CN113492087B - extrusion method - Google Patents

Abstract

The present invention provides an extrusion method, which is an extrusion method using a die formed with a slit for ejecting a fluid, wherein the extrusion method is performed in order to adjust the thickness of the ejected material ejected from the slit An adjustment step for adjusting the height of the slit is provided, and the adjustment step includes the step of calculating arbitrary positions 1 to 1 in a direction perpendicular to the flow direction of the ejected material using a predetermined formula (1). Thickness d _2n at position n in N so that calculated thickness d ₂ ={d ₂₁ ...d _2N } and target thickness d _ref ={d _ref1 .. The height of the gap is determined in such a way that the difference e={e ₁ ... e _N } between .d _refN } becomes smaller.

Description

Extrusion method

Technical Field

The present invention relates to an extrusion method.

Background Art

Conventionally, dies having slits for ejecting fluids are used to manufacture various products. For example, a coating device called a coater equipped with such a die is used to form a coating film on the surface of a film or the like. In addition, a die called a T-die for extruding a molten resin in a film shape is used to manufacture a film.

The manufacturing method using the die head includes a step for adjusting the thickness of the ejected material ejected from the slit to a desired value. For example, Patent Document 1 describes a manufacturing method including an adjustment step for adjusting the height of the slit so as to adjust the thickness of the ejected material ejected from the slit.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2006-346649

Summary of the invention

Problem that the invention aims to solve

However, in the past, the adjustment of the thickness of the ejected material depended on the intuition of the operator, and there was a problem that it was difficult to adjust the ejected material to a desired thickness. Specifically, there was a problem that when the height of the slit at a position corresponding to the thickness of a part of the ejected material was adjusted in order to change the thickness of the part to a desired value, the thickness at other positions of the slit also changed. In other words, there was a problem that even if the thickness of a part of the ejected material was adjusted to a desired thickness, the thickness of other parts that did not need to be changed also changed.

Furthermore, in the extrusion method using the die head, the thickness of the ejected product must not only be uniform but also may vary locally, and in this case, there is also a problem of adjusting the thickness.

In view of the above problems, an object of the present invention is to provide an extrusion method capable of adjusting the thickness of a discharged material relatively easily and with high accuracy.

Solutions for solving problems

The present inventors have conducted intensive studies and found that the amount of change in the slit height and the amount of change in the thickness of the ejected matter before and after the slit height is adjusted are in a proportional relationship, thereby completing the present invention.

The present invention provides an extrusion method using a die head having a slit for ejecting a fluid material, wherein the extrusion method comprises an adjustment step of adjusting the height of the slit in order to adjust the thickness of the ejected material ejected from the slit, the adjustment step comprising the step of calculating a thickness _d2n at a position n among any positions 1 to N in a direction perpendicular to the flow direction of the ejected material using the following formula (1), and determining the height of the slit in such a way that a difference e={ _e1 ... _eN } between a calculated thickness _d2 ={ _d21 ... _d2N } calculated using the following formula (2) and a target thickness _dref ={ _dref1 ... _drefN } becomes smaller.

【Mathematical formula 1】

d _2n : The calculated thickness of the ejecta after adjustment d ₂ = the value at position n in {d ₂₁ .. d _2N }

_d2ave : average value of _d2 = { _d21 ... _d2N }

K _n : proportionality constant K = the value at position n in {K ₁ ...K _N }

h _2n : the hypothetical adjusted height of the gap h ₂ = the value at position n in {h ₂₁ ..h _2N }

_h2ave : _h2 = average value of { _h21 ... _h2N }

h _0n : the height of the gap before adjustment h ₀ = the value at position n in {h ₀₁ ..h _0N }

_h0ave : _h0 = average value of { _h01 ... _h0N }

d _0n : The thickness of the ejected material before adjustment d ₀ = the value at position n in {d ₀₁ .. d _0N }

_d0ave : _d0 = average value of { _d01 ... _d0N }

【Mathematical formula 2】

e _n =(d _refn -d _2n )…(2)

e _n : the value at position n in the difference e = {e ₁ ...e _N }

d _refn : target value of the ejected material thickness d _ref = the value at position n in {d _ref1 ...d _refN }

With this structure, if the height _h0 of the gap before adjustment, the thickness _d0 of the ejected material before adjustment, and the value of the proportional constant K are known, the height of the gap can be determined based on the difference e between the calculated thickness _d2 calculated by equation (1) and the target value _dref of the thickness, thereby making it possible to adjust the thickness of the ejected material relatively easily and with good accuracy.

In the extrusion method of the present invention, it is preferred that h ₂ ={h ₂₁ ...h 2N } which minimizes the total value of the squares of the differences e ={e ₁ ...e _N } represented by the following formula ( ₃ ) is obtained, and the height of the slit is determined based on h ₂ .

【Mathematical formula 3】

According to this configuration, the height of the slit is determined based on _h2 which minimizes the total value of the squares of the differences e represented by equation (3), so that the thickness of the ejected material can be adjusted with greater accuracy.

Effects of the Invention

As described above, according to the present invention, it is possible to provide an extrusion method capable of adjusting the thickness of a discharged material relatively easily and with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a die head used in an extrusion method according to one embodiment.

FIG. 2 is an exploded perspective view of the die head of FIG. 1 .

FIG. 3 is a schematic cross-sectional view of the die head taken along line III-III of FIG. 1 .

4 is a graph for comparing changes in the height of the slit and the thickness of the coating film before and after adjustment in Example 1. FIG.

5 is a graph for comparing changes in the height of the slit and the thickness of the coating film before and after adjustment in Example 2. FIG.

FIG. 6 is a graph for comparing changes in the thickness of the coating film before and after adjustment in Comparative Example 1. FIG.

7 is a graph for comparing changes in the height of the slit and the thickness of the coating film before and after adjustment in Example 3. FIG.

Description of Reference Numerals

1. Coater; 10. Die head; 11. Gap; 110. Opening; 13. Spouting part; 20. First module; 21. Passage; 22. Chamber; 30. Second module; 40. Gasket member; 42. Opening; 50. Adjustment mechanism; 51. Slit; 52. Adjustment screw; 521. External screw; 522. Internal screw.

DETAILED DESCRIPTION

Hereinafter, an extrusion method according to an embodiment of the present invention will be described with reference to the drawings.

The extrusion method of this embodiment is as follows: a coating device called a coater 1 as shown in Figures 1 to 3 is used to coat a coating liquid as a fluid on the surface of a coated object such as a film F to form a coating film as a sprayed object, and the coating film is formed on the surface of the film F.

The coating machine 1 is provided with a die head 10 having a slit 11 for ejecting a coating liquid. The die head 10 is configured to form a coating film on the surface of the film F by applying the coating liquid ejected from the slit 11 on a coated object such as a film F, and the film F is supported by a roller member and moves in a manner close to the opening 110 of the slit 11. The die head 10 is formed so that the ejection portion 13 having the opening 110 of the slit 11 protrudes toward the coated object such as the film F. In the present embodiment, the die head 10 has a first module 20 (a module on the lower side in the figure) and a second module 30 (a module on the upper side in the figure), and a slit 11 is formed between each module. In addition, hereinafter, the direction in which the film F or the coating film flows is sometimes referred to as MD, and the direction orthogonal to MD is referred to as TD. In addition, the height of the opening 110 of the slit 11 is referred to as the height h of the slit 11.

Furthermore, the die head 10 of the present embodiment has an adjustment mechanism 50 for adjusting the height h of the slit 11 on the second module 30 side. In the present embodiment, the adjustment mechanism 50 has: a slit 51, which is arranged on the second module 30 along the width direction of the slit 11; and a plurality of adjustment screws 52, which adjust the interval of the slit 51 to adjust the height h of the slit 11. The plurality of adjustment screws 52 are arranged along the extension direction of the slit 51 (in other words, along the width direction of the slit 11). By rotating each adjustment screw 52 to move forward or backward, the interval of the slit 51 is expanded or reduced, and the height h of the slit 11 is expanded or reduced accordingly.

As the adjustment screw 52, for example, a differential screw 52 can be preferably used. Thus, it is easy to finely adjust the height h of the slit 11. The differential screw 52 includes an outer screw 521 formed to be hollow and an inner screw 522 formed to be coupled to the inner thread of the outer screw 521. In addition, the outer screw 521 and the inner screw 522 are formed to have different pitch sizes. Thus, if the outer screw 521 is rotated one circle, the slit 51 is enlarged or reduced by the amount of the pitch difference between the outer screw 521 and the inner screw 522.

As shown in Fig. 2, in the present embodiment, the die head 10 has a plate-like spacer member 40, which is arranged to be sandwiched between the first module 20 and the second module 30. The spacer member 40 is formed in a C-shape so as to open toward the opening 110 of the slit 11. By adjusting the width of the opening 42 of the spacer member 40 of the die head 10, the width of the coating film can be adjusted.

The slit 11 is configured so that the height h can be adjusted to 0.01 mm to 5 mm in general. Also, the width of the slit 11 is generally set to 200 mm to 5000 mm.

The number of the adjusting screws 52 is usually 3 to 90. In addition, the distance between the centers of the rotation axes of the adjusting screws 52 is usually set to 10 mm to 400 mm. The distances between the centers of the rotation axes are preferably equal to each other, but can also be different from each other. In the present embodiment, the adjusting mechanism 50 has N adjusting screws 52. In addition, hereinafter, the position of the gap 11 and the position of the coating film corresponding to 1 to N adjusting screws 52 are set as position 1 to position N.

As shown in FIG3 , the first module 20 has a chamber 22 for temporarily storing the coating liquid supplied from a container (not shown) for storing the coating liquid via a passage 21 . The chamber 22 is formed in a concave shape and is connected to the slit 11 .

At least the second module 30 of the first module 20 and the second module 30 may be made of a material that can be elastically deformed by the pressing force of the adjustment screw 52 or the like. Usually, the first module 20 and the second module 30 are made of metal such as stainless steel. In addition, the spacer member 40 is usually made of a metal foil such as stainless steel or brass or a plastic film such as polyethylene terephthalate.

As the coating liquid, for example, a polymer solution is cited. The viscosity of the coating liquid is usually set to 0.0005Pa·s to 200Pa·s, preferably set to 0.001Pa·s to 100Pa·s. In addition, the viscosity is measured by a rheometer (manufactured by HAAKE). In addition, the measurement conditions are a shear rate of 1 [1/s] and a temperature of 20°C.

Next, the extrusion method of this embodiment will be described in detail.

The extrusion method of the present embodiment is a coating method using a coating machine 1 for forming a coating film on the surface of a coated object such as a film F. In order to adjust the thickness d of the coating film formed on the surface of the film F by ejecting the coating liquid from the slit 11, the coating method includes an adjustment step P for adjusting the height h of the slit 11 and an extrusion step for extruding the coating liquid after the adjustment step P. In addition, in the present embodiment, the flow rate of the coating liquid supplied from the storage part of the coating machine 1 is made constant.

In the present embodiment, the flow rate of the coating liquid preferably refers to the mass flow rate. In addition, the flow rate of the coating liquid being constant includes the case where the value calculated as [maximum flow rate - minimum flow rate]/average flow rate is 0.2 or less, preferably 0.1 or less during stable operation.

The adjustment step P includes: a data acquisition step P1 in which the heights _h0 = { _{h01 ... h0N} of the slit 11 at positions 1 to N before adjustment and the thicknesses d0 = {d01 ... d0N }} of the coating film at positions 1 to N before adjustment, and the heights h1 = { _h11 ... _h1N } of the slit 11 at positions 1 to N after arbitrary adjustment and the thicknesses _d1 = { _d11 ... _d1N } of the coating film at positions 1 to _N after arbitrary adjustment are measured; a constant calculation step P2 in which a proportionality constant K correlating a change in the height h of the slit ₁₁ and a change in the thickness d of the coating film are determined based on the data obtained in the data acquisition step P1; and a height determination step P3 in which the thickness _d2n of the coating film at position n among positions 1 to N is calculated by the following formula (1): The height h of the slit 11 is determined so that the difference e = {e ₁ ... e _N } between the calculated thickness d ₂ = {d ₂₁ ... d _2N } calculated by the following formula (2) and the target thickness value d _ref = {d _ref1 ... d _refN } becomes small.

【Mathematical formula 4】

【Mathematical formula 5】

e _n =(d _refn -d _2n )…(2)

[Data acquisition process P1]

In the data acquisition step P1, the flow rate of the coating liquid supplied from the storage unit of the coater 1 is set to be constant, and the thickness d of the coating film is measured before and after the height h of the slit 11 is arbitrarily adjusted. That is, the height h ₀ ={h ₀₁ ...h _0N } of the slit 11 at positions 1 to N before the arbitrary adjustment and the thickness d ₀ ={d ₀₁ ...d _0N } of the coating film at positions 1 to N before the arbitrary adjustment, and the height h ₁ ={h ₁₁ ...h _1N } of the slit 11 at positions 1 to N after the arbitrary adjustment and the thickness d ₁ ={d ₁₁ ...d _1N } at positions 1 to N after the arbitrary adjustment are measured.

The measured values of the height h of the slit 11 at positions 1 to N can be the measured values of the height of the portion corresponding to the adjustment screw 52. That is, the height h of the slit 11 at the same position as the adjustment screw 52 in the TD direction is used as the measured value.

The measured values of the coating film thickness d at positions 1 to N can be the coating film thickness d at the same position in the TD direction as the adjustment screw 52. The coating film thickness d is measured, for example, by a linear gauge (manufactured by Ozaki Seisakusho).

In the data acquisition step P1, the average value _h0ave of _h0 ={ _h01 ... _h0N }, the average value _d0ave of _d0 ={ _d01 ... _d0N }, and the average value _h1ave of _h1 ={ _h11 ... _h1N } and the average value _d1ave of _d1 ={ _d11 ... _d1N } are calculated. In the present embodiment, since the flow rate of the coating liquid is constant, it can be regarded as _d0ave = _d1ave . In this case, only one of _d0ave and _d1ave needs to be calculated.

[Constant calculation step P2]

In the constant calculation step P2, the proportional constant K is calculated using the data acquired in the data acquisition step P1 and the following formula (4) indicating the proportional relationship between the change in the height h of the slit 11 at the position n and the change in the thickness d of the coating film. More specifically, the calculated coating film thickness d _1cal = {d _1cal1 ... d _1calN } at the positions 1 to N is calculated using the following formula (4), and the proportional _constant K = {K 1 ... _{K N} } at the positions 1 to N is calculated so that the difference e ₁ = {e ₁₁ ... e _1N } between d _1cal = {d _1cal1 ... d _1calN } and d 1 = {d ₁₁ ... d _1N } calculated by the following formula ( ₅ ) becomes smaller. The proportional constant K is a constant that is substituted into the formula (1) and used in the following height determination step P3.

【Mathematical formula 6】

【Mathematical formula 7】

e _1n = (d _1n -d _1caln )…(5)

d _1caln represents the value at position n in the calculated thickness d _1cal ={d _1cal1 . . . d _1calN } of the coating film after arbitrary adjustment.

d _1calave represents an average value of d _1caln ={d _1cal1 ...d _1calN }. In the present embodiment, since the flow rate of the coating liquid is constant, it can be considered that d _1calave =d _0ave .

K _n represents the value at position n in the proportionality constant K={K ₁ . . . K _N }.

h _1n represents a value at position n in the height h ₁ ={h ₁₁ . . . h _1N } of the slit 11 after arbitrary adjustment measured in the data acquisition step P1 .

h _0n represents a value at position n in the height h ₀ ={h ₀₁ . . . h _0N } of the slit 11 before arbitrary adjustment measured in the data acquisition step P1 .

d _0n represents a value at position n in d ₀ ={d ₀₁ . . . d _0N } of the coating film before arbitrary adjustment measured in the data acquisition step P1.

e _1n represents the value at position n in the difference e ₁ ={e ₁₁ . . . e _1N }.

d _1n represents a value at position n in the arbitrarily adjusted coating film thickness d ₁ ={d ₁₁ . . . d _1N } measured in the data acquisition step P1 .

K = {K ₁ ... K _N } is preferably calculated by the least square method so that the total value of the squares of the differences e ₁ = {e ₁₁ ... e _1N } represented by the following equation (6) becomes minimum.

【Mathematical formula 8】

The proportionality constant K may be considered to be constant at position 1 to position N (K ₁ =K ₂ = . . . =K _N ) and calculated by the least square method using the above-mentioned equations (4) to (6).

For example, K can be calculated by assigning an arbitrary initial value and using a solver of EXCEL (registered trademark).

[Height determination process P3]

In the height determination step P3, the thickness _d2n at position n among positions 1 to N is calculated using the following formula (1), and the height _h2 = { _h21 ... _h2N } of the virtual adjusted gap at positions 1 to N is calculated so that the difference e = { _e1 ... _eN } between the calculated thickness _d2 = { _d21 ... _d2N } calculated using the following formula ( ₂ ) and the target thickness value _dref = { _dref1 ... drefN } becomes smaller.

【Mathematical formula 9】

【Mathematical formula 10】

e _n =(d _refn -d _2n )…(2)

d _2n represents the value at position n in the calculated thickness d ₂ ={d ₂₁ . . . d _2N } of the coating film after adjustment.

d _2ave represents an average value of d ₂ ={d ₂₁ . . . d _2N }. In the present embodiment, since the flow rate of the coating liquid is constant, it can be considered that d _2ave =d _0ave .

K _n represents the value at position n in proportional constant K={K ₁ ...K _N }. K _n may be substituted with each K calculated in the constant calculation step P2 or with K calculated while assuming that it is constant.

h _2n represents the value at position n in the height h ₂ ={h ₂₁ . . . h _2N } of the gap 11 after the virtual adjustment.

h _2ave represents the average value of h ₂ ={h ₂₁ . . . h _2N }.

e _n represents the value at position n in the difference e = {e ₁ .. e _N }.

d _refn represents the value at position n in the target value d _ref ={d _ref1 . . . d _refN } of the thickness of the ejected matter.

In the present embodiment, h ₂ ={h ₂₁ ...h _2N } is calculated by the least square method in such a way that the total value of the squares of the differences e ={e ₁ ...e _N } represented by the following equation (3) is minimized. For example, h ₂ ={h ₂₁ ...h _2N } can be calculated by assigning an arbitrary initial value and using the solver of EXCEL (registered trademark). And, based on the value of h ₂ ={h ₂₁ ...h _2N }, the height h ₃ ={h ₃₁ ...h _3N } of the adjusted gap 11 is determined. As the height h ₃ ={h ₃₁ ...h _3N } of the adjusted gap 11, the value of h ₂ ={h ₂₁ ...h _2N } may be directly used, or a value obtained by fine-tuning the value of h ₂ ={h ₂₁ ...h _2N } may be used as a reference.

【Mathematical formula 11】

As described above, according to the extrusion method of the present embodiment, if the height h ₀ ={h ₀₁ ...h _0N } of the slit 11 before adjustment, the thickness d ₀ ={d ₀₁ ...d _0N } of the coating liquid before adjustment, and the value of the proportional constant K are known, the height h ₂ ={h 21 ...h _2N } of the slit 11 can be determined based on the difference e ={e ₁ ...e _N } between the calculated thickness d ₂ ={d ₂₁ ...d 2N } calculated by equation ( ₁ ) and the target thickness d _ref ={d ref1 ...d _refN }, and the height h ₃ ={h ₃₁ ...h _3N } of the slit 11 _after adjustment can be determined based on the value of h ₂ ={h ₂₁ ...h _2N }, thereby making _it possible to adjust the thickness of the coating liquid relatively easily and accurately. Furthermore, the extrusion method of the present embodiment is excellent not only in adjusting the thickness d of the coating liquid to a target uniform thickness but also in adjusting the thickness d of the coating liquid to a target non-uniform thickness.

In addition, the extrusion method of the present invention is not limited to the above-mentioned embodiment. In addition, the extrusion method of the present invention is not limited by the above-mentioned effects. The extrusion method of the present invention can be variously modified within the scope of the present invention.

For example, in the above embodiment, a coating method using the coater 1 is described, but a resin film forming method using a T-die or the like for extruding molten resin may also be used. In this case, the viscosity of the molten resin is preferably 1000 Pa·s to 5000 Pa·s.

In addition, in the above-mentioned embodiment, a method of adjusting the height h of the gap 11 by using the adjustment mechanism 50 having the slit 51 and the adjustment screw 52 is shown, but it is not limited to this. As another adjustment mechanism 50, a hot bolt can be used instead of the adjustment screw 52. In addition, for example, the height h of the gap can be adjusted by processing the gasket member 40 and each module. In addition, the coating machine 1 for trial production can also be used to implement the data acquisition step P1 and the constant calculation step P2 to manufacture a coating machine 1 having a gap height h set in the height determination step P3 to obtain the desired coating film thickness d.

Furthermore, in the above-described embodiment, the least square method is described as the approximation method, but other methods, for example, Newton's method may also be adopted.

[Example]

Hereinafter, the present invention will be further described by showing examples.

In this example, a method of forming a coating film using a coater was studied.

[Coating device]

The coating machine used in this embodiment is made of stainless steel, and a gap of 1300 mm in width is formed between the first module and the second module. In addition, as a gap height adjustment mechanism, the coating machine has a slit provided in the second module and 26 (i.e., N=26, positions 1 to 26) adjustment screws (the distance between the centers of the rotation axes: 50 mm and constant) arranged in the entire TD direction.

[Coating conditions]

Under the coating conditions shown in Table 1, an acrylic polymer dissolved in a solvent as a coating liquid was applied to the surface of a thin film as an object to be coated, thereby forming a coating film composed of an acrylic polymer as a sprayed product.

【Table 1】

[Example 1]

In Example 1, a method is described in which proportional constants K={K ₁ . . . K ₂₆ } are obtained at positions 1 to 26 and the height of the slit is adjusted so that the thickness of the coating film changes from a non-uniform state to a uniform state.

(Data acquisition process P1)

The heights of the slits at positions 1 to 26 before adjustment, h ₀ ={h ₀₁ ...h _{0_26} }, and the thicknesses of the coating films at positions 1 to 26 before adjustment, d ₀ ={d ₀₁ ...d _{0_26} }, were measured. Next, the height of the slits was arbitrarily adjusted, and the heights of the slits at positions 1 to 26 after the arbitrarily adjustment, h ₁ ={h ₁₁ ...h _{1_26} }, and the thicknesses of the coating films at positions 1 to 26 after the arbitrarily adjustment, d ₁ ={d ₁₁ ...d _{1_26} }, were measured. The measurement results are shown in Table 2.

(Constant calculation process P2)

The proportional constant K = {K ₁ ... K ₂₆ } was calculated from the above measured values. Specifically, in the calculation of the proportional constant K, the proportional constant K = {K 1 ... K 26 } which minimizes the total value of the squares of the differences e ₁ = {e ₁₁ ... e _{1_26} } between d _1cal = {d _1cal1 ... d _1cal26 } and d ₁ = {d ₁₁ ... d _{1_26} } was calculated by the least square method using the above equations ( ₄₎ to ( ₆ ). The results are shown in Table 2.

(Height determination process P3)

The target value d _ref ={d _ref1 ...d _ref26 } of the coating film thickness shown in Table 2 was set, and the height h ₂ ={h ₂₁ ...h _{2_26} } of the gap after adjustment at positions 1 to 26 was calculated so that the total value of the squares of the differences e ={e ₁ ...e _{26 } between the calculated thickness d 2 ={d 21 ...d 2_26 } at positions 1 to 26 and the target value d ref ={d ref1 ...d ref26 } of the thickness was minimized} by the least square method using the above-mentioned equations (1) to (3). The results are shown in Table 2.

(Extrusion process)

Using h ₂ ={h ₂₁ ...h _{2_26} } calculated above as the gap height h ₃ ={h ₃₁ ...h _3N }, a coating film was formed on the thin film, and the thickness after adjustment was measured. The results are shown in Table 2 and FIG. 4 .

As shown in Table 2 and FIG. 4 , the thickness of the coating film before adjustment was non-uniform near a width of 225 mm and near a width of 1075 mm, and the thickness of the coating film after adjustment was adjusted to be substantially uniform over the entire width direction as intended.

【Table 2】

[Example 2]

In Example 2, a method of adjusting the height of the slit so that the thickness of the coating film becomes uniform is exemplified by obtaining a proportional constant K={K ₁ =K ₂ =...=K ₂₆ } which is considered to be constant at positions 1 to 26. In Example 2, the values of h ₀ , d ₀ and d _ref are set to the same values as in Example 1. In addition, in the calculation of the proportional constant K, the proportional _{constant K={K 1 =K 2 =...=K 26 } which minimizes the total value of the square of the difference e 1 ={e 11 ...e 1_26 } between d 1cal = { d 1cal1 ...} d _1cal26 } and d ₁ ={d ₁₁ ...d _{1_26} } is calculated using the above formula ( ₄ ). Except for this, the height of the slit is adjusted in the same manner as in Example 1, and a coating film is formed on the thin film. The results are shown in Table ₃ and FIG. 5 .

As shown in Table 3 and FIG. 5 , similarly to Example 1, the thickness of the coating film after adjustment was adjusted to be substantially uniform over the entire width direction as intended.

【Table 3】

[Comparative Example 1]

Comparative Example 1 shows the result of adjusting the gap height by a skilled operator without using this method. In Comparative Example 1, the values of h ₀ , d _{0 ,} and d _ref were set to the same values as those in Example 1. In addition, the gap height was adjusted five times using the adjustment screw based on the measured values of h ₀ and d _0. The results are shown in Table 4 and FIG6 .

As shown in Table 4 and Figure 6, the result is that the target value is deviated in the entire width direction. In particular, the thickness that was originally less than the target value becomes greater than the target value near the position of the adjustment screw 225mm, and the thickness that was originally greater than the target value becomes less than the target value near the position of the adjustment screw 625mm, which shows that it is difficult to adjust based on the experience of the operator.

【Table 4】

The following Table 5 summarizes the thickness accuracy of the coating films before and after adjustment of Examples 1 and 2 and Comparative Example 1. The thickness accuracy is calculated by [maximum thickness - minimum thickness]/average thickness × 100. As can be seen from the results of Table 5, compared with Comparative Example 1, the thickness of the coating film can be easily and accurately adjusted by the extrusion method of Example 1.

【Table 5】

Example 1 Example 2 Comparative Example 1 Adjustment times of adjusting thread (times) 1 1 5 Thickness accuracy before adjustment (%) 9.46 9.46 9.46 Thickness accuracy after adjustment (%) 0.65 0.69 5.77

[Example 3]

In Example 3, a method of adjusting the height of the slit so that the thickness of the coating film changes from a uniform state to a non-uniform state is described by obtaining a proportionality constant K={K ₁ =K ₂ =...=K ₂₆ } which is considered constant at positions 1 to 26. The coating conditions are shown in Table 6. The results are shown in Table 7 and FIG. 7 .

【Table 6】

As shown in Table 7 and FIG. 7 , the thickness of the coating film after adjustment was adjusted to be substantially in the target non-uniform state in the entire width direction.

【Table 7】

Claims (1)

1. An extrusion method, which is an extrusion method using a die formed with a slit for ejecting a fluid with a constant flow rate, wherein, The extrusion method includes an adjustment step of adjusting the height of the slit in order to adjust the thickness of the ejected material ejected from the slit, The adjustment step includes the step of calculating the thickness d _2n at a position n from any position 1 to position N in a direction perpendicular to the flow direction of the ejected material using the following formula (1), so that The difference between the calculated thickness d ₂ ={d _{21 ...} d _2N } and the target thickness d _ref ={d _ref1 ...d _refN } calculated from the following formula (2) ...e _N } becomes smaller to determine the height of the gap, Use the following formula (4) to calculate the thickness d _1cal ={d _1cal1 ... d _1calN } of the ejected material at positions 1 to N, so that d _1cal ={ The proportionality constant K={K ₁ at positions 1 to N is calculated in such a way that the difference e 1 ={e 11 ...e _1N } between d _1cal1 ...d _{1calN }} and d ₁ ={d ₁₁ ...d _1N } becomes _smaller ... K _N }, Find h ₂ ={h ₂₁ ...h _2N } that minimizes the sum of the squares of differences e={e ₁ ...e _N } represented by the following formula (3), and based on this h ₂ to determine the height of the gap, d _2n : the adjusted calculated thickness of the ejecta d ₂ = the value at position n in {d ₂₁ ... d _2N } d _2ave : d ₂ = average value of {d ₂₁ ... d _2N } K _n : the value at position n in the proportionality constant K={K ₁ ... K _N } h _2n : the imaginary adjusted height of the gap h ₂ = the value at position n in {h ₂₁ ... h _2N } h _2ave : h ₂ = average value of {h ₂₁ ... h _2N } h _0n : the height of the gap before adjustment h ₀ = the value at position n in {h ₀₁ ... h _0N } h _0ave : h ₀ = average value of {h ₀₁ ... h _0N } d _0n : the thickness of the ejected material before adjustment d ₀ = value at position n in {d ₀₁ ... d _0N } d _0ave : d ₀ = average value of {d ₀₁ ... d _0N } e _n ＝(d _refn -d _2n )···(2) e _n : the value at position n in the difference e={e ₁ ... e _N } d _refn : Target value d _ref = value at position n in {d _ref1 ... d _refN } of the target value of the thickness of the ejection d _1caln : the value at position n of the calculated thickness d _1cal = {d _1cal1 ...d _1calN } of the ejection after arbitrary adjustment d _1calave : d _1caln = average value of {d _1cal1 ... d _1calN } h _1n : the height h ₁ of the slit after arbitrary adjustment = the value at position n in {h ₁₁ ... h _1N } h _1ave : h ₁ = average value of {h ₁₁ ... h _1N } e _1n ＝(d _1n -d _1caln )···(5) e _1n : difference e ₁ = value at position n in {e ₁₁ ... e _1N } d _1n : the value at the position n of the thickness d1={d ₁₁ ...d _1N } of the ejected object after arbitrary adjustment.