JP6524747B2 - Film flatness inspection apparatus and film flatness inspection method - Google Patents

Description

  The present invention relates to a film planarity inspection apparatus and a film planarity inspection method, and more specifically, in a film roll state, to accurately and easily obtain information on the slack of the film when the film is rewound. Film planarity inspection apparatus and film planarity inspection method that can

  When the film has poor flatness, film slack may occur when the film is rewound from the film roll. This sagging results from the partial elongation of the film either due to the production of the film or its subsequent handling. When the film sags, the productivity in the secondary processing of the film becomes very poor.

  Conventionally, as a method of detecting the amount of change in the outer diameter of a film roll, a method of accurately measuring the amount of change in the outer diameter of the film roll in the roll axial direction using a contact or non-contact displacement sensor is disclosed (For example, patent documents 1-3 etc.). However, in practice, it is unclear to what extent the amount of change in the outside diameter of the film roll affects the film sag when the film roll is rewound.

  On the other hand, as a method of detecting the amount of slack of the film when the film is unwound from the film roll, the film is actually unwound from the film roll between the two rolls, and the slack when a specific load is applied is measured. Methods are known (for example, the 7.3 A method and the 7.4 B method described in the measurement of sag according to JIS C 2151, FIG. 3 of Patent Document 1, etc.). Such methods can foresee problems arising in the process of unwinding and using the film from the film roll.

  Further, it is a flatness inspection apparatus and method for inspecting the flatness of a film in the state of a film roll, wherein the outer diameter value of each measurement point in the width direction is obtained by scanning the film roll outer peripheral surface with a laser beam scanning device After calculating the average value of them and calculating the difference between the outer diameter value of each measurement point and the average value as the displacement amount, the positive maximum displacement amount is extracted as the maximum slack amount, and a preset reference value The film flatness inspection apparatus and method which determine the defect by comparing good with the said positive maximum displacement amount, and defect are disclosed (patent document 4).

JP, 2004-286563, A JP 2005-31005 A International Publication 2013/099539 JP, 2010-185763, A

  However, according to the examination by the present inventors, it is a skilled measurer in the method of measuring the amount of film sag when the film is rewound from the film roll described in Patent Document 3 and the like. It was also found that there is a measurement variation of about ± 7 mm, and also the variation by the measurer is large. Moreover, in this method, since it takes time for measurement, there is a problem that accuracy and productivity fall. In the method disclosed in Patent Document 4 above, the maximum displacement amount of the outer diameter of the film roll is extracted using the average value as the maximum slack amount, and compared with a preset reference value, the film is slackened. In order to determine the presence or absence, it is not possible to detect the presence or absence of the occurrence of sag other than the portion having the maximum amount of sag.

Furthermore, in practice, when the film roll is rewound and the film is subjected to secondary processing, the conditions such as the unwinding tension applied when the film is rewound varies, so that the conventionally known inspection method of the film flatness However, it is difficult to detect the occurrence of film sag and the amount of film sag at the actual work site.
Also, in order to increase productivity by secondary processing of the film, when using a wider or longer film than before, it is important to maintain the flatness over the full width and the entire length of the film, and the flat surface of the film There is a need for an inspection apparatus and a measurement method for inspecting the property more accurately and easily.

  SUMMARY OF THE INVENTION In view of the problems of the prior art described above, the present invention more accurately and easily obtains information on the generated slack in the film roll state when the film is rewound from the film roll with an arbitrary unwinding tension. It is an object of the present invention to provide an apparatus and method that can

  The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, information on the slack in a state where the film was unwound from the film roll with an arbitrary tension represents the change in the outer diameter dimension of the film roll and the aforementioned information. Given the fact that it is possible to predict from the amount of strain in the unwound state by tension, in fact, the predicted value of the amount of film slack due to any unwound tension is within the error of the measured value of the direct film sag measurement. The present invention has been completed.

  That is, according to the first aspect of the present invention, it is an apparatus for inspecting the planarity of a film in the state of a film roll, and an amount indicating the change amount of the outer diameter dimension of the film roll; A film plane comprising an arithmetic processing unit for acquiring information on the longitudinal sag based on the relationship between the amount of distortion in the longitudinal direction of the film in a state of being unwound between two rolls by tension. A sex inspection device is provided.

  Further, the information on the sag may include information on the presence or absence of the occurrence of the longitudinal sag and the site in the tensioned state.

Further, in the arithmetic processing device, when the amount indicating the amount of change in the outer diameter dimension is less than the threshold ε _max , the amount indicating the amount of strain in the vertical direction is a positive value, and the change in the outer diameter dimension When the quantity indicating the amount is equal to or more than the ε _max , the ε _max is calculated when the amount indicating the amount of strain in the longitudinal direction is 0, and the amount indicating the amount of change in the outer diameter dimension is The site exceeding the ε _max can be determined as the site of occurrence of sag.

（上記式中、ｘは、前記縦方向の任意の部位を示し、ε（ｘ）は、前記張力によりフィルムを巻き戻した状態における歪量を示す。なお、ε_ｐ（ｘ）は、前記外径寸法の変化量を示す量であり、以下により示される。）

（上記式中、Ｄ（ｘ）は、前記外径寸法を示し、Ｄ^＊は、基準外径寸法を示す。） The ε _max may be calculated by the following equation.

(In the above formula, x represents an arbitrary part in the longitudinal direction, and ε (x) represents the amount of distortion in a state in which the film is rewound by the tension. Ε _p (x) is the outer diameter This is an amount that indicates the amount of change in diameter size, as indicated by the following :)

(In the above-mentioned formula, D (x) shows the above-mentioned outside diameter size, and D ^* shows a standard outside diameter size.)

  The arithmetic processing unit is configured to apply the tension when an amount indicating a change amount of the outer diameter dimension is an amount indicating the length of the film in the longitudinal direction in a state where the tension is not applied. The amount indicating the length of the film in the longitudinal direction is calculated at the portion where the amount indicating the amount of change in the outer diameter dimension is the smallest, and the portion indicating the amount of change in the outer diameter dimension is the minimum The site | part exceeding the quantity which shows the said film length of can be determined to be a generation | occurrence | production site | part of a sag.

  Furthermore, the film planarity inspection apparatus includes a shape measuring device that measures the amount of change in the shape of the film roll in the roll axis direction by a contact type or non-contact type displacement sensor, and the shape measuring device It may have output means for outputting measurement information of the amount of change of the shape to the arithmetic processing unit.

  Further, the arithmetic processing unit can calculate an outer diameter dimension of the film roll based on measurement information of the measured amount of change in shape.

  In addition, the arithmetic processing unit calculates the amount of sag at any inter-roll distance by comparing the amount of strain in the longitudinal direction between the portion where the sag occurs and the portion where the sag does not occur in the tensioned state. can do.

  According to a second aspect of the present invention, there is provided a method for inspecting the planarity of a film in the state of a film roll, the step of calculating the film roll outer diameter dimension and the amount of change in the outer diameter dimension of the film roll. Based on the relationship between the amount of sagging and the amount of strain in the longitudinal direction in a state where the film is unwound between two rolls with an arbitrary tension, information on the presence or absence of occurrence of the longitudinal sag and the site Providing a film planarity inspection method.

  Further, the film planarity inspection method calculates the amount of sag at an arbitrary distance between rolls by comparing the amount of strain under the tension between the portion where the sag occurs and the portion where the sag does not occur. Can be provided.

  The film planarity inspection apparatus and the film planarity inspection method according to the present invention, in the state of a film roll, more accurately and, more accurately, information on sag when the film is rewound between two rolls with an arbitrary tension. It can be acquired easily.

FIG. 1 is a view showing a film flatness inspection apparatus according to the first embodiment. FIG. 2 is a view showing a film flatness inspection apparatus according to a second embodiment. FIG. 3 is a view showing a film flatness inspection apparatus according to a third embodiment. FIG. 4 is a view showing an example of the shape measuring device of the first embodiment. FIG. 5 is a diagram showing the relationship between ε _max , ε _p (x) and ε (x). FIG. 6 is a diagram showing determination of the presence or absence of the occurrence of sag. FIG. 7: is a figure which shows the variation | change_quantity of the shape of the roll axial direction of a film roll measured by the shape measuring apparatus of 1st Embodiment. FIG. 8 is a view showing the correlation between the predicted value of the amount of sag calculated by the film flatness inspection apparatus of the first embodiment and the measured value obtained by actually unwinding the film roll and measuring the amount of slack of the film. . FIG. 9 is a view showing a method of measuring film sag when the film roll is rewound according to the prior art.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same structure. In addition, the embodiments described below are merely examples, and the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art, including the following embodiments.

1. Flatness Inspection Apparatus FIG. 1 is a view showing a first embodiment of a film flatness inspection apparatus according to the present invention. The film flatness inspection apparatus 1 of FIG. 1 calculates the amount of change in the outer diameter dimension of the film roll from the change in shape of the shape measuring device 20 which measures the amount of change in shape of the film roll in the roll axis direction. A second calculation unit 12 to obtain information about the presence or absence of occurrence of the longitudinal sag and the portion in a state where the tension of the film is applied, from the amount indicating the change amount of the outer diameter dimension It comprises an arithmetic processing unit 10 including a unit 11 and a third arithmetic unit 13 that calculates the amount of sag in the tensioned state.

  Conventionally, when measuring the slack of a film, the film is actually rewound between two predetermined rolls, and the slack generated when a predetermined tension is applied is directly measured. An example of measurement of conventional film sag is shown in FIG. Conventionally, measurement of film slack is performed by unwinding the film from the film roll 21 between the two rolls 102a and 102b and fixing a weight 103 (or spring load) to the end of the film hanging down from the roll 102b. Apply a predetermined unwind tension so that tension is applied as evenly as possible in the direction. At this time, it is determined that sag has occurred when a portion lowered below the flat surface between the two rolls is generated, and the distance L0 to the film portion lowered most directly is measured by: The amount of sag is measured.

  On the other hand, the film flatness inspection apparatus 1 according to the first embodiment can easily calculate the information on the slack in the film roll state without unwinding the film with the same accuracy of the above-described measured values.

In addition, it does not specifically limit as a film used for 1st Embodiment, Various films or sheets can be used. Specifically, plastic films, plastic sheets, woven fabrics, non-woven fabrics, glossy papers, metal foils and the like can be mentioned. Among these, a film which is breathable and in which the amount of change in the outer diameter of the film roll tends to increase when formed into a film roll can be suitably used. Specifically, a polyolefin microporous film, a woven fabric, Nonwoven films, films such as paper may be mentioned. Moreover, even if it is a non-air-permeable plastic sheet, it can be used suitably by raising a surface pressure and setting it as a film roll wound up by the core so that air may not enter between films. In addition, in the film roll which the air entered between films, slack does not generally arise.
The details of each configuration in the first embodiment will be described below.

(1) Shape Measurement Device An embodiment of the shape measurement device 20 is shown in FIGS. 4 (A) and 4 (B). The shape measuring apparatus 20 shown in FIG. 4 includes non-contact type displacement sensors, and the sensor heads 23 a, 23 b, 24 a, 24 b attached to the upper and lower surfaces of the shape measuring apparatus 20 use the laser light 25 to form the film roll. Measure the change amount of The plurality of sensor heads are attached so as to be relatively movable along the roll axial direction (x direction) 28. The movement of the plurality of sensor heads causes a fill in the roll axial direction (x direction). It is possible to measure the amount of change in the shape of the roll.
The amount of change in the shape of the film roll can be measured at one place, but it can be measured more accurately by performing it at two places of opposing surfaces such as the upper surface and the lower surface. Also, although two or more measurement points may be used, measurement information with sufficient accuracy can be obtained with only two points as the measurement information used in the first embodiment. In addition, by using the shape measuring device 20 and taking the amount of change in the shape of the film roll at a plurality of points, it is possible to simply and accurately measure the exact accuracy of the fixing position of the film roll at the time of measurement. Can.
Although not shown in the figure, the shape measuring device 20 is configured to have output means for outputting measurement information of the measured amount of change to the arithmetic processing unit.

  Also, for example, as described in Patent Documents 1 and 2, as the shape measuring device 20, contact-type displacement is performed in three or more places in the circumferential direction of the film roll surface in a plane orthogonal to the roll axis direction of the film roll. The amount of change in the shape of the film roll may be measured by bringing the sensor into contact and relatively moving in the roll axis direction. In addition, when using the said contact-type displacement sensor, it is necessary to fix so that a film roll center may become a predetermined | prescribed center position at the time of a measurement.

(2) Arithmetic processing unit The arithmetic processing unit 10 measures the amount of change in the outer diameter dimension of the film roll, and the longitudinal direction of the film in a state where the film is rewound between two film rolls with an arbitrary tension. Information on the longitudinal sag can be obtained based on the amount of distortion. Here, the information on the slack refers to the information on the slack generated in the tensioned state, and the information on the presence or absence of the occurrence of the longitudinal sag in the longitudinal direction and the part, the amount indicating the distortion amount, and the amount indicating the distortion amount Etc. can be included.

As shown in FIG. 1, the arithmetic processing unit 10 includes an arithmetic processing unit including the first to third arithmetic units and an output unit. Although not shown, the arithmetic processing unit 10 has a keyboard, a mouse, an input unit having a known interface used to connect to the Internet, an external device, etc., a data storage unit such as a CPU, a memory, a hard disk, etc. It may be configured by a computer provided with a display unit and the like provided with a monitor and the like.
For example, the input unit may include measurement information of the amount of change in shape of the film roll in the roll axis direction measured by the shape measuring device, and information such as the amount of change in the shape and the outer diameter distribution measured in advance. It can have a function of inputting to a data storage unit or an arithmetic processing unit. Further, the data storage unit is capable of executing data necessary for an operation including data such as the amount of change in the shape and an outer diameter distribution and a program necessary for an operation, and the output unit is an operation processing unit The output data of at least the first to third calculation units to be executed in step S. can be read out from the calculation unit or the data storage unit and output.
The first to third calculation units will be described below.

(3) Second operation unit (outside diameter dimension calculation unit)
The second calculation unit 12 calculates the outer diameter dimension in the roll axial direction (x direction) based on the information of the change amount of the shape of the film roll in the roll axial direction (x direction) obtained by the shape measuring device 20 Do. Hereinafter, the amount of change in shape in the roll axial direction (x direction) is also referred to as u (x), and the external dimension of the film roll in the roll axial direction (x direction) of the film roll is also referred to as D (x). Further, the amount of change in shape u (x) indicates the amount of change in the thickness direction (z direction) of the film roll measured along the roll axis direction (x direction). The shape change amount u (x) may be an accurate value (absolute value) of the change amount in the z direction with reference to the central axis of the roll, or a measured value of an arbitrary position x ₁ The amount of change (relative value) in the z direction may be measured based on u (x ₁ ).
Hereinafter, an example of a method for calculating the outer diameter dimension D (x) when the amount of change (relative value) in the z direction is measured as the amount of change in shape u (x) by the shape measuring device 20 will be described.

First, the outer diameter dimension D (x) in the x direction is defined as follows.

In equation (1), min (u (x)) represents the minimum value of the amount of change in shape u (x), and D ^* represents the reference outer diameter dimension.

A theoretical value can be used for reference | standard outer-diameter dimension D ^* of a film roll, for example, it can calculate by the following formula.

Wherein (2), t is the thickness of the design value (unit: m), L is the winding length (unit: m), _{D C} is a core outside diameter (unit: m) indicating the.

  Further, instead of the calculation method of the outer diameter dimension D (x) described above, for example, as disclosed in Patent Documents 1 and 2, displacement of a plurality of points is made by the shape measuring device 20 in which the setting position of the sensor is preset. The outer diameter dimension D (x) may be calculated from the data of which the amount was measured by using a simultaneous equation of circles. In addition, as disclosed in Patent Document 3, in the case of the shape measuring apparatus 20 in which a pair of sensors are attached at positions facing the upper surface and the lower surface on the outer periphery of the film roll in advance, The outer diameter dimension D (x) can also be calculated directly by obtaining it.

  As in the above-mentioned Patent Documents 1 to 3, in the case of directly calculating the outer diameter dimension D (x) in consideration of the positional information of the sensor, it is necessary to control the fixing position of the roll film at the time of measurement strictly to some extent If the fixed position of the roll film is deviated from the assumed position, the outer diameter dimension D (x) with sufficient accuracy may not be obtained. Therefore, using u (x) obtained by measuring the amount of change (relative value) in the z direction with reference to the measurement value at an arbitrary position as described above, the outer diameter dimension D ( By calculating x), even if the fixing position of the film roll at the time of measurement is somewhat deviated, it is possible to easily obtain a value having sufficient accuracy that can withstand practical use.

(4) First Arithmetic Unit The first arithmetic unit 11 of the arithmetic processing unit 10
1) Based on the relationship between an amount indicating the amount of change in the outer diameter dimension of the film roll and an amount indicating the amount of distortion in the longitudinal direction of the film in a state in which the film is unwound between two rolls with an arbitrary tension. If the amount indicating the change in the outer diameter dimension is less than the threshold ε _max , the amount indicating the amount of strain in the longitudinal direction is a positive value, and the amount indicating the change in the outer diameter dimension is If it is the epsilon _max or more, when the amount indicating a distortion amount of the vertical direction is set to 0, it calculates the epsilon _max,
2) It is possible to determine a portion where the amount of change in the outer diameter size exceeds the ε _max as the occurrence portion of sag.
Hereinafter, an example of the first arithmetic unit according to the present invention will be described.

The amount indicating the amount of change in the outer diameter dimension is, for example, the longitudinal direction (longitudinal direction; y direction) of the film at any part in the roll axial direction (x direction) which the film in the film roll state already has. It can be expressed by a strain amount ε _p (x) corresponding to the plastic deformation amount of. Specifically, the strain amount ε _p (x) can be expressed as shown in the following formula (3).

In Formula (3), D (x) shows the outside diameter size (unit: m) in arbitrary parts in the roll axial direction (x direction), and D ^* shows the standard outside diameter size (unit: m) . Note that D (x) and D ^* are values that can be obtained from the above equation (1).

In the film in a state in which the film is unwound between two rolls (hereinafter, also referred to as “a state in which no tension is applied”), ε _p (x) is an unwinding tension at which distortion does not occur. It can be said that the amount indicates the distribution of the film length in the y direction.

  The above-mentioned standard outside diameter size shows the ideal outside diameter size which a film roll has when it is assumed that the above-mentioned plastic deformation does not arise at all to a film, and a product representative outside diameter may be used. Alternatively, the minimum value of the outer diameter dimension D (x) may be used.

  The amount indicating the amount of distortion in the longitudinal direction of the film means, for example, a film of a film in a state of being rewound between two rolls by an arbitrary tension T (hereinafter, also referred to as “a state in which the tension T is applied”). The amount of strain ε (x) in the longitudinal direction (longitudinal direction; y direction) of the film at an arbitrary portion in the width direction (x direction) is shown, and can be calculated, for example, as follows.

First, the stress σ (x) (unit: N / m ² ) in the y direction at an arbitrary part x in a state where tension T (unit: N) is applied may be calculated by the following equation (4) it can.

  In Formula (4), t is the film thickness (unit: m) of a film, W shows the full width (unit: m) of a film.

Moreover, the relationship between the amount of strain ε (x) in the y direction and the stress σ (x) in the state where tension T is applied ignores the effect of Poisson's ratio, and applies Hooke's law to the following equation (5 It can be represented by).

  In Formula (5), E shows the Young's modulus (Pa) of the y direction (MD direction) of the film to be used.

  From the above formulas (4) and (5), it is possible to calculate the total sum of the strain amount ε (x) in the y direction in the state where the tension T is applied.

  The amount indicating the amount of strain in the longitudinal direction of the film can also be indicated by, for example, the stress σ (x) in the y direction. In this case, the strain amount ε (x) in the y direction can be calculated from the stress σ (x) in the y direction by the above equation (5).

Further, the threshold value ε _max can be calculated, for example, by the following equation (6).

In equation (6), ε (x) represents the amount of strain in the y direction in a state where an arbitrary tension T is applied, and ε _p (x) represents the amount of strain corresponding to the amount of plastic deformation in the y direction described above Indicates Also, ε _max is a threshold indicating the boundary of the presence or absence of strain in a state where an arbitrary tension T is applied, and ε _p (x) is a positive value when ε _p (x) is less than ε _max Yes, if ε _p (x) is equal to or greater than ε _max , a constant value that can be determined from the values of ε _p (x) and ε (x) when ε (x) is 0 It is.

FIG. 5 is a diagram showing the relationship of the above equation (6). That is, when an arbitrary tension T is applied, the film stretches uniformly between the two rolls, and a non-sagging portion of the film is produced, the strain amount ε in the y direction is obtained at the non-sagging portion x _a. x _a ) has a positive value. On the other hand, in the state where tension T is applied, the strain amount ε (x _b ) in the y direction becomes 0 at the portion x _b where the film sag occurs.

That is, in the above equation (6), ε _max represents the maximum value (predicted value) of the strain amount ε (x) in the y direction in a state where tension T is applied, and ε _p (x) is It can be said that the distortion amount ε (x _min ) in the y direction is shown at the smallest portion x _min .

Further, as described above, when ε _p (x) is an amount indicating the length of the film in the y direction in a state where tension T is not applied, ε _max is a state in which tension T is applied, It can be said that the amount indicates the length of the film in the y direction. In this case, since it is assumed that the film of a portion where ε _p (x) <ε _max is uniformly stretched, an amount indicating the length in the y direction indicated by ε _max is ε It is assumed that a constant value is assumed at any site among sites where _p (x) <ε _max .

Here, the sum of the strain amount ε (x) in the y direction in the state of applying tension T, which is indicated by the area of the hatched portion in FIG. 5B, is the above equation (4) using Hooke's law. And (5), and the ε _max can be determined by an optimization algorithm based on the sum of strain amounts ε (x). As an optimization algorithm to be used, although a conventionally known algorithm can be used, for example, a Newton method can be used.

Then, by calculating ε _max , it is possible to determine that a portion where ε _p (x) exceeds ε _max , that is, when the following formula (7) is satisfied, as a sag generation portion (FIG. 6) .

Further, in the first arithmetic unit, the value of ε _max is calculated with the unwinding tension as the value of each of the arbitrary tensions T _{1 to} T _n , and the tension T _{a at which} ε _max = ε _p (x) It is also possible to estimate that the film does not sag if the tension T _a or more is obtained by specifying the value of.

In the above equation (6), the strain amount ε _p (x) is used as the amount of change of the outer diameter size, but D (x) or u (x) is used as the amount of change of the outer diameter size. You can also. In this case, for example, ε _max can be calculated from D (x) or u (x) by substituting the above equations (1), (3) and the like into the above equation (6).

Further, the formula (6), a film having an outer diameter of the plastic deformation does not occur in the film D ^* or D (x _min) on the basis of the epsilon and the original shape (x), epsilon _max It is also possible to calculate ε _max based on ε (x) in which a film having an outer diameter dimension of the outer diameter dimension D (x) is the original shape.

Furthermore, in the first computing unit, the amount indicating the amount of change in the outer diameter dimension is the actual length of the film (plastic deformation) between the predetermined inter-roll distance in the y direction when the tension is not applied. The amount of change in the outer diameter dimension at a portion x _min at which the amount of change in the outer diameter dimension is minimized, the amount indicating the actual length of the film in the tensioned state By calculating, the maximum value of the elongation rate in the full width of the film can be determined. Therefore, the elongation rate measured by the measurement method of sag (Method B; JIS C2151) can also be estimated by calculating the maximum value of the elongation rate when tension T _a is applied.

(5) Third operation unit (distortion amount operation unit)
The third arithmetic unit 13 calculates the amount indicating the amount of sag at any inter-roll distance by comparing the amount of strain between the portion where the sag occurs and the portion where the sag does not occur.
As the amount indicating the amount of slack, for example, there is a amount of slack d (x) at an arbitrary distance L between rolls. The calculation of the amount of slack d (x) will be described below.

ｐ（ｘ）だけ長くなっている分は重力とフィルム内の巻き戻し張力により懸垂曲線を形成すると推定でき、その量は２つのロール間の中間位置で最大となる。よって、最大のたるみ量ｄ（ｘ）は、下記式（９）から演算できる。

The amount of slack d (x) at an arbitrary distance L between rolls (for example, 102a and 102b) is calculated using the strain amount ε (x) in a state where the tension T obtained by the first calculation unit is applied.
For example, in FIG. 5, the position x _b at which sag occurs is compared with the position x _a at which sag does not occur, as shown in the following formula (8), the film is longitudinally oriented by p (x) It can be estimated that the

The portion that is longer by p (x) can be estimated to form a suspension curve due to gravity and the unwinding tension in the film, the amount being maximum at an intermediate position between the two rolls. Therefore, the maximum amount of slack d (x) can be calculated from the following equation (9).

  Here, L indicates an arbitrary distance (unit: m) between two rolls.

FIG. 2 is a view showing a second embodiment of the film flatness inspection apparatus of the present invention. The film planarity inspection apparatus 1 ′ of FIG. 2 may be configured by a computer that does not include the shape measuring device but includes an arithmetic processing unit 10 ′ that includes the first arithmetic unit 11. In this case, it is possible to determine the presence or absence and occurrence of the occurrence of the film sag by using information of an amount indicating the amount of change of the outer diameter of the film roll measured by a known device in advance.
FIG. 3 is a view showing a third embodiment of the film flatness inspection apparatus of the present invention. The film planarity inspection apparatus 1 ′ ′ of FIG. 3 may be configured of a computer that does not include the shape measuring device but includes an arithmetic processing unit 10 ′ including the first arithmetic unit 11 and the third arithmetic unit 13. .
In the above embodiment, although not shown, the arithmetic processing devices 10 ′ and 10 ′ ′ may further include the first arithmetic unit 12.
Moreover, film planarity inspection apparatus 1 ', 1''of the said embodiment may be comprised by computer provided with arithmetic processing unit 10', 10 ''.

2. Film Flatness Inspection Method The film planarity inspection method of the present invention will be described.
The film planarity inspection method of the present invention is
A method for inspecting the flatness of a film in the form of a film roll,
Step S1 of calculating the film roll outer diameter dimension, an amount indicating a change amount of the outer diameter dimension of the film roll, and the longitudinal direction (y direction) in a state where the film is rewound between two rolls by an arbitrary tension. And a step S2 of acquiring information regarding the presence or absence of occurrence of the sag in the longitudinal direction (y direction) and the portion based on the relationship between the amount of distortion and the portion.

The step S1 of calculating the film roll outer diameter dimension is based on the measurement information on the amount of change in the shape in the thickness direction (z direction) at an arbitrary part in the roll axis direction (x direction) of the film roll wound with a film. It is a process of calculating a diameter dimension.
The measurement information of the amount of change in the shape of the film roll can be measured by a known method, and can be measured by, for example, the shape measuring device 20 described above.

  The step S2 of acquiring information regarding the presence or absence and occurrence of the occurrence of the sag in the longitudinal direction (y direction) is an amount indicating a change amount of the outer diameter dimension of the film roll and a strain in the y direction in a state where the tension is applied. This is a step of acquiring information regarding the presence or absence of occurrence of sag in the y direction and the region based on the relationship with the amount.

For example, as described above, when the amount indicating the amount of change in the outer diameter dimension is less than the threshold ε _max , the amount of distortion in the vertical direction is obtained as described above. is the amount is a positive value that indicates the amount of change between said outer diameter dimension, if it is the epsilon _max or more, when the amount indicating a distortion amount of the vertical direction is set to 0, the epsilon _max The amount of change in the outer diameter dimension may be determined as a part where the amount of change in the outer diameter size exceeds the ε _max as a part where sag occurs. Further, as described above, the threshold ε _max can be obtained from the above equation (6).

  From the above, the presence or absence of sag in the y direction and the occurrence site in an arbitrary site in the width direction (x direction) of the film can be predicted, so that the planarity of the film can be suitably inspected.

  The film planarity inspection method of the present invention further calculates the amount of sag at an arbitrary distance between rolls by comparing the amount of strain under the tension between the portion where the sag occurs and the portion where the sag does not occur. Step S3 may be provided.

  The calculation of the sagging amount at any given inter-roll distance is, for example, the sagging amount at any given inter-roll distance using the strain amount distribution in the film axial direction which occurs when given an arbitrary unwinding tension as described above. This can be done by computing

As one embodiment of the film planarity inspection method of the present invention, each of the steps 1S to 3S can be performed by executing each step on a computer using a predetermined program.
Further, as another embodiment, a program (film flatness inspection program) for causing a computer to execute the steps S1, S2 and S3 is created. For example, in a desktop personal computer, the film flatness inspection program The above steps S1 to S3 can also be performed by mounting and executing. The film flatness inspection program can be stored in a computer readable recording medium.

  From the above, since the amount of sag in the film width direction at an arbitrary distance between rolls can be predicted, the planarity of the film can be inspected more suitably.

The amount of change in the outer diameter shape of the film roll was measured using the film flatness inspection device according to the present invention, and the amount of strain was calculated.
As the film roll, a polyethylene microporous film (film thickness: 12 μm, film width: 750 mm, film length: 1000 m, Young's modulus: 540 MPa) wound on a core with an outer diameter of 172 mm was used (Product Typical outer diameter: 212 mm). As shown in FIG. 4, the amounts of change in the roll axis direction of the two opposing surfaces of the outer periphery of the film roll were measured using a laser dimension measuring device shown below.
(Laser dimension measuring instrument)
Measurement unit: Sensor head LS-3060 manufactured by Keyence Corporation
Controller section: Keyence Corporation controller LS-3000

The measurement is carried out every width 1 mm from the end of the film roll in the roll axial direction (x direction) at each point, and the thickness (z direction) at a position of 50 mm from the end in the roll axial direction The value of the thickness (z direction) at each point was obtained with 0 (reference value). As thickness (shape) data at each point, in order to reduce noise such as wrinkles generated at the time of winding, an average of about eight adjacent points is taken and used as shape measurement data used for calculation. The shape measurement data used for the calculation is shown in FIG. The intersection of the straight line in FIG. 7 and the shape indicates an example of a boundary value as to whether or not stress is applied, which is calculated based on ε _max when a predetermined unwinding tension is applied. Further, in FIG. 7, the sum of the areas indicated by oblique lines has a value corresponding to the size of the unwinding tension.

  Moreover, maximum sag amount d (x) was computed using said Formula (1)-(9) from the said shape measurement data u (x) obtained by the arithmetic processing unit of the film flatness inspection apparatus. The film roll is rewound by the maximum sag amount d (x) calculated and the sagging method (according to JIS C2151 (2006) 7.3 A method; distance between rolls: 1 m), and the recoiling tension is 10 N / m. The result of comparing the measured value of the actual amount of sag in the case of being applied is shown in FIG. The correlation coefficient of the scatter diagram of FIG. 8 is 0.91, and the measured value of the actual sag amount and the calculated slack amount show a strong correlation. The inventor has also confirmed that the actual sag measurement value includes a measurement error of about ± 7 mm, while measuring the shape of the same film roll five times using the above-described laser dimension measuring device. When the amount of sag was calculated, each calculated amount of sag was almost included within the error range of the actual measured value, and the range of the measurement error was smaller than the actual measured value (within ± 2 mm) ).

  From the above, it is clear that the present invention makes it possible to predict the amount of slack when the film is rewound easily and accurately from the outer diameter distribution of the film roll.

  The film planarity inspection apparatus or the film planarity inspection method according to the present invention is to obtain information on the slack generated when the film is rewound under the unwinding tension used at the actual work site in the film roll state. The film planarity inspection can be carried out simply and accurately. Furthermore, according to the present invention, when using any film roll, it is also possible to estimate the unwinding tension at which the film does not sag.

1, 1 ′, 1 ′ ′ film roll flatness inspection apparatus 10, 10 ′, 10 ′ ′ arithmetic processing unit 11 first arithmetic unit 12 second arithmetic unit 13 third arithmetic unit 20 shape measuring apparatus 21 film roll 22 core 23a, b Sensor head (a: light emitting side, b: light receiving side)
24a, b Sensor head (a: light emitting side, b: light receiving side)
25 Laser beam 26 Frame for fixing sensor head 27 Rod 28 Direction of movement of frame 100 Conventional slack measurement device 101 Film 102a, b Roll 103 Weight for applying load to film 104 Virtual line connecting the upper side of two rolls L0 The distance between the virtual line connecting the top sides of the two rolls and the film

Claims (9)

An apparatus for inspecting the flatness of a film in the form of a film roll in which the film is wound on a core ,
Based on the relationship between the amount that indicates the amount of change in the outer diameter of the film roll and the amount that indicates the stress applied to the film in the longitudinal direction when the film is unwound between two rolls by an arbitrary tension. An arithmetic processing unit for acquiring information on the longitudinal sag;
The arithmetic processing unit calculates the stress σ (x) when the film is unwound at an arbitrary position x in the roll axis direction of the film roll according to the following formula (1):
A film planarity inspection device characterized in that.

In the above equation (1), u (x) is a change in the shape of the film roll at the portion x with respect to the shape of a predetermined portion in the roll axis direction of the film roll, and min (u (x Shows the minimum value of the amount of change u (x) of the shape in the entire roll axis direction of the film roll, t is the film thickness of the film, L is the winding length, and D _c is the outer diameter of the core And ε _max represents a threshold value calculated by the following procedures (1) to (5) using an optimization algorithm of Newton's method.
Step (1): A target function for optimization is prepared as the following formula (2).

In the above equation (2), T represents the tension, and W represents the entire width of the film.
Step (2): Temporarily determine an arbitrary value as ε _max .
Step (3): Create a derivative of the following equation (3). However, the minute amount: Δε.

Step (4): The ε _max tentatively determined in the above step (2 ) is updated by the following formula (4).

Step (5): Repeat the calculation of the above steps (3) to (4) until f (ε _max ) approaches 0 sufficiently with the updated ε _max .   The film flatness inspection apparatus according to claim 1, wherein the information regarding the slack includes information regarding the presence or absence of the occurrence of the longitudinal sag and a portion in the state where the tension is applied. The arithmetic processing unit
When the amount indicating the amount of change in the outer diameter dimension is the amount indicating the film length in the longitudinal direction in the state where the tension is not applied, the change in the outer diameter dimension in the state where the tension is applied The amount indicating the film length in the longitudinal direction of the portion where the amount indicating the amount is minimum is calculated as ε _max
A portion where an amount indicating a change in the outer diameter dimension exceeds ε _max , which is an amount indicating the film length of the minimum portion, is determined as a sag occurrence portion.
The film planarity inspection apparatus according to claim 1 or 2 , characterized in that Furthermore, a shape measuring device for measuring the amount of change in shape of the film roll in the roll axis direction by a contact type or non-contact type displacement sensor is provided, and the shape measuring device measures information on the amount of change in the measured shape. The film planarity inspection apparatus according to any one of claims 1 to 3 , further comprising: output means for outputting the signal to the arithmetic processing unit. The film flatness inspection apparatus according to claim 4 , wherein the arithmetic processing unit calculates an outer diameter dimension of the film roll based on measurement information of the measured amount of change in shape. The arithmetic processing unit calculates the amount of sag at any inter-roll distance by comparing the amount of strain in the longitudinal direction between the portion where sag occurs and the portion where sag does not occur in the tensioned state. The film planarity inspection apparatus according to any one of claims 1 to 5 , characterized in that: Film A method for in wound up film roll state on the core to check the flatness of the film,
A step of calculating a film roll outer diameter dimension, an amount indicating a change amount of the outer diameter dimension of the film roll, and stress applied to the film in a longitudinal direction in a state where the film is rewound between two rolls by an arbitrary tension. If, for on the basis of the relationship, comprising the step, to obtain information about the presence and site of generation of the longitudinal direction of the slack,
In the step of acquiring information regarding the presence or absence and occurrence of the slack, the stress σ (x) at the time of unwinding the film at an arbitrary location x in the roll axis direction of the film roll is expressed by the following equation (1) Calculated by
A film planarity inspection method characterized in that.

In the above equation (1), u (x) is a change in the shape of the film roll at the portion x with respect to the shape of a predetermined portion in the roll axis direction of the film roll, and min (u (x Shows the minimum value of the amount of change u (x) of the shape in the entire roll axis direction of the film roll, t is the film thickness of the film, L is the winding length, and D _c is the outer diameter of the core And ε _max represents a threshold value calculated by the following procedures (1) to (5) using an optimization algorithm of Newton's method.
Step (1): A target function for optimization is prepared as the following formula (2).

In the above equation (2), T represents the tension, and W represents the entire width of the film.
Step (2): Temporarily determine an arbitrary value as ε _max .
Step (3): Create a derivative of the following equation (3). However, the minute amount: Δε.

Step (4): The ε _max tentatively determined in the above step (2 ) is updated by the following formula (4).

Step (5): Repeat the calculation of the above steps (3) to (4) until f (ε _max ) approaches 0 sufficiently with the updated ε _max . Furthermore, the strain in the state where the tension is applied between the step of determining the portion where the strain amount of the film roll exceeds the ε _max as the sag generation portion at the portion x and the sag generation portion and the portion where the slack is not generated. The film planarity inspection method according to claim 7 , further comprising the step of: calculating the amount of sag at any inter-roll distance by comparing the amounts. 9. The film planarity inspection apparatus according to claim 7 , further comprising the step of measuring the amount of change in the shape of the film roll in the roll axial direction by a contact or noncontact displacement sensor.

Images