KR20020061685A - Laminated Film for Fruit Bag with Excellent Air Permeability - Google Patents

Abstract

PURPOSE: A synthetic film for the manufacture of an air permeable fruit bag and a manufacturing method thereof are provided to achieve a fruit bag capable of expressing good water resistance and air permeability and various colors as well as maintaining stiffness. CONSTITUTION: The synthetic film for the manufacture of an air permeable fruit bag consists of an air permeable film composed of an inorganic filler of 30 to 70 wt percent, and a matrix component selected from a group consisted of polyethylene, polypropylene, and their mixture of 70 to 30 wt percent; and a synthetic resin non-woven fabric made of polypropylene or polyester. The inorganic filler is selected from a group consisted of calcium carbonate, barium sulfate, clay, and talc.

Description

Laminated Film for Fruit Bag with Excellent Breathability and Manufacturing Method Thereof {Laminated Film for Fruit Bag with Excellent Air Permeability}

The present invention relates to a paper film for producing a fruit bag with excellent air permeability and a method for manufacturing the same, and more specifically, a laminated film laminated with a non-woven fabric of the inorganic filler and a breathable film made of polyethylene or polypropylene and a synthetic resin system, and a method for manufacturing the same It relates to a fruit bag excellent in breathability made of a laminated film.

The bag cultivation method, which encloses the fruit on the bag, was used in Korea and Japan, where pests were frequently damaged during the long summer season, when the development of pesticides was insignificant. His main purpose was to prevent damage from pests. Since the spread of pesticides and industrialization and the reduction of rural labor force, stage cultivation is becoming common instead of bag cultivation. However, bag cultivation can prevent corruption, anthrax, and the occurrence of copper rust, which is a problem in recent years. In addition, as the exports of pears, apples, etc. have soared recently, the importance of fruit appearance has been greatly emphasized, and bag cultivation is on the rise. In particular, bag cultivation for the control of pests, which is a problem in quarantine when exporting fruit, The need for more is increasing.

Most fruit bags used to date are newspaper bags made from imported newspapers, but newspaper bags have high moisture absorption rate and have a high possibility of occurrence of rust. Thus, the inner bag was used by paraffin wax treatment so as to lower the humidity in the bag, but the effect was insignificant in the summer rainy season and thus was not greatly improved. Recently, in order to increase the effect of bag cultivation, various attempts have been made, such as increasing the light shielding property of a bag, or using a double-colored bag treated with antibacterial and insect repellent in the bag itself.

A number of methods are known for redesigning the form of various attempts to improve the fruit bag and increasing its utility. Republic of Korea Patent Publication No. 97-50567 discloses a form in which only the insertion portion for inserting the fruit is opened by bonding two portions of paper or vinyl paper except the upper portion. Korean Patent Publication No. 98-69 discloses a form in which the opening of the storage space through the opening is facilitated so that the storage space can be easily expanded and the storage space of the enlarged envelope can be more expanded. In addition, the Republic of Korea Patent Publication No. 96-13179 discloses a double bag for fruit protection, a bag for coloring the outer skin in black and the outer skin and the inner skin to the front and rear surfaces of the upper end is bonded. However, the above-mentioned prior arts redesign the shape of the fruit bag itself, and do not mention a technique for increasing the utility of the material.

On the other hand, Korean Patent Publication No. 97-61059 describes a fruit bag manufacturing technique using a coating material of artificial fiber made of polyester yarn as a material. However, not only the manufacturing process is very complicated but also the material Its own air permeability is poor and it is difficult to dissipate the generated moisture inside the fruit bag.

In order to solve the weak water resistance of the conventional paper bag described above, and to effectively overcome the problem of air permeability, which is a limitation of the fruit bag of the plastic bag material, a technique using various breathable films has been proposed.

Such breathable films are largely produced according to two methods. That is, European Patent No. 0066672 (1982), European Patent No. 0307116 (1988), European Patent No. 0459142 (1991), and Korean Patent Publication No. 96-8583 and the like. Alternatively, certain techniques, such as embossing, can be used on the post-processing of the film to control the mechanical strength of the breathable film (European Patent No. 0232060 (1987)), or to increase moisture permeability and improve tear strength (US patent). 4777073 (1988).

In the case of the breathable film manufactured by the above techniques, the air permeability is equivalent to or higher than the paper material, but the material itself is too soft to be used as a fruit bag. Attached to the fruit has the disadvantage of risk of damage to the skin. In addition, the colored bag according to a specific fruit should be used, but the above-mentioned breathable film has difficulty in coloring.

Accordingly, the inventors of the present invention have conducted extensive research to form a film with a synthetic resin obtained by mixing polyethylene resin with inorganic materials such as calcium carbonate, barium sulfate, cray, and uniaxially or biaxially stretch the molded film to obtain a porous structure. If a laminated film made by manufacturing a breathable film and then bonding it to a synthetic resin nonwoven fabric (polypropylene nonwoven fabric, polyester nonwoven fabric) as a fruit bag, exhibits air permeability equal to or greater than that of a conventional paper bag, and maintains the stiffness of the bag. And, it was found that the color of the bag can be variously adjusted according to the color control of the nonwoven fabric, the present invention was completed based on this.

Accordingly, it is an object of the present invention to provide a laminated film for fruit bag production that can exhibit various colors while maintaining excellent stiffness of the bag while exhibiting excellent water resistance and breathability.

Still another object of the present invention is to provide a method of manufacturing a laminated film for fruit bag production.

The fruit film encapsulation laminated film of the present invention for achieving the above object is a breathable film comprising 30 to 70% by weight of the inorganic filler and 70 to 30% by weight of the matrix component selected from the group consisting of polyethylene, polypropylene and mixtures thereof; And it is characterized in that the non-woven fabric of synthetic resin system made of polypropylene or polyester material.

Method for producing a laminated fruit film for fruit bag to achieve the above object of the present invention comprises 30 to 70% by weight of inorganic fillers and 70 to 30% by weight of the matrix component selected from the group consisting of polyethylene, polypropylene and mixtures thereof Forming a film from the composition; Uniaxially or biaxially stretching the film to impart breathability; And laminating the stretched film and a nonwoven fabric of a synthetic resin system made of polypropylene or polyester.

Hereinafter, all of the present invention can be achieved by the following description.

The fruit bag manufacturing film of this invention has a laminated structure of the nonwoven fabric of a breathable film and a synthetic resin system.

The breathable film is uniaxially stretched or biaxially stretched after forming a film from a composition comprising from 30 to 70% by weight of an inorganic filler and from 70 to 30% by weight of a matrix component selected from the group consisting of polyethylene, polypropylene and mixtures thereof Manufactured through the process. At this time, the inorganic filler used may include calcium carbonate, barium sulfate, cray, talc, and the average particle size preferably has a range of 0.5 to 10 μm. The inorganic filler is added to impart breathability to the film produced by forming a porous film through a subsequent stretching process, when the average particle size is less than 0.5 ㎛ there is a difficult problem in dispersing the inorganic filler, exceeding 10 ㎛ In this case, there is a problem such as the generation of holes during film molding. In addition, when the content of the inorganic filler is less than 30% by weight, it is difficult to have the desired breathability due to insufficient pore formation, whereas when the content of the inorganic filler exceeds 70% by weight, the physical properties and processability of the film are deteriorated. As the polyethylene used as the matrix component, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), or a mixture thereof is used, and the density of 0.910 to 0.970 g / cm 3 and It is preferable that the melt index (MI) measured according to this is in the range of 0.01 to 20 g / 10 min. In the present invention, the method of forming the film from the inorganic filler and the matrix component is not limited to a specific method, but as is commonly known in the art, for example, using a Benbury mixer, a mixing roll, a twin screw extruder, or the like. In order to mix and shape into a film according to a casting molding method, a calendering molding method, a blow molding method and the like, a casting molding method using a T-die is preferably used. In the present invention, titanium dioxide may be added in an amount of about 0.1 to 15% by weight based on the total weight of the composition in order to improve light blocking property of the fruit bag. In addition, it may further include components that can be generally added, such as antioxidants, lubricants. The film mixed and formed as described above is uniaxially or biaxially stretched at a temperature below the softening point of the film to impart porosity. Preferable draw ratio is 1.3-4.0, and the thickness of a stretched film has the preferable range which is 10-60 g / m <2>. In particular, it is preferable to have the air permeability of about 1,000-20,000 g / m <2> * 24hr for JIS Z0208 so that it may be suitable for a fruit bag production.

On the other hand, in the present invention, the synthetic resin-based non-woven fabric (non-woven fabric) to be laminated with a breathable film is produced using a colorless or colored polypropylene or polyester as having a function of breathability and strength reinforcement, the color of the nonwoven fabric By variously changing the color of the fruit bag according to the present invention can be variously changed. The nonwoven fabric may be one having a thickness of 10 to 100 g / m 2.

As a method of laminating the above-mentioned breathable film and the nonwoven fabric, a thermal lamination method, a hot melt lamination method, an adhesive lamination method, or the like may be used. The thermal lamination method is a method of heating only heat, wherein the heating temperature is preferably in the range of 110 to 160 ° C, and the hot melt method is a method in which the hot melt is applied by applying a thickness of 1 to 5 μm and bonded. In addition, the adhesive lamination method is a method using a polyurethane-based adhesive.

In the present invention, it is possible to form a multilayer film in which a general polyolefin film is further laminated on a film on which the above-mentioned breathable film and a synthetic resin nonwoven fabric are laminated. When the multi-layer film prepared as described above is used for fruit bag production, one side is made of a laminated film made of the breathable film and the nonwoven fabric, and the other side is made of the polyolefin film. The polyolefin film is to impart a breathable function while adjusting the amount of light to be suitable for a fruit bag, such as grapes, low density polyethylene, high density polyethylene, linear low density polyethylene, homopolypropylene, random polypropylene, impact polypropylene, etc. It is manufactured by blown film forming method, casting film forming method, etc. using the material of. As a method of further attaching the polyolefin film, a heat sealing method, an adhesion method using an adhesive, or the like is used.

The present invention can be more clearly understood by the following examples, which are only intended to illustrate the present invention and are not intended to limit the scope of the invention.

Comparative Example 1

After using the paper fruit bag (Nonghyup Agrosa), which is currently used by farmers, for pear cultivation, the color of the bag, air permeability, moisture permeability, light transmittance, temperature in the bag, relative humidity in the bag, average fruit weight, sugar content, pest incidence rate, Skin sheath color, and magpie damage rate were evaluated, and the results are shown in Table 1 below.

Comparative Example 2

Using a general linear low density polyethylene (MI = 2.8, density = 0.99 g / cm 3), a non-breathable casting film was prepared by casting molding to have a film thickness of 18 g / m 2. The non-breathable film and 18 g / m 2 polypropylene nonwoven fabric (Saehan Corp.) prepared as described above were laminated using a hot melter using a hot melt (Polytachi Co., Ltd.) to prepare an fruit bag. The fruit bag prepared as described above was tested in the same items as in Comparative Example 1, the results are shown in Table 1 below.

Example 1

Breathable by casting molding method using a breathable compound resin (SK Corporation BRESPOL AT810) consisting of 50% by weight of calcium carbonate having an average particle size of 1.2 μm and 50% by weight of a matrix resin composed of a mixture of linear low density polyethylene and low density polyethylene. The film was molded, and the film was stretched 2.5 times using a stretching roll at a heating condition of 60 ° C. to prepare a breathable film having a breathability of 10,000 g / m 2 · 24hr (JIS Z0208 method) and a thickness of 18 g / m 2. The film and 18 g / m 2 polypropylene nonwoven fabric were laminated in the same manner as in Comparative Example 2 to prepare an fruit bag. The fruit bag produced was tested with the same items as in Comparative Example 1, and the results are shown in Table 1 below.

Example 2

10 wt% of titanium dioxide masterbatch (60% TiO ₂ ) having excellent light blocking property was added to the breathable compound resin used in Example 1, and then the film was molded by a casting molding method. The film formed using the stretching roll was stretched 2.7 times to prepare a breathable film having a permeability of 10,000 g / m 2 · 24 hr and a thickness of 18 g / m 2 measured according to JIS Z0208. After the nonwoven fabric was laminated in the same manner as in Comparative Example 2, a fruit bag was produced.

The fruit bag produced was tested with the same items as in Comparative Example 1, and the results are shown in Table 1 below.

Example 3

After the breathable film was prepared in the same manner as in Example 1, and then laminated with a 18 g / m 2 polyester nonwoven fabric colored in blue in the same manner as in Example 2 to produce a fruit bag.

The fruit bag produced was tested with the same items as in Comparative Example 1, and the results are shown in Table 1 below.

Example 4

First, a film in which a breathable film and a polypropylene nonwoven fabric were laminated in the same manner as in Example 1 was prepared. Subsequently, a general polyethylene film having a thickness of 30 μm was prepared by a blown film forming method using linear low density polyethylene (MI = 1.0, density = 0.919 g / cm 3) as a raw material. Using two kinds of films prepared above, one side was sealed with a breathable laminated film and the other side was a general polyethylene film to prepare an fruit bag that can be used for certain fruits such as grapes.

Evaluation result of pear growth characteristics of fruit bag Item Comparative Example Example One 2 One 2 3 Bag color yellow White White White blue Speculation (seconds / 100cc) 18.6 1228.6 322.0 349.5 297.3 Water vapor permeability (g / ㎡, 24hr) 1553.3 Not measurable 1718.8 1675.2 1809.6 Light transmittance (%) 47.8 65.3 49.2 38.5 47.4 Temperature in bag (℃) 30.5 29.2 29.6 28.7 30.7 Relative Humidity in Bag (%) 73.8 81.1 75.6 75.8 74.3 Average weight (g) 427 456 413 425 418 Sugar (Bx) 11.7 12.0 12.7 12.3 12.5 Infection rate (%) 1.6 6.3 1.9 1.7 1.5 Skin color Good Turquoise Good Good Good Magpie damage rate (%) 6.7 1.2 1.1 1.3 0.9

As can be seen from the table, when compared to the fruit bag made of a paper film according to the present invention, the fruit bag is particularly equivalent in terms of moisture permeability, it was confirmed that the magpie damage rate can be significantly reduced. In addition, when compared to the fruit bag made of a non-breathable casting film material of the fruit bag made of the laminated film according to the present invention, the incidence of insect pests was lowered to about 80%, and excellent in terms of skin color, which directly affects the value of the product. It was confirmed.

The fruit bag produced using the laminated film of the present invention exhibits air permeability equal to or higher than that of the paper bag used in the prior art, and can solve the problem of water resistance of the paper bag and can significantly reduce algae damage. In addition, it maintains the stiffness of the bag and has the advantage of expressing various colors while reducing the risk of damaging the skin.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of the present invention will be apparent from the appended claims.

Claims (10)

A breathable film comprising 30 to 70 wt% of an inorganic filler and 70 to 30 wt% of a matrix component selected from the group consisting of polyethylene, polypropylene, and mixtures thereof; And a non-woven fabric of synthetic resin system made of polypropylene or polyester material. The method of claim 1, wherein the inorganic filler is a laminated film for fruit bag production, characterized in that selected from the group consisting of calcium carbonate, barium sulfate, cray, talc. 3. The laminated film for fruit bag manufacturing according to claim 2, wherein the inorganic filler has a particle size of 0.5 to 10 m. The method of claim 1, wherein the polyethylene is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and mixtures thereof, and has a density of 0.910-0.970 g / cm3 and 0.01-20 A laminated film for fruit bag production, characterized in that it has a melt index of g / 10 min. The method of claim 1, wherein in order to improve the light blocking property of the permeable film, the laminated film for producing a fruit bag, characterized in that it further comprises 0.1 to 15% by weight of titanium dioxide. 2. The laminated film for fruit bag manufacturing according to claim 1, wherein the polyolefin film is further attached. The method of claim 6, wherein the polyolefin is a low density polyethylene, high density polyethylene, linear low density polyethylene, homopolypropylene, random polypropylene, impact film made of a laminated polypropylene film, characterized in that selected from the group consisting of impact polypropylene. An fruit bag made of the laminated film of claim 1. Forming a film from a composition comprising from 30 to 70 weight percent of an inorganic filler and from 70 to 30 weight percent of a matrix component selected from the group consisting of polyethylene, polypropylene and mixtures thereof; Uniaxially or biaxially stretching the film to impart breathability; And Laminating the stretched film and a synthetic resin nonwoven fabric made of polypropylene or polyester; Method for producing a laminated film for fruit bag production, characterized in that it comprises a. The method according to claim 9, wherein the lamination method is a thermal lamination method, a hot melt lamination method or an adhesive lamination method.