartments 10. By having at least one through-hole 50 formed or provided along the sealing line 40, the steam and pressure can be transferred between the two compartments 10, via the through-hole 50 or multiple through- holes 50. Not only the through- hole <s) 50 can suitably transfer pressure and steam between the compartments 10 of the packaging, sensory quality of the foodstuffs is also kept tasty like individually heat. Further, excessive steam and pressure may also be vented out of the compartments 10 through other mechanisms, for instance through a pressure releasing means 60 provided to one of the compartments 10. The pressure releasing means 60 may also be configured to vent the excessive steam and pressure when a certain pressure is reached.

If the first sealing line 40 comprises only one through- hole 50 formed along the sealing line 40, such through- hole 50 may preferably have a size LI of 15 mm to 20 mm. However, the optimized size of the through- hole 50 may be determined based on the properties or types of the foodstuffs to be contained in the compartment (s) 10 (in order to prevent undesirable mixing of foodstuffs) , as well as the pressure release capability of the packaging. Delamination of the packaging film due to the insufficient venting of pressure and steam out of the packaging may easily be observed on the surface of the packaging and may also affect the optimized size of the through-hole 50

If the first sealing line 40 comprises two through- holes 50 formed along the sealing line 40, each through-hole 50 may preferably have a size LI of 5 mm to 10 mm.

Further, the distance between two adjacent through-holes 50 (L3) may be 15 mm or more. Further, the distance between at least one of the through hole 50 and the inner edge of the sealed edge of the packaging ₍L2₎ may be more than or equivalent to 20% of the length of the sealing line 40. However, the optimized size of the through- holes 50 may be determined based on the properties or types of the foodstuffs to be contained in the compartment ₍s₎ 10 ₍in order to prevent undesirable mixing of foodstuffs), as well as the pressure release capability of the packaging.

Delamination of the packaging film due to the insufficient venting of pressure and steam out of the packaging may easily be observed on the surface of the packaging may also affect the optimized size of the through-hole 50.

The packaging of the present invention may further comprise a second sealing line 41 The second sealing line 41 comprises an easily peelable sealing line which forms a weakened sealing area along the sealing line or portions of the sealing line. In particular, the second sealing line 41 may comprise an easily peelable sealing line or a weakened sealing area having a length of at least 20 mm. Further, the easily peelable sealing line may comprise a seal strength lower than the other sealed areas, and the seal strength of the easily peelable sealing line may range from 5 to 35 N/15 mm or preferably from 5 to 20 N/l 5 mm.

The packaging of the present invention may, in some embodiments, comprise at least one or a combination of first sealing line 40 and second sealing line 41. By providing these sealing lines, the packaging can be used in a wide range of applications. While the presence of the first sealing line 40 on a packaging allows different types of dry foodstuffs to be contained separately before and after heating in a microwave oven, the second sealing line 41 may also be provided to the packaging to contain dry foodstuffs and liquid/ dry foodstuffs in the respective compartments and then allow the foodstuffs to mix together after heating. In some other embodiments, the packaging of the present invention may further comprise at least one pressure releasing means provided on the film surface of the packaging. In some preferred embodiments, the pressure releasing means are provided to the compartment 10 which is used to contain dry foodstuffs. A variety of pressure releasing means may also be used in the present invention, such as but not limited to:

₍a₎ The weakened sealing pattern: To provide weak seal strength in some of the sealing areas, so that these areas can be easily opened to form pressure releasing opening parts, when the pressure is building inside the packaging.

₍b₎ The film scoring pattern: To reduce the thickness of specific areas of a film. In particular, the packaging film is processed in such a way that score lines may be formed on the film without penetrating the film or making a hole. Upon heating the foodstuffs contained in the packaging, water contents in the food will become high-pressure steam which“pushes” the packaging until it is tom-open hole along the score line.

(c) The incomplete sealing pattern: To use a chemical coating or an easily-peelable tape

Based on this method, when the packaging is pressurized by heated steam from the food, the coated or taped sealing line will be separated until they are fully opened to be proper areas to enable a release of pressure and steam.

₍d) The wing-like venting portion: To provide a wing-like venting portion protruding from an exterior of the pouch, wherein its seal strength is lower than that of neighbourhood area by adjusting the seal conditions or by coating with chemicals.

(e) The pressure releasing valve: To provide a pressure releasing valve by perforating on the film surface and then mounting the valve on the packaging. When heating the foodstuffs in the packaging, the valve will release steam pressure through the valve.

(f) A combination of a film scoring pattern with a chemical coating: To provide one or more coating substances on the packaging, which facilitate to reduce the adhesion force between the laminated film layers of the packaging. The surface of the coated area may further be scored by a laser beam. Upon heating the foodstuffs contained in the packaging, water contents in the food will become high-pressure steam which“stretches” the scored film to expand and move apart until it creates a pressure releasing hole.

Accordingly, it should be appreciated that the packaging of the present invention is preferably made of a flexible film having characteristics defined in the foregoing. The flexible film may also preferably be a laminated film comprising an inner film layer contacting and surrounding the foodstuffs contained in the interior chamber and an outer film layer adjacent to the inner layer film. In some embodiments, the inner layer film may be made of polyolefin- type polymer, low- density polyethylene ₍LDPE) , linear low- density polyethylene ₍ LLDPE) , high- density polyethylene ₍ HDPE) , polypropylene homopolymer, polypropylene copolymer or a combination thereof. While for the outer layer film, it may be made of polyamide- type polymer, biaxially-oriented polyamide ₍BOP A) or polyester or biaxially-oriented polyethylene terephthalate ₍BOPET).

In various embodiments, the packaging of the present invention is suitable to be used as a hermetically sealed packaging or a heatable hermetically sealed packaging, for heating or cooking in a conventional oven or a microwave oven. It can also be used to contain dry foodstuffs and/or wet/liquid foodstuffs in separate compartments.

In various embodiments, the packaging of the present invention can be used as vacuum packaging and/or as a packaging that undergoes pasteurization or sterilization and/or as packaging to be used in chilled or frozen conditions. The description of the present invention will be described in more detail in conjunction with the experiments and the accompanying figures which does not intend to limit the scope of the present invention.

Experiment 1: a study of sealing line patterns on pressure release capability

The packaging used to carry out Experiment 1 was a three-side sealed pouch. The packaging was prepared using a laminated film of dimension 180 x 280 mm², where the laminated film was made of an outer layer of nylon film and an inner layer of linear low-density polyethylene ₍LLDPE) film.

The laminated film was also scored, so that score lines, shapes or patterns were formed to reduce the thickness of the areas along the score lines, shapes or patterns. Then, the laminated film was sealed to form a three- side sealed pouch by using a heat sealing device. The two compartments were divided by 1) partial sealing, by providing a partial sealing line to the centre of the pouch, in which the partial sealing line was extending from the bottom edge of the pouch and has a length of approximately three-quarter of the length of the pouch; 2₎ full sealing, by providing a sealing line having a total of four through-holes formed along the sealing line, each through- hole having a size of 5 mm and spaced equally along the sealing line; and 3) full sealing, by providing a sealing line with low seal strength (according to ASTM F88) of 5 N/15 mm. To ensure that pouch had no leakage, 50 ml of water containing sponge (representing foodstuff) was placed into the said pouch. Then, tightly sealed the sponge containing pouch and heated in a microwave oven ₍model NE- 1753 manufactured by Panasonic and with an electric power of 1300 W) for 60 seconds.

Table t shows the results of the pressure release capability of the two-compartment pouches with various sealing line patterns.

The results in Table 1 show that only the Pouch No. 2 and Pouch No. 3 allowed pressure and steam to be transferred between the compartments when being heated in a microwave oven, and could perform good self-venting function with the provided pressure releasing means.

Experiment 2: a study of the sizes of the through-holes of the sealing line on pressure release capability and packaging film delamination The aim was to identify the suitable size of through-holes ₍LI) for transferring the pressure and steam sufficiently during heating, while being able to facilitate automatic pressure release around the area where the pressure releasing means was provided. The packaging was prepared according to the procedure detailed in Experiment 1. While some of the three-side sealed pouches were provided with a sealing line having a through- hole formed along the sealing line, some of the other three- side sealed pouches were provided with a sealing line having two through- holes formed along the sealing line. Various through-hole sizes were also tested.

Table 2 shows the results of the pressure release capability of the two- compartment pouches provided with different numbers and sizes of through-holes formed on the sealing line

* The delamination is a separation of the laminated film layer after being heated in a microwave oven.

The results in Table 2 show that when two through-holes were formed on the sealing line, the sealing line having through-holes each with a size of 5 mm were able to provide good transfer of pressure and steam between the two compartments during heating, and at the same time, were able to automatically release pressure without causing delamination of the packaging. The results in T able 2 also show that when only one through-hole was formed on the sealing line, the sealing line having the through- hole with a size of at least 15 mm was able to provide good transfer of pressure and steam between the two compartments during heating and at the same time, was able to automatically release pressure without causing delamination of the packaging. Experiment 3: a study of distances between two adjacent through-holes of the sealing line for dividing on pressure release capability and packaging film delamination

The aim was to identify the appropriate distance between two adjacent through-holes (L3) formed on the sealing line, for transferring pressure and steam sufficiently during heating, while being able to release pressure automatically. The packaging was prepared according to the procedure detailed in Experiment 2. In specific, the three-side sealed pouches were provided with a sealing line having two through-holes (each having a size of 5 mm) formed along the sealing line, and the distance between these through-holes being adjusted to 5, 10, 15 or 20 mm.

Table 3 shows the results of pressure release capability of the pouches provided with a sealing line having two through- holes of an identical size formed on a sealing line, but with a distance between these through-holes being adjusted to different values.

The results in Table 3 show that the two through-holes must have a distance of at least 15 mm apart from each other, in order to allow the pressure and steam to vent out of the packaging during heating and at the same time, allow the pressure to be automatically released without causing film delamination of the packaging.

Experiment 4: a study of distances between a sealed edge of packaging and at least one of the through hole of the sealing line on pressure release capability and packaging film delamination

The aim was to identify the suitable distance between the inner edge of the sealed edge and at least one of the through hole (L2) which was formed on the sealing line, for transferring pressure and steam sufficiently during heating, while being able to automatically release pressure. The packaging was prepared according to the procedure detailed in Experiment 2 and in accordance with Figures 2. 1, 2.2 and 2.3. In specific, the pouches were provided with a sealing line having two through- holes and one through- hole formed along the sealing line, and for each pouch, the distance L2 between the sealed edge of the pouch and the adjacent through-hole of the sealing line was adjusted to 5, 15, 25 or 35 mm Table 4 shows the results of pressure release capability of the pouches provided with different L2 values.

The results in Table 4 show that the distance L2 between a sealed edge of the pouch and the through- hole formed on the sealing line of length 160 mm must be 35 mm or more, in order to enable sufficient transfer of pressure and steam during heating, while enabling automatic release of pressure without causing delamination of the packaging. It is also found from the results in Table 2 that the distance L2 was about 20% of the total length of the sealing line and it was not affected by the number of through-holes formed along the sealing line, the position of the through- holes formed on the sealing line, the size LI of through- holes formed on the sealing line or the distance L3 between the pair of through-holes on the sealing line.

Experiment 5: a study of seal strengths of an easily peelable sealing line on pressure release capability and packaging film delamination

The aim was to identify the seal strength for suitably dividing the pouch into at least two compartments. The experiment was performed by adjusting the sealing conditions so that sealing lines with various seal strengths could be formed on the packaging pouch. The packaging pouch was prepared using a laminated film of dimension 120 x 200 mm², where the laminated film was made up of an outer layer of nylon film and an inner layer of LLDPE film. The laminated film was also scored, so that score lines, shapes or patterns were formed to reduce the thickness of the areas along the score lines, shapes or patterns. Subsequently, the laminated film was heat- sealed to form a three-side sealed pouch. The interior chamber of the three-side sealed pouch was then divided into two compartments by a sealing line formed at the centre of the pouch via the low seal-strength sealing method. The low seal-strength sealing method was performed in various sealing conditions. The seal strength was also measured according to the ASTM F88 Standard. To ensure that pouch had no leakage, 50 ml of water containing sponge ₍representing foodstuff) was placed into the said pouch. Then, tightly sealed the sponge containing pouch and heated in a microwave oven ₍model NE-1753 manufactured by Panasonic and with an electric power of 1300 W₎ for 60 seconds

Table 5 shows the results of pressure release capability of the two- compartment pouches comprising easily peelable sealing lines with different seal strengths

The results in Table 5 show that the sealing lines with a seal strength of 5 to 35 N/ 15 mm could be classified as low seal strength sealing lines. It is also found that the easily peelable sealing line could be automatically opened by the pressure and steam generated inside the pouch during heating. By having such opening, it also facilitates in the transfer of pressure and steam between the compartments within the pouch, thereby enabling automatic release of pressure without causing delamination of the pouch. Experiment 6: a study of a length of an easily peelable sealing line on pressure release capability and packaging film delamination

The aim was to study a pouch provided with a sealing line, where such sealing line was an easily peelable sealing line formed along a portion of the sealing line. The pouch was designed to allow different types of foodstuffs (such as dry foodstuffs and wet/ liquid foodstuffs) to mix together during heating in a microwave oven, while ensuring that the wet/liquid foodstuffs would not mix with the dry foodstuffs prior to heat. The pouch was prepared according to the procedure detailed in Experiment 1. In particular, the interior chamber of the three- side sealed pouch was divided into two compartments by a sealing line where 15 and 20 mm of the sealing line was the easily peelable sealing line with a seal strength of 5 N/15 mm.

Table 6 shows the pressure release capability of the pouches comprising easily peelable sealing lines in different lengths.

The results in Table 6 show that the sealing line should comprise at least 20 mm of the easily peelable sealing line formed thereon, to enable good transfer of pressure and steam between the compartments of the packaging during heating, while being able to automatically release pressure without causing delamination of the packaging.

Experiment 7: a study of seal strengths of an easily peelable sealing line having a length of 20 mm on pressure release capability and packaging film delamination

The aim was to study a pouch provided with a sealing line, in which such sealing line was an easily peelable sealing line formed along only a portion of the sealing line but with different seal strengths. The packaging pouch was prepared according to the procedure detailed in

Experiment 1. In particular, the interior chamber of the three- side sealed pouch was divided into two compartments by a sealing line formed at the centre of the pouch through the low seal-strength sealing method. Further, the sealing line was formed at the centre of the pouch in such a way that 20 mm of the sealing line was the easily peelable sealing line with different seal strengths.

Table 7 shows the results of the pressure release capability of the pouches comprising an easily peelable sealing line of length 20 mm but with different seal strengths.

The results in Table 7 show that when the easily peelable sealing line of length 20 m had a seal strength ranging from 5 to 20 N/ 15 mm, it was peeled off and opened by the pressure and steam generated and accumulated inside the pouch during heating in the microwave oven. Such easily peelable sealing line also enabled transfer of pressure and steam between the compartments of the pouch and automatic release of pressure without causing delamination.

Experiment 8: a study of packaging compartment sizes on pressure release capability and packaging film delamination

The aim was to study a pouch comprising compartments divided in an unequal manner or different ratio by using an easily peelable sealing line. The pouch was designed to allow different types of foodstuffs (e g. dry foodstuffs and wet/liquid foodstuffs) to mix together during heating or cooking in a microwave oven. The pouch was also designed to contain the dry foodstuffs in the compartment provided with a pressure releasing means, while the wet/liquid foodstuffs were to be contained in the other compartment without any pressure releasing means. Experiment 8 was performed by dividing the interior chamber of the pouch into two compartments in varying sizes. The test was carried out with a minimum compartment size of 45 mm, as small compartment sizes would not be able to contain foodstuffs and therefore, not suitable to be used as a food packaging. The pouch was prepared according to the procedure detailed in Experiment 5. In particular, the interior chamber of the three- side sealed pouch was divided into two compartments of varying sizes by an easily peelable sealing line with a seal strength of 5 N/l 5 mm.

Table 8 shows the results of pressure release capability of pouches comprising compartments of varying sizes.

The results in Table 8 show that the sizes of the compartments of the pouch do not affect the pressure releasing function of pouch, as all of the pouches are able to provide good transfer of pressure and steam between the compartments during heating and at the same time, they are able to automatically release pressure without causing delamination of the packaging.

Experiment 9: a study of various pressure releasing means on pressure release capability and packaging film delamination The aim was to study the various pressure releasing means of the two- compartment divided pouch. The experiment was performed by preparing pouches as shown in Figure 3, where each of the pouches was provided with a type of pressure releasing means, for example, 1 ) by way of a film scoring pattern to reduce the thickness of specific areas 60, 61 ; 2) by way of a film scoring pattern combined with a chemical coating to form a pressure release pattern 62; and 3) by way of a weakened sealing to form weak seals 63 at specific areas.

To conduct Experiment 9, the pouch was prepared using a laminated film of dimension 180 x 280 mm², where the laminated film was made up of an outer layer of nylon film and an inner layer of LLDPE film. The laminated film was further processed, so a specific type of pressure releasing means was formed thereon. Subsequently, the laminated film was heat- sealed to form a three- side sealed pouch. The interior chamber of the three- side sealed pouch was then divided into two compartments by a sealing line comprising two of through- holes of size 5 mm formed along the sealing line It should be noted that the sealing line having two through- holes was formed at the centre of the pouch for transferring pressure between its compartments. To ensure that pouch had no leakage, 50 ml of water containing sponge ₍representing foodstuff₎ was placed into the said pouch. Then, tightly sealed the sponge containing pouch and heated in a microwave oven ₍model NE-1753 manufactured by Panasonic and with an electric power of 1300 W₎ for a period of 60 seconds.

Table 9 shows the results of pressure release capability of the pouches with various pressure releasing means.

The results in Table 9 show that various types of pressure releasing means provided to the packaging pouches are all able to provide good transfer of pressure and steam between the compartments during heating, and at the same time, they are also able to release pressure automatically without causing delamination of the packaging pouch.

Experiment 10: a study of the number of compartments of a pouch on pressure release capability and packaging film delamination

The aim was to study a pouch having more than two compartments formed by using two or more types of sealing lines. A three-compartment pouch was prepared with a laminated film of dimension 180 x 280 mm², where the laminated film was made of an outer layer of nylon film and an inner layer of LLDPE film. Subsequently, the laminated film was heat- sealed to form a three-side sealed pouch. The interior chamber of the three-side sealed pouch was then divided into three compartments as shown in Figures 4.1 and 4.2, by using two of first sealing lines, each comprising two through- holes of size 5 mm formed along the sealing line. A pressure releasing means was provided to the left side compartment of one pouch and the central compartment of the other pouch. The interior chamber of the three- side sealed pouch may also be divided into three compartments as shown in Figure 4.3, by using a first sealing line ₍which comprises two through- holes of size 5 mm formed along the sealing line) and a second sealing line ₍which comprises an easily peelable sealing line formed along the sealing line).

A four-compartment pouch was also prepared by using the aforementioned laminated film with a dimension of 280 x 280 mm². The laminated film was subsequently heat- sealed to form a three- side sealed pouch, and the interior chamber of the three- side sealed pouch was divided into four compartments as shown in Figure 4.4, by a pair of intersecting sealing lines each comprising two through-holes of size 5 mm formed on the sealing line.

To ensure that pouch had no leakage, 50 ml of water containing sponge (representing foodstuff) was placed into the said pouch. Then, tightly sealed the sponge containing pouch and heated in a microwave oven (model NE- 1753 manufactured by Panasonic and with an electric power of 1300 W) for a period of 60 seconds.

Table 10 shows the results of pressure release capability of the pouches having more than two compartments

The results in Table 10 show that the pouches were divided by sealing lines into three or four compartments. All of the pouches are able to facilitate good transfer of pressure and steam between the compartments during heating. It is also found that they are all able to release pressure automatically without causing delamination of the pouch. Experiment 11: Effect of numbers and sizes of through- holes on the sealing line in pressure release two-compartment pouch on food sensory

The aim was to study the sensory of shumai and steamed buns which were packed in each compartment of the pressure release pouch having through- holes formed on the sealing line for transferring the pressure and steam between compartments while heating in the microwave oven. The pouches were prepared according to the procedure detailed in Experiment 2 above. In particular, the two-compartment pouches provided with different numbers and sizes of through- holes formed on the sealing line.

Table 11 shows the results of food sensory

The results in Table 1 1 show that the foodstuffs heated in the pouch having a sealing line comprising two through-holes of size 5 mm gave the best results.

It should be noted that the foodstuffs contained in the compartments are different. As these foodstuffs, each comprise different compositions and water contents, the time required to heat or cook these foodstuffs in the microwave oven would consequently be different. In the event where the through-hole or through-holes formed on the sealing line is/are large or where a plurality of through-holes is formed along the sealing line, it enables that the pressure and steam generated within the packaging be transferred between the two compartments rapidly. It also enables that the pressure and steam be automatically released out of the pouch rapidly. However, it would not contribute to optimized heating conditions in both compartments. As a result, the foodstuffs contained in both of the compartments would not be sufficiently heated.

BEST MODE OF THE INVENTION

The best mode of the invention is as described in the detailed description of the invention

Claims

1. A multi-compartment packaging comprising: a pouch made of a flexible film material and sealed on all of its edges, thereby defining an interior chamber for containing foodstuffs; one or a plurality of first sealing lines for dividing the interior chamber into two or more compartments; and at least one pressure releasing means provided to one of the compartments; characterised in that each of the first sealing lines comprises at least one through- hole formed along the sealing line, thereby allowing the compartments of the interior chamber to communicate with each other, and also allowing pressure and steam generated upon heating the foodstuffs to be transferred between the compartments.

2 The packaging according to claim 1 further comprising one second sealing line, wherein the second sealing line is an easily peelable sealing line which forms a weakened sealing area along the sealing line or portions of the sealing line.

3. The packaging according to claim 1 or 2, wherein if the first sealing line comprises only a through-hole, the through-hole has a size of 15 to 20 mm.

4. The packaging according to claim 1 or 2, wherein if the first sealing line comprises more than one through-hole, each through-hole has a size of 5 to 10 mm.

5. The packaging according to claim 1 or 2, wherein if the first sealing line comprises more than one through-hole, two adjacent through-holes are spaced apart by a distance of more than or equal to 15 mm.

6. The packaging according to any one of claims 1 to 5, wherein a through-hole of the first sealing line and an inner edge of the pouch are spaced apart by a distance of more than or equal to 20% of a total length of the packaging.

7. The packaging according to claim 2, wherein the easily peelable sealing line has a seal strength of 5 to 35 N/ 15 mm.

8. The packaging according to claim 2, wherein the easily peelable sealing line has a seal strength of 5 to 20 N/l 5 mm.

9. The packaging according to claim 2, wherein the easily peelable sealing line forms a weakened sealing length along at least 20 mm of the sealing line.

10. The packaging according to claim 1, wherein the pressure releasing means is one or any combination of a weakened sealing pattern, a film scoring pattern, and a film scoring pattern with chemical coating.

1 1. The packaging according to claim 1 , wherein the flexible film material is a laminated film comprising an inner film layer contacting and surrounding the foodstuffs contained in the interior chamber and an outer film layer adjacent to the inner film layer.

12 The packaging according to any one of claims 1 to 1 1 is a hermetically sealed packaging or a heatable hermetically sealed packaging for heating in an oven, preferably a microwave oven.

13. The packaging according to claim 12, wherein the packaging is used to contain dry foodstuffs and/or wet/liquid foodstuffs in the separate compartments.

14. The packaging according to claim 1 or 10, wherein the pressure releasing means is provided to the compartment of the packaging which is used to contain dry foodstuffs.

15. The packaging according to any one of claims 12 to 14, wherein the packaging is used as a vacuum packaging.

16. The packaging according to any one of claims 12 to 15, wherein the packaging is capable of undergoing pasteurization or sterilization.

17. The packaging according to any one of claims 12 to 16, wherein the packaging is able to be used in chilled or frozen conditions.