JP3961533B2 - Evaluation method for rolls of long rolls - Google Patents

Description

  The present invention relates to a method for evaluating the shape of a roll-shaped original fabric of a long body (for example, a tape-shaped recording medium, various coated sheets, a metal thin film, a film sheet, etc.). More particularly, the present invention relates to a tape-shaped recording medium and a method for evaluating the shape of a roll-shaped raw sheet of a film sheet used in the width direction.

  The roll-shaped original fabric in which the sheet-like long body is wound has a shape in which the roll-shaped original fabric width direction is not a complete straight line but is distorted due to uneven thickness in the longitudinal direction or width direction of the sheet. Understanding the distortion of the roll-shaped original fabric, that is, evaluating the shape, is the cause of various defects when the roll-shaped original fabric is cut into a predetermined width to form the final product form. This is important in preventing such problems in advance and leads to an improvement in yield. For example, in the case of a tape-shaped recording medium (hereinafter also referred to as a magnetic tape or tape), a tape cut into a predetermined width by distortion of a roll-shaped original fabric is bent to the right or left in the tape width direction as shown in FIG. It becomes like the tape 1. This may cause turbulence when the tape is wound, edge damage when it is run, output fluctuation, and the like. If the original film sheet before the magnetic layer is applied is distorted, the magnetic layer is not formed with a uniform thickness, and the above-described phenomenon occurs in the same manner. Therefore, the shape evaluation of the roll-shaped raw fabric is extremely important in terms of product quality and production cost.

  In this type of conventional evaluation method, for example, Japanese Patent Laid-Open No. 8-102064 discloses a measurement in which the shape of the peripheral surface is detected by scanning from one side edge part to the other side edge part of an original roll of magnetic tape. There is disclosed a method for evaluating the amount of bending of a magnetic tape having means and a correlation with the shape of the peripheral surface. According to this method, it is possible to easily and surely determine the shape of the magnetic tape, and to make only the magnetic tape having a value smaller than the specified value of the amount of bending of the magnetic tape as a product, and to greatly improve the yield and reliability of the product. It can be improved.

  Japanese Patent Application Laid-Open No. 2002-283438 discloses a method and apparatus for producing a roll-like sheet that reduces unevenness in the thickness of the sheet and also improves the roll-shaped original fabric shape. This is a method of manufacturing a roll-like sheet in which a molten resin is extruded from a lip into a sheet, and the sheet is stretched and wound up into a roll-shaped raw material. Using a temperature adjustment mechanism that adjusts the temperature, a thickness meter that measures the thickness of the sheet after stretching, a shape measuring means that measures the outer diameter of the original fabric shape, or a shape calculating means that predicts the thickness unevenness of the sheet Until the thickness is within the range, the thickness unevenness control that eliminates the deviation between the sheet thickness unevenness based on the thickness shape information and its target value is performed using the mechanical adjustment mechanism, and then the shape adjustment means or shape calculation is performed using the temperature adjustment mechanism. The control is switched so as to perform the original shape deviation control that eliminates the deviation between the original shape deviation based on the information of the means and its target value.

  According to this method, when the sheet thickness unevenness at the start of sheet production is not stable, the thickness unevenness is within the target value in a relatively short time by controlling the lip gap width by the mechanical adjustment mechanism. After reaching the value, since the temperature adjustment mechanism controls the original shape deviation to be within the target value based on the information of the original shape measuring means or the shape calculating means, not only the thickness unevenness but also the original thickness It is said that it can have a beautiful appearance with no conspicuous irregularities.

JP-A-8-102064 JP 2002-283438 A

  In Patent Document 1, paying attention to the amount of bending of the tape, the yield and reliability of the product are greatly improved. However, the cause of the failure when the long roll of raw material is put into the product state is not only the amount of bending, but also when, for example, a defect such as defective appearance (unevenness defect) occurs in the manufacturing process and the product is used as it is. If it is found to be a defective product, or if it is already a defective product before processing, that is, the roll-shaped original sheet of the film sheet alone before coating the magnetic layer to be a magnetic tape is distorted. However, Patent Document 1 does not mention these problems. In addition, when the magnetic tape roll is made to have a tape width, only the determination of whether the amount of bending of the magnetic tape satisfies the specified value or not, the shape evaluation of the roll itself is not quantified. Quantitative quality control of the raw roll is not possible.

  In Patent Document 2, the sheet thickness unevenness and the original fabric shape deviation are controlled to be within the target values to reduce the sheet thickness unevenness and to improve the roll-shaped original fabric shape. However, this method is effective only when the molten resin is formed into a sheet and then rolled into a roll-shaped raw material, and cannot be applied to a roll that has already been formed.

The present invention solves such problems and quantifies the shape of the roll-shaped raw material such as a tape-shaped recording medium and the roll-shaped raw material of the film sheet that is the basis thereof, thereby improving the yield of the product. And a shape evaluation method that substantially enables quality control in production.

The present invention has been made result of intensive studies to solve the above problems, an evaluation method of the rolled raw sheet in the width direction of the surface shape of the elongate body, rolled raw, the final use A long body cut to a predetermined width during winding is wound, the surface shape of the roll-shaped original fabric is measured, the roll-shaped original fabric width direction position is plotted on the vertical axis, and the roll-shaped original fabric displacement is plotted on the vertical axis Taking a quantity to obtain a measured value at each point, performing a moving average operation on the measured value of the surface shape multiple times in a predetermined moving section to obtain a moving average value, and the deviation between the moving average value and the measured value at each point A numerical value quantified as a numerical index, including a step of using a two-dimensional curve obtained by connecting the deviation of each point as a K-line and a step of quantifying the surface shape from the K-line as a numerical index. and judging the thickness nonuniformity of the elongated member by b It is a Le-shaped raw sheet of the evaluation method.

An example of the evaluation method of the present invention is shown below.

  First, the surface shape of the roll-shaped raw fabric of a long body is measured along the roll width direction and represented by a two-dimensional curve. A conventional technique can be used as a method for measuring the surface shape of the roll-shaped raw fabric of the long body at this time. Next, the moving average of the measured values at each point where the two-dimensional curve is obtained is taken in a predetermined moving section, and this is used as the primary moving average value. The primary moving average value is also taken as a secondary moving average value in a predetermined moving section, and this operation is counted multiple times counting from the first moving average operation. The movement section at the first average operation and the movement section at the second and subsequent average operations may not be the same.

  The moving average operation mentioned here is not a fluctuation in a narrow area of data, but a filtering process for checking a general tendency in a wide area. The number of moving average operations varies depending on the product to which the roll-shaped raw material is applied, but the numerical index for evaluating the yield in the subsequent process from the roll-shaped raw material and the roll-shaped original surface shape described below. From this relationship, it may be determined appropriately according to the yield of the desired issue. In view of data processing time and simplicity, 2 to 3 times are usually preferred.

A two-dimensional curve obtained by connecting the final moving average values is defined as an average center line. The deviation between the numerical value at the average center line and the measured value at each point of the surface shape obtained by the first measurement is determined. A two-dimensional curve obtained by connecting the deviations of these points is defined as a K line. For the required quality items, such as the maximum height of the K-line, the depth of the deepest valley, the difference between the maximum peak and the deepest valley, or the comparison of the area of the portion closed by the K-line and the zero displacement base line Accordingly, it is possible to perform data processing accordingly and use it appropriately. It has been found that by processing these various data, the required quality items can be used.

According to the present invention, the surface shape in the width direction of the elongated roll-shaped original fabric is represented by a two-dimensional curve, and the surface shape of the elongated roll-shaped original fabric is processed by data processing in relation to the average center line. Can be quantitatively evaluated and shape evaluation can be performed using a numerical index, so that the roll-shaped original fabric is measured and evaluated before or after the processing of the long roll raw material, and the subsequent process Reflecting this in the productivity can improve productivity and quality, and can be applied to production management.

Originally, it can be said that the measurement of the thickness unevenness of the surface shape of the elongated roll-shaped original fabric is performed in order to reduce the occurrence of wrinkles and deformation due to the uneven thickness of the roll-shaped original fabric in the subsequent process. The present invention clarifies the index of occurrence of wrinkles and deformation. The evaluation method based on the data processing in the surface shape measurement of the present invention will be described in detail below, using the roll-shaped raw material of the film sheet used for the magnetic tape as the evaluation object for the evaluation method of the elongated roll-shaped raw material shape. .

The procedure of the example is summarized as follows.
(1) The surface shape of the roll-shaped raw fabric is measured.
(2) The measured value obtained in (1) is taken as the roll-shaped original fabric width direction position on the horizontal axis and the roll-shaped original fabric displacement amount is taken on the vertical axis, and the measured values at each point are connected and displayed as a two-dimensional curve.
(3) The moving average section of the primary moving average is set / input, and the primary moving average is averaged using the measurement value obtained in (1) as the original data to obtain the primary moving average value. A primary moving average line is displayed by connecting the primary moving average value at each point on the same graph surface as the two-dimensional curve of the measured value obtained in (1).
(4) A moving average section of the secondary moving average is set and input, and the secondary moving average is averaged using the primary moving average value as the original data to obtain the secondary moving average value. The secondary moving average line connecting the secondary moving average values at each point is used as the secondary moving average line, and this secondary moving average line is set as the average center line. The two-dimensional curve of the measured value obtained in (2) and (3) An average center line is displayed on the same graph as the obtained primary moving average line. In this case, the predetermined moving section may not be the same in the average operation for obtaining the primary moving average value and the average operation for obtaining the secondary moving average value.
(5) The deviation between the value at each point of this average center line (in this case, the secondary moving average value) and the measured value at each point is taken, and the two-dimensional curve displayed by connecting the points is defined as the K line. The K line is displayed on the same graph as the two-dimensional curve of the actually measured value obtained in (2), the primary moving average line obtained in (3), and the average center line obtained in (4).
(6) The average value of the absolute values at each point on the K line is defined as the K value.

FIG. 1 shows a graph representing the two-dimensional curve obtained in steps (2) to (5). FIG. 5 is a flowchart showing the procedure of the embodiment. Hereinafter, it demonstrates according to the procedure of (1)-(6) mentioned above. (See Figure 1)
The roll-shaped original fabric used in the example in the procedure (1) was a roll-shaped original fabric of a film sheet having a thickness of 9.0 μm, a width of 1015 mm, and a length of 6000 m used for a magnetic tape. As shown in FIG. 4, the surface shape was measured using a measuring device equipped with a guide 12 that moves from one end of the roll-shaped raw fabric 21 to the other end and a contact-type shape sensor 13 (Mitutoyo linear gauge). A total of 1013 measurement points were measured.

  (3) The first moving average operation was performed in a moving section of ± 30 points using the measured values as the original data.

  (4) The second moving average operation was performed in a moving section of ± 50 points using the primary moving average value as the original data. In the case of this example, a two-dimensional curve obtained by the moving average of two degrees (from the relationship with the wrinkle defect rate in the film sheet in the preliminary experiment as shown in FIG. 2) was used as the center average line.

  (5) A K-line was obtained from the deviation between the center average line and the two-dimensional curve of the measured surface shape obtained in (2).

  (6) From this K line, the K value calculated using a computer for the average absolute value at each point was 0.020.

FIG. 2 shows the K value obtained by data processing of the two-dimensional curve of each surface shape and the actual magnetic coating applied to each film sheet for a plurality of rolls of the film sheet in this example. It is a graph of the defect occurrence rate resulting from the uneven thickness of the roll of the tape. The horizontal axis represents the K value, and the vertical axis represents the defect occurrence rate (unevenness defect rate) due to the uneven thickness of the roll-shaped raw surface shape of the tape coated with the magnetic paint . As can be seen from the figure, there is a correlation between the K value and the nonuniformity rate, and when the K value is smaller than a certain value (0.008 in this embodiment), the tape coated with magnetic paint is used. It was clarified that the defect occurrence rate due to the uneven thickness of the surface shape of the roll-shaped raw fabric becomes zero.

When the K value is less than or equal to a certain value, it was found that the roll wrinkle generation and deformation of the tape coated with magnetic paint was zero, so measure it before or during the processing of the roll original fabric. Thus, it is possible to know the K value at that time and take measures to bring it closer to a certain value. For example, in the case of a roll-shaped raw material of a magnetic tape before a mirror-finishing process by calendar processing, the K value is calculated from the surface shape measurement, and if the K value is evaluated to be large, the linear pressure of the calendar is increased than usual. In response to the results of measurement and evaluation, such as calendar processing, it can be corrected and corrected in a later process. Moreover, in the case of the film sheet before coating the paint as in this embodiment, it is possible to eliminate the defective product before putting it into the next process.

  In other words, the present inventor has found that a numerical index for evaluating the surface shape of the roll-shaped raw fabric can be used by expressing the surface shape as a two-dimensional curve and processing the data in relation to the average center line based on a new concept. It was. Here, the K value is described as a numerical index from the average center line, but of course, not limited to this, data such as the maximum mountain height, the deepest valley depth, the difference between the maximum mountain and the deepest valley in the K line or the K line It is also possible to perform data processing according to the required quality items, such as comparing the area of the portion closed by the basic line of 0 and displacement 0, and use it appropriately.

The moving section of the moving average operation is not limited to ± 30 points and ± 50 points, and it is needless to say that the section can be appropriately changed according to the required accuracy. Here, the examples are given with the roll-shaped raw material of the film sheet for magnetic tape as the object to be evaluated, but the object to be evaluated of the present invention is not limited to the magnetic tape .

Measured value, primary moving average line and average center line Relationship between K value and uneven defect rate Tape bent Perspective view of measuring means for roll material Flow chart for evaluating roll-shaped raw material

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bent tape 11 Measuring means 12 Guide 13 Contact type sensor 21 Original fabric roll

Claims (3)

It is an evaluation method of the surface shape in the width direction of the roll-shaped raw fabric of a long body,
A roll-shaped raw fabric is formed by winding a long body that is cut into a predetermined width at the time of final use.
Measure the surface shape of the roll-shaped original fabric, take the roll-shaped original fabric width direction position on the vertical axis, take the roll-shaped original fabric displacement amount on the vertical axis, obtain the measured value at each point,
A step of obtaining a moving average value by performing a moving average operation on a surface shape measurement value a plurality of times in a predetermined moving section; and
A step of determining a deviation between the moving average value and the measured value at each point, and using the two-dimensional curve obtained by connecting the deviations of each point as a K line;
Quantifying the surface shape from a K-line into a numerical index,
An evaluation method of a roll-shaped raw fabric, characterized in that thickness unevenness of a long body is determined by a numerical value quantified as a numerical index . The method for evaluating a roll-shaped raw material according to claim 1, wherein the final use form is a magnetic tape. The roll raw material evaluation method according to claim 1 or 2, wherein the step of quantifying the deviation curve into a numerical index calculates a numerical value from an average value of absolute values of each point of the deviation curve.

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