JP6948281B2 - Film molding equipment - Google Patents

Description

The present invention relates to a film molding apparatus.

A film molding apparatus is known in which a molten resin is extruded from a die and solidified to form a film. Conventionally, a film molding apparatus has been proposed in which the variation in film thickness (hereinafter referred to as “film thickness”) is reduced by changing the width of the discharge port (Patent Document 1).

Japanese Unexamined Patent Publication No. 6-99472

According to the conventional film molding apparatus described in Patent Document 1, the variation in film thickness can be reduced to some extent, and the accuracy as a film can be satisfied. However, there is usually some variation in film thickness. Even if this variation satisfies the accuracy of the film, if the variation is accumulated when the film is wound to form a film roll body, more specifically, the thick portions or the thin portions of the film are overlapped with each other. When stacked, humps and dents are formed on the film roll body. The humps and dents on the film roll cause distortion of the film.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a film forming apparatus capable of forming a film roll body having relatively few humps and dents or a small dent.

In order to solve the above problems, the film molding apparatus according to an embodiment of the present invention extrudes a molten resin from a die, solidifies the molten resin to form a film, and winds the molded film to form a film roll. The film forming apparatus includes a determination unit for determining whether or not there is an abnormality in the winding shape based on a change in the radius of the film roll body in the axial direction.

It should be noted that any combination of the above components and those in which the components and expressions of the present invention are mutually replaced between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to form a film roll body having relatively few or small humps and dents.

It is a figure which shows the schematic structure of the film forming apparatus which concerns on embodiment. It is sectional drawing which shows the die and the film thickness adjustment part of FIG. It is a top view of the die and the film thickness adjustment part. It is a top view of the die and the film thickness adjustment part. It is a block diagram which shows the function and structure of the control device of FIG. It is a figure for demonstrating the process which a determination part determines whether or not there is an abnormality in a winding shape. It is a figure which shows the pick-up machine of the film forming apparatus which concerns on a modification, and its periphery. It is a block diagram which shows the function and structure of the control device of the film forming apparatus which concerns on a modification.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description will be omitted as appropriate.

FIG. 1 shows a schematic configuration of a film forming apparatus 1 according to an embodiment. The film forming apparatus 1 forms a tubular film. The film forming apparatus 1 includes a die 2, a film thickness adjusting portion 15, a pair of stabilizers 4, a take-up machine 5, a thickness measuring sensor 6, a winding machine 20, a winding shape measuring sensor 22, and a control device. 7 and.

The die 2 forms a molten resin supplied from an extruder (not shown) into a tube shape. The die 2 particularly forms the molten resin into a tube shape by extruding the molten resin from a ring-shaped slit 18 (described later in FIG. 2).

The film thickness adjusting unit 15 adjusts the film thickness and cools the molten resin extruded from the die 2. When the molten resin is cooled, the film is formed.

The pair of stabilizers 4 are arranged above the cooling device 3 and guide the formed film to the take-up machine 5. The take-up machine 5 is arranged above the stabilizer 4. The pick-up machine 5 includes a pair of pinch rolls 38. The pair of pinch rolls 38 are driven by a motor (not shown) to rotate, and fold the guided film flat while pulling it up. The winder 20 winds a film that is folded and has a predetermined width to form a film roll body 11.

The thickness measurement sensor 6 is arranged between the film thickness adjusting unit 15 and the stabilizer 4. The thickness measurement sensor 6 measures the film thickness at each position in the circumferential direction while rotating around the tubular film. The thickness measurement sensor 6 measures the film thickness at each position in the circumferential direction at a predetermined cycle. The value measured by the thickness measurement sensor 6 is sent to the control device 7.

The winding shape measurement sensor 22 is arranged adjacent to the film roll body 11. The winding shape measurement sensor 22 measures information on the radius of the film roll body 11 at each position in the axial direction, that is, information on the axial change of the radius of the film roll body 11 at a predetermined cycle. In the present embodiment, the winding shape measurement sensor 22 specifies the radius itself as information regarding the radius, but as information regarding the radius, for example, the diameter at each position in the axial direction may be measured, and for example, the film roll body 11 The distance between a certain axis parallel to the central axis and the film roll body 11 at each position in the axial direction may be specified.

The winding shape measurement sensor 22 is, for example, a laser displacement meter, and is a first position to a first position in which each position in the axial direction, specifically, a first position to be arranged at regular intervals in the axial direction while moving along the central axis of the film roll body 11. The radius of the film roll body 11 at each of n positions up to the position of n (n is a natural number) is measured. The first position and the nth position are positions corresponding to one side end portion and the other side end portion of the film roll body 11 in the axial direction, respectively. The value measured by the winding shape measurement sensor 22 is sent to the control device 7.

The control device 7 sends a control command according to the measured value received from the thickness measuring sensor 6 and the winding shape measuring sensor 22 to the film thickness adjusting unit 15. In response to this control command, the film thickness adjusting unit 15 adjusts the width of the slit 18 (particularly its discharge port) and adjusts the air volume of the cooling air so that the variation in thickness becomes small.

FIG. 2 is a cross-sectional view showing the die 2 and the film thickness adjusting portion 15. 3 and 4 are top views of the die 2 and the film thickness adjusting unit 15. FIG. 3 shows a state in which the inside of the cooling device 3 is seen through. In FIG. 4, the display of the cooling device 3 is omitted.

The die 2 includes a die main body 10, an inner peripheral member 12, and an outer peripheral member 14. The inner peripheral member 12 is a substantially columnar member mounted on the upper surface of the die body 10. The outer peripheral member 14 is an annular member and surrounds the inner peripheral member 12. A ring-shaped slit 18 extending in the vertical direction is formed between the inner peripheral member 12 and the outer peripheral member 14. The molten resin flows upward through the slit 18, and the molten resin is extruded from the discharge port (that is, the upper end opening) 18a of the slit 18, to form a film having a thickness corresponding to the width of the discharge port 18a.

The film thickness adjusting unit 15 includes a cooling device 3 and a plurality of (32 pieces in this case) adjusting units 16.

The cooling device 3 is arranged above the die 2. The cooling device 3 includes an air ring 8 and a plurality of (20 valves in FIG. 3) valve devices 9 provided in the air ring 8 for adjusting the amount of cooling air blown from the air ring 8. The air ring 8 is a ring-shaped housing having an inner peripheral portion recessed downward. A ring-shaped outlet 8a opened on the upper side is formed on the inner peripheral portion of the air ring 8. The outlet 8a is particularly formed so as to be concentric with the ring-shaped slit 18.

A plurality of hose ports 8b are formed on the outer peripheral portion of the air ring 8 at equal intervals in the circumferential direction. A hose (not shown) is connected to each of the plurality of hose ports 8b, and cooling air is sent into the air ring 8 from a blower (not shown) via this hose. The cooling air sent into the air ring 8 is blown out from the air outlet 8a and blown onto the molten resin.

The plurality of valve devices 9 are arranged in the ventilation path between the air outlet 8a and the hose port 8b without any gap in the circumferential direction. By adjusting the opening degree of each of the plurality of valve devices 9, the air volume of the cooling air blown out from the air outlet 8a can be adjusted. For example, by making the opening degrees of all the valve devices 9 the same, the air volume of the cooling air blown out from the air outlet 8a can be made uniform in the circumferential direction. Further, for example, by setting the opening degree of at least one valve device 9 to be different from that of the other valve devices 9, the air volume of the cooling air blown out from the outlet 8a can be changed in the circumferential direction. When the thickness of the film varies, for example, the opening degree of the valve device 9 corresponding to the thin wall portion (for example, located below the thin wall thickness portion) is increased to increase the thickness of the thin wall portion. Increase the amount of air blown to the molten resin below. As a result, the uneven thickness of the film formed thereafter is reduced.

The plurality of adjusting units 16 are arranged so as to surround the upper end side of the outer peripheral member 14 with almost no gap in the circumferential direction. The adjusting unit 16 is particularly cantilevered and attached to the outer peripheral member 14. A cooling device 3 is fixed above the plurality of adjusting units 16. Each of the plurality of adjusting units 16 is configured to be able to apply a radial inward pressing load or a radial outward tensile load to the outer peripheral member 14. The outer peripheral member 14 is elastically deformed by applying a pressing load or a tensile load. Therefore, by adjusting the plurality of adjusting units 16, the width of the discharge port 18a can be partially adjusted in the circumferential direction, and the film thickness can be partially controlled in the circumferential direction. When the film thickness varies in the circumferential direction, for example, a tensile load is applied to the outer peripheral member 14 from the adjusting unit 16 corresponding to the thin portion (for example, located below the thin portion). The gap of the discharge port 18a below the thin portion is increased. As a result, the variation in film thickness is reduced.

As an example, as shown in FIG. 2, the adjustment unit 16 has an actuator 24 that is driven based on a control command from the control device 7, and a lever 34 that is supported with the rotation shaft 32 as a fulcrum and receives the rotational force of the actuator 24. And the actuating rod 36 supported by the outer peripheral member 14 so as to be displaceable in the axial direction and supported by the action point of the lever 34. Then, the rotational force of the lever 34 is converted into a force in the axial direction of the operating rod 36, the force in the axial direction becomes a load on the inner peripheral member 12 or the outer peripheral member 14, and the lever 34 becomes the operating rod 36 at the point of action of the lever 34. Gives power directly to.

FIG. 5 is a block diagram showing the functions and configurations of the control device 7. Each block shown here can be realized by elements such as the CPU of a computer or a mechanical device in terms of hardware, and can be realized by a computer program or the like in terms of software, but here, it is realized by their cooperation. The functional block is drawn. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by combining hardware and software.

The control device 7 communicates with the communication unit 40 that executes communication processing with the thickness measurement sensor according to various communication protocols, and the U / I unit 42 that receives operation input by the user and displays various screens on the display unit. A data processing unit 46 that executes various data processing based on the data acquired from the unit 40 and the U / I unit 42, a storage unit 48 that stores data referenced and updated by the data processing unit 46, and a storage unit 48. including.

The storage unit 48 includes an allowable film thickness storage unit 60, an actually measured film thickness storage unit 62, and a winding shape information storage unit 64. The permissible film thickness storage unit 60 stores a range of permissible film thickness. The actually measured film thickness storage unit 62 stores the film thickness at each position measured by the thickness measurement sensor 6 in association with each position in the circumferential direction of the film when it is in the shape of a tube, and the measurement time thereof. The winding shape information storage unit 64 stores the radius of the film roll body 11 at each position measured by the winding shape measuring sensor 22 and the measured time in association with each position of the film roll body 11 in the axial direction. do. The time when the acquisition unit 50, which will be described later, acquires the film thickness and the radius may be regarded as the respective measurement times.

The data processing unit 46 includes an acquisition unit 50, a determination unit 52, a determination unit 54, an operation control unit 56, and a notification unit 58. The acquisition unit 50 acquires the film thickness measured by the thickness measurement sensor 6.

The determination unit 52 determines whether or not there is an abnormality in the winding shape of the film roll body 11 based on the axial change of the radius of the film roll body 11 in a predetermined cycle, in other words, a hump or a dent in the film roll body 11. Is determined.

FIG. 6 is a diagram for explaining a process of determining whether or not the winding shape is abnormal by the determination unit 52. In FIG. 6, the horizontal axis represents the axial position of the film roll body 11, and the vertical axis represents the radius. That is, FIG. 6 shows the radial change of the radius of the film roll body 11 at each position in the axial direction, that is, the radius of the film roll body 11.

_{In the present embodiment, the determination unit 52 is in the range R i} from the axial i (i = 1, 2, ..., Nm (m is a constant that is a natural number)) position to the i + m position. _{When the difference between the maximum value R i} max and the minimum value R _i max of the radius of the film roll body is equal to or more than a predetermined difference threshold D, the range R _i has a hump or a dent, that is, there is an abnormality in the winding shape. Is determined.

The value to be set in m may be determined based on an experiment or the like. Even if there is a difference of the difference threshold D or more in the radius like the two axial positions surrounded by the dotted line, if the two axial positions are relatively far apart, the axial direction of the radius Since the change is gentle, it does not cause distortion of the film. If the value of m is too large, it will be determined as a hump or a dent even in such a case. Further, if the value of m is too small, it can be determined that there is an abnormality in the winding shape only when there is a hump or a dent in which the radius changes extremely rapidly in the axial direction. Therefore, the value to be set in m needs to be determined in consideration of these.

The notification unit 58 displays on the display unit that there is an abnormality in the winding shape together with the range determined to have a hump or a dent _{in the range R 1} , the range R ₂ , ..., The range R _nm. Or voice notification.

The determination unit 54 determines the load to be applied to the outer peripheral member 14 by each adjustment unit 16 and / or the opening degree of each valve device 9. In particular, the determination unit 54 is the film thickness measured by the thickness measuring sensor 6, and each adjusting unit is such that the film thickness at each position in the circumferential direction of the tubular film falls within the allowable film thickness range. 16 determines the load to be applied to the outer peripheral member 14 and / or the opening degree of each valve device 9.

The operation control unit 56 controls the operation of the film thickness adjusting unit 15, that is, the operation of the adjusting unit 16 and the valve device 9. Specifically, the operation control unit 56 transmits a control command to the adjustment unit 16 so as to apply the load determined by the determination unit 54 to the outer peripheral member 14, and controls indicating the opening degree determined by the determination unit 54. The command is transmitted to the valve device 9.

The operation of the film forming apparatus 1 configured as described above will be described.
The molten resin is extruded from the discharge port 18a of the die 2, and cooling air is blown from the cooling device 3 of the film thickness adjusting unit 15 to solidify the molten resin and form a film. During film forming, the thickness measurement sensor 6 measures the film thickness at each position in the circumferential direction of the tubular film at a predetermined cycle. Further, during film forming, the winding shape measurement sensor 22 measures the radius of each position in the axial direction of the film roll body 11 at a predetermined cycle. The control device 7 controls the film thickness adjusting unit 15 so that the film thickness measured by the thickness measuring sensor 6 falls within the allowable film thickness range. Further, the control device 7 further determines whether or not there is an abnormality in the wound shape of the film roll body 11, and if it is determined that there is an abnormality, notifies the user to that effect. Upon receiving this notification, the user manually adjusts the film thickness adjusting unit 15 so as to eliminate the abnormality of the winding shape, that is, to eliminate humps and dents.

Subsequently, the effect of the present embodiment will be described. According to the film forming apparatus 1 according to the present embodiment, it is determined whether or not there is an abnormality in the wound shape of the film roll body 11, that is, whether or not a hump or a dent is formed, so that the existence thereof can be grasped. As a result, it is possible to deal with the problem of the winding shape so as to eliminate the abnormality, and it is possible to form a film roll body having relatively few or small humps and dents.

Further, according to the film forming apparatus 1 according to the present embodiment, the winding shape measuring sensor 22 directly measures the information regarding the radius of the film roll body 11. Therefore, the information regarding the radius of the film roll body 11 can be measured with relatively high accuracy, and whether or not there is an abnormality in the winding shape can be determined with relatively high accuracy.

The configuration and operation of the film forming apparatus according to the embodiment have been described above. It will be appreciated by those skilled in the art that these embodiments are exemplary and that various modifications are possible in the combination of their respective components, and that such modifications are also within the scope of the present invention.

(Modification example 1)
FIG. 7 is a diagram showing a pick-up machine 5 of the film forming apparatus 1 and its surroundings according to a modified example. The pick-up machine 5 includes a pair of first pinch rolls 138, a pair of second pinch rolls 140, and first turn rolls 142 to fifth turn rolls 150. The first pinch roll 138 and the first turn roll 142 to the fifth turn roll 150 are configured to be able to reciprocate around a vertical axis. Since the configuration of such a take-up machine 5 is known, detailed description thereof will be omitted, but the film is twisted by the rotation of the first pinch roll 138 and the first turn roll 142 to the fifth turn roll 150, whereby the film is twisted. The position of the tubular film before being folded into the first pinch roll 138 in the circumferential direction and the position of the film to be stacked when the winder 20 winds the film are relatively gradually deviated and averaged, and the film is averaged. Reduces the occurrence of abnormalities in the winding shape of the film.

Also in this modification, it may be determined whether or not there is an abnormality in the wound shape of the film roll body 11 and the determination result may be notified in the same manner as in the embodiment. Then, upon receiving the notification of the determination result, the user may manually adjust the film thickness adjusting unit 15 so as to eliminate the abnormality of the winding shape. Further, the user eliminates the abnormality of the winding shape by changing the turning speed of at least one of the first pinch roll 138 and the first turn roll 142 to the fifth turn roll 150, or by shifting the turning timing. You may.

(Modification 2)
In the embodiment and the above-described modified example, the case where the winding shape measurement sensor 22 measures the information regarding the radius at each position in the axial direction of the film roll body 11 has been described. As a modification, information on the radius at each position in the axial direction of the film roll body 11 may be specified (estimated) based on the film thickness measured by the thickness measuring sensor 6. FIG. 8 is a block diagram showing the functions and configurations of the control device 7 of the film molding device 1 according to the modified example. FIG. 8 corresponds to FIG. In this modification, the data processing unit 46 further includes the specific unit 59. The specifying portion 59 specifies the radius at each axial position of the film roll body 11 based on the film thickness at the corresponding circumferential position in the tubular film before folding. More specifically, since the film roll body 11 is obtained by folding and winding a tube-shaped film, the radius of the film roll body 11 at each position in the axial direction corresponds to the tube-shaped film before being folded. It can be specified by integrating the film thicknesses of the two circumferential positions.

According to the film forming apparatus 1 according to this modification, the information regarding the radius of the film roll body 11 is specified based on the measured value of the thickness measuring sensor 6, so that the winding shape measuring sensor 22 becomes unnecessary. Therefore, the cost of the film forming apparatus 1 can be reduced.

(Modification example 3)
In the embodiment and the above-described modification, when the control device 7 determines that the film roll body 11 has a hump or a dent, the case where the control device 7 notifies the fact by display on the display unit or by voice has been described. As a modification, the control device 7 may automatically adjust the film thickness adjusting unit 15 so as to eliminate the hump or dent. In this case, the determination unit 54 further eliminates the abnormal state when the determination unit 52 determines that the winding shape of the film roll body 11 is abnormal, that is, the film roll body 11 has a hump or a dent. The load to be applied to the outer peripheral member 14 by each adjusting unit 16 and / or the opening degree of each valve device 9 is determined so as to eliminate the hump or dent when it is determined to be.

Specifically, determining unit 54, when it is determined that there is an abnormality in the winding shape of a range R _i, radius certain criteria for each position of the range R _i (i-th position, second i + m position) The load to be applied to the outer peripheral member 14 by each adjusting unit 16 and / or the opening degree of each valve device 9 is determined so as to approach the value. For example determining section 54, the range of the film thickness corresponding to where thicker than a reference value among the respective positions of R _i thinned within acceptable film thickness range, the film thickness corresponding to where thinner than the reference value The load to be applied to the outer peripheral member 14 by each adjusting unit 16 and / or the opening degree of each valve device 9 is determined so as to increase the thickness within the allowable film thickness range.

Reference value, measured by winding shape measurement sensor 22, even the maximum value of the radius of the measurement values of the position of the range R _i, even minimum, be an average value, an intermediate value It may be a variance value. If the average value, the intermediate value, or the variance value is used as the reference value, the abnormal winding shape can be eliminated relatively quickly. It should be noted that which of the maximum value, the minimum value, the average value, the intermediate value, and the variance value is used as the reference value may differ from time to time. Further, for example, _{when there is no abnormality in the winding shape of a nearby range such as the range R i + 1} and the range R _i-1 , the average value, the intermediate value, or the variance value of any one of the ranges may be used as a reference value. ..

(Modification example 4)
In the embodiment and the above-described modification, the case where the discharge port 18a of the die 2 is a so-called round die having an annular shape has been described, but the present invention is not limited to this. At least a part of the technical idea of the embodiment can be applied to a so-called T-die having a linear discharge port.

Any combination of the embodiments and modifications described above is also useful as an embodiment of the present invention. The new embodiments resulting from the combination have the effects of the combined embodiments and variants.

1 film forming device, 2 die, 6 thickness measurement sensor, 7 control device, 22 winding shape measurement sensor, 52 judgment unit.

Claims (6)

A film forming apparatus that extrudes molten resin from a die, solidifies it to form a film, and winds the formed film to form a film roll.
Equipped with a determination unit that determines whether or not there is an abnormality in the winding shape based on the change in the radius of the film roll body in the axial direction.
The film forming apparatus is characterized in that the determination unit determines that there is an abnormality in the wound shape when the difference between the maximum value and the minimum value of the radius of the film roll body in a predetermined range is equal to or more than a predetermined difference threshold value. .. The film forming apparatus according to claim 1 , further comprising a sensor for measuring information regarding the radius of the film roll body at each position in the axial direction. Extruding a molten resin into a tubular shape from a discharge port of the annular die, solidifying it by forming a tubular film, flat folding the tubular film that is formed, the tubular film is folded flat A film forming apparatus that winds up to form a film roll.
A sensor that measures the thickness of the film at each position in the circumferential direction,
Based on the film thickness at each position in the circumferential direction measured by the sensor, a specific portion that specifies information about the radius at each position in the axial direction of the film roll body, and a specific portion.
Film forming apparatus characterized by comprising: a determination unit for determining whether or not there is an abnormality in the winding shape on the basis of the radial axial change of the film roll. Extruding a molten resin into a tubular shape from a discharge port of the annular die, solidifying it by forming a tubular film, flat folding the tubular film that is formed, the tubular film is folded flat A film forming apparatus that winds up to form a film roll.
A sensor that measures the thickness of the film at each position in the circumferential direction,
Based on the film thickness at each position in the circumferential direction measured by the sensor, a specific portion that specifies information about the radius at each position in the axial direction of the film roll body, and a specific portion.
And whether the determination unit is abnormal winding shape on the basis of the radial axial change of the film roll, comprising a,
The specific portion is characterized in that information on the radius at each position in the axial direction of the film roll body is specified by integrating the film thicknesses at the two corresponding circumferential positions of the tubular film before folding. Film forming equipment. The film forming apparatus according to any one of claims 1 to 4, further comprising a notification unit for notifying the user when it is determined by the determination unit that there is an abnormality in the winding shape. A film thickness adjustment unit that adjusts the thickness of the film to be molded,
An operation control unit that controls the operation of the film thickness adjusting unit is provided.
The method according to any one of claims 1 to 4, wherein the motion control unit controls the film thickness adjusting unit so as to eliminate the abnormality when the determination unit determines that there is an abnormality in the winding shape. Film molding equipment.

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