KR102352977B1 - Apparatus and method for controlling production temperature of blown film for uniform film thickness - Google Patents

Abstract

The objective of the present invention is to provide a technology that allows the position of a frost line to vary autonomously according to changes in the surrounding environment. An apparatus for controlling production temperature of a blown film for uniform film thickness according to one embodiment of the present invention comprises: a die generating a cylindrical film by allowing a molten resin to pass through; a laser unit irradiating laser light passing through the central axis of the cylindrical film from the outside of the cylindrical film; a light receiving unit receiving the laser light irradiated from the laser unit; a blower unit that is coupled to the die and allows a cooling gas to be introduced into the inside of the cylindrical film; and an environmental measurement unit that collects information about the environment around the cylindrical film.

Description

APPARATUS AND METHOD FOR CONTROLLING PRODUCTION TEMPERATURE OF BLOWN FILM FOR UNIFORM FILM THICKNESS

The present invention relates to a blown film manufacturing temperature control apparatus and method for uniform film thickness, and more particularly, to a technology for enabling the position of an ice line to be actively varied according to changes in the surrounding environment.

The system used in the film blowing process for manufacturing films, such as for agricultural purposes, is an extruder die that can be injected, an internal bubble control (IBC) that can blow the film, and the blowing process. It may be composed of a device such as a nip roll that is then combined.

Most of the internal cooling devices used in the prior art film blowing process are passive devices that depend on set values, so there is a problem that changes in the surrounding environment are not immediate.

In addition, although cooling is mainly performed in the film blowing process, there is a problem in that it is difficult to have a film having a desired level of width due to too fast freezing in winter or depending on circumstances.

In addition, in the film blowing process, there is a limit to productivity improvement, such as manufacturing and pasting several times to satisfy the width and thickness required by consumers, or the yield is lowered in the process.

In Korean Patent Registration No. 10-1989691 (Title of the Invention: Film cooling device for blow film molding machine for preventing thermal deformation), air is blown into the film extruded from the die to expand the film and make the film at the same time A film cooling device for a blow film forming machine having a blower hose for cooling to 1 temperature and a discharge hose for discharging heated air after cooling, comprising a corona discharge treatment unit, a cooling roller unit, and a chiller unit, and the corona discharge treatment unit includes a first A high frequency is generated to form an oxide film on the surface of the film cooled to the temperature, and the cooling roller unit is rotatably installed on the transport path of the film so as to be in rolling contact with the film on which the oxide film is formed, a circulation path is provided inside, and a chiller unit Disclosed is an apparatus for supplying a refrigerant to a circulation passage of a cooling roller unit so that the cooling roller unit is cooled to a lower temperature than a first temperature.

Republic of Korea Patent Registration No. 10-1989691

It is an object of the present invention to solve the above problems, so that the position of the ice line can be varied according to the change of the surrounding environment.

And, an object of the present invention is to improve the productivity and yield of the film by automatically controlling the position of the freezing line.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. There will be.

The configuration of the present invention for achieving the above object is a die for producing a cylindrical film by passing a molten resin; a laser unit irradiating laser light passing through the central axis of the cylindrical film from the outside of the cylindrical film; a light receiving unit for receiving the laser light irradiated from the laser unit; a blower coupled to the die and configured to introduce a cooling gas into the cylindrical film; and an environment measuring unit that collects information about the environment around the cylindrical film, wherein the laser unit and the light receiving unit perform linear motion in an up-down direction, and the icing line of the cylindrical film is caused by the laser unit and the light receiving unit. (Frost line) is characterized in that it is measured.

In an embodiment of the present invention, after receiving and analyzing the environmental information by the environmental measurement unit and the location information of the ice line by the laser unit and the light receiving unit, a control signal is transmitted to the blower to control the temperature of the cooling gas It may further include a control unit.

In an embodiment of the present invention, the environment measuring unit may include a temperature sensor for measuring the temperature outside the cylindrical film.

In an embodiment of the present invention, the environment measuring unit may further include a wind speed sensor for measuring the wind speed outside the cylindrical film, and a humidity sensor for measuring the humidity outside the cylindrical film.

In an embodiment of the present invention, a driving unit coupled to the laser unit and the light receiving unit may further include a driving unit that linearly moves the laser unit and the light receiving unit in a vertical direction.

In an embodiment of the present invention, it may further include a cutting unit positioned on the upper end of the cylindrical film for cutting the cylindrical film.

In an embodiment of the present invention, it may further include a roller unit having a nip roll for pressing the plate-shaped film formed by separating the cylindrical film by the cutting unit.

In an embodiment of the present invention, it is coupled to the die and may further include an exhaust for discharging the cooling gas whose temperature has risen inside the cylindrical film.

The configuration of the present invention for achieving the above object is a first step of forming the cylindrical film by receiving the cooling gas from the blower while passing the molten resin through the die; a second step of transmitting information on a location of an ice line to the control unit by performing a linear motion in the vertical direction by the laser unit, the light receiving unit, and the environment measuring unit; a third step in which the environmental measurement unit transmits environmental information about the circumference of the cylindrical film to the control unit, and a reference position of an ice line that is a reference position stored in advance in the control unit is selected; a fourth step in which the position of the ice line is changed by comparing the position of the ice line measured in the second step with the reference position of the ice line, the control unit transmitting a control signal to the blower and controlling the temperature of the cooling gas; and a fifth step in which the laser unit and the light receiving unit perform linear motion in the vertical direction, so that the control unit receives information on the position of the ice line again and determines whether the position of the ice line matches the reference position of the ice line. do.

The effect of the present invention according to the above configuration is that, by optimizing the position of the ice line according to the surrounding environment, the width and thickness of the film to be manufactured can be maximized, and thus productivity and yield can be improved.

And, the effect of the present invention is that the position of the ice line can be actively changed according to the change of the surrounding environment because the location of the ice line is automatically controlled by analyzing the surrounding environment and using it.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 and 2 are schematic diagrams of a configuration of a temperature control device according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, coupled)” with another part, it is not only “directly connected” but also “indirectly connected” with another member interposed therebetween. "Including cases where In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

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

1 and 2 are schematic diagrams of a configuration of a temperature control device according to an embodiment of the present invention. 1 and 2, the temperature control device of the present invention includes a die 410 for passing a molten resin to produce a cylindrical film 10; a laser unit 110 for irradiating laser light passing through the central axis of the cylindrical film 10 from the outside of the cylindrical film 10; a light receiving unit 120 for receiving the laser light irradiated from the laser unit 110; a blower 510 coupled to the die 410 and introducing a cooling gas into the cylindrical film 10; and an environmental measurement unit 200 that collects information about the environment around the cylindrical film 10 . In addition, the temperature control device of the present invention may further include an exhaust unit 520 coupled to the die 410 and discharging a cooling gas having an increased temperature inside the cylindrical film 10 . Here, the matter in which the cooling gas is supplied from the blower 510 to the cylindrical film 10 and the matter in which the cooling gas is discharged to the exhaust unit 520 in the cylindrical film 10 are described in detail as for the prior art. is to be omitted.

The die 410 may be combined with an extruder (not shown) that extrudes the molten resin, and the molten resin flows to the die 410 under pressure while passing through the extruder, and then passes through the die 410 and a blower The cylindrical film 10 may be formed while receiving the cooling gas from the 510 and expanding. Here, the cylindrical film 10 is cooled by the cooling gas supplied into the cylindrical film 10 from the blower 510, and after cooling the cylindrical film 10, the cooling gas whose temperature is increased by heat exchange is discharged from the exhaust unit. It may be discharged to the outside of the cylindrical film 10 through 520 .

The temperature control device of the present invention may further include a cutting unit 420 positioned on the upper end of the cylindrical film 10 and cutting the cylindrical film 10 . After the production of the cylindrical film 10 as described above, the cylindrical film 10 may be bisected by the cutting parts 420 on both sides, and the two films generated by the bisecting cutting are combined to form a film. can be

To this end, the temperature control device of the present invention includes a roller unit 430 having nip rolls 431 and 432 for pressing the plate-shaped film formed by separating the cylindrical film 10 by the cutting unit 420 . may include more. Each of the two films formed by the bisecting cutting as described above is formed into a plate-shaped film, and each plate-shaped film is compressed while passing between both nip rolls 431 and 432 of the roller unit 430, whereby the two plate-shaped films are combined to form one A film may be formed.

The film blown process using the temperature control device of the present invention as described above is a process for making a film of a suitable thickness and width after extruding a resin at a high temperature and high pressure, in the inside of the cylindrical film 10 . It may be desired to perform cooling to cool the cylindrical film 10 to an appropriate level.

In addition, in order to accurately confirm the precise thickness and diameter of the cylindrical film 10, it may be necessary to check a frost line. The freezing line means a line in the circumferential direction of the cylindrical film 10 as a point at which the semi-solid resin changes into a solid in the cylindrical film 10. It can be greatly affected, and since the productivity of the film depends on where the freezing line is located in the cylindrical film 10, it may be the most important part in the film blowing process.

The blow-up ratio refers to how wide the width (Layflat width or Bubble diameter, D) of the cylindrical film 10 can be compared to the width of the die 410 (extruder die, d) from which the film is injected. In order to maximize this BUR, it may be necessary to perform optimization according to the surrounding environment of the ice vessel.

To this end, the laser unit 110 and the light receiving unit 120 perform a linear motion in the vertical direction, and a frost line of the cylindrical film 10 is measured by the laser unit 110 and the light receiving unit 120 . can Then, the temperature control device of the present invention receives and analyzes the environmental information by the environmental measurement unit 200 and the ice line position information by the laser unit 110 and the light receiving unit 120, and then controls it with the blower 510 It may further include a control unit for controlling the temperature of the cooling gas by transmitting a signal.

In order to continuously receive the laser light of the laser unit 110 , vertical linear motions of the laser unit 110 and the light receiving unit 120 may be simultaneously performed. The laser light emitted by the laser unit 110 may pass through the central axis in the longitudinal direction of the cylindrical film 10, and the laser light is continuously emitted while the laser unit 110 and the light receiving unit 120 linearly move in the vertical direction. can be

As described above, in the cylindrical film 10 , the resin may be in a semi-solid state in the lower portion of the freezing line with respect to the freezing line, and the resin may be in the solid state in the upper portion of the freezing line. In addition, the change in the frequency of laser light when the laser light passes through the resin in the semi-solid state and the change in the frequency of the laser light when the laser light passes through the resin in the solid state may be different.

Accordingly, while the laser unit 110 and the light receiving unit 120 perform upward linear motion, the frequency of the laser light received at the lower portion of the ice line in the cylindrical film 10 and the frequency of the laser light received at the upper portion of the ice line may be different, and while the laser unit 110 moves from the lower end to the upper end of the cylindrical film 10, a frequency inflection point in which the frequency difference as described above remarkably occurs may occur, and such a frequency inflection point is When the measured signal is transmitted to the controller, the controller may determine a portion of the cylindrical film 10 measured as a frequency inflection point as an ice line.

Here, the position of the ice line may be indicated by a vertical distance from the die 410 , that is, a distance from the die 410 on the longitudinal central axis of the cylindrical film 10 . In addition, in the control unit, data on a reference position of an ice line, which is a location of an ice line for maximizing a blow-up ratio (BUR) in the film blow-up process as described above, may be stored in advance.

The temperature control apparatus of the present invention may further include a driving unit 300 coupled to the laser unit 110 and the light receiving unit 120 and linearly moving the laser unit 110 and the light receiving unit 120 in the vertical direction. And, as shown in FIG. 2 , the environment measuring unit 200 may also be coupled to the driving unit 300 to perform a linear motion in the vertical direction.

The driving unit 300 includes a first driver 310 that is coupled to the light receiving unit 120 to linearly move the light receiving unit 120 in an upward direction, and a laser unit in combination with the laser unit 110 and the environment measuring unit 200 . A second actuator 320 for linearly moving the 110 and the environment measuring unit 200 in the vertical direction may be provided. In addition, the first driver 310 and the second driver 320 may be driven by receiving a control signal from the controller, which will be described in detail below.

The environmental measurement unit 200 may include a temperature sensor for measuring the temperature outside the cylindrical film 10 . In addition, the environmental measurement unit 200, a wind speed sensor for measuring the wind speed outside the cylindrical film 10, and a humidity sensor for measuring the humidity outside the cylindrical film 10 may be further provided. Here, the environment measuring unit 200 may also perform vertical linear motion in response to the vertical linear motion of the laser unit 110 . Accordingly, information on the environment around a portion of the cylindrical film 10 adjacent to the laser unit 110 and the light receiving unit 120 may be measured.

In addition, each of the temperature sensor, the wind speed sensor and the humidity sensor may continuously transmit a signal generated by real-time measurement to the control unit, and the control unit may select a reference position of the freezing line as described above according to each signal.

Specifically, the freezing line reference position can be changed according to the temperature, wind speed and humidity around the cylindrical film 10, and the control unit is the temperature and wind speed around the cylindrical film 10 from the data for the freezing line reference position stored in advance. And after searching for the reference position of the ice line according to the humidity, it is possible to select the reference location of the ice line as a reference.

First, the laser unit 110 , the light receiving unit 120 , and the environment measuring unit 200 are linearly moved in the vertical direction, the frequency change of the laser light is measured, and the corresponding information is transmitted to the control unit to analyze the location of the ice line. Here, the control unit may transmit a control signal to the driving unit 300 and linearly move the laser unit 110 , the light receiving unit 120 , and the environment measuring unit 200 in the vertical direction by the respective drivers.

And, when the ice line reference position is selected based on the information about the environment around the cylindrical film 10 at the corresponding ice line position, the controller compares the previously measured ice line position with the ice line reference position and transmits a control signal. It can pass to abundance 510 .

When the cooling temperature for the cylindrical film 10 increases, the freezing rate of the resin injected from the die 410 decreases, so that the location of the ice line increases (gradually away from the die 410), and the cylindrical film ( 10), the freezing rate of the resin injected from the die 410 may increase, so that the position of the ice line may be decreased (gradually closer to the die 410).

By comparing the previously measured ice line position and the freezing line reference position, when the previously measured ice line position is further away from the die 410 than the ice line reference position, the control unit transmits a control signal to the blower 510 to cool it. By reducing the temperature of the gas to decrease the ice line position, the ice line position can be moved to the ice line reference position.

And, by comparing the previously measured position of the freezing line with the reference position of the freezing line, when the previously measured position of the ice line is closer to the die 410 than the reference position of the ice line, the control unit transmits a control signal to the blower 510 Thus, by increasing the temperature of the cooling gas and increasing the position of the ice line, the location of the ice line can be moved to the reference position of the ice line.

And, when the temperature of the cooling gas is controlled by the control of the blower 510 as described above, the laser unit 110 and the light receiving unit 120 continuously perform a linear motion in the vertical direction to determine the position of the freezing line. The information is transmitted to the control unit, and the control unit receives such ice line position information in real time, and can measure and determine the moment when the variable ice line position and the ice line reference position coincide.

Here, after the control unit determines that the ice line position and the ice line reference position match, the control unit sends the laser unit 110, the light receiving unit 120, the environment measurement unit 200 and the driving unit 300 at predetermined time intervals. By transmitting a control signal, it is possible to periodically receive information about the location of the ice line and the environment around the cylindrical film 10 .

When using the temperature control device of the present invention as described above, by optimizing the location of the ice line according to the surrounding environment, the width and thickness of the film to be manufactured can be maximized, and thus productivity and yield can be improved.

In addition, since the surrounding environment is analyzed and the location of the ice line is automatically controlled using the analysis, the location of the ice line can be actively changed according to changes in the surrounding environment.

Hereinafter, the temperature control method of the present invention will be described.

In the first step, the molten resin may be provided with a cooling gas from the blower 510 while passing through the die 410 to form a cylindrical film 10 . And, in the second step, the laser unit 110 , the light receiving unit 120 , and the environment measuring unit 200 may perform linear motion in the vertical direction to transmit information on the location of the ice line to the control unit.

Next, in the third step, the environmental measurement unit 200 transmits environmental information about the circumference of the cylindrical film 10 to the control unit, and the reference position of the freezing line, which is a reference position stored in advance in the control unit, may be selected. Here, the controller may pre-determine whether the previously measured position of the ice line is the same as the reference position of the ice line, and when the position of the ice line and the reference position of the ice line are the same, the control unit may stop the progress to the fourth step.

Then, in the fourth step, by comparing the position of the ice line measured in the second step with the reference position of the ice line, the control unit transmits a control signal to the blower 510 and controls the temperature of the cooling gas, so that the position of the ice line can be changed

And, in the fifth step, the laser unit 110 and the light receiving unit 120 perform linear motion in the vertical direction so that the control unit receives information on the location of the ice line again, and whether the location of the ice line coincides with the reference location of the ice line can be judged

Here, steps 1 to 5 may be repeatedly performed at predetermined time intervals. In addition, whether the location of the ice line and the reference location of the ice line are the same may be determined if they match within a predetermined range such as an error range.

The description of the present invention described above is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

10: cylindrical film
110: laser unit
120: light receiving unit
200: Environmental Measurement Department
300: drive unit
310: first driver
320: second actuator
410: die
420: cutting part
430: roller unit
431, 432: nip roll
510: blower
520: exhaust

Claims (9)

a die through which the molten resin is passed to produce a cylindrical film;
a laser unit irradiating laser light passing through the central axis of the cylindrical film from the outside of the cylindrical film;
a light receiving unit for receiving the laser light irradiated from the laser unit;
a blower coupled to the die and configured to introduce a cooling gas into the cylindrical film;
an environmental measurement unit for collecting information about the environment around the cylindrical film;
A first driver coupled to the light receiving unit to linearly move the light receiving unit in a vertical direction, and a second driver coupled to the laser unit and the environment measuring unit to linearly move the laser unit and the environment measuring unit in a vertical direction. drive unit; and
After receiving and analyzing the location information of the ice line, which is the environmental information by the environmental measurement unit and information on the frequency change of the laser light transmitted from the laser unit and the light receiving unit, a control signal is transmitted to the blower to control the cooling gas. A control unit for controlling the temperature,
The control unit derives a reference ice line reference position, which is a reference according to the environment information, from data about the ice line reference position stored in advance, and generates a measured frost line using the ice line position information do,
The control unit compares the reference position of the freezing line with the measured position of the freezing line, and transmits a control signal to the blower, thereby adjusting the temperature of the cooling gas flowing into the cylindrical film,
When the temperature of the cooling gas is controlled, the linear motion of the laser unit and the light receiving unit is continuously performed so that the ice line position information is transmitted to the control unit in real time,
The control unit, a blown film manufacturing temperature control device for a uniform film thickness, characterized in that for measuring the moment when the freezing line reference position and the measured ice line position coincide.
delete The method according to claim 1,
The environmental measurement unit, blown film manufacturing temperature control device for a uniform film thickness, characterized in that provided with a temperature sensor for measuring the temperature outside the cylindrical film.
4. The method according to claim 3,
The environmental measurement unit, a blown film manufacturing temperature control device for a uniform film thickness, characterized in that it further comprises a wind speed sensor for measuring the wind speed outside the cylindrical film, and a humidity sensor for measuring the humidity outside the cylindrical film .
delete The method according to claim 1,
Blown film manufacturing temperature control device for uniform film thickness, characterized in that it is located on the upper end of the cylindrical film and further comprises a cutting part for cutting the cylindrical film.
7. The method of claim 6,
Blown film manufacturing temperature control device for an even film thickness, characterized in that it further comprises a roller having a nip roll for pressing the plate-shaped film formed by separating the cylindrical film by the cutting part.
The method according to claim 1,
The blown film manufacturing temperature control device for a uniform film thickness, characterized in that it is coupled to the die and further comprises an exhaust for discharging the cooling gas whose temperature has risen inside the cylindrical film.
In the method for controlling a temperature for producing a blown film for uniform film thickness using the blown film production temperature control device for uniform film thickness of claim 1,
a first step of forming the cylindrical film by receiving the cooling gas from the blower while passing the molten resin through the die;
a second step of transmitting the information on the location of the ice line to the control unit by performing a linear motion in the vertical direction by the laser unit, the light receiving unit, and the environment measuring unit;
a third step in which the environmental measurement unit transmits environmental information about the circumference of the cylindrical film to the control unit, and a reference position of an ice line that is a reference position stored in advance in the control unit is selected;
a fourth step in which the position of the ice line is changed by comparing the position of the ice line measured in the second step with the reference position of the line of ice, and the control unit transmits a control signal to the blower and controls the temperature of the cooling gas; and
A fifth step of determining whether the laser unit and the light receiving unit perform linear motion in the vertical direction so that the control unit receives information on the position of the ice line again and determines whether the position of the ice line coincides with the reference position of the ice line; Blown film manufacturing temperature control method for an even film thickness, characterized in that.

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