JP3369910B2 - Automatic thickness control method for resin film using T-die - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a resin laminated film or a resin film using a T-die.
The present invention relates to a method for preventing uneven thickness of a resin film. [0002] A resin laminated film in which a resin film is coated on a base material such as paper, aluminum foil, or plastic by a T-die, or a resin film manufactured by a T-die, is wound up with these films. In some cases, a streak-like appearance may appear due to local uneven wall thickness, and a technology for forming a flat roll is required. Conventionally, the amount of molten resin flowing out of a T-die is
It has been adjusted by manually rotating a gap adjusting bolt provided on the lip portion. However, since this adjustment requires a great deal of experience, the need for an automatic thickness deviation control T-die has increased in end users. Further, the entire extruder connected to the T-die is installed on a movable carriage, and the carriage is advanced and retreated a small amount in a direction perpendicular to the film unwinding direction, so that uneven thickness is uniformly formed on the entire film. On the contrary, there is a method in which a film feeding device is installed on a movable cart and the cart is slightly moved at right angles to the film feeding direction (referred to as an EPC device). However, the method of finely moving these extruders or feeding devices requires the addition of a large-scale structure for rocking the entire device,
Further, the ear loss of the film was increased, and it was difficult to make the entire film width uniform. [0005] Today, there is an increasing need for a film thickness control system from the viewpoint of improving the processing quality of a resin laminate film or a resin film, saving resin, saving manpower, and saving energy. In order to realize the control system, a T-die (die) capable of controlling the flow rate of the resin melted by the extruder is required. At present, the proposed uneven thickness control T-die employs a heat bolt method, that is, a thermal expansion is generated by heating and cooling a gap adjusting bolt, and the expansion is utilized to reduce a gap at a resin outflow portion. There is a method of adjusting. Further, there is a servo motor method, that is, a method of sequentially rotating the gap adjusting bolts using a servo motor. However, the above-mentioned heat bolt method has disadvantages such as a long time required for heating and cooling, poor response, and an adverse effect on the viscosity of the molten resin due to heating and cooling of the gap adjusting bolt. Further, in the above-mentioned servo motor system, it is impossible to drive all the gap adjustment bolts at the same time, so that there is a problem that the adjustment time becomes long and processing accuracy such as backlash of the bolts is deteriorated when adjusting the bolts. is there. As a solution to the problems of the above-mentioned method, the present applicant has already proposed an air lever method capable of adjusting the gap with good responsiveness, at high speed, and with high accuracy (Japanese Patent Application Laid-Open No. H05-1993). 286015). FIG.
1 is a perspective view of an air lever type extrusion die T for lamination. In FIG. 1, the T-die is roughly divided into two parts, that is, a T-die main body 1 having an actuator 4 for driving a flexible lip portion 3 and a T-die main body 2 having a fixed lip 5. The T-die body 1 is
The actuator 4 is provided for each of a plurality of zones in the width direction. Compressed air is individually supplied to the bellows 6 of the actuator 4 for each zone to expand the bellows 6, and the lever 7 is rotated via the hinge 8, and the lever 7 is rotated.
The gap of the molten resin outflow gap Δ flowing down the flexible lip portion 3 from the manifold 19 strongly by the push bolt 9 attached to the lower part of
Finally, the flow rate of the resin is controlled. [0009] In the conventional T-die for extrusion lamination having the air lever type uneven thickness control means, the film thickness can be controlled with good responsiveness and high accuracy, but the manufacturing conditions are limited. It was necessary to set the operating conditions of each actuator every time it changed, and it was necessary to constantly monitor minute changes in the resin film thickness even in the same lot and fine-tune the settings of each actuator. Therefore, according to the present invention, a resin laminated film or a resin film having a uniform film thickness can be manufactured using an air lever type uneven thickness control T-die, and the operating conditions of each actuator can be set by a simple method. It is an object of the present invention to provide a method for automatically controlling the thickness deviation of a resin film. In order to solve the above-mentioned problems, a method for automatically controlling the thickness deviation of a resin film using a T-die according to the present invention is provided on a side portion of a T-die main body 1 in a width direction. Actuators 4 are arranged side by side, and the actuator 4 is
The part is fixed to the bellows 6 and the lower part is a hinge block and a pivot.
And a lever 7 pivoted to the lower part of the T-die body 1 by
And a push bolt 9 provided at the lower part of the pivot below the pivot.
To supply compressed air to each actuator 4.
By feeding, the bellows 6 expands and the lever 7
Rotated around the pivot, provided at the lower end of lever 7
Connect the tip of the push bolt 9 to the flexible
Shibururippu portion contacting 3 two points, changing the molten resin outlet clearance of the flexible lip portion 3, over time waves extrusion width direction at a constant cycle said change is you characterized in that remembering to move. Since the present invention is configured as described above,
When laminating a molten plastic resin in the form of a film extruded from a T-die onto paper or a film (substrate), or when obtaining a resin film, the thickness of the resin is changed at a certain position over time at a constant period. Further, by moving the film alternately in the width direction at a constant cycle, uneven thickness can be continuously and uniformly distributed, and the obtained film has a uniform film thickness as a whole. FIG. 1 is a perspective view of an air lever type T-die for extrusion lamination that can be used in the automatic thickness deviation control method of the present invention. In FIG. 1, the T-die is roughly divided into two parts, that is, a T-die main body 1 having an actuator 4 for driving a flexible lip portion 3 and a T-die main body 2 having a fixed lip 5. The T-die main body 1 is provided with actuators 4 for each of a plurality of zones in the width direction. FIG. 2 shows a cross section of the T-die for extrusion lamination of FIG. 1 cut in the thickness direction of the film. 1 and 2
The T die for extrusion lamination used in the present invention will be described based on the following. Each bellows 6 is fixed to each lever 7 with a bolt 11. A seal member 12 a or 12 b is provided at a fixing portion by the bolt 10 and the bolt 11 to prevent leakage of compressed air from inside the bellows 6. In the example of FIG. 1, eight levers 7 are arranged in the width direction, and two upper and lower bellows 6 are provided for each.
The lower part of the lever 7 is a narrow hanging part 7a, on which a push bolt 9 having a spherical end is attached so as to be adjustable in the amount of protrusion with a lock nut 13, and the distal end makes point contact with the flexible lip 3. ing. Reference numeral 14 denotes a pivot of the lever 7, which is pivotally connected to the lever 7 via a bush 14a. The actuator 4 including the bellows 6, the lever 7, and the push bolt 9 is usually used for the T-die main body 1.
It is common that 20 to 30 units are mounted in the width direction. The hinge block 8a is attached to the lower part of the T-die main body 1 by a bolt 15, and the hinge 8 is constituted by the hinge block 8a and the pivot 14. Reference numeral 16 denotes an air supply port formed in the T-die main body 1 and communicates from the air passage 17 into the bellows 6. The air passage 17 further extends from the inside of the bellows 6 to the lever 7, communicates with the air passage 18, and communicates with the lower bellows 6. The air supply port 16 is provided with an air tube 20 for introducing compressed air. The T for extrusion lamination used in the present invention described above.
When the compressed air is supplied to each bellows 6 from the air supply port 16 through the air tube 20, the operation of the die is started.
A force is generated between the actuator and the actuator 4 in the axial direction of the bellows 6. By this force, the lever 7 fixed to the bellows 6 is pushed outward and pivots about the pivot 14 of the hinge 8. Then, the tip of the push bolt 9 is pushed inward, so that the flexible lip portion 3 is pushed,
The clearance Δ of the resin flowing out of the manifold 19 from the molten resin is adjusted. The uneven thickness automatic control diagram 3-5, an actuator plurality disposed on the side of the T die body, for example, in the case of 31 Konami設No. 1
31 shows the distribution of the air pressure applied to the levers No. to No. 31. FIG. 3 shows an initial pattern in which the pressure applied to each lever by compressed air is the same. FIG. 4 shows an example of a pressure application pattern according to the automatic thickness deviation control method of the present invention. The pressure applied to each lever is changed with time at a constant cycle and amplitude in the order of the lever number. Such a pressure application pattern is changed so that the wave moves as shown in FIG. 5 with the lapse of time, and by repeatedly performing the pressure application pattern, the gap Δ of the molten resin outflow of the flexible lip portion is reduced. As a result, the thickness of the resin laminate film and the thickness of the resin film to be manufactured become uniform throughout the film. According to the method for automatically controlling the thickness of a resin film using a T-die according to the present invention, the pressure of compressed air supplied to each actuator of the T-die is varied in the extrusion width direction. The change is oscillated in the extrusion width direction at regular intervals over time.
Is changed so as to move, so that even if the thickness of the resin film is uneven, the thickness of the entire resin film is uniform. The method for automatically controlling the thickness deviation of a resin film by the T-die according to the present invention is different from the conventional method for automatically controlling the thickness deviation of a resin film by rocking the extruder itself by a small amount or by rocking a film feeding device. This eliminates the need for a large-scale swinging device, minimizes the ear loss of the entire film, and can evenly prevent uneven thickness of the resin film over the entire film.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a T-die for extrusion lamination of an air lever type. FIG. 2 is a cross-sectional view of the T-die for extrusion lamination of FIG. 1 cut in a thickness direction of a film. FIG. 3 is a diagram showing an example in which a plurality of actuators provided on a side portion of a T-die main body, for example, 31 actuators are arranged in parallel. 1-3
7 shows an initial pattern of a distribution of air pressure applied to one lever. FIG. 4 shows an example of a pressure application pattern according to the automatic thickness deviation control method of the present invention. FIG. 5 shows a pressure application pattern when the pressure application pattern of FIG. 4 is changed so that a wave moves with time. [Description of Signs] 1, 2 T die body 3 Flexible lip portion 4 Actuator 5 Fixed lip 6 Bellows 7 Lever 7a Hanging portion 8 Hinge 8a Hinge block 9 Push bolt 10, 11 Bolt 12a, 12b Seal material 13 Lock nut 14 Axis 14a Bush 15 Bolt 16 Air supply port 17, 18 Air passage 19 Manifold 20 Air tube

Claims (1)

(57) [Claims 1] A plurality of actuators are juxtaposed in the width direction on the side of a T-die main body, and the actuator has
The lower part is fixed to the rose by the hinge block and the pivot.
Lever that is pivotally supported at the lower part of the T-die body, and from the pivot
A push bolt provided at a lower pivot portion for supplying compressed air to each of the actuators;
The bellows expands to move the lever around the pivot.
And push the bolt
Point the tip to the flexible lip at the bottom of the T-die body
The thickness of the resin film by the T-die, wherein the gap of the molten resin flowing out of the flexible lip portion is changed, and the change is caused to move in the extrusion width direction at a constant period with time. Automatic control method.