KR100973441B1 - Laminated flim for making pouch and making method thereof - Google Patents

Abstract

PURPOSE: A laminate film for a pouch and a manufacturing method thereof are provided to prevent the deformation of a product after sealing a container containing high temperature liquid. CONSTITUTION: A laminate film for a pouch comprises the following: an outer film layer(10) formed with a polyester material; a first adhesive layer(20); a middle film layer(30) formed with a low density polyethylene material; a second adhesive layer(40); and an inner film layer(50) formed with a polypropylene material. The thickness of the outer film layer is 12~30 micrometers. The thickness of the middle film layer is 30~70 micrometers. The thickness of the inner film layer is 20~80 micrometers.

Description

Laminated film for pouch production and its manufacturing method {LAMINATED FLIM FOR MAKING POUCH AND MAKING METHOD THEREOF}

The present invention relates to a laminate film for manufacturing a pouch and a method of manufacturing the same, and specifically, a pouch having a liquid substance therein is used to prepare a pouch having a strong cold resistance and burst resistance so as not to burst even when pressure is applied from the outside in winter. It relates to a laminate film and a method for producing the same.

Recently, according to the trend of convenience and convenience, various food packaging containers have been developed and provided to safely seal and package foods or beverages, and easily package liquid contents such as retort foods or herbal medicines. In order to provide a pouch and the like made of a laminated film of a multi-layer structure is mainly used.

Pouches, which are containers for packaging Chinese medicines and the like, should be considered to be stored and distributed in a cold or cold state of 0 ° C. or lower from long-term storage of the contents at room temperature for a long time, so that they are required to have both heat resistance and cold resistance. However, the use of polyethylene-based resin, which is a resin generally used as an inner layer among pouch laminate films, has excellent cold resistance, ie low-temperature impact strength, but low melting point, resulting in the appearance and heat-sealing of the film when sterilizing the contents. There was a serious problem that the deformation caused the product's value, and the contents of the package were discharged, and if the contents contained high temperature, the food's safety was threatened by the environmental hormones from the low melting point polyethylene-based resin. It became.

On the other hand, when polypropylene-based resin having a relatively high melting point is used as the inner film, it has excellent heat resistance, so that even when packaging with retort sterilization treatment or high temperature contents, there is no deformation of the appearance of the film and environmental hormone leaks due to its high melting point. However, due to the characteristics of the film itself, it has low cold resistance and flexibility, so that the pouch itself may burst or be pin-hole (PIN-HOLE) due to cracking caused by falling, bumping, and bending, which may occur during freezing, cold storage, and distribution. By causing the packaging contents and the air is in contact with the problem of increasing the possibility of corruption.

Generally, a pouch for food or herbal medicine packaging, which is used for general purpose, is made by laminating a non-stretched polypropylene film (CPP) having a thickness of 80 µm to a polyester film having a thickness of 25 µm. The thing which laminated | stacked the aluminum plate of 7 micrometers in thickness between the ester film and CPP film is used.

As described above, in the case of pouches made of laminate film using CPP as an inner film, even if the packaging is packed with high temperature liquid, the product does not deform and the polypropylene itself has a high melting point. However, there was a disadvantage in that the container itself was torn or broken by the impact applied from the outside during the packaging and transporting process, because it was cold and shock resistant.

Meanwhile, recently, a polyester film having a thickness of 19 μm is used as an outer film, and a low density polyethylene film having a thickness of 95 μm is adopted as an inner film, and then laminated as a laminate film for manufacturing a pouch. Impact resistance and rupture resistance is better than the case, but when the packaging containing a high temperature liquid inside there was a risk that the deformation of the product form or environmental hormones can leak.

On the other hand, in order to solve the above problems, Korean Patent Publication No. 1998-077268 is prepared by mixing an amorphous or low-crystalline α-olefin copolymer with a propylene-based copolymer using a metallocene catalyst (metallocene) catalyst By using an unstretched polypropylene film prepared from the polypropylene resin composition as an inner film, as an outer film, aluminum foil, nylon film, polyester film (PET), biaxially stretched film (OPP), etc. Although a multi-layer sheet for packaging manufactured by lamination has been proposed, the limitation of cold resistance, low temperature impact strength and low temperature drop band strength still remained when a large number of pouches are packaged and distributed in winter.

The present invention has been made to solve the above problems,

Even if the packaging is sealed with high temperature liquid inside, the product does not deform and there is no risk of environmental hormones spilling into the liquid contents.It is safe even when stored at low temperature near 0 ℃ or stored in cold winter. It is an object of the present invention to provide a laminate film for making pouches having a strong cold resistance, burst resistance and low temperature impact strength or low temperature drop burst strength so as not to burst even from the impact applied from the outside.

In addition, another object of the present invention to provide a manufacturing method that can be manufactured in a cheap and safe laminate film for manufacturing the pouch as described above.

In order to solve the above problems, the laminate film for manufacturing a pouch according to the present invention is a polyester outer film layer, a first adhesive layer, a low-density polyethylene intermediate film layer, a second adhesive layer and a polypropylene inner film The layers are formed by sequentially stacking.

In this case, the material of the outer film layer is polyethylene terephthalate resin, the material of the intermediate film layer is a linear low density polyethylene resin polymerized by addition of an alpha olefin comonomer in the low density polyethylene resin, the material of the inner film layer is an unstretched polypropylene It is preferable that it is resin.

Linear Low Density Poly Ethylene (hereinafter referred to as LLDPE) is a linear polyethylene resin prepared by adding a small amount of α-olefin comonomer to the purified ethylene and polymerizing the same. As it has a molecular structure with long side chains and short side chains due to copolymerization, the molecular size distribution is small and its molecular weight distribution is similar to that of high density polyethylene (HDPE), and its melt viscosity is relatively high when heated, and low density polyethylene ( Compared with LDPE, linear low density polyethylene (LLDPE) has good tensile strength, tensile elongation, rigidity, and the like, and thus, thin film can be made thin when manufacturing a film or the like. On the other hand, alpha-olefin-based comonomers such as butene-1, hexene-1, and octene-1 are used in the manufacturing process of LLDPE, and the use of such comonomers reduces the density and melt index, and the tear strength and Physical properties such as impact strength are improved. Among the alpha-olefins, the physical properties of the octene-1 products, which are usually higher alpha-olefins than the butene-1, are excellent, but in the preparation of the pouches, butene-1 alone may satisfy performance requirements that are sufficiently required. By using these alpha-olefins as comonomers, it is possible to produce thinner products of the same application than general low density polyethylene resins, and has excellent toughness, stiffness, tear strength, pinhole resistance and impact strength, and heat adhesive strength and heat sealing. Not only is it excellent in transparency but also excellent in transparency and optical properties, it has a very good performance as a packaging material.

Oriented Polypropylene (OPP) resins generally have better mechanical strength, cold resistance, gloss, transparency, and moisture resistance than unoriented polypropylene resins, but they are expensive in terms of cost savings due to the high cost of raw materials. There was a need to manufacture laminate films for pouches having the high quality properties required for pouches using inexpensive unstretched polypropylene resins instead of stretched polypropylene resins.

On the other hand, the thickness of the outer film layer is 12 ~ 30㎛, the thickness of the intermediate film layer is 30 ~ 70㎛, the thickness of the inner film layer is 20 ~ 80㎛ cold resistance, impact resistance, rupture desired by the present invention It has the advantage of being able to reduce the manufacturing cost while providing sufficient strength.

In addition, in order to enhance the quality of the product, block ultraviolet rays and promote the quality of the product as necessary, it is inserted and laminated between the outer film layer and the first adhesive layer as necessary, and an aluminum thin adhesive layer is formed on the upper surface thereof. It is preferable that the formed aluminum foil layer is further included, wherein the thickness of the aluminum foil layer is 6 ~ 50㎛.

Meanwhile, the laminate film for manufacturing a pouch according to the present invention is laminated by a dry laminating technique, wherein the adhesive is formed between the respective films to form a first adhesive layer and a second adhesive layer to bond the two films to each other. It is preferable to use a polyurethane-based adhesive, and in the case of the above-described aluminum thin adhesive layer, it is preferable to use a polyurethane-based adhesive.

According to another aspect of the present invention, a method of manufacturing a laminate film for manufacturing a pouch may include a polyester film used as an external film, a linear low density polyethylene film used as an intermediate film, and a polypropylene film used as an inner film. A film manufacturing step for producing each; A first lamination step of laminating a linear low-density polyethylene film after applying a polyurethane-based adhesive for dry lamination to one side of the polyester film of the prepared film; A first resting step of aging the first laminated film for 10 to 14 hours; Secondary lamination step of laminating a polypropylene film after applying the polyurethane-based adhesive for dry lamination again on the surface of the linear low-density polyethylene film of the first laminated film after the adhesive is completed through the first resting step ; And it characterized in that it comprises a secondary resting step of aging the secondary laminated laminate film for 48 to 72 hours again.

The first and second rest steps as described above are intended to reinforce the adhesive force to be formed between each film and facilitate the pouch processing process when laminating after applying the adhesive.

In this case, after the film preparation step, it is preferable that an embossing step of forming an embossing surface on at least one surface of both surfaces of the linear low density polyethylene resin film used in the intermediate film layer is further included. This is because the adhesive force can be improved when the both sides are embossed and laminated after applying the adhesive.

In addition, in order to improve the quality of the pouch product or to block UV rays, it is necessary to additionally add a thin aluminum plate. For this purpose, after the film manufacturing step, a polyurethane is disposed under the outer film layer made of polyester. After applying a series of adhesives, it is preferable that the aluminum plate addition step for bonding the aluminum thin plate further comprises.

On the other hand, in order to manufacture the pouch with the laminate film according to the present invention by cutting the laminate film prepared by the present invention described above to a predetermined size to the hot pressing the remaining portion except the contents injection portion for injecting the liquid contents into the inside It is completed by fusing through to have an encapsulation shape. When the contents are contained therein, the contents of the finished encapsulation pouch are filled with the liquid contents through the contents injection portion, and then the sealing portion is heat sealed to finish the conventional method. do.

When the laminate film for manufacturing a pouch according to the present invention manufactures and provides a pouch which is a food packaging container using the same, even if a sealed package is packed with a high temperature liquid inside, deformation of the product does not occur and environmental hormone leaks into the liquid contents. It has the advantage of being safe because there is no risk of it.

In addition, when the pouch is manufactured using the laminate film for manufacturing the pouch according to the present invention, the pouch may be stored in a normal storage distribution process even when stored in a state containing the contents at a low temperature near 0 ° C. or stored in a cold winter. Another advantage is that it is possible to maintain the sealability without being easily burst by external impacts.

In addition, the manufacturing method of the laminate film for manufacturing a pouch, which is another aspect of the present invention, has another advantage that a pouch having the above advantages can be manufactured at low cost and safely.

1 shows a cross-sectional view of a laminate film for manufacturing a pouch according to the present invention.
Figure 2 is a process chart showing the entire process for producing a laminate film and pouch for manufacturing a pouch according to the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a cross-sectional view of a laminate film for manufacturing a pouch according to the present invention.

The outer film constituting the outer film layer 10 was processed by using a film having a thickness of 19 ㎛ made of polyethylene terephthalate resin, a kind of hard polyester resin, and having a thickness of 25 μm in consideration of texture and the like. You can also use

The intermediate film constituting the intermediate film layer 30 is made of a linear low-density polyethylene in which the butenes form side chains, and processed into a film having a thickness of 50 μm, after which the embossing surface is embossed on both sides. To form.

As the inner film forming the inner film layer 50, a non-stretched polypropylene resin, which is a kind of polypropylene suitable for high temperature, was used as a material having a thickness of 40 μm.

The first adhesive layer 20 was formed by applying an adhesive made of a polyurethane resin for dry lamination between the outer film layer and the intermediate film layer, and the adhesive forming the first adhesive layer between the intermediate film layer and the inner film layer. The second adhesive layer 40 was formed by applying an adhesive made of polyurethane resin of the same material as the above.

Figure 2 is a process chart showing the entire process for producing a laminate film and pouch for manufacturing a pouch according to the present invention.

In the film manufacturing step (S100), a film of a polyester material used as an external film, a linear low density polyethylene film used as an intermediate film, and a film of a polypropylene material used as an inner film are respectively produced. The embossing step (S150) of adding the embossing on both sides of the linear low density polyethylene film used as the intermediate film may be further roughened.

Then, in the first lamination step (S200), the polyurethane-based adhesive for dry laminating is applied to one side of the polyester film among the prepared films, and then the linear low density polyethylene film is laminated. Done. The non-stretched polypropylene resin is not directly adhered to the manufactured primary laminated film immediately, and the adhesive is made of a polyurethane-based adhesive through the first rest step (S300) and left for about 12 hours after adhesion. Allow complete hardening at the joint.

After the first rest step, the second step of laminating the unstretched polypropylene resin (S400) is again performed. In the second step of lamination, the surface of the linear low-density polyethylene film among the first laminated films that have been bonded is completed. After applying the polyurethane-based adhesive for dry laminating again, the polypropylene film is laminated. At this time, after the adhesive is applied in the same manner as in the first step of the first step, the non-stretched polypropylene resin film is bonded and heat-compressed with hot water for lamination.

On the other hand, the secondary laminated laminate film is left again for 72 hours after the secondary lamination step in order to fully cure the adhesive surface through the secondary paper recycling step (S500) to finally complete the laminated film for manufacturing the pouch It will be prepared.

On the other hand, after producing a laminate film for manufacturing the pouch as described above, the non-stretched polypropylene film was cut to be an inner film using the material to be made into a rectangular pouch having a size of 10 × 17 horizontal. At this time, the pouch packaging material was formed by heat-sealing all the remaining sides except for the upper injection hole.After injecting 120ml of water into the pouch, the pouch was sealed by internal sealing by heat-sealing the remaining side. Was prepared.

(Example 1)

As an experimental group, the pouch produced using the laminated film for pouch manufacture which concerns on this invention was used. Specifically, a 19 μm-thick PET film was used as the outer film, a butene-1 linear low density polyethylene film 50 μm thick as the intermediate film, and an unstretched polypropylene film having a thickness of 40 μm as the inner film. The laminated film prepared by gluing was cut and heat-sealed so that the unstretched polypropylene film was brought inward, and then a pouch was formed. Meanwhile, 120 ml of water was injected into the inside of each pouch, followed by sealing to prepare 100 pouches in which water was sealed.

(Example 2)

On the other hand, as a control, 120ml of water was injected into a pouch made of a PET film having a thickness of 25 μm as an outer film and a laminated film of an unstretched polypropylene film having a thickness of 80 μm as an inner film. 100 pouches which were sealed and water-sealed were also prepared.

Experimental Example 1

As described above, the drop burst strength of the pouch manufactured from the laminate film according to the present invention and the general pouch were compared.

The pouches divided into the experimental group and the control group were left for one day at an external temperature of 0 ° C., which is the storage and storage temperature of the conventional pouches, and then 100 pieces were dropped freely at a height of 1 m to measure the number of ruptured and ruptured ones. It was. At this time, in order to apply an impact from the outside in a predetermined direction with respect to the pouch, the free drop was put into a cylinder having a diameter slightly larger than the transverse length of the pouch.

As a result, none of the pouches belonging to the experimental group were ruptured when free-falling. However, when the pouches belonging to the control were free-falling under the same conditions as above, 99 were ruptured and the water of the contents flowed out.

Experimental Example 2

On the other hand, considering that the actual pouches are separated and packaged and stored in 30 to 50 paper boxes without being transported or shipped one by one, 35 pouches each manufactured as the experimental group and the control group are packed in one paper box and then Again the same as the experimental conditions in Experimental Example 1, but the number of pouches contained was broken by free-falling 10 times in a paper box containing 35 pouches 10 times 1m height.

As a result, there was no ruptured pouch in the case of the pouch packed paper box belonging to the experimental group, but in the case of the pouch packed paper box belonging to the control group, five pouches were ruptured and the water of the contents flowed out.

Experimental Example 3

In addition, in the case of the pouch belonging to the experimental group in order to find out additionally to the rupture when the free fall at what height to prepare 10 pouches belonging to the experimental group under the conditions of Experimental Example 1 and gradually freed from 1m by 50cm I tried to drop the height.

At the height of free drop, up to 3.5m, no one broke the pouch. However, from 4m, two of the 10 free pouches were broken.

When the results of the experiments described above, the actual pouch is packed in a number of paper boxes packed and stored in distribution, and in the logistics delivery management system, the pouch is packed in a paper box does not fall more than 1m high, Experimental Example from Experimental Example 1 Considering the results up to 3, the pouch manufactured by using the laminate film according to the present invention has a strong bursting strength and the like, and the built-in contents are cooled, as well as the weather does not rupture well even when the weather is cold. There is this.

10: outer film layer 20: first adhesive layer
30: intermediate film layer 40: second adhesive layer
50: inner film layer

Claims (9)

A laminate film for manufacturing a pouch, characterized in that the outer film layer of polyester, the first adhesive layer, the intermediate film layer of low density polyethylene, the second adhesive layer and the inner film layer of polypropylene are sequentially stacked. In claim 1,
The material of the outer film layer is a polyethylene terephthalate resin, the material of the intermediate film layer is a linear low-density polyethylene resin polymerized by addition of an alpha olefin comonomer, the material of the inner film layer is characterized in that the non-stretched polypropylene resin Laminate film for pouch making. In claim 2,
The thickness of the outer film layer is 12 ~ 30㎛, the thickness of the intermediate film layer is 30 ~ 70㎛, the thickness of the inner film layer is laminated film for pouch manufacturing, characterized in that 20 ~ 80㎛. In claim 1,
The laminate film for pouch manufacturing, characterized in that the outer film layer is inserted between the first adhesive layer is laminated and bonded, the upper surface further comprises an aluminum thin film layer formed with an aluminum thin film adhesive layer. In claim 4,
The thickness of the aluminum sheet layer is a laminate film for pouch manufacturing, characterized in that 6 ~ 50㎛. The method according to any one of claims 1 to 5,
The first adhesive layer and the second adhesive layer is a laminate film for pouch manufacturing, characterized in that made of a polyurethane-based adhesive used for dry laminating. A film manufacturing step of preparing a film of polyester material used as an outer film, a film of linear low density polyethylene used as an intermediate film, and a film of polypropylene used as an inner film;
A first lamination step of laminating a linear low-density polyethylene film after applying a polyurethane-based adhesive for dry lamination to one side of the polyester film of the prepared film;
A first resting step of aging the first laminated film for 10 to 14 hours;
Secondary lamination step of laminating a polypropylene film after applying the polyurethane-based adhesive for dry laminating again on the surface of the linear low-density polyethylene film of the first laminated film that has been bonded through the first resting step ; And
Method of manufacturing a laminate film for pouch manufacturing, characterized in that it comprises a secondary resting step of aging the secondary laminated laminate film for 48 to 72 hours again. In claim 7,
After the film manufacturing step, pouch manufacturing method for producing a laminate film, characterized in that it further comprises an embossing step of forming an embossed surface on any one or more of both sides of the linear low density polyethylene resin film used in the intermediate film layer. In claim 7,
After the film manufacturing step of applying a polyurethane-based adhesive to the bottom of the outer film layer of the polyester material, the aluminum plate addition step for adhering the aluminum thin plate further comprises a laminated film for manufacturing pouch Manufacturing method.

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