JPH03286828A - Film thickness-regulating method and its device - Google Patents

Abstract

PURPOSE:To heighten the regulation-precision of film thickness by a method in which the aimed value-vector of film thickness-changing amount for correcting the film thickness is multiplied by an inverse matrix, thereby obtaining a vector, and a lip piece is displaced, based on the pattern of said vector. CONSTITUTION:When the gap interval of a section 5 is changed by displacing a lip piece 1b1, the film-thickness of said section 5 is reduced, but as its reaction, the film thicknesses of adjacent sections 4, 6, 7 an increased. Such relation is obtained as a matrix T. The inverse matrix T<-1> of said matrix T is preliminarily obtained, and is stored in a memory 9. On one hand, the aimed vector DELTAdref of the changing amount DELTAdji of the film thickness for correcting the film thickness of a film 2 is obtained on the basis of the thickness-signal from a film thickness-measurer 6. Next, the vector DELTAdref of said aimed value is multiplied by the inverse matrix T<-1>, and then the vector DELTAg which has as its element, the changing amount DELTAgj of the gap distance of each section is obtained, and the vector DELTAg is given to a gap distance-controlling device 11. The gap distance-controlling device 11 controls the gap distance (g) by replacing each lip piece 1b1 to the pattern of the vector DELTAg.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a film thickness adjustment method and apparatus for adjusting the film thickness of a film used in a film processing machine.

[Prior Art] Conventionally, as a film processing machine, extrusion dies are used to form a resin film so that the film thickness is uniform, and the extrusion dies are arranged in parallel to form a plurality of lips. It is known to have a movable lip mechanism in which the gap spacing can be varied by displacing the pieces specifically.

In a film thickness adjusting device for adjusting the film thickness in this type of film processing machine, the gap interval is controlled by displacing a lip piece corresponding to a region where the film thickness is desired to be changed.

[Problems to be Solved by the Invention] However, in the conventional film thickness adjusting device, only the lip piece corresponding to the area where the film thickness is to be changed is changed, but the influence of the change in resin flow rate is Therefore, there is a problem in that it is difficult to adjust the film thickness because the film thickness changes even in areas where it is not necessary to change the film thickness.

An object of the present invention is to provide a film thickness adjustment method and device that can improve the accuracy of adjusting the film thickness.

[Means for Solving the Three Problems] According to the present invention, an extrusion die equipped with a movable lip mechanism that can change the gap interval by specifically displacing a plurality of lip pieces arranged in parallel is used. In a film thickness adjustment method used in a film processing machine that molds a resin film.

The inverse of a matrix T showing the relationship between the gap interval change Δgj in the gap region j corresponding to the lip j by displacing the lip j of the extrusion die and the resulting film thickness change Δdij in the region i. The film thickness is determined by determining the matrix T-1, measuring the film thickness by scanning the film thickness measuring means in the width direction of the film, and correcting the film thickness based on the film thickness signal which is the measured value. A target value vector Δdij1 of the amount of change is obtained, and this target value vector Δd, el
is multiplied by the inverse matrix T-1 to obtain the gap interval change amount Δ
A method for adjusting the film thickness 2I is obtained, which is characterized by determining a vector Δg having g as an element, and controlling the gap interval by displacing the lip piece based on the pattern of this vector Δg.

Further, according to the present invention, a film processing method in which a resin film is formed using an extrusion die equipped with a movable lip mechanism that can change the gap interval by specifically displacing a plurality of lip pieces arranged in parallel. In the film thickness adjusting device used in the machine, the lip piece j of the extrusion die
A matrix T showing the relationship between the amount of change in gap distance Δgj in region j of the gap corresponding to lip piece j by displacing , and the amount of change in film thickness Δdij in region i caused by this.
a storage means for storing an inverse matrix T-1 of the film; a film thickness measuring means for scanning in the width direction of the film to measure the film thickness of the film and outputting a film thickness signal; A target value vector Δd2 for the film thickness change amount for correcting the film thickness. a film thickness correction eye #l value calculation means for calculating the target value vector Δd tar and the inverse matrix T-
gap interval target value calculation means for calculating a vector Δg whose element is the gap interval change amount Δgj by multiplying by ';
There is obtained a film thickness adjusting device characterized in that it includes a gap interval control means for controlling the gap interval by displacing the lip piece based on the pattern of the vector Δg.

[Function] In the present invention, an inverse matrix of a matrix T showing the relationship between the gap distance change amount Δgj in the region j and the resulting film thickness change amount Δdij in the region i when the lip piece j of the extrusion die is displaced. T-1 is obtained, and vector Δg is obtained by multiplying the target value vector Δd r *+ of the film thickness change amount for correcting the film thickness by the inverse matrix T-1, and based on the pattern of this vector Δg. to displace the lip piece.

[Example] Next, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an outline of an embodiment of the present invention.

In FIG. 1, reference numeral 1 indicates an extrusion die. A resin film 2 is extruded from the gap G of the extrusion die 1. This film 2 is cooled and solidified by the cooling roller 3, guided by a guide roller 45, and wound up by a winding device (not shown).

A film thickness gauge 6 is placed on the film 2. As shown in FIG.
7 in the longitudinal direction of the film 2 (i.e. running direction a)
is scanned back and forth in a direction perpendicular to

The film thickness signal from the film thickness gauge 6 and the scanning position signal from the scanning device 7 indicating the position of the film thickness gauge 6.

At the same time, it is applied to the storage section 9 of the microcomputer 8. Based on the information in the storage section 9 of the microcomputer 8, the calculation section 10 calculates the amount of change in the gap distance of the extrusion die 1, and provides the amount of change in the gap distance to the gap distance control device 11. This gap interval control device 11 controls the position of each lip piece 1bl of the extrusion die 1.

FIG. 3 shows one embodiment of the extrusion die 1, which will be described below.

The extrusion die 1 has a gap G for extruding the resin.
It has lips la and lb forming a. The distance between the gaps G is g. One lip 1a is formed so that it can only be displaced. The other lip 1b consists of a plurality of lip pieces lbl arranged in parallel in the longitudinal direction X of the gap G. 1 bl of these lip pieces
has a thin elastic part 1b2 at the base and a flexible piece 1b3 at the projecting part. These flexible pieces 1b3 are formed at a predetermined distance from the die body. Several FM bellows ICs are arranged between these flexible pieces 1b3 and the die body.

When the compressed gas pressure supplied to the bellows IC is changed, the pressing force against the flexible piece 1b3 changes.

Lip piece 1. The elastic portion 1b2 of b1 is deformed and the position of the lip piece 1bl changes. multiple bellows]C,
Since the compressed gas pressure supplied to each lip piece can be changed separately, the position of each lip piece 1b1 can be changed independently from that of the other lip pieces. When the position of each lip piece 1b1 changes, the gear spacing g between them and the opposing lip 1a
changes. The compressed gas pressure supplied to the bellows 1c is controlled by a gap interval control device 11.

Note that the movable lip mechanism for displacing the lip piece 1bl is not limited to the embodiment shown in FIG.

Next, the calculation of the calculation section 10 in the microcomputer 8 will be explained.

As shown in FIG. 4(A), the lip piece 1b1 is displaced to reach the area f! When the gap interval g of 55 is changed, the fourth
As shown in Figure (B) I, the film thickness in the region 5 decreases or
As a reaction, the film thickness of the adjacent region 34.6.7 increases.

Therefore, such a relationship is determined as a matrix T.

The amount of gap interval displacement in area j with gap G is Δgj
The amount of film thickness change in region i caused by this is Δd
When ijI, one matrix T is expressed by the following formula.

...-(1) Obtain the inverse matrix T-1 of this matrix T in advance and store it in the storage section 9 (this J
Let me remember it myself.

On the other hand, based on the film tv signal from the film thickness meter 6, a target value vector Δdij0. seek. This target value vector Δd7. is expressed by the following formula.

Δd 0, = (Δd lr*l+ ”'* Δd lr*l+
"・, Δd a+*l)... (2) This target value vector Δd rel is 1, for example, the total width average value which is the average value of the film thickness signal in one scan of the film thickness meter 6, and The partial width average value, which is the l! film thickness signal average value, for each corresponding region is calculated, the deviation between these full width average values and the partial width average value is calculated, and the difference between each region is calculated based on these deviations. It is obtained by determining the amount of film thickness change Δdij for each i.

Next, this target value vector Δdij. ．． and the inverse matrix T
Multiply by −I to obtain the gap interval change amount Δgj for each region.
Find a vector Δg whose elements are Δg.

This vector Δg is expressed by the following equation.

Δg−(Δgj+ ..., Δgj+ ...Δgo)
(3) Provide information on this vector Δg to the gap interval control device 11. This gap interval control device 11 controls the gap interval g by displacing each lip piece 1bl in a pattern of vector Δg.

[Effects of the Invention] According to the present invention, it is possible to not only displace the lip piece corresponding to the area where the film thickness is desired to be changed, but also to displace the lip piece corresponding to the area affected by the change in resin flow caused by the displacement of the lip piece. Since the position of the film is also controlled, the accuracy of adjusting the film thickness can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an outline of an embodiment of the present invention. Fig. 2 is a diagram showing the relationship between the film thickness gauge and the film in the embodiment of Fig. 1, Fig. 3 is a partially cutaway perspective view showing the extrusion die in the embodiment of Fig. 1, and Fig. 4 is the diagram of Fig. 1. It is a figure for explaining the relationship between the amount of change in the gap interval of the extrusion die and the amount of change in film thickness caused by this in the example. 1... Extrusion die, la, lb... lip, 1b1
...Lip piece, 2...Film, 6...Film thickness gauge,
8...Microcomputer, 9...Storage unit, 10
...Arithmetic section.

Claims (2)

[Claims] (1) A film used in a film processing machine that forms a resin film using an extrusion die equipped with a movable lip mechanism that can change the gap distance by specifically displacing multiple lip pieces arranged in parallel. In the thickness adjustment method, the relationship between the gap distance change amount Δg_j in the region j of the gap corresponding to the lip piece j by displacing the lip piece j of the extrusion die and the film thickness change amount Δd_i_j in the region i caused by this is as follows. The inverse matrix T of the matrix T shown
^-^1 is calculated, the film thickness is measured by scanning the film thickness measuring means in the width direction of the film, and the film thickness is corrected based on the film thickness signal which is this measurement value. A target value vector Δd_r_e_f of the amount of change is determined, and this target value vector ΔdR_r_e_f and the inverse matrix T^-^
A film thickness adjustment method characterized by multiplying by 1 to obtain a vector Δg whose element is the amount of change in gap interval Δg_j, and controlling the gap interval by displacing a lip piece based on the pattern of this vector Δg. . (2) A film used in a film processing machine that forms a resin film using an extrusion die equipped with a movable lip mechanism that can change the gap distance by specifically displacing multiple lip pieces arranged in parallel. In the thickness adjustment device, the relationship between the gap distance change amount Δg_j in the region j of the gap corresponding to the lip piece j by displacing the lip piece j of the extrusion die and the film thickness change amount Δd_i_j in the region i caused by this is as follows. The inverse matrix T of the matrix T shown
^-^1; a film thickness measuring means that scans in the width direction of the film to measure the film thickness of the film and outputs a film thickness signal; Target value vector Δ of film thickness change amount for correcting film thickness
A film thickness correction target value calculation means for calculating d_r_e_f, the target value vector Δd_r_e_f and the inverse matrix T^-
Gap spacing target value calculation means for calculating a vector Δg having the gap spacing change amount Δg_j as an element by multiplying by ^1; and gap spacing control for controlling the gap spacing by displacing the lip piece based on the pattern of the vector Δg. A film thickness adjusting device characterized by comprising: means.