KR20200049229A - Vacuum Shrink Packaging Film and Manufacturing Method thereof - Google Patents

Abstract

The present invention relates to a vacuum-shrinkable film which protects, at upper and lower portions, a gas barrier layer vulnerable to moisture by a sandwich structure using a pair of protective layers that are resistant to contamination and have excellent tensile strength, durability, and gas barrier properties, such that infiltration of oxygen into the inside during a shelf life can be prevented, and thus, it is possible to effectively prevent the browning of meat. According to the present invention, the vacuum-shrinkable film comprises: a gas barrier layer with excellent gas barrier properties (properties of blocking a gas); first and second protective layers protecting the gas barrier layer in a sandwich structure at upper and lower portions; a sealing layer arranged on an inner side and making a contact with a meat product; and an adhesive layer provided to adhere the second protective layer to the sealing layer.

Description

Vacuum Shrink Packaging Film and Manufacturing Method thereof

The present invention relates to a vacuum shrink film, and more particularly to a vacuum shrink film having a browning prevention function and a method for manufacturing the same.

In general, the vacuum packaging film is for packaging a product that is essential for maintaining freshness of meat products or vegetables, and the product is packaged to discharge the air inside and seal the inside in a vacuum state and compress it to pack it. .

However, the conventional vacuum packaging film as described above, after vacuum packaging the product, the packaging film of the remainder is left around the product, and the vacuum packaging film of the residual is not only good in appearance but also inconvenient to transport and store the packaged product. There are problems such as.

On the other hand, in order to solve the above problems, a method of cutting the vacuum packaging film of the residual powder is used, but this is not only cumbersome, but when cutting is not precise, there is a problem that air may be introduced into the packaged product.

In addition, the conventional manufacturing facility for manufacturing a vacuum packaging film has a separate means for controlling the size of the vacuum packaging film through manual (i.e., manually blowing air) or controlling its size even if air is automatically supplied. There is also a problem that the size of the vacuum packaging film cannot be kept constant.

In Korean Patent Registration No. 10-1036754 (Patent Document 1), after vacuum-packing meat products, etc., the vacuum packaging film of the remaining amount unnecessarily around the product is easily immersed in hot water at 70 ~ 80 ℃. A technique has been disclosed that is capable of shrinking and stabilizing (forced shrinking), whereby the residual is eventually naturally removed, thereby producing a consistent size.

When the oxygen penetrates into the vacuum packaging film during the distribution period, it decays and generates gas, and browning of livestock products, especially meat, occurs.

The vacuum packaging film of Patent Document 1 is a multi-layer structure laminated in the order of ethylene vinyl alcohol copolymer (Ethylene Vinyl Alcohol Copolymer), nylon (Nylon), adhesive resin, ethylene vinyl acetate copolymer (Ethylene-Vinyl Acetate Copolymer) from the lowest layer Since it is made of a film, it cannot prevent browning of meat due to low gas barrier properties (gas barrier performance) that can effectively prevent oxygen from penetrating into the interior during the distribution period.

On the other hand, in the above-mentioned Patent Document 1, when manufacturing a vacuum packaging film, a method of expanding the film in a compressed state into a cylindrical shape is injecting air by inserting an air-injection gun into one side of the film in a compressed state being transported. In the case of performing a continuous manufacturing process for modifying the properties of the film in the form of a tube, there is a problem that the method of patent document 1 cannot be applied.

In addition, in the case of a meat product in which a sharp bone such as a backbone or a rib protrudes to the outside, a burst phenomenon may occur during vacuum packaging.

: Korean Registered Patent Publication No. 10-1036754

Accordingly, the present invention has been proposed to solve the problems of the prior art described above, the purpose of which is a sandwich structure in which a gas barrier layer weak against moisture is used as a pair of protective layers that are resistant to contamination and have excellent tensile strength, durability, and gas barrier properties. It is to provide a vacuum shrink film that can effectively prevent the browning of meat by preventing oxygen from penetrating into the inside during the distribution period by protecting the furnace.

Another object of the present invention is to provide a vacuum shrink film capable of preventing a bursting phenomenon in a vacuum packaging for a bone product and having a low defect rate during vacuum packaging by providing a sealing layer having excellent sealing performance in an inner layer.

Another object of the present invention is to improve the efficiency of the overall production process by implementing a multi-layer vacuum shrink film fabric that can effectively prevent browning of meat by in-line process by allowing long-term preservation of primary meat products. It is to provide a method of manufacturing a vacuum shrinkable film that can be achieved.

In order to achieve the above object, the vacuum shrink film according to an aspect of the present invention is a gas barrier layer having excellent gas barrier properties; First and second protective layers for protecting the gas barrier layer in a sandwich structure at upper and lower portions; A sealing layer disposed inside to make contact with the meat product; And an adhesive layer for adhering the second protective layer and the sealing layer.

In addition, the method of manufacturing a vacuum shrink film according to the present invention includes a raw material inlet 12, a screw cylinder 14, a circular die 16, a first cooling processing device 18, a first roller 20, and hot water 22 ), The second roller 24, the cooler 26, the third roller 28, the fourth roller 30, the heater 32, the second cooling processing device 34, the fifth roller 36 and winding The roll 38 is connected in an in-line process, and the winding roll 38 is characterized in that a two-ply 10-layer vacuum shrink film fabric is wound.

As described above, in the present invention, oxygen is penetrated during the distribution period by protecting the gas barrier layer, which is weak against moisture with a sandwich structure, from the upper and lower portions with a pair of protective layers that are resistant to contamination and have excellent tensile strength, durability, and gas barrier properties. It can effectively prevent the browning of meat.

In addition, in the present invention, by providing a sealing layer having excellent sealing performance in the inner layer, a defective rate is low in vacuum packaging and a bursting phenomenon in vacuum packaging for a bone product can be prevented.

Moreover, in the present invention, a long-term preservation of the primary meat processing product is possible, and the vacuum shrink film fabric having a multilayer structure capable of effectively preventing browning of meat is implemented by an in-line process, thereby improving the efficiency of the overall production process. can do.

1 is a cross-sectional view showing a vacuum shrink film of a multi-layer structure according to an embodiment of the present invention.
Figure 2 is a schematic process diagram showing the manufacturing process of the vacuum shrink film according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In this process, the size or shape of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be made based on the contents throughout this specification.

The vacuum shrink film of the present invention is a pair of protective layers that are resistant to contamination and have excellent tensile strength, durability, and gas barrier properties, so that the gas barrier layer, which is weak to moisture, is protected by a sandwich structure from the upper and lower portions, thereby enabling long-term preservation of the primary meat products It can effectively prevent the browning of meat and can be used for vacuum packaging of primary meat products.

Attached Figure 1 is a cross-sectional view showing a vacuum shrink film of a multi-layer structure according to an embodiment of the present invention, Figure 2 is a schematic process diagram showing the manufacturing process of the vacuum shrink film according to an embodiment of the present invention.

The vacuum shrink film 10 according to an embodiment of the present invention, as shown in Figure 1, the gas barrier layer (excellent gas barrier performance) excellent gas barrier layer (2), the gas barrier layer (2) The first and second protective layers 1 and 3, which are protected from the upper and lower portions by a sandwich structure, are disposed inside to make contact with the meat products, and the sealing layer 5 and the second protective layer 3 and the sealing layer 15 It includes an adhesive layer (4) for bonding.

First, the gas barrier layer 2, for example, gas-barrier (gas-barrier), chemical resistance, surface gloss is excellent and can be used EVOH is very high rigidity. EVOH is a thermoplastic resin obtained by copolymerizing (hybrid polymerization) ethylene and vinyl alcohol under high pressure, and is also referred to as EVOH resin.

Because EVOH (ethylene vinyl alcohol) resin is thermoplastic, it can be extruded and used mainly for food packaging. In addition, EVOH resin is often used for other thermoforming materials, such as engineering plastics and fibers, or for improving the properties of other resins. In addition, it is widely used for construction materials such as wallpaper and pipes for ondol.

EVOH resin is used to block the intake of oxygen from the outside into the film by using a high gas barrier property in the vacuum shrink film of the present invention, and shows the best oxygen barrier properties among existing chemical resins.

The first and second protective layers 1 and 3 serve to protect the gas barrier layer 2 in a sandwich structure from the upper and lower portions in consideration of, for example, EVOH resin being weak to moisture, resistant to contamination and tensile Nylon with excellent strength, durability, and gas barrier properties can be used.

Nylon is a general term for synthetic polymer polyamide, and is connected by an amide bond (-CONH-) and is a chain-shaped polymer. As the strongest fiber among synthetic fibers, many types of objects can be made using this nylon fiber. Nylon is thin and light, durable and resistant to contamination, and is widely used as a material for mountaineering clothes and various climbing equipment.

Nylon improves the performance of tensile strength in the vacuum shrink film of the present invention to improve the durability of the film and has good gas barrier properties, making it suitable for food storage. Especially, since EVOH resin is weak to moisture, it can block moisture with a nylon layer to prevent EVOH. It serves to protect the strata.

Moreover, since the first protective layer 1 is located at the top of the vacuum shrink film of the present invention, it also has properties suitable for printability.

The sealing layer 5 may be, for example, ethylene-vinyl acetate (EVA), but is not limited thereto, and other materials may be used.

EVA (ethylene-vinyl acetate) is a polymer generally obtained by copolymerizing ethylene and vinyl acetate monomers. As the content of vinyl acetate increases, density increases, and crystallinity decreases, increasing flexibility. Low-content EVA is processed like ordinary low-density polyethylene and has excellent impact resistance (especially at low temperatures) and excellent stress cracking resistance, and is used for medium packaging materials, laminate film adhesives, etc.

EVA is used to improve adhesion when sealing a meat product when it is disposed on an inner layer in the vacuum shrink film of the present invention and in contact with a meat product, and is also used to increase the soft feeling of the film.

The adhesive layer 4 is for bonding the second protective layer 3 and the sealing layer 5, in order to prevent the film from being peeled off, an adhesive resin is added to form an adhesive layer, and the nylon layer and the EVA layer are adhered. Any adhesive resin for films that can be used and harmless to the human body can be used.

The vacuum shrink film 10 according to the present invention is the order of the sealing layer 5, the adhesive layer 4, the second protective layer 3, the gas barrier layer 2, and the first protective layer 1 from the inner layer to the uppermost layer. It is composed of a film of a five-layer structure laminated.

The vacuum shrink film 10 according to the present invention, as can be seen from the manufacturing process with reference to Figure 2, the molten resin is extruded through a circular die 16 into a cylindrical tube of a 5-layer structure and cooled. It is a vacuum shrink film obtained by going through a post-treatment process in which air (bubble) is injected into a tube while heating and heating.

Referring to Figure 2, the manufacturing facility of the vacuum shrink film 10 according to the present invention is a raw material inlet 12, a screw cylinder 14, a circular die 16, a first cooling processing device 18, a first roller (20), hot water (22), second roller (24), cooler (26), third roller (28), fourth roller (30), heater (32), second cooling processing device (34), agent The 5 roller 36 and the winding roll 38 are connected in an in-line process, and the vacuum shrink film fabric of a 2-ply 10-layer structure is wound on the winding roll 38.

The raw material inlet 12 has a five-layer structure as the vacuum shrink film 10 is made of a five-layer structure, the sealing layer 5, the adhesive layer 4, the second protective layer 3, the gas barrier layer 2 ), 5 raw materials necessary for the formation of the first protective layer 1 are added.

The five raw materials introduced into the raw material inlet 12 are melted by an electric heater embedded in a screw cylinder 14 having a 5 screw channel, and serve to push the circular dies 16 in the subsequent stages.

Each raw material melted in the screw cylinder 14 is stacked while forming a multi-layer and is extruded through a circular die 16 and discharged in the form of a cylindrical tube.

The cylindrical tube of the multi-layer structure discharged from the circular dies 16 passes through the first cooling processing device 18 to prevent adhesion to each other, and is transferred downward by the first roller 20 disposed at the lower rear end.

The cylindrical tube of the multi-layer structure transferred to the lower side is in a hardened state, and then, while passing through the hot water 22, the hardened state is released and the inside is heated to generate air bubbles.

The cylindrical tube in which the air bubble is generated is expanded, and is drawn by the air bubble while being transferred upward by the second roller 24, the cooler 26, and the third roller 28. In this case, the cooler 26 disposed between the second roller 24 and the third roller 28 serves to prevent the cylindrical tubes from sticking together.

The drawn cylindrical tube is heat treated through the heater 32 while passing through the fourth roller 30, the heater 32, the second cooling processing device 34, and the fifth roller 36, and then the second cooling processing device. In (34), a kind of annealing treatment is performed so that the shrinkage does not stick to each other.

The cylindrical tube having been annealed is wound on a winding roll 38 in the form of a film fabric having a 10-layer structure.

The film fabric of the 10-layer structure is then separated and various types of desired shapes such as a 5-layer packaging bag and a 5-layer vacuum packaging film cut through a 2-layer film by injecting air into the tube similar to the above process. The product can be obtained by post-processing.

In the present invention, it is connected in one in-line process from the extrusion of the cylindrical tube from the circular die (16) to the winding roll (38), and the tube using the hot water (22) without injecting a separate air bubble Since air bubbles are generated therein, the manufacturing process can be simplified.

<Example>

In order to test the performance according to the thickness of the vacuum shrinkable film according to the present invention, the content of the raw material to prepare a sample film having a 5-layer structure for each thickness of 40㎛, 50㎛, 60㎛, 70㎛, 80㎛, 90㎛, 100㎛ After preparing the composition and preparing the film, the properties were investigated and described in Table 1 below.

In this case, the first and second protective layers 11 and 13 applied nylon, and the combined contents were shown in Table 1, and EVOH was used as the gas barrier layer 12 and EVA was used as the sealing layer 15. . The content unit of raw materials for each thickness is% by weight.

Raw material name 40㎛ 50㎛ 60㎛ 70㎛ 80㎛ 90㎛ 100㎛ nylon 40 39 35 33 35 38 42 EVOH 5 13 21 24 21 16 13 EVA 40 35 34 32 34 36 37 glue 15 13 10 11 10 10 8 Shrinkage (%) 25 ~ 35% 25 ~ 35% 20% Vacuum packaging × (tear phenomenon) ○ (browning) ○ ○ ○ ○ ○ (Vacuum packaging available, shrink packaging not available) Retention (Sun) 40-45 days 45 days Remark Good sealing △ (The meat packaging is too strong to be unsuitable)
○ (suitable for bone products) ○ (suitable for bone products) ○ (suitable for strong bone products)

As shown in Table 1 above, the 40 micron film had a thin film thickness, so that the tensile strength was weak, so that a phenomenon of tearing during vacuum packaging occurred, and thus there was no product value.

The 50 micron film had good completeness of the shape of the film. There was no problem in vacuum packaging, but after the vacuum shrinking, the preservation period was significantly reduced, causing browning.

The 60micron film has good film completion, no problem when vacuumed, and a shrinkage rate of 25% to 35% was obtained, and browning did not occur for 40 to 45 days in the storage test.

The 70micron film has good film completion, no problem in vacuum shrink packaging, and has obtained a shrinkage rate of 25% to 35%, and the sealing layer is thickened, indicating that the defect rate is low when moving or throwing the product. There was no browning and no browning occurred for more than 45 days of storage testing.

The 80micron film obtained the same results as the 70micron film, and its purpose was to use pork ribs and other bone products when packaging, and it was too strong when packaging lean meat.

The 90micron film obtained the same results as the 70micron film, and the use was when packaging pork ribs and the shrinkage was 20%.

Vacuum packaging is possible for 100 micron films, but shrink packaging was not effective. It is used for packaging products containing strong bones, has little shrinkage, is not competitive in terms of product price, and can be used for special products.

When the thickness was 100 micron or more, it was found that film products of 300 mm or more cannot be produced, and the use of the product was inappropriate because the shrinkage rate, which is a characteristic of the shrink film, was not captured.

<Raw material input rate by thickness>

As shown in Table 1, the raw material input ratio is different depending on the film thickness, and when the raw material is formed at the same ratio regardless of the thickness, a film may not be formed.

For example, in the case of a 50 micron thick film, EVOH could not be increased further because the film became stiff when added in excess of 13% by weight.

The vacuum shrinkable film according to the present invention can be used for packaging a meat product having a bone thickness of 55 µm to 100 µm for the packaging of meat products with bone, and the film thickness for producing the most desirable product is 55 µm to 80 µm. .

The present invention is a pair of protective layers that are resistant to contamination and have excellent tensile strength, durability, and gas barrier properties. The gas barrier layer, which is weak against moisture, is protected by a sandwich structure from the upper and lower portions, thereby preventing oxygen from penetrating into the meat during the distribution period. It can be applied to a vacuum shrink film that can effectively prevent browning.

10: vacuum shrink film 1, 3: protective layer
2: Gas barrier layer 4: Adhesive layer
5: sealing layer 12: raw material inlet
14: screw cylinder 16: round die
18,34: Cooling treatment unit 20,24,28,30,36: Roller
22: hot water 26: cooler
32: heater 38: winding roll

Claims (2)

A gas barrier layer having excellent gas barrier properties;
First and second protective layers protecting the gas barrier layer in a sandwich structure at upper and lower portions;
A sealing layer disposed inside to make contact with the meat product; And
Vacuum shrink film comprising a; adhesive layer for bonding the second protective layer and the sealing layer. Raw material inlet 12, screw cylinder 14, circular die 16, first cooling treatment device 18, first roller 20, hot water 22, second roller 24, cooler 26 , The third roller 28, the fourth roller 30, the heater 32, the second cooling processing device 34, the fifth roller 36 and the winding roll 38 in an in-line process A method of manufacturing a vacuum shrink film in which a vacuum shrink film fabric having a two-ply 10-layer structure is wound on a winding roll 38 is connected.

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