KR100839298B1 - Gas-penetration film having groove and method of fabricating the same - Google Patents

Abstract

A method of manufacturing breathable microporous film is provided to make plural pores on a plastic sheet/film simultaneously with pulsed laser. A method of manufacturing breathable microporous film with pulsed laser includes a step(S100) of generating pulsed laser with a light source, a step(S200) of exposing pulsed laser to plastic film with a beam collector after passing pulsed laser through a transmitter and a distributor, and a step(S300) of forming plural pores on the plastic film sequentially by moving a stage holding the plastic film exposed to a laser beam.

Description

Breathable film having fine grooves and a method of manufacturing the same {Gas-Penetration Film having Groove and Method of Fabricating the same}

1 is a block diagram showing an example of a manufacturing apparatus using a processing method of a breathable film according to a preferred embodiment of the present invention.

2 is a block diagram illustrating a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

3 is a flowchart illustrating a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

4 is another block diagram for explaining a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

5 is a fine groove measurement photograph of a breathable film formed according to a preferred embodiment of the present invention.

Figure 6 is a micro groove measurement photograph of another breathable film formed according to a preferred embodiment of the present invention.

7 is a micro groove measurement photograph of another breathable film formed according to a preferred embodiment of the present invention.

FIG. 8 is a photograph of measurement of fine grooves of a breathable film processed using a pulse laser of 100 mm and a pulse intensity of 92 uJ according to a preferred embodiment of the present invention.

FIG. 9 is a three-dimensional measurement photograph of the micro groove shape of FIG. 8.

FIG. 10 is a micro groove-shaped micrograph of a breathable film processed using a pulse energy of 100 mm focal length and 153 uJ according to a preferred embodiment of the present invention.

FIG. 11 is a three-dimensional measurement photograph of a fine groove shape of the breathable film of FIG. 10. The processed microgroove is 31um wide and about 20um deep.

Explanation of symbols on the main parts of the drawings

100: laser light source 120: beam transmission system

140: beam splitter 160: condenser

170: scanner 175: scanner mirror

180: driving stage 200: film

202: fine groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a breathable film for packaging various articles and foods, and more particularly, to a breathable film having fine grooves formed by using a pulse laser. The breathable film in which the fine grooves are formed may block moisture and the like and may allow air to pass through.

A breathable film having a breathable characteristic refers to a film that can permeate air or gas, but cannot permeate liquid. In particular, the breathable film has a function of blocking the evaporation of moisture in the packaging container while discharging various gases generated in the packaging container containing the perishable contents. In order to perform this function, the breathable film must have a plurality of fine grooves.

Breathable film having a plurality of air permeable fine grooves to maintain the freshness of perishable fruit or food when used as a food packaging material. In addition, the breathable film can be used in various places where the ventilation and waterproofing is required, such as to prevent corrosion of the machinery, food packaging, fruit bags, diapers and sanitary napkins, disposable clothing and sheets.

A method of manufacturing the above-mentioned breathable film is disclosed in Japanese Patent Laid-Open No. 2004-283871. This publication discloses a technique for forming a plastic structure through laser processing using multiphoton absorption. In particular, the plastic materials to be processed include plastic sheets and films.

In addition, the disclosed patent discloses a method for forming a through hole using a pulse laser, finely adjusting the size of the through hole, and a plastic structure formed accordingly. Such a disclosed patent does not disclose a method for processing a breathable film suitable for mass production. In particular, the technology of forming a plurality of fine grooves through a series of devices is silent.

A first object of the present invention for solving the above problems is to provide a processing method of a breathable film that can simultaneously form a plurality of fine grooves in the film.

In addition, a second object of the present invention is to provide a breathable film obtained by achieving the first object.

The present invention for achieving the first object, generating a pulse laser; And forming fine grooves by irradiating the pulse laser to the film, wherein the formation of the fine grooves is performed by continuously forming the fine grooves at regular intervals by moving the driving stage provided with the film. It provides a method for producing a breathable film, characterized in that.

In addition, the first object of the present invention, generating a pulsed laser through a laser light source; Passing the pulse laser through a beam transmission system and a beam splitter and irradiating the pulse laser to the film through a condenser; And transferring a driving stage for supporting the film to which the pulse laser is irradiated, thereby providing at least one pulse laser continuously forming a plurality of fine grooves.

The present invention for achieving the second object, generating a pulse laser; And forming a fine groove by irradiating the pulse laser to the film, wherein the fine groove is continuously formed at regular intervals by relative movement of the driving stage and the pulse laser having the film. Provides breathable film.

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

Example

1 is a block diagram showing an example of a manufacturing apparatus using a manufacturing method of a breathable film according to a preferred embodiment of the present invention.

Referring to FIG. 1, a manufacturing apparatus for manufacturing a breathable film includes a laser light source 100, a beam transmission system 120, a beam splitter 140, a light collector 160, and a driving stage 180.

The laser light source 100 is preferably a femtosecond laser (femtosecond laser) having a specification of 785nm, 1W, 184fs, 1kHz or using an ultraviolet laser.

The pulse laser generated from the laser light source 100 is incident to the beam transmission system 120. The beam transmission system 120 has optical systems and devices for controlling the pulse laser.

The pulse laser beam passing through the beam transmission system 120 is incident to the beam splitter 140. The beam splitter 140 reflects the incident pulse laser to the light collector 160, and transmits visible light so that the camera 210 can check the processing state of the film 200.

The collector 160 collects the pulsed laser beam incident from the beam splitter 140 and irradiates the pulsed laser on the film 200 which is a workpiece.

When the pulse laser is irradiated from the light collector 160 onto the film 200, the stage 180 performs a continuous moving operation. As the stage 180 moves, fine grooves are continuously formed in the workpiece. That is, in the pulse laser having a predetermined period, a region having a high energy and a region where a low or no laser is applied are regularly repeated. Therefore, when continuously irradiating a pulsed laser and moving the stage 180 at a constant speed, regular fine grooves are formed on the film 200 which is a workpiece.

2 is a block diagram illustrating a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

Referring to Figure 2, the manufacturing method of the breathable film according to the present embodiment uses a pulse processing method. That is, a plurality of fine grooves 202 are continuously formed using one pulse laser without irradiating a plurality of pulse lasers in succession. Therefore, there is an advantage that the continuous production at high speed is possible, and as the stage 180 moves at a constant speed, patterns in the form of periodic dots may be processed at high speed.

In addition, in the present invention, when not using a special pulse switching device, the processing speed may be determined according to the repetition rate of the pulse laser. Preferably a thousand grooves are processed every second using a femtosecond laser or an ultraviolet laser having a repetition rate of 1 kHz.

In addition, the spacing of the processed micro grooves can be adjusted by changing the feed speed of the stage. Therefore, the number of fine grooves processed per unit area can be arbitrarily selected, and the air permeability can be adjusted by adjusting the number and spacing of the fine grooves.

3 is a flowchart illustrating a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

Referring to FIG. 3, first, a pulse laser is generated (S100). Generation of the pulsed laser is performed by a laser light source as shown in FIG.

In addition, the generated pulsed laser light is focused on the film (S200). Irradiation of the pulsed laser is implemented by irradiating a film provided on the driving stage with a pulsed laser transmitted by the beam transmission system, the beam splitter and the condenser. The pulsed laser is continuously repeated with a portion having high energy and a portion where low energy or no energy is applied.

When the driving stage moves continuously, fine grooves are formed on the film at regular intervals. That is, when the driving stage moves, fine grooves are formed in a section having high energy in the pulse laser, and fine grooves are not formed in a section in which energy is low or energy is not applied.

In addition, the movement of the driving stage is generated at the same time as the step of condensing the pulse laser to the film (S300). That is, while the drive stage is constantly moving, the pulsed laser is irradiated onto the film.

The drive stage may also initiate a continuous movement operation prior to the step in which the pulsed laser is generated.

In addition, in FIG. 1, FIG. 2 and FIG. 3, only the driving stage with the film, which is a workpiece, is moved, but it can be seen that the present invention is realized by relatively moving the film and the pulse laser. Thus, even when the pulse laser moves continuously with respect to the film, fine grooves can be formed continuously in accordance with the present invention.

4 is another block diagram for explaining a method of manufacturing a breathable film according to a preferred embodiment of the present invention.

Referring to FIG. 4, the apparatus using the pulse laser has a different configuration from the apparatus disclosed in FIG. 2. The pulse laser is scanned at high speed through the scanner 170 to the film 200 on the driving stage 180 to process the periodic and continuous fine grooves 202. That is, the path of the pulse laser is changed by the rotation of the scanner mirror 175 included in the scanner 170, so that the plurality of fine grooves 202 can be fastened by the relative movement with the film 200 on the driving stage 180. It can be processed continuously. In addition, the distance between the fine grooves 202 is adjusted by the rotational speed of the scanner mirror 175. That is, the scanner mirror in FIG. 4 corresponds to the beam splitter shown in FIG. 2. In FIG. 2, the beam splitter serves as a splitter. In FIG. 4, the beam splitter has a scanner mirror to adjust irradiation of a pulse laser by rotating the scanner mirror.

As shown in FIG. 2, FIG. 3 and FIG. 4, the relative movement between the pulse laser and the driving stage equipped with the film may be implemented through various methods.

5 is a fine groove measurement photograph of a breathable film formed according to a preferred embodiment of the present invention.

Referring to FIG. 5, a breathable film having a periodic interval of 0.05 mm was formed using a pulse laser at a feed rate of 50 mm / s in the stage of FIG. 1 or 2.

Figure 6 is a micro groove measurement photograph of another breathable film formed according to a preferred embodiment of the present invention.

Referring to FIG. 6, a breathable film having a periodic interval of 0.1 mm was formed using a pulse laser at a feed rate of 100 mm / s in the stage of FIG. 1 or 2.

7 is a micro groove measurement photograph of another breathable film formed according to a preferred embodiment of the present invention.

Referring to FIG. 7, a breathable film having a periodic interval of 0.2 mm was formed using a pulse laser at a feed rate of 200 mm / s in the stage of FIG. 1 or 2.

In the manufacturing process of the breathable film shown in FIGS. 5, 6 and 7, the focal length of the light collector was 20 mm, the laser light source was a femtosecond laser, the intensity of the pulse laser was 6.67 uJ, and the film used was poly Polypropylene film, 30um thick.

In the present invention, it is possible to control the width and depth of the fine groove formed in the film by adjusting the pulse intensity of the laser light source. That is, in the case of using the conventional mechanical drilling method using a punching pin, it is virtually impossible to form a fine groove having a diameter of 0.1mm or less, and when the diameter of the fine groove exceeds 0.1mm, the air inside the outside Although it may be released quickly, a problem arises in that a small bee or a foreign substance may be introduced into the container during the storage and display of the packaged article. In addition, the film in which the microgrooves of several microns are densely distributed as a whole has a problem of low air permeability and tensile strength.

Therefore, when processing the fine groove of the breathable film using the pulse laser of the present invention, the shape of the fine groove, that is, the width and depth can be adjusted by adjusting the processing conditions such as the intensity of the pulse laser, the size of the beam, the focal length And, accordingly, it is possible to adjust the air permeability.

 In the present invention, when the focal length of the concentrator is 20 mm to 100 mm to change the pulse intensity of the femtosecond laser to 1 uJ to 200 uJ to form the micro grooves, the micro grooves having a diameter of 0.001 mm to 0.1 mm can be obtained.

FIG. 8 is a photograph of measurement of fine grooves of a breathable film processed using a pulse laser of 100 mm and a pulse intensity of 92 uJ according to a preferred embodiment of the present invention.

9 is a three-dimensional photograph of the shape of the fine groove of FIG. 8. The width of the micro grooves processed in FIG. 9 is 24 μm, and the depth is about 16 μm.

FIG. 10 is a micro groove-shaped micrograph of a breathable film processed using a pulse energy of 100 mm focal length and 153 uJ according to a preferred embodiment of the present invention.

FIG. 11 is a three-dimensional measurement photograph of a fine groove shape of the breathable film of FIG. 10. The processed microgroove is 31um wide and about 20um deep.

Thus, the manufacturing method of the breathable film using the pulse laser processing method can change the width and depth of the processed micro groove using the intensity of a laser pulse. Therefore, the air permeability can be easily adjusted, and the fusion phenomenon between the film and the punching device is also prevented by the non-contact method, which is an advantage of laser processing.

In addition, in the present embodiment, although the microgroove does not penetrate the film, when the energy of the pulse laser is increased, the microgroove may penetrate the film. That is, in the present invention, the energy of the pulse laser may be increased to form fine grooves penetrating the film.

According to the present invention as described above, using a pulse laser to produce a breathable film provided with a fine groove. Using a pulsed laser, the film, which is a workpiece, is continuously moved to form fine grooves at regular intervals at high speed. In addition, since the shape and spacing of the processed fine grooves can be changed, the air permeability can be adjusted, and the fusion phenomenon between the film and the drilling apparatus is prevented by the non-contact method, which is an advantage of laser processing. The breathable film formed as described above is used as a packaging film. Therefore, the freshness of the food is maintained, and the fermentation gas is not released to the outside through the packaging of fermented food such as kimchi to prevent the film from being torn off, and to prevent the inflow of liquid to penetrate the packaged moisture. You can prevent it.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (11)

Generating a pulsed laser; And Irradiating the pulse laser to the film to form fine grooves, The pulse laser avoids irradiating a series of pulse trains in succession, allowing one pulse laser to process a plurality of fine grooves continuously, The formation of the micro grooves is a method of manufacturing a breathable film, characterized in that the formation of the micro grooves at regular intervals by the relative movement of the drive stage and the pulse laser provided with the film is made continuously. The pulse laser of claim 1, wherein the pulse laser is formed using a femtosecond laser or an ultraviolet laser, and the spacing between adjacent fine grooves is controlled by adjusting a relative feeding speed of the driving stage and the pulse laser. Method for producing a film. The method of claim 1, wherein the fine groove is provided in the shape of a groove in the film, or the width or depth of the fine groove is controlled by adjusting a pulse intensity of the pulse laser. delete Generating a pulsed laser through a laser light source; Passing the pulse laser through a beam transmission system and a beam splitter and irradiating the pulse laser to the film through a condenser; And A driving stage for supporting the film to which the pulse laser is irradiated and a pulse laser are relatively transferred so that at least one pulse laser continuously forms a plurality of fine grooves, The pulsed laser avoids irradiation with a series of consecutively superimposed pulse trains, and allows one pulsed laser to continuously process a plurality of fine grooves. The method of claim 5, wherein the spacing between the adjacent fine grooves is controlled by the relative transfer speed of the drive stage and the pulsed laser, and the depth or width of the fine grooves is controlled by the pulse intensity of the pulsed laser. Method of producing a breathable film. 6. The method of claim 5, wherein the step of relatively conveying the drive stage is performed substantially simultaneously with the step of irradiating the pulsed laser. 6. A method according to claim 5, wherein the beam splitter has a scanner mirror and achieves relative movement of the drive stage and the pulsed laser by rotation of the scanner mirror. Generating a pulsed laser; And Irradiating the pulsed laser to the film to form fine grooves, The pulse laser avoids irradiating a series of pulse trains in succession, allowing one pulse laser to process a plurality of fine grooves continuously, The fine groove is a breathable film, characterized in that the continuous at regular intervals by the relative movement of the drive stage and the pulse laser provided with the film. The method of claim 9, wherein the fine groove is provided in the shape of the groove or through the film in the film, the width or depth of the fine groove to control by adjusting the pulse intensity of the pulse laser Breathable film characterized by. delete

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