JP2003266525A - Sheetlike article take-up roll and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheetlike article take-up roll with little change in raw material shape data and little unevenness when used by a user and to obtain a favorable wound posture having no winding bump and winding wrinkles. <P>SOLUTION: A thermoplastic resin is formed into a sheet and this sheet is taken up by a winder to be slit by a slitter. The slit sheet is taken up to form the sheetlike article take-up roll. This sheetlike article take-up roll is characterized in that the difference between the maximum and minimum values of a winding diameter distribution in the width direction of the take-up roll measured after the elapse of a time predetermined according to the winding hardness of the take-up roll after taking-up is not more than 500 μm. A manufacturing method for the sheetlike article take-up roll is also disclosed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding roll in which the thickness of a sheet-like material is continuously controlled in a film forming process, and after winding with a winder, slitting with a slitter to a predetermined width and winding. The present invention relates to a manufacturing method thereof, and more particularly to a sheet-like material winding roll capable of controlling a good winding shape and a manufacturing method thereof.

[0002]

2. Description of the Related Art In the process of manufacturing a film made of a thermoplastic resin such as polyethylene terephthalate, polyethylene naphthalate or polypropylene, it is necessary to control the thickness of the film in the width direction to a predetermined profile, for example, to make the thickness uniform over the entire width. Required. This film thickness control is based on the thickness of the film measured by a thickness gauge on the downstream side to control the thickness adjusting means arranged over the entire width of the die in order to extrude the molten polymer to obtain the full width of the die. It is common to use a thickness control method in which the amount of each polymer discharged is adjusted to control the desired film thickness.

The method for controlling the film thickness profile by the thickness control means is to biaxially stretch a polymer composed of a wide sheet discharged from a die into a biaxially stretched film, and then a predetermined film. The width is slit to form a take-up roll. At this time, there is a problem that unevenness in film thickness is laminated on the surface of the take-up roll, and a hump or a wrinkle is generated at a specific position in the width direction. The lumps and wrinkles are formed by coating a film with a magnetic material,
It is known to cause unevenness in the thickness of the magnetic layer during vapor deposition, and improvement is needed.

Therefore, the thickness of the biaxially stretched film is measured for a certain period of time with a thickness gauge, and the measured data is integrated to predict the humps and wrinkles in the width direction of the film roll wound in a roll shape. It may be possible to control it.
However, in the film manufacturing process, uneven thickness occurs not only in the width direction but also in the length direction of the film.
There are also changes in manufacturing conditions that are difficult to predict, such as fluttering when the film runs and changes in the film forming environment in the width direction of the film. Furthermore, since the influence of the measurement accuracy of the thickness gauge is also added to measure the thickness of the film, it is necessary to detect the thickness unevenness of the biaxially stretched film which forms a hump or a wrinkle on the film roll. It is difficult in itself.

In order to prevent the rolled humps and wrinkles, an operation called oscillation for swinging the film roll to the left and right is performed in a slit process of slitting the wound wide film roll into a plurality of winding rolls. By doing this, the slits are made while averaging the variation in thickness, but it is not possible to remove the effect of a large lump, which may cause wrinkles on the take-up roll or leave lumps remaining. Many.

As a method for solving the above problems, Japanese Patent Application Laid-Open No.
In 001-30339, the winding diameter distribution in the width direction of the film roll wound in the film forming step is measured, and the predicted value is estimated from the winding diameter distribution to perform control. However, the winding roll that is actually wound in the slitting process is wound in such a manner that it entrains air during winding, so that it is usually wound in a convex shape regardless of the film thickness unevenness. Even if the winding shape can be measured to some extent by adjusting the winding conditions, etc., it is difficult to obtain an accurate predicted winding shape value from the measured value because it has an air entrapment distribution in the width direction of the roll. is there. That is,
It is extremely difficult to find a preset ideal winding diameter target value described in this known example.

Therefore, in order to form a highly accurate take-up roll having no winding hump or wrinkle, the winding diameter distribution in the width direction of the take-up roll wound in the slitting process (hereinafter referred to as the original shape). ) Must be accurately measured and the data must be quickly fed back to the die to control the film thickness. However, the original shape of the take-up roll changes as the trapped air escapes over time. For this reason, if the data of the original fabric shape is measured when the air is not sufficiently discharged, the original fabric shape may change more than expected when the user coats and deposits the magnetic material.
Further, if the data of the original shape measured when the air is not sufficiently released is fed back to the mouthpiece, there remains a problem that the humps and creases are not eliminated or deteriorated.

[0008]

SUMMARY OF THE INVENTION The problems of the present invention are as follows.
To solve the problems of the prior art as described above, to provide a take-up roll with little change in original shape data and less unevenness when used by a user, and good winding without winding humps or wrinkles. It is intended to provide a manufacturing method capable of obtaining a sheet-like material winding roll having an appearance.

[0009]

In order to solve the above-mentioned problems, a sheet-like material winding roll according to the present invention is a sheet obtained by forming a thermoplastic resin into a sheet, winding it with a winder and slitting it with a slitter. In the take-up roll of the object, the maximum value of the winding diameter distribution in the width direction of the take-up roll measured after a predetermined time or more has elapsed according to the winding hardness of the take-up roll after the take-up of the take-up roll. And a minimum value difference is 500 μm or less.

Specifically, the time t1 (min) from the time when the slit of the winding roll is finished to the time when the measurement of the winding diameter distribution in the width direction of the winding roll is started is the winding time of the winding roll. It is desirable that the following expression be satisfied with respect to the hardness K (degree). 3 × 10 ²⁷ × e ^(−0.65 × K ⁾ ≦ t1 Here, K is the winding hardness (degree) of the winding roll measured by the JIS K6301 (1995) spring type hardness test (A type).

Further, the method for manufacturing a sheet-like material winding roll according to the present invention comprises a thickness adjusting means for adjusting the thickness of the sheet-like material installed across the width direction in a die for discharging the thermoplastic resin into a sheet shape. The measuring means for measuring the thickness distribution in the width direction of the sheet-like material adjusted by the thickness adjusting means, the slit means for slitting the sheet-like material into a winding roll having a predetermined sheet width, and the winding roll An outer diameter measuring means for measuring a winding diameter distribution in the width direction, and a device having a control means for controlling the thickness adjusting means by the measured value of the thickness distribution and the measured value of the winding diameter distribution, using the winding roll. From the time when the slit is finished to the time when the measurement of the winding diameter distribution in the width direction of the winding roll is started is changed according to the winding hardness of the winding roll.

Specifically, the time t2 (min) from the time when the slit of the winding roll is finished to the time when the measurement of the winding diameter distribution in the width direction of the winding roll is started is the winding time of the winding roll. It is desirable that the following expression be satisfied with respect to the hardness K (degree). 3 × 10 ²⁷ × e ^(−0.65 × K ⁾ ≦ t2 ≦ 1440 where K is the winding hardness (degree) of the winding roll measured by the JIS K6301 (1995) spring type hardness test (A type).

Further, the winding hardness of the winding roll is preferably 88 degrees or more and 98 degrees or less, and more preferably 92 degrees or more and 96 degrees or less.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below along with its embodiments. FIG. 1 shows a typical manufacturing process of a sheet-like material such as a polyethylene terephthalate (PET) film. The polymer melted by the extruder 30 is filtered by the filter 31, discharged into a sheet form from the die 32, and then cooled and solidified by the cooling drum 33 to form a sheet. Vertical stretching device 34, horizontal stretching device 35
The film is stretched so as to obtain predetermined physical properties and then wound up by a winder 36. The film thickness is measured by a thickness gauge 37 before being wound up by the winder 36, and the film thickness is adjusted by the mouthpiece 32 in order to correct the difference from the target value (generally, uniform thickness). Although polyethylene terephthalate is described as the polymer here, a polymer such as polyethylene naphthalate may be used,
It may be a copolymer of these. Further, fine particles of silica, calcium carbonate, alumina or the like may be added to form surface protrusions. The film structure may be a monolayer film or a composite film in which different additives and different raw materials are combined. As a method for adjusting the thickness of the die 32, for example, a thermal expansion method is known in which a plurality of members arranged substantially evenly in the die width direction are heated and cooled to change the lip gap of the die to change the discharge amount of the polymer. ing. Further, a viscosity method is also known in which a region divided into a plurality in the width direction of the die is partially heated and cooled to change the viscosity of the polymer to change the discharge amount of the polymer. Although the thermal expansion method and the viscosity method are most often used, other film thickness adjusting mechanisms may be used.
Moreover, the method which combined these may be sufficient. The stretching method is generally longitudinal stretching-horizontal stretching, but longitudinal stretching-
After transverse stretching, longitudinal stretching may be performed again, or transverse stretching may be performed again. Further, a method of simultaneously stretching the length and width may be used. As the thickness gauge, those using the β-ray type and the optical interference type are most often used, but thickness gauges of other types may be used. Further, by combining these, the light interference type may be used for a thin film and the β ray type may be used for a thick film.

The film roll 41 wound by the winder 36 is moved to the slitter 40, and is cut into a width desired by the user using the cutter 43, and the winding roll 42 is cut.
a and 42b are manufactured. The take-up rolls 42a and 42b mean an odd-numbered take-up roll and an even-numbered take-up roll cut in the width direction, respectively. Generally, due to space issues in slitters, the pass line is changed depending on whether the winding roll is odd or even. As shown in FIG. 3, the outer shape 1 of the winding roll 42 wound as shown in FIG. 2 is measured by an outer shape measuring device (not shown), and the outer shape distribution is shown as the outer diameter distribution of the winding roll as shown in FIG. Make a graph. When the unevenness of this shape exceeds the allowable range 2 of the target original shape, the film thickness is adjusted by the die so that it falls within the allowable range. Generally, the original shape of each winding roll 42 is measured, and the original shape of the film roll 41 before collecting and collecting the data is created. This shape is compared with the target original shape to find the difference. Here, the target original shape is usually preferably flat, but various shapes such as a convex shape and a concave shape may be adopted depending on the tendency when a user applies or deposits a magnetic material or the like. The film thickness is adjusted with a die so that the difference from this target is minimized. At this time, if the control is performed in consideration of the data from the thickness gauge, the thickness of one sheet and the original shape can be brought close to the ideal shape.

Generally, the thickness unevenness of one film in the width direction is on the order of several% of the product thickness. In contrast,
The unevenness of the original fabric shape is, for example, several hundreds of microns or less for about 10,000 film laminations, and the unevenness per sheet is on the order of 0.01 micron. If the product thickness is 1
When the thickness is 0 micron, the thickness unevenness of the original shape is on the order of 0.1%, which is one digit less than the thickness unevenness in the width direction of the film. Therefore, if the film thickness adjusting mechanism using the spinneret is divided into adjusting means for controlling a large thickness and adjusting means for controlling a small thickness, a highly accurate take-up roll can be obtained.

[0017]

[Example] Using a polyethylene terephthalate (PET) film having a thickness of 6 μm, the winding diameter distribution (original shape)
The relationship between the time t (min) required to start the measurement and the winding hardness K (degree) of the winding roll was investigated.

4 and 5, the winding hardness K = 90 degrees, respectively.
It shows how the original shape of the winding roll at K = 95 degrees changes with time. The time when the winding roll finished slitting with a slitter was set to 0, and the original fabric shape was measured every time elapsed from that time. In FIG. 4 where the winding hardness is low, it can be seen that the original fabric shape changes with time. On the other hand, in FIG. 5 in which the winding hardness is high, it can be seen that there is almost no change in the original shape even after a lapse of time. When the winding hardness is low as described above, it is considered that the air trapped during the winding gradually escapes and the original shape is changed.

Therefore, in the product film having a low winding hardness, the final original shape cannot be known until some time has passed after slitting. When measuring the original fabric shape as inspection data for the user, there is a problem that the true original fabric shape when used by the user changes if the original fabric shape is measured before a certain period of time. In addition, when measuring the original fabric shape during film formation and feeding it back to the thickness adjustment, using the data immediately after the slit to quickly correct the original fabric shape results in the deterioration of the original fabric shape. It will also happen. However, if it is left for a long time, a large amount of scraps will be generated during that time.

Therefore, the time t elapsed until reaching 90% of this shape was measured with reference to the one in which the change of the original shape disappeared after a long time. The results are shown in Table 1. Strictly speaking, the winding hardness changes slightly with time,
Here, the winding hardness after a sufficient time has elapsed is described.

[0021]

[Table 1]

In Table 1, for example, when K = 90 degrees,
It can be said that the original shape measured after 111 minutes or more after slitting has little error even if it is fed back to the die. From Table 1, time t1 (min) until the measurement of the winding diameter distribution (original shape) and the winding hardness K of the winding roll K are started.
When the relationship of (degrees) is expressed by an approximate expression, t1 = 3 × 10 ²⁷ × e ^(−0.65xK) . Therefore, when the original fabric shape is measured as inspection data for the user, the previous equation t1 determined according to the winding hardness from the slitting of the winding roll 42 by the slitter to the measurement of the original fabric shape. The original shape must be measured after (min) time has elapsed. From the results of Table 1, the relationship between t1 and the winding hardness of the winding roll is shown in FIG. The area below the characteristic line shown in FIG. 6 is an area in which the original fabric shape data cannot be fed back to the thickness adjustment or the like.

In the original fabric shape data, the difference between the maximum value and the minimum value of the winding diameter distribution of the winding roll 42 (hereinafter referred to as the original fabric shape unevenness) needs to be 500 μm or less. If it exceeds this, the film is partially stretched at the unevenness of the original fabric, especially at the convex portion, resulting in a plane defect, and a problem occurs that the film is thickly applied in the step of applying and depositing the magnetic material or the like by the user. Therefore, it is more preferable that the unevenness of the original shape is 200 μm or less. Generally, it is ideal that the original shape unevenness is 0 μm, that is, the surface of the winding roll is uniform. However, depending on the delicate characteristics when a user coats or deposits a magnetic material, it may have a convex shape or a concave shape. May create patterns.

Further, in the case of measuring the original fabric shape during film formation and feeding it back to the thickness adjustment, it is necessary to measure the original fabric shape after a lapse of the above equation t1 (min) determined according to the winding hardness. is there. However, in order to prevent the winding roll from being scrapped due to the defect in the original shape, at most 1
It is desirable to measure and feed back the original fabric shape on the day, that is, 1440 (min) or less. Therefore, the time t until the actual measurement of the winding diameter distribution (original shape) is started
The relationship between 2 (min) and the winding hardness K (degree) of the winding roll 42 is preferably in the range of 3 × 10 ²⁷ × e ^{(-0.65xK) ≤t2 ≤1440} .

As a position for measuring the original fabric shape, when the winding hardness is high, it is desirable to perform measurement on the slitter after completion of slitting so that the data of the original fabric shape can be immediately fed back to the thickness adjusting means. When the winding hardness is low, the slitting work is delayed when the slitter waits for a predetermined time on the slitter. Therefore, it is preferable to lower the winding roll 42 from the slitter and measure the original fabric shape at another place.
The method for measuring the original fabric shape is not particularly limited, and may be a non-contact method using a laser or the like or a contact method using a dial gauge or the like.

The winding hardness of the winding roll 42 is preferably 88 degrees or more and 98 degrees or less, and more preferably 92 degrees or more and 96 degrees or less. Roll hardness is 8
If it is less than 8 degrees, the air will enter into the take-up roll 42 too much, and the roll will be stiff and the winding form will be poor. The winding hardness is 98.
If it exceeds the limit, winding defects such as vertical stripes become remarkable, which is not preferable.

As a result of producing the film according to the above conditions, it is possible to reduce the occurrence rate of scraps due to the defective original fabric shape by half.

The above numerical values are not applicable to all cases, but change depending on the raw material, film thickness, winding speed, and the like. Therefore, it is necessary to find the optimum times t1 and t2 for measuring the original web shape depending on the raw materials actually used, the film forming conditions, and the winding conditions.

[0029]

As described above, according to the present invention,
Since the original web shape measurement data of the winding roll does not change when the user uses it, it is possible to prevent the processing loss by the user. Further, it becomes possible to form a take-up roll having an original shape, which is superior to the conventional technique in which the thickness in the width direction is measured and fed back to the die. For this reason, it is possible to prevent the occurrence of winding rolls in which the original fabric shape deviates from the permissible range, and even if it occurs, it is possible to correct it in an early stage and improve productivity and quality. You can

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a manufacturing process of a polyethylene terephthalate (PET) film.

FIG. 2 is a schematic perspective view showing an example of an original fabric shape.

FIG. 3 is a graph showing an outer diameter distribution of the winding roll of FIG.

FIG. 4 is a characteristic diagram showing changes over time in a roll shape having a winding hardness K = 90 degrees.

FIG. 5 is a characteristic diagram showing a change with time in a raw fabric shape having a winding hardness K = 95 degrees.

FIG. 6 is a relationship diagram between the winding hardness of the winding roll and the time until the measurement of the winding diameter distribution is started in the example of the present invention.

[Explanation of symbols]

1 Winding roll outline 2 Tolerance range of target original shape 30 extruder 31 Filter 32 mouthpiece 33 Cooling drum 34 Vertical stretching device 35 Horizontal stretching device 36 winder 37 Thickness gauge 40 slitter 41 film roll 42, 42a, 42b Winding roll 43 cutter

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3F055 AA05 BA12 FA13                 4F207 AG01 AP11 AR12 KA01 KA17                       KL76 KM06 KM15 KW23

Claims (6)

[Claims] 1. A winding roll of a sheet-like material obtained by forming a thermoplastic resin into a sheet, winding with a winder, slitting with a slitter and winding, and having a winding hardness of the winding roll after winding with the winding roll. A sheet-like material winding roll, wherein a difference between the maximum value and the minimum value of the winding diameter distribution in the width direction of the winding roll, which is measured after a predetermined time or more has elapsed, is 500 μm or less. 2. The time t1 (min) from the end of slitting of the winding roll to the start of measurement of the winding diameter distribution in the width direction of the winding roll is the winding hardness K ( Degree), the following formula is satisfied: The sheet-like material winding roll according to claim 1. 3 × 10 ²⁷ × e ^(−0.65 × K ⁾ ≦ t1 Here, K is the winding hardness (degree) of the winding roll measured by the JIS K6301 (1995) spring type hardness test (A type). 3. The winding hardness of the winding roll is 88 degrees or more and 9 or more.
It is 8 degrees or less, The sheet-like material winding roll of Claim 1 or 2 characterized by the above-mentioned. 4. A thickness adjusting means for adjusting a thickness of a sheet-like object installed across a width direction in a die for discharging a thermoplastic resin in a sheet shape, and a width-wise direction of the sheet-like object adjusted by the thickness adjusting means. Measuring means for measuring the thickness distribution in, a slit means for slitting the sheet-like material into a winding roll having a predetermined sheet width, and an outer diameter measuring means for measuring a winding diameter distribution in the width direction of the winding roll, Using a device having a measured value of the thickness distribution and a control means for controlling the thickness adjusting means by the measured value of the winding diameter distribution, winding in the width direction of the winding roll from the time when slitting of the winding roll is completed. A method for manufacturing a sheet-like material winding roll, wherein the time until the measurement of the diameter distribution is started is changed according to the winding hardness of the winding roll. 5. The time t2 (min) from the end of slitting of the winding roll to the start of measurement of the winding diameter distribution in the width direction of the winding roll is a winding hardness K ( Degree), the following formula is satisfied: The method for producing a sheet-like material winding roll according to claim 4, wherein 3 × 10 ²⁷ × e ^(−0.65 × K ⁾ ≦ t2 ≦ 1440 where K is the winding hardness (degree) of the winding roll measured by the JIS K6301 (1995) spring type hardness test (A type). 6. The winding hardness of the winding roll is 88 degrees or more and 9 or more.
It is 8 degrees or less, The manufacturing method of the sheet-like material winding roll of Claim 4 or 5 characterized by the above-mentioned.