JPS62161007A - Method for measuring slackening amount of sheet like article - Google Patents

Abstract

PURPOSE:To make is possible to measure the slackening distribution of a sheet like article in the lateral direction thereof with good accuracy, by slitting the sheet like article along the longitudinal direction thereof and comparing the predetermined length of each narrow strip like slit tape with the length of an adjacent tape. CONSTITUTION:A sheet like article 3 grasped by a guide roll 1 and a nip roll 2 at one end thereof is slit into narrow strip like slit tapes by a cutter 5 in a state tensioned horizontally and the other end thereof is grasped by the roll 2 like one end thereof. The slit tapes are grasped by the rolls 1, 2 preliminarily arranged at a predetermined interval but displace to a vertical direction by external force, for example, a weight 4 at almost central parts thereof. If this displacement quantity H is small in a degree capable of neglecting the elongation of the tapes due to the weight 4, said quantity H corresponds to the length of each tape. That is, because the part generating slackening of the sheet like article 3 is longer than the tape of other part, the displacement quantity H in the vertical direction becomes large. By this method, if the displacement quantities H of the tapes are arranged in the lateral direction, distribution of continuous slackening amount can be measured with good accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for quantitatively measuring unevenness in the flatness of a wide sheet-like material such as paper, fabric, film, sheet, etc. More specifically, it is a method for quantitatively and accurately measuring the irregularities that occur during the manufacturing and processing of sheet-like objects, such as sag (badgey) that tends to occur in sheet-like objects and irregular sagging at the side edges (loose edges). related to.

[Prior Art] Relatively wide sheet-like materials such as plastic films and paper cannot always maintain a constant width and constant length during manufacturing and processing. For example, in the production of synthetic resin films, sagging occurs in the center and side edges of the film due to subtle changes in stretching conditions, unevenness in heat treatment temperature, uneven cooling conditions, and the like. The change in length in the width direction can be maintained at a predetermined width by trimming both ends, but
Local length changes in the longitudinal direction are observed as sag.

If there is slack in the sheet material, processing operations become difficult. For example, when printing on the surface of a sheet-like object, printing misalignment may occur; for example, when applying a coating to the surface of a sheet-like object, uneven coating of the coating film or uneven coating thickness may occur. is. Typical examples include poor running of seams during production and processing processes and skew in video tapes.

As a means for temporarily dealing with such problems with the flatness of a sheet-like object and improving or restoring the flatness, it is known to heat-treat the sheet-like object under tension or non-tension conditions. However, accurately measuring flatness issues is not well known.

Conventional flatness restoration methods have simply relied on the experience and intuition of skilled workers and have been solved by trial and error. Therefore,
The first challenge is to accurately measure the sagging of sheet-like materials and the distribution of sag generation, and solving these problems will lead to the production of high-quality products in the manufacturing or processing of sheet-like materials. By quantitatively measuring the force that causes sag, we can determine the local temperature (heating/cooling conditions) and tension (faults in tenter clips, etc., and tension failures) at that location of the sheet material. By knowing the state of uniformity (condition of uniformity) and taking adjustment measures, it is possible to immediately apply the technology to obtain uniform, high-quality products.

OBJECT OF THE INVENTION] An object of the present invention is to provide a technique for accurately measuring the sag distribution in the width direction of a sheet-like object.

[Structure of the Invention] When a sheet-like object has slack, it cannot be measured quantitatively because of interference from surrounding parts. Therefore,
The present invention slits a sheet-like material along the longitudinal direction,
By using a strip-shaped slit tape and comparing a predetermined length of this tape with an adjacent tenip, the local difference in length can be measured, and the sagging of the sheet-like material can be accurately determined.

That is, by using a slit tape, interference from the surroundings can be removed. Therefore, the length of each slit tape is determined in relation to the position in the width direction of the sheet material.
When measured, an accurate state of the sag distribution is required.

The present invention cuts a sheet-like material in the longitudinal direction to obtain a plurality of strip-shaped slit tapes, grips the tapes at predetermined intervals, and then applies an external force to the tapes from a substantially perpendicular direction, thereby causing displacement due to the external forces. This is a method of measuring the amount of slack in a sheet-like object based on the position of the tape in the width direction of each sheet-like object and the amount of displacement thereof.

To explain the present invention, the cutting width when cutting a sheet-like object along the longitudinal direction is related to how precisely the slack distribution in the width direction of the sheet-like object is measured. Then, select an appropriate slit width as a production/processing control index. Generally, the sheet-like material is slit to obtain about 10 to 30 slit tapes, or 2
There are two selection criteria for cutting to a width of approximately 0 to 300 mm.

Of course, the width of the slit tape can be determined arbitrarily.

The slit tape is gripped by a nip roller or the like at regular intervals. The state before gripping must be the same state as the sheet before being slit. It is a feature of the invention that the individual lengths of the slit tape are measured while still being held. An external force is applied from a direction substantially perpendicular to the tape at approximately the center of the gripped tape, and the amount of displacement of the tape is read at that position.

To explain this situation with reference to the drawings, FIG. 1 is a perspective view showing a state in which a sheet-like object is slit and held at predetermined intervals. The sheet material 3 whose one end is held by a pair of rolls, the guide roll 1 and the nip roll 2, is slit by a cutter 5 while being stretched horizontally.
The other end is held between the nip rolls 2 in the same way as the one end. The slit tape is held by guide rolls and nip rolls that are necessarily crimped at predetermined intervals, and is vertically displaced approximately in the center by an external force (the peg 4 in the figure). This vertical displacement corresponds to the bending of the gripped tape if the elongation of the slit tape due to external force is negligible. That is, since the tape in the sagging portion of the sheet material is longer than the tape in other portions, the amount of displacement in the vertical direction increases.

Figure 2 schematically shows that the amount of displacement H in the vertical direction reflects the length in the horizontal direction, and a slight difference in length in the horizontal direction is observed as a large displacement in the vertical direction. This shows the principle behind how it can be done.

In fact, as shown in Figure 3, the difference in the actual length of the tape is 1~
If it is 5 mm, it can be expanded and measured as a displacement of about 20 to 60 mm in the vertical direction. FIG. 3 also shows the ratio of the true length and displacement in the perpendicular direction as an amplification factor.

Figure 1 shows the case where the slit tape is stretched horizontally, but it is possible to measure the length (amount of walnuts) of each tape by applying a horizontal external force to the tape stretched vertically. Needless to say. Furthermore, although a weight is used as the external force in FIG. 1, the amount of displacement under constant tension can also be measured by a device that is equipped with a tension detection means and whose length can be changed. It goes without saying that such a device has the same measurement principle as that shown in FIG.

Other examples include a weight suspension method, a support method using air pressure, and an air blowing method (air micrometer, etc.).

In the present invention, the sheet material is slit into strips, supported at regular intervals, nipped, and external force is applied to measure the amount of displacement from the reference position, so the results are measured in the width direction. By arranging them side by side, the distribution of continuous Kurjis can be measured with high accuracy.

Furthermore, as a result of the strip-shaped slits, the influence of adjacent interference can be completely ignored. The width when slitting into strips can be arbitrarily selected depending on the purpose and use, but it is 500 to 1000 mm.
When grasping the internal width of 50 to 100 mm
It is better to divide it into parts. The method of measuring the amount of displacement by applying an external force according to the present invention not only makes it possible to magnify the difference in the length of the strip, but also amplifies and reads minute amounts of luminescence, which greatly improves measurement accuracy. The resolution becomes higher as the value of the external force applied during measurement is as large as possible within the elastic limit range of the object.

[Effects of the Invention] The Kurzi distribution in the width direction, which could not be grasped conventionally, can be resolved with high precision, so the following effects can be obtained.

■It becomes possible to adjust and manage conditions with high precision in the sheet-like product manufacturing process, achieving process stability and productivity improvement.

■Quality assurance can be established according to usage and purpose.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of the present invention, FIG. 2 is an explanatory diagram of the configuration in which the weight is suspended and the amount of hanging from the reference position is expanded;
and FIG. 3 are theoretical graphs showing the characteristics of the method of the present invention for each Kurji m. In the figure, 1: nip guide roll, 2: nip roll, 3: sheet-like material, 4: weight, and 5: cutter.

Claims (1)

[Claims] A sheet-like material is cut along the longitudinal direction to obtain a plurality of strip-shaped slit tapes, and after gripping the tapes at predetermined intervals, an external force is applied to the tapes from a substantially perpendicular direction, and the amount of displacement due to the external forces is calculated. A method of measuring the amount of slack in a sheet-like object based on the position of the tape in the width direction of each sheet-like object and its displacement.