KR20210036067A - Sheet for food container and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a fabric sheet for a food container and a method for manufacturing the same. The multilayer fabric sheet includes: an oxygen barrier non-foamed multilayer sheet having a first non-foamed polypropylene resin layer on one surface, having a second non-foamed polypropylene resin layer on another surface, and made by coextrusion such that one to five oxygen barrier resin layers and two to six binder resin layers are alternately disposed between the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer; and a foamed polypropylene sheet having a single- or double-layer structure and made through a process separately from the oxygen barrier non-foamed multilayer sheet. The multilayer structure of the fabric sheet is formed by laminating the non-foamed multilayer and foamed polypropylene sheets. The fabric sheet can be manufactured into various types of instant food containers through a thermoforming process as a post process. An instant food container manufactured using the fabric sheet functions as an oxygen barrier and is unlikely to be deformed during microwave cooking. The surface of the container does not become hot and a user can be protected from the risk of burns.

Description

Fabric sheet for food container and its manufacturing method {SHEET FOR FOOD CONTAINER AND MANUFACTURING METHOD THEREOF}

The present invention relates to a fabric sheet for a food container and a method of manufacturing the same. Specifically, the present invention relates to a fabric sheet having oxygen barrier properties, heat resistance, and heat insulation properties together by laminating a non-foaming multilayer sheet having oxygen barrier properties and a foamed polypropylene sheet manufactured in a separate process, and a manufacturing method thereof. The fabric sheet manufactured according to various embodiments of the present invention may be thermoformed into various types of food containers.

With the recent rapid increase in single-person households and the increase in consumer demand that values convenience and convenience, the demand for ready-to-eat foods that allows consumers to conveniently eat anytime, anywhere is rapidly increasing. In particular, as the types of instant foods sold at convenience stores are very diverse and their quality increases, instant foods are satisfying the tastes of many people.

Instant foods sold in the market can be divided into instant foods distributed at low temperatures and instant foods distributed at room temperature. Among them, ready-made foods distributed at room temperature use containers with an added function to prevent spoilage of food by remarkably improving oxygen barrier properties. Instant rice containers are typical, and these ready-to-eat food containers generally have a multi-layered structure in order to obtain high oxygen barrier properties. Specifically, the multi-layered structure of the instant food container for instant rice or the like includes at least one oxygen blocking layer to block contact between the food inside and oxygen from the outside. The oxygen barrier layer is made of at least one of a material having very low oxygen permeability, for example, nylon, ethylene vinyl alcohol (EVOH), or polyvinylidene chloride (PVDC). . A two-layered ready-to-eat food container with an oxygen barrier function has already been commercialized and widely used.

In addition to oxygen barrier properties, additional properties required for ready-to-eat food containers are heat resistance that does not deform when heated through a microwave oven, etc., and thermal insulation that does not transfer heat of food to the surface. When a container for ready-to-eat food such as instant rice is heated in a microwave, the surface of the container becomes hot and the shape of the container is apt to change, and it is easy for the user to make a mistake when holding the container. In some cases, a user may suffer burn damage due to a hot ready-to-eat container. Therefore, in addition to oxygen barrier properties, there is a need for a fabric sheet and a method of manufacturing the same as a material for a ready-to-eat food container having heat resistance and heat insulation properties.

Furthermore, there is a need for a fabric sheet and a method of manufacturing the same as a material for a ready-to-eat food container in which toxic environmental hormones are not eluted during a high-temperature cooking process such as being heated in a microwave oven.

Republic of Korea Patent Publication No. 10-2013-0121217 (2013.11.06.) (Microwave instant food container)

An object of the present invention is to solve the following problems in order to solve the above-described problems.

An object of the present invention is to provide a fabric sheet for a food container having oxygen barrier properties, heat resistance, and heat insulation properties, and a method of manufacturing the same.

An object of the present invention is to provide a fabric sheet for a food container in which toxic environmental hormones are not eluted during a high-temperature cooking process, and a method of manufacturing the same.

An object of the present invention is to provide a fabric sheet obtained by laminating a non-foaming multilayer sheet and a foamed polypropylene sheet having oxygen barrier properties, and a method of manufacturing the same.

An object of the present invention is to provide a raw sheet in which a non-foamed multilayer sheet and a foamed polypropylene sheet are laminated, and a non-foamed polypropylene layer is disposed on the surface of a container, and a method of manufacturing the same.

The problem of the present invention is not limited to those mentioned above, and other problems that are not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

In the fabric sheet having a multilayer structure for a food container according to various embodiments of the present invention, a first non-foaming polypropylene resin layer is disposed on one side, and a second non-foamed polypropylene resin layer is disposed on the other side, Oxygen barrier manufactured by coextrusion so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed between the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer Non-foaming multilayer sheet; And an oxygen-barrier non-foaming multi-layer sheet and a single-layer or two-layer expanded polypropylene sheet manufactured in a separate process, and the non-foaming multi-layer sheet and the expanded polypropylene sheet are laminated to form a multi-layered structure of the fabric sheet. do.

In a method of manufacturing a fabric sheet having a multilayer structure for a food container according to various embodiments of the present invention, a first non-foaming polypropylene resin layer is disposed on one side, and a second non-foamed polypropylene resin layer is disposed on the other side. And the oxygen barrier ratio so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed between the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer. The process of discharging the foamed multilayer sheet from the coextrusion die, and the oxygen barrier non-foaming multilayer sheet and the foamed polypropylene sheet manufactured in a separate process are put into the cooling roll together with the oxygen barrier non-foaming multilayer sheet discharged from the coextrusion die. By doing so, it includes a process of laminating the non-foamed multilayer sheet and the expanded polypropylene sheet.

The manufacturing method of a fabric sheet having a multilayer structure for a food container according to various embodiments of the present invention includes heating one side of an oxygen barrier non-foaming multilayer sheet and one side of the expanded polypropylene sheet to a temperature of 100°C to 300°C. The process includes the process of making the heated surface of the oxygen-barrier non-foaming multilayer sheet and the expanded polypropylene sheet in contact with the heated surface and then pressing and laminating it into a fabric sheet, and introducing the laminated fabric sheet into a cooling roll.

The present invention can provide a fabric sheet for a food container with oxygen barrier properties, heat resistance and heat insulation properties, and a method of manufacturing the same.

The present invention can provide a fabric sheet for a food container in which toxic environmental hormones are not eluted during a high-temperature cooking process, and a method of manufacturing the same.

The present invention can provide a fabric sheet obtained by laminating a non-foaming multilayer sheet and a foamed polypropylene sheet having oxygen barrier properties, and a method of manufacturing the same.

The present invention can provide a raw sheet in which a non-foamed multilayer sheet and a foamed polypropylene sheet are laminated, and a non-foamed polypropylene layer is disposed on the surface of a container, and a method of manufacturing the same.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those of ordinary skill in the art from the following description.

1 shows an example of a cross-sectional structure of a multi-layered sheet capable of manufacturing a ready-to-eat food container that can be heated in a microwave oven and has oxygen barrier properties.
2 is a multilayer sheet having heat resistance and heat insulation properties along with oxygen barrier properties in-line by introducing a foamed polypropylene sheet during a manufacturing process of a non-foaming multilayer sheet having oxygen barrier properties according to various embodiments of the present invention. It shows an example of the process of manufacturing.
3 is an example of a process of manufacturing a multilayer sheet having heat resistance and heat insulation properties along with oxygen barrier properties by thermally bonding lamination of a foamed polypropylene sheet with a non-foaming multilayer sheet having oxygen barrier properties, according to various embodiments of the present invention. Shows.
FIG. 4 is a cross-sectional view of a ready-to-eat food container that can be manufactured by thermoforming a fabric sheet having oxygen barrier properties, heat resistance, and heat insulation properties, which is manufactured using a foamed polypropylene sheet having a single layer structure according to various embodiments of the present invention. .
5 is a cross-sectional view of a ready-to-eat food container that can be manufactured by thermoforming a fabric sheet having oxygen barrier properties, heat resistance, and insulation properties manufactured using a two-layered foamed polypropylene sheet according to various embodiments of the present invention. do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

The present invention is a fabric sheet of a ready-made food container having heat resistance that does not deform when heated in a microwave oven, and a method for manufacturing the same, along with oxygen barrier properties so that cooked food can be packaged and stored and distributed at room temperature. It is about.

Instant foods distributed at room temperature use containers with an added function to prevent spoilage of food by remarkably improving oxygen barrier properties.

In addition to oxygen barrier properties, additional properties required for ready-to-eat food containers are heat resistance that does not deform when heated through a microwave oven, etc., and thermal insulation that does not transfer heat of food to the surface. When a container for ready-to-eat food such as instant rice is heated in a microwave, the surface of the container becomes hot and the shape of the container is apt to change, and it is easy for the user to make a mistake when holding the container. Conventional ready-to-eat food containers have a very hot surface when heated in a microwave, so that the shape of the container is apt to change, and the user is often burned during handling. Therefore, in addition to oxygen barrier properties, there is a need for a fabric sheet and a method of manufacturing the same as a material for a ready-to-eat food container having heat resistance and heat insulation properties.

It is an object of the present invention to provide a fabric sheet for a ready-to-eat food packaging container that can be eaten more safely by solving the disadvantages of the instant food container commonly used in the prior art, and a method of manufacturing the same.

In order to solve the problems of the conventional ready-to-eat food container, the present invention proposes a fabric sheet of a multi-layered ready-to-eat food container in which a porous foamed polypropylene resin layer is laminated, and a method of manufacturing the same. According to various embodiments of the present invention, since the foamed polypropylene layer of the instant food container imparts heat resistance and heat insulation, even if the instant food container is heated in a microwave oven, the temperature of the food rises to a level of 70 to 100 degrees Celsius. The shape of the container is easy to change, and the heat of the food is not completely transferred to the surface while the outer surface of the ready-to-eat container maintains a level of 30 to 40 degrees Celsius. Accordingly, according to various embodiments of the present disclosure, a safe ready-to-eat food container may be provided that does not cause the user to get burned during the cooking process. In addition, the instant food container according to various embodiments of the present invention maintains the heated food in the instant food container for a longer time than the conventional instant food container because of the insulating property of the porous foamed polypropylene resin layer, so that the quality of eating is better. You can increase it.

With a volume ratio of 2 to 30 times, the porous foamed plastic material has excellent heat resistance that does not change shape even at high temperatures. Therefore, if the instant food container includes at least one layer composed of a porous expanded polypropylene resin, the instant food container can obtain excellent heat resistance, so even when the instant food container is heated by a microwave oven, the instant food container It is possible to prevent the shape from being deformed.

With a volume ratio of 2 to 30 times, the porous foamed plastic material has excellent thermal insulation properties that block heat transfer. Therefore, if the instant food container includes at least one layer composed of a porous foamed polypropylene resin, the instant food container can obtain excellent heat insulation properties, so even when the instant food container is heated by a microwave oven, the exterior of the instant food container The temperature of the noodles can be prevented from rising excessively.

The present invention proposes a fabric sheet for a ready-to-eat food container that contains at least one porous polypropylene layer and is heated in a microwave oven, and a method for manufacturing the same.

In order to achieve this object, in various embodiments of the present invention, a foamed polypropylene sheet having a single-layer structure or a two-layer structure is first prepared by using a separate extrusion foaming process. The foamed polypropylene sheet having a single-layer structure or a two-layer structure thus prepared needs a process of lamination with a multi-layer sheet having excellent oxygen barrier properties. As a method of laminating the sheet, thermal adhesive lamination, adhesive lamination through adhesive application, or extrusion coating lamination may be used. According to various embodiments of the present invention, the laminated multilayered fabric sheet may be thermoformed into various types of ready-to-eat food containers through an additional vacuum forming process.

The ready-made food container manufactured according to various embodiments of the present invention has excellent oxygen barrier properties as well as excellent heat resistance and heat insulation, so when it is heated in a microwave and eaten easily, it prevents deformation of the instant food container and is free from the risk of burns. Has an advantage. In addition, due to the insulating properties of the porous foamed polypropylene layer, it also has the advantage of being able to keep warm and keep warm while eating a heated ready-to-eat food.

1 shows an example of a cross-sectional structure of a multi-layered sheet capable of manufacturing a ready-to-eat food container that can be heated in a microwave oven and has oxygen barrier properties.

The conventional ready-to-eat food container manufactured by using the multi-layered sheet 10 of FIG. 1 has oxygen barrier properties to enable distribution and storage at room temperature for a long period of time.

Referring to FIG. 1, a multilayer sheet 10 capable of manufacturing a conventional ready-to-eat food container includes a non-foaming polypropylene resin layer 11, a binder resin layer 12, an oxygen barrier resin layer 13, and a number of binders. The formation layer 14 and the non-foaming polypropylene resin layer 15 are included.

The multilayer sheet 10 of FIG. 1 uses a non-foaming polypropylene resin as a main material. Referring to FIG. 1, the two-layered sheet fabric 10 includes non-foaming polypropylene resin layers 11 and 15.

The multilayer sheet 10 of FIG. 1 is coextruded by coextrusion casting an oxygen barrier resin layer 13 having a high oxygen barrier property into a thin film in the middle of the non-foaming polypropylene resin layers 11 and 15. It is manufactured by extrusion casting) method. Conventional ready-to-eat food containers are manufactured by thermoforming a two-layer structure non-foaming sheet fabric 10 manufactured by coextrusion of the non-foaming polypropylene resin layers 11 and 15 and the oxygen barrier resin layer 13 into a container shape. do. Here, the oxygen barrier resin layer 13 is composed of at least one of nylon, ethylene vinyl alcohol (EVOH), and polyvinylidene chloride (PVDC).

The binder resin layers 12 and 14 serve as a binder to improve the interfacial adhesion between the oxygen barrier resin layer 13 and the polypropylene resin layers 11 and 15. The polypropylene resin layers 11 and 15 are disposed on both surfaces of the oxygen barrier resin layer 13 by the binder resin layers 12 and 14.

In some cases, the oxygen barrier resin layer may be composed of two or more layers, for example, two layers, three layers, or four layers. In this case, the entire fabric sheet may be coextruded into 7 layers, 9 layers, or 11 layers. As the number of the oxygen barrier resin layer increases, the oxygen permeability of the fabric sheet decreases, and thus the period during which food can be stored and distributed is significantly longer.

The polypropylene resin used for the non-foaming polypropylene resin layers (11, 15) has not only excellent heat resistance, but also the safety of the human body that no toxic substances are dissolved into food even in a microwave heating environment. It is a plastic resin.

Referring to FIG. 1, a conventional non-foaming oxygen barrier multilayer sheet 10 has a two-layer structure of 5 to 11 layers in the thickness direction. The non-foaming oxygen barrier two-layer structure oxygen barrier sheet fabric 10 may be finally completed and used as a ready-made food container of various types through a vacuum forming process.

The conventional ready-to-eat food container manufactured using the oxygen-blocking multilayer sheet 10 of FIG. 1 has oxygen-blocking properties so that it can be distributed and stored at room temperature for a long period of time, but the temperature of the packaged food is Since it rises high, the temperature outside the container rises from 70 degrees to 100 degrees. Therefore, the conventional ready-to-eat food container manufactured by using the two-layered sheet fabric 10 of FIG. 1 has a problem that when a user grabs the container and moves it, it often causes burns to his or her hand or body.

In order to solve the shortcomings of the conventional instant food container, in various embodiments of the present invention, in addition to the conventional non-foaming oxygen barrier multi-layered sheet structure, a sheet fabric laminated with a polypropylene foam layer is manufactured, and a molding process using this Through this, a method of manufacturing a ready-to-eat food container with added heat resistance and insulation is proposed.

2 is a multilayer sheet having heat resistance and heat insulation properties along with oxygen barrier properties in-line by introducing a foamed polypropylene sheet during a manufacturing process of a non-foaming multilayer sheet having oxygen barrier properties according to various embodiments of the present invention. It shows an example of the process of manufacturing.

Specifically, FIG. 2 shows in-line lamination by putting together a foamed polypropylene sheet manufactured in a separate process during a co-extrusion casting process for manufacturing a non-foaming multilayer sheet having oxygen barrier properties. It shows the process of lamination.

Referring to FIG. 2, extrusion coating lamination is performed by introducing a foamed polypropylene sheet manufactured in a separate process into a two-layer coextrusion sheet extrusion facility having oxygen barrier properties.

Each layer extruded from the oxygen barrier resin layer extruder 20, the non-foamed polypropylene resin layer extruder 21 and the binder resin layer extruder 22 is co-extrusioned through a T-die 23 Thus, a non-foaming multilayer sheet having oxygen barrier properties is produced.

The coextruded non-foaming multilayer sheet corresponds to the non-foaming oxygen barrier multilayer sheet described in FIG. 1.

The non-foamed multilayer sheet discharged from the coextrusion die T-die 23 enters the first casting cooling roll 25.

At this time, the polypropylene foam sheet manufactured by a separate process in advance is put between the casting cooling rolls 25. Specifically, after matching the rotation speed of the backup roll 24 for the expanded polypropylene sheet 27 and the rotation speed of the first cooling roll 25 for the non-foamed multilayer sheet discharged from the T-die 23, The expanded polypropylene sheet 27 is fed between the back-up roll 24 and the first cooling roll 25 together with the non-foamed multilayer sheet discharged from the T-die 23. Accordingly, the non-foaming multilayer sheet discharged from the coextrusion die T-die 23 is put into the first cooling roll 25 together with the foamed polypropylene sheet 27 manufactured in a separate process, so that one fabric sheet ( 28).

In the embodiment of FIG. 2, the foamed polypropylene sheet 27 may have a single-layer structure consisting of a 0.5 to 5 millimeter thick foamed polypropylene layer, or, a 0.5 to 5 millimeter thick foamed polypropylene layer and 5 to 500 microns. It may be a two-layer structure made of a non-foamed polypropylene layer of micrometer thickness.

The oxygen-blocking non-foamed polypropylene multilayer sheet and the expanded polypropylene sheet may be laminated in-line while passing through the first cooling roll 25 and the second cooling roll 26 connected together.

The fabric sheet 28 in which the oxygen barrier multilayer sheet and the expanded polypropylene sheet are laminated is collected in the form of a fabric roll. The laminated fabric sheet 28 may be manufactured into various types of ready-to-eat food containers through a subsequent molding process.

The fabric sheet 28 in which the oxygen barrier multilayer sheet and the expanded polypropylene sheet are laminated is a non-foamed polypropylene resin layer 11 in contact with food, a binder resin layer 12, an oxygen barrier resin layer 13, and a binder. A resin layer 14, a non-foamed polypropylene resin layer 15, and a foamed polypropylene resin layer 29 are included.

According to an embodiment, when a sheet having a two-layer structure of a foamed polypropylene layer and a non-foamed polypropylene layer is used for the foamed polypropylene sheet 27, the polypropylene layer matches the oxygen barrier multilayer sheet 10. Touch, and the non-foamed polypropylene layer may be laminated so that the outside of the expanded polypropylene resin layer 29, that is, the outermost of the laminated fabric sheet 28. Through this, it is possible to maximize the print adhesiveness, glossiness, and aesthetics of the surface of the ready-to-eat food container.

Fabric sheet (28) obtained by laminating the oxygen-barrier non-foamed polypropylene multilayer sheet and expanded polypropylene sheet discharged from the coextrusion T-die (23) in-line by adjusting the rotational speed on the cooling rolls (25, 26). ) Can have excellent interfacial adhesion between each layer.

3 is an example of a process of manufacturing a multilayer sheet having heat resistance and heat insulation properties along with oxygen barrier properties by thermally bonding lamination of a foamed polypropylene sheet with a non-foaming multilayer sheet having oxygen barrier properties according to various embodiments of the present invention. Shows.

Specifically, FIG. 3 shows a process of laminating the non-foamed multilayer sheet 10 and the expanded polypropylene sheet 27 having oxygen barrier properties by a thermal bonding method according to various embodiments of the present invention.

According to an embodiment, after each of the non-foaming multilayer sheet 10 and the expanded polypropylene sheet 27 having oxygen barrier properties are manufactured in a pre-process, heat-adhesive lamination may be performed in a separate process. According to another embodiment, after preparing the foamed polypropylene sheet 27 in advance, one step of the manufacturing process of the non-foaming multilayer sheet 10 having oxygen barrier properties, for example, non-foaming having oxygen barrier properties. Immediately before the step of winding the multilayer sheet 10 in a roll state, the foamed polypropylene sheet 27 may be thermally adhesively laminated.

The non-foaming oxygen barrier multilayer sheet 10 corresponds to the non-foaming oxygen barrier multilayer sheet described in FIG. 1.

The foamed polypropylene sheet 27 can be manufactured to have a foaming ratio of 2 to 30 times using a tandem foaming extruder. In the manufacturing process of the foamed polypropylene sheet 27, a nucleating agent such as talc and carbon dioxide, nitrogen, propane, butane, pentane A blowing agent such as the like is added as an additive.

In the embodiment of FIG. 3, the foamed polypropylene sheet 27 may have a single-layer structure consisting of a 0.5 to 5 millimeter thick foamed polypropylene layer, or, a 0.5 to 5 millimeter thick foamed polypropylene layer and 5 to 500 microns. It may be a two-layer structure made of a non-foamed polypropylene layer of micrometer thickness.

Referring to FIG. 3, the prepared two types of sheet fabrics 10 and 27 are strongly adhered by pressing the surface while heating the surface with instantaneous high heat.

Specifically, the multi-layered sheet fabric 10 and the expanded polypropylene sheet fabric 27 having oxygen barrier properties are introduced by adjusting the rotational speed of each roll so as to be laminated.

After heating with high heat through the surface heating device 30 for each fabric, in-line lamination of the two types of sheet fabrics 10 and 27 in a heated state with a pressure lamination roll is performed. . Specifically, lamination is performed by heating the contact surfaces of the two fabrics 10 and 27 with a high heat of 100 to 300 degrees through the surface heating device 30 for each fabric, and then pressing them through a pressure lamination roll 31.

After passing through the pressurized paper roll 31, the laminated fabric 28 undergoes a cooling process through the third cooling roll 32 so that each layer is adhered to each other.

The fabric sheet 28 on which the oxygen barrier multilayer sheet 10 and the foamed polypropylene sheet 27 are laminated is collected in the form of a fabric roll. The laminated fabric sheet 28 may be manufactured into various types of ready-to-eat food containers through a subsequent molding process.

The fabric sheet 28 in which the oxygen-barrier multilayer sheet 10 and the expanded polypropylene sheet 27 are laminated is a non-foamed polypropylene resin layer 11, a binder resin layer 12, and an oxygen-barrier water. The formation layer 13, the binder resin layer 14, the non-foaming polypropylene resin layer 15, and the expanded polypropylene resin layer 29 are included.

According to an embodiment, when a sheet having a two-layer structure of a foamed polypropylene layer and a non-foamed polypropylene layer is used for the foamed polypropylene sheet 27, the foamed polypropylene layer is formed with the oxygen barrier multilayer sheet 10 Abutting, the non-foaming polypropylene layer may be laminated so that the outside of the expanded polypropylene resin layer 29, that is, the outermost of the laminated fabric sheet 28. When manufacturing a container by thermoforming the raw sheet 28, a non-foaming polypropylene layer may be disposed on the outermost surface of the container. Through this, it is possible to maximize the printing adhesion, glossiness, and aesthetics of the instant food container surface.

The fabric sheet 28 obtained by laminating in-line by heating the oxygen barrier multilayer sheet 10 and the expanded polypropylene sheet 27 with instantaneous high heat and pressing it can have excellent interfacial adhesion between each layer. .

According to various embodiments of the present invention, in a fabric sheet having a multilayer structure for a food container, a first non-foaming polypropylene resin layer is disposed on one side, and a second non-foamed polypropylene resin layer is disposed on the other side. And coextrusion so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed between the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer. The prepared oxygen barrier non-foaming multilayer sheet; And a foamed polypropylene sheet having a single-layer or two-layer structure manufactured in a separate process from the oxygen-barrier non-foaming multi-layer sheet, wherein the non-foaming multi-layer sheet and the foamed polypropylene sheet are laminated to form the fabric sheet. A raw sheet is provided, forming a multi-layered structure. According to various embodiments of the present invention, in the fabric sheet, the foamed polypropylene sheet may have a single-layer structure of a foamed polypropylene layer, or a two-layer structure of a foamed polypropylene layer and a non-foamed polypropylene layer. According to various embodiments of the present invention, in the fabric sheet, when the foamed polypropylene sheet has a two-layer structure, the foamed polypropylene layer abuts the oxygen barrier non-foamed multilayer sheet, and the non-foamed polypropylene A layer may be disposed on the outside of the fabric sheet.

According to various embodiments of the present invention, in the manufacturing method of the fabric sheet, a first non-foaming polypropylene resin layer is disposed on one side, and a second non-foamed polypropylene resin layer is disposed on the other side, and the The oxygen barrier non-foaming so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed between the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer. The process of discharging the multilayer sheet from the coextrusion die, and cooling the oxygen barrier non-foaming multilayer sheet and the foamed polypropylene sheet manufactured in a separate process together with the oxygen barrier non-foaming multilayer sheet discharged from the coextrusion die There is provided a manufacturing method comprising the process of laminating the non-foamed multilayer sheet and the expanded polypropylene sheet by putting it in a roll.

According to various embodiments of the present invention, in the manufacturing method of the fabric sheet, heating one side of the oxygen-barrier non-foaming multilayer sheet and one side of the expanded polypropylene sheet to a temperature of 100 degrees to 300 degrees, and , Laminating the fabric sheet by pressing the oxygen-barrier non-foaming multilayer sheet and the heated surface of the foamed polypropylene sheet to contact and pressurizing the sheet, and introducing the laminated fabric sheet into a cooling roll. , A manufacturing method is provided.

The fabric sheet having a multilayer structure having both oxygen barrier properties, heat resistance, and insulation properties manufactured through the embodiment of FIG. 2 or 3 may be formed into various types of containers as shown in FIGS. 4 or 5 through a vacuum thermoforming process.

4 is a cross-sectional view of a ready-to-eat food container that can be manufactured by thermoforming a fabric sheet having oxygen barrier properties, heat resistance, and heat insulation properties, which is manufactured using a foamed polypropylene sheet having a single layer structure according to various embodiments of the present invention. .

4 is a cross-sectional view of a ready-to-eat food packaging container that can be manufactured through a vacuum thermoforming process according to various embodiments of the present invention.

Referring to FIG. 4, a ready-made food container 40 manufactured by thermoforming a fabric sheet 28 in which an oxygen barrier multilayer sheet 10 and a foamed polypropylene sheet 27 are laminated is a non-foamed poly Including a propylene resin layer 11, a binder resin layer 12, an oxygen barrier resin layer 13, a binder resin layer 14, a non-foaming polypropylene resin layer 15, and a foamed polypropylene resin layer 29 do.

According to the embodiment of FIG. 4, the foamed polypropylene resin layer 29 is disposed outside the instant food container 40 to maximize heat resistance and heat insulation.

In FIG. 4, a foamed polypropylene resin layer 29 that imparts heat resistance and heat insulation is illustrated to be disposed outside the instant food container 40, but according to an embodiment, the foamed polypropylene resin layer 29 is an instant food container ( 40) can also be placed inside.

FIG. 5 is a cross-sectional view of a ready-to-eat food container that can be manufactured by thermoforming a fabric sheet having oxygen barrier properties, heat resistance, and heat insulation properties made using a foamed polypropylene sheet having a two-layer structure according to various embodiments of the present invention. do.

5 is a cross-sectional view of a ready-to-eat food packaging container that can be manufactured through a vacuum thermoforming process according to various embodiments of the present disclosure.

Referring to FIG. 5, a ready-made food container 41 manufactured by thermoforming a fabric sheet 28 on which an oxygen barrier multilayer sheet 10 and a foamed polypropylene sheet 27 are laminated is a non-foamed poly Propylene resin layer 11, binder resin layer 12, oxygen barrier resin layer 13, binder resin layer 14, non-foamed polypropylene resin layer 15, expanded polypropylene resin layer 29 and non- It includes a foamed polypropylene resin layer 42.

According to the embodiment of FIG. 5, a foamed polypropylene resin layer 29 is disposed outside the instant food container 41 to maximize heat resistance and heat insulation, and at the same time, a non-foaming polypropylene resin layer 42 is used for instant food. It is disposed on the outermost side of the container 41 to maximize the printing adhesion, glossiness, and aesthetics of the container.

In FIG. 5, a foamed polypropylene resin layer 29 that imparts heat resistance and heat insulation is illustrated to be disposed outside the instant food container 41, but according to an embodiment, the foamed polypropylene resin layer 29 is an instant food container ( 41) can also be placed inside.

The instant food containers 40 and 41 according to various embodiments of the present invention reduce the possibility of deformation of the instant food container during the cooking process by adding new functions such as heat resistance and heat insulation to the conventional oxygen barrier instant food container, It reduces the likelihood of a user getting burned during handling, and has the advantage that the heated food does not cool down quickly and is kept warm.

In addition, the ready-made food containers 40 and 41 according to various embodiments of the present invention have an advantage that toxic environmental hormones are not eluted during a high-temperature cooking process.

Hereinafter, an embodiment of the present invention will be described. The following examples are only examples of the present invention, and the present invention is not limited to the following examples.

(Example 1)

During the co-extrusion casting process of manufacturing a non-foaming multilayer sheet having a five-layer structure of oxygen barrier properties, a foamed polypropylene sheet with a thickness of 2 mm having ^{an average density of 50 kg/m 3 manufactured in a separate process was added together and in-line (} In-line) lamination was performed.

In the non-foaming multilayer sheet having oxygen barrier properties, nylon resin was used as the oxygen barrier resin layer.

As a result of performing a vacuum thermoforming process on the fabric sheet laminated with a foamed polypropylene sheet layer, a ready-to-eat food container for packaging instant rice was prepared. At this time, the laminated foamed polypropylene sheet was arranged on the outer surface of the container.

As a result of taking out the ready-to-eat food container prepared in this example after heating for 3 minutes in a microwave oven, the surface temperature was not high at 30 to 40 degrees, so there was no inconvenience in carrying it with bare hands, and there was no risk of burns.

(Example 2)

During the co-extrusion casting process of manufacturing a non-foaming multilayer sheet having an 11-layer structure of oxygen barrier properties, a ^{foamed polypropylene sheet having an average density of 60 kg/m 3} and a thickness of 2.03 mm manufactured in a separate process was added together and in-line ( In-line) lamination was performed. A 2.03 mm thick expanded polypropylene sheet having an average density of 60 kg/m ³ has a two-layer structure consisting of a 2 mm thick expanded polypropylene layer and a 0.03 mm thick non-foamed polypropylene layer. The foamed polypropylene sheet was prepared by coextrusion of the foamed polypropylene layer and the non-foamed polypropylene layer.

In the middle of manufacturing a non-foamed multi-layered sheet having an 11-layer structure of oxygen barrier property while inserting the foamed polypropylene sheet of the two-layer structure between the cooling casting rolls of the co-extrusion facility, in-line lamination was performed.

At this time, by laminating a 2 mm thick expanded polypropylene layer in contact with the non-foamed multilayer sheet having oxygen barrier properties, a 0.03 mm thick non-foamed polypropylene layer was disposed on the surface of the laminated fabric sheet.

In the non-foaming multilayer sheet having oxygen barrier properties, ethylene vinyl alcohol (EVOH) resin was used as the oxygen barrier resin layer.

As a result of performing a vacuum thermoforming process on the sheet fabric in which the non-foaming multilayer sheet and the expanded polypropylene sheet having oxygen barrier properties were laminated, a ready-to-eat food container for packaging instant rice was manufactured. At this time, the laminated two-layer foamed polypropylene sheet was arranged on the outer surface of the container. Specifically, the non-foamed polypropylene layer among the foamed polypropylene sheets having a two-layer structure was arranged on the outermost surface of the instant food container. The non-foaming polypropylene layer was disposed on the outermost surface of the ready-to-eat food container to obtain the effect of increasing the printing adhesion, glossiness and aesthetics of the container.

As a result of taking out the ready-to-eat food container prepared in this example after heating for 3 minutes in a microwave oven, the surface temperature was not high at 30 to 40 degrees, so there was no inconvenience in carrying it with bare hands, and there was no risk of burns. In addition, since a non-foaming polypropylene resin layer was disposed on the outer surface of the instant food container, the surface gloss was excellent and the printing quality was excellent.

It will be apparent to those skilled in the art that the present invention can be embodied in other forms without departing from the technical spirit and essential features of the present invention. Therefore, the above embodiments should be considered from all viewpoints, not limiting. The scope of the present invention should be determined by rational interpretation of the appended claims and all possible changes within the equal scope of the present invention.

10: non-foaming multilayer sheet having oxygen barrier properties
11: non-foaming polypropylene resin layer 12: binder resin layer
13: oxygen barrier resin layer 14: binder resin layer
15: non-foaming polypropylene resin layer 20: oxygen barrier resin layer extruder
21: non-foaming polypropylene resin layer extruder
22: binder resin layer extruder 23: T-die
24: backup roll 25: cooling roll
26: cooling roll 27: foamed polypropylene sheet
28: laminated fabric sheet 29: foamed polypropylene layer
30: surface heating device 31: pressurized paper roll
32: cooling roll
40: ready-to-eat food container with an outermost layer of foamed polypropylene
41: ready-to-eat food container with a non-foaming polypropylene layer disposed on the outermost
42: non-foaming polypropylene layer

Claims (5)

In the multi-layered fabric sheet for a food container,
A first non-foamed polypropylene resin layer is disposed on one side, a second non-foamed polypropylene resin layer is disposed on the other side, and the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer An oxygen barrier non-foaming multilayer sheet manufactured by coextrusion so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed therebetween; And
It includes the oxygen-blocking non-foaming multi-layer sheet and a single-layer or two-layer expanded polypropylene sheet manufactured in a separate process,
The non-foaming multi-layered sheet and the expanded polypropylene sheet are laminated to form a multi-layered structure of the original sheet,
Fabric sheet.
In the original sheet of claim 1,
The foamed polypropylene sheet,
A single-layer structure of a foamed polypropylene layer, or a two-layer structure of a foamed polypropylene layer and a non-foamed polypropylene layer,
Fabric sheet.
In the original sheet of claim 2,
When the foamed polypropylene sheet has a two-layer structure,
The foamed polypropylene layer abuts the oxygen barrier non-foaming multilayer sheet,
The non-foaming polypropylene layer is disposed on the outside of the fabric sheet,
Fabric sheet.
In the manufacturing method of the original sheet according to any one of claims 1 to 3,
A first non-foamed polypropylene resin layer is disposed on one side, a second non-foamed polypropylene resin layer is disposed on the other side, and the first non-foamed polypropylene resin layer and the second non-foamed polypropylene resin layer The process of discharging the oxygen barrier non-foaming multilayer sheet from a coextrusion die so that 1 to 5 oxygen barrier resin layers and 2 to 6 binder resin layers are alternately disposed therebetween,
The non-foaming multi-layer sheet and the foaming by injecting the oxygen-barrier non-foaming multi-layer sheet and the foamed polypropylene sheet prepared in a separate process together with the oxygen-barrier non-foaming multi-layer sheet discharged from the co-extrusion die. Including the process of laminating a polypropylene sheet,
Manufacturing method.
In the manufacturing method of the original sheet according to any one of claims 1 to 3,
Heating one side of the oxygen-barrier non-foaming multilayer sheet and one side of the expanded polypropylene sheet to a temperature of 100 to 300 degrees,
A process of laminating to the fabric sheet by pressing the oxygen-barrier non-foaming multilayer sheet and the heated surface of the expanded polypropylene sheet to abut,
Including the process of injecting the laminated fabric sheet into a cooling roll,
Manufacturing method.

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