JPS5933121A - Manufacture of film - Google Patents

Abstract

PURPOSE:To obtain a film whose thickness is less scattered in the transversal direction using the calendering method, by arranging a plurality of heaters widthwise of a film at suitable points of takeoff zones of the film or a widening zone of the film width. CONSTITUTION:After the take-off zones 5, 6 after a melted resin rolling zone A consisting of three or more rolls 1-4 or after the film widening zone 7 after the takeoff zones 5, 6, the plurality of heaters 24 are arranged transversely of the film 27 with a certain distance between the heaters 24, and the temperatures of the heaters 24 are controlled independently to each other. The diameter of the roll of the film 27 taken up via a cooling zone 9 is measured at points in the transversal direction of the roll, and the temperatures of the heaters are controlled according to the measured diameters.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a film.

More specifically, it relates to a method for producing a thermoplastic resin film with little thickness fluctuation using a calendar molding method. It is something to do.

When producing a film using the calendar molding method, the film is heated and kneaded on the rolls of a calendar device, then rolled with the rolls,
The film is stretched and cooled to a predetermined thickness, processed into a predetermined width using a slitter, and then wound into a film roll using a winding device.

In manufacturing the film, it is extremely difficult to make the film uniform in thickness from one end to the other. Normally, when measuring thickness +' in the width direction of a film, changes in thickness such as thinner or thicker film appear.

For this reason, films with such uneven thickness are rolled and rolled. Even if the roll is rolled, the result is a defective product with variations in the diameter of the roll.

Is the change in film thickness due to the calendering method due to insufficient adjustment of the distance between the Ωth roll from the end and the last roll in the calendaring device? Other than the interval?
Deficiency in mechanical parts? Does it depend? , between rolls? Interval. Tree eggs discharged from... 1 amount: i{L, K”″′゛・1
．． Zoni y. ．． ．． ．． *. ．． This is thought to occur due to i(7)@1″′.

Can the uneven film thickness caused by the above phenomenon be made uniform? Correction? The following methods are conventionally known for this purpose. ? ? (a) What is the measured value of the thickness measured using various film thickness measurement devices? Based on the experience of the workers, the amount of resin fed to the calender roll, the temperature of the resin, etc. should be adjusted to compensate for non-uniformity. Row saving level, roll spacing, amount of stretching! Cooling conditions? How to adjust etc.

(mouth) Measurement of various film thicknesses. Measure the entire thickness with the device,
A method of adjusting the film thickness by feeding back the measured value to a device that adjusts the roll spacing, a device that bends one roll at the center (roll pending), etc.

However, method (a) above requires constant monitoring by a skilled worker. Lately, there has been a shortage of experienced members, and this method has been lacking.

．． The direction of (・). From method (b). Although it is practical, it has the following drawbacks. ...Zunawaji, for example, when measuring the thickness of a film using a Beta wire thickness meter (Beta gauge), does the thickness measuring device measure the collapse of each part of the film while moving in the width direction of the film? Is it fi? Leb"Id is moving in the longitudinal direction, ?llll
] 'm'''-ah:, the value includes not only the thickness change in the width direction, but also the thickness change in the one-hand direction.Therefore, this constant result Even if the data based on the image data is fed back to the Karetsuda device and adjusted, the film thickness cannot be corrected uniformly, and the result is sometimes worse than before the adjustment.Film manufacturing When the speed (line speed) is high, problems such as those described in "2" are likely to occur, and reliability is extremely low.

The present inventors developed calender molding, which has a high film production speed (line speed). To eliminate the above-mentioned problems in the method, and provide a method for manufacturing a film with slight thickness fluctuation. As a result of extensive research, we have completed the present invention.

However, the gist of the present invention is that it consists of at least three rolls. When manufacturing a film using equipment equipped with a molten resin rolling zone, film take-off zone, film widening zone, film cooling zone, film winding zone, etc., the appropriate location of the film take-off zone or film widening zone. Is it perpendicular to the film's direction of travel? Ni, one? Multiple heaters at regular intervals. First, each heater is arranged so that it can be controlled independently, and the thermoplastic
After rolling and widening the plastic resin into a film, after cooling it, it is wound up in a winding zone, and the diameter distribution of the film roll after winding and winding is completed is determined. The method of manufacturing a film is characterized in that the electric power applied to the heater is adjusted in accordance with the distribution.

Hereinafter, the present invention will be explained in detail based on the drawings, but the present invention is not limited to the following examples.

Fig. 1 is a schematic diagram of an example of an apparatus used in carrying out the present invention. FIG. 2 is a schematic plan view showing an example of the arrangement of heaters, and FIG. 3 is a schematic view of an example of a film roll diameter measuring device.

．． ．． '1 In the figure, /1 is the final roll of the pot, and ko is the 2nd r:I roll.
3 is number 3. 3 rolls, Guha front roll, 3'', Otsu are take-off rolls, 7 is film widening device, g is pin, ji is cooling zone, /0 is roll, // is both sides, edge cutting device/equipment, /Jy / is the winding core, L.3', //l'
,'． ? λ is a film roll, /, ta is a diameter side regulator, /6 is an arithmetic circuit, /7 is an amplifier, 7g is a terminal for inputting a setting command signal, /9 is an amplifier for a setting command signal, . 2θ is an arithmetic device, 2/ is an operating device, . 2.2 is the power supply, . 23 is a town resistor for power adjustment; The 2nd one is a heater,
．． 25 is wiring, . 2A, 2? Each film is 33
3 indicates a differential transformer.

In the present invention, an apparatus with a molten resin rolling zone consisting of at least three rolls is used. This rolling zone is an area where the molten resin is rolled into a film. Examples of the combination of rolls may be any combination of ordinary calendering devices, such as inverted L-shape, ■-shape, L-shape, Z-shape, etc.

A film take-off zone is provided next to the rolling zone. This film take-off zone is an area where the film rolled in the rolling zone is taken off. As for the combination of rolls in the film take-off zone, a number of rolls may be introduced to each other as shown in Figure 1, or three or more rolls may be combined.

A film widening zone is provided next to the film take-off zone. This film widening zone d is an area where the film is widened within a range that does not cause molecular orientation in the film. To widen the film, hold both edges of the film λ and widen it to make a wide film mook. To hold both ends of the film, a conventionally known widening device such as a bin tenter or clamp may be installed.

After the film widening zone, there is a film cooling zone,
A film winding zone is provided.

In the present invention, a plurality of heaters are arranged at regular intervals in a direction perpendicular to the film traveling direction at appropriate locations in the film take-off zone or the film widening zone, and each heater can be independently controlled. do.

The heater may be placed in either the film take-off zone or the film widening zone. When placed in the film take-off zone, either take-off roll Shio or Otsu is placed parallel to the center axis of the take-off roll. The heater may be arranged so as to directly heat the film or may be arranged so as to heat the take-off roll surface. When the heater is placed in the film widening zone, it is placed on the entrance side of the film widening zone at right angles to the film traveling direction.

Kou: The figure shows an example in which the heater 2 is placed on the entrance side of the film widening zone.

The heater is... In this way, they are arranged at predetermined intervals in a direction perpendicular to the direction of travel of the film at appropriate locations in the film take-off zone or the film widening zone.

A plurality of heaters are combined, and each heater can be controlled independently. In this way, partial thickness fluctuations in the width direction of the film can be easily and preferably corrected by adjusting the voltage applied to the heater.

The figure shows the heater λ. An example is shown in which the film λB is arranged in a direction perpendicular to the traveling direction of the film λB (indicated by an arrow in the figure). H. One tar. The 2G is composed of a plurality of blocks, and each block is connected to the 2G by a wire. It is connected to the power supply λa. Furthermore, in the middle of the wiring 2 (between the heater 2 and the power supply !), there are multiple power adjustment variable resistors 2 corresponding to the heater blocks.
An example is shown in which 3 is installed.

A film cooling zone and a film winding zone are provided after the film widening zone.

The film cooling zone is an area where the film, which has been widened in the widening zone, is cooled in a trench at room temperature. In the cooling zone, the film is passed between multiple rolls,
A method may be adopted in which this method is combined with a method of blowing air at room temperature or cooled to below room temperature onto the film.

The film winding zone is an area where the cooled film is wound into a roll. In the film winding zone, a conventionally known film winding device can be used.

In the present invention, the diameter distribution of the film roll after winding is completed is detected, and the power of the heater is adjusted in accordance with the detected diameter distribution.

In order to detect the diameter distribution of the film roll, it is preferable to use a film roll diameter measuring device, an example of which is schematically shown in FIG. No. ? In the example shown in the figure, when the film roll is cut along the length direction through the central axis, the presser rolls 33, , ? 3. Soylum roll,
? Arrangement 1~ with the yu facing each other, and reciprocating along the dotted line in Figure 3 with the yaws facing each other. At this time, what is the diameter of film roll 3.2? The shaft of the presser roll 33 is connected to a differential transformer. It can be detected by linking to ylI.

One set of film roll diameter measuring instruments is sufficient, but two or more sets can also be arranged. d′ when two or more sets are arranged;
When these are reciprocated on a film roll, it is preferable to change their arrangement positions so that they do not collide with each other.

The signal measured by the film roll diameter measuring device is sent to an arithmetic circuit consisting of an integrating circuit and a dividing circuit. The signal from the arithmetic circuit/t is amplified by the amplifier/7, and the output signal of the amplifier/7 is sent to the arithmetic unit. ．． Enter 20.

Measure the relationship between the Y number of film windings on the film core and the diameter of the film roll by actually measuring the relationship between the number of film windings on the film core and the diameter of the film roll, and input this from the setting command signal input 1/river terminal 7g. This signal is then amplified by a 14-width amplifier/9.

The signal from this amplifier/9 is compared with the signal from the film roll diameter 4-meter/ta (<<the signal from the original amplifier/7> is compared and calculated by the calculation device λ0.)
: Input the calculation result to the embankment production device 2/1 along with the correction signal 1
〜, Through this, the power adjustment variable resistor 23 is adjusted in detail, and the heater. Apply electricity to the two required blocks and heat them.

For example, if the thickness of the film suddenly increases in some areas, this phenomenon is detected by a diameter measuring device on the film lawn, and this detection signal is processed via an arithmetic circuit and an amplifier. Sent to the device. On the other hand, the arithmetic unit 10 compares the actual measured value with the target value (the value input from the setting command input/river terminal/g) and calculates ? The calculation result is inputted as a correction signal to the operating device 2/, and the amount of electricity applied to the heater corresponding to the thick and large portions of the film is increased to heat the film and widen it in the film widening zone. In this case, the thickness of the film is the same as that of other parts.

Film roll of flexible compounded polyvinyl chloride film produced continuously according to the method of the present invention (rolling core diameter 7.2 g,
Film roll diameter: approx. 300 mm, film width: 300 mm
m). A.O. Lie the diameter of the film in the width direction for each book:
Lumuror - it's true. Measure at 20 locations, find the difference between the maximum value and minimum value and use it as the horizontal axis, and the frequency of occurrence as the vertical axis.
? It is shown in Fig. In the example shown in this figure, the average value of the difference between the maximum and minimum values is o. )t. '． ? rran
Met.・? Well, 60 film rolls (approximately the same size as above) of soft blended polyvinyl chloride film were manufactured in succession using the conventional method while manually adjusting the film thickness, and each of these film rolls was , measure the diameter as above and find the difference between the maximum and minimum values (shown on the horizontal axis),
Part 1] The current frequency (indicated on the vertical axis) is shown in Figure S.

In the example shown in this figure, the average value of the difference between the maximum value and the minimum value was in the order of 80'3.

From FIG. 1 and FIG. S, it is clear that when the method of the present invention is used, the vibration due to the difference in diameter of the film roll is reduced.

? The present invention has the following particularly remarkable effects, and its industrial utility value is extremely significant. Ru.

(1) In the manufacturing process of Tfilm, what is the best way to minimize changes in film thickness that occur due to rolling, widening, cooling, winding, and other factors? After the final process? The diameter distribution of each film roll is detected using a diameter measuring device, and a correction signal is sent to the variable resistor setting signal for adjusting the power of the heater. The thickness of the film can be adjusted to be uniform by adjusting the feeding method. Is this against change? Can you respond quickly and create a final state that includes all of the factors? Since it is corrected based on the measured value, the operation can be performed accurately.

(2) In addition, since the diameter distribution of the roll and roll is measured in the width direction of the film, it is possible to measure each position in the width direction, which eliminates unnecessary factors like conventional thickness measurement. Because there are no heaters, it is possible to inspect the heater with high precision, and only the necessary parts of the heater can be inspected. By automatically applying only the amount of force that is actually required, it is possible to produce a film with a uniform thickness and lifetime.

(3) When the method of the present invention is used, it is possible to control the diameter of the wound film roll, and a film roll having a uniform diameter without uneven diameter distribution can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an example of a device used in carrying out the present invention, Fig. 1 is a plan view showing an example of the arrangement of heaters, and Fig. 3 is a schematic diagram of two examples of a film roll diameter measuring device. The schematic diagram, Figure 1, shows the width of the film in the film width direction per 0 film rolls of soft blended polyvinyl chloride film produced continuously by the method of the present invention. Measure the diameter, find the difference between the maximum value and the minimum value, and plot it on the horizontal axis. Figure s is a diagram showing the frequency of appearance on the vertical axis, and Figure s is similar to Figure q for 0 film rolls manufactured by the conventional method. In the figure, /(rif'$ final roll., λ first roll, 3.Irl, third roll, roof front roll, left, O is the take-off roll, 7 is the film widening device,
gld pin, wa is cooling zone, /θd roll, //'(
r3H both ends cut long, /Jin 3/C1, each winding core, /
3, /'1,3;l is the film roll with a difference, /S is the diameter measuring device, /A←arithmetic circuit, /ku is the amplifier, /,g is the setting command signal input 1/river terminal device, /9 is the Setting command signal amplifier, 10 is i'Iit calculating device, 2/ is operating device, ;l-! is a power supply, C3 is a variable resistor for power adjustment, . 2
Gahahi... 1 ter and ko S are wiring, 3 and Ω7 are each film, 33 is a presser roll, 3 DA is a differential transformer:. Indicates the Applicant Mitsubishi Monsanto Chemicals Co., Ltd. Representative Patent Attorney Hajime Hasegawa (and others/names) -126

Claims (1)

[Claims] (1) When manufacturing a film using a device that includes a molten resin rolling zone, a film take-off zone, a film expansion zone, a film cooling zone, a film winding zone, etc. consisting of at least three rolls, At appropriate locations in the take-off zone or film widening zone, they are placed at regular intervals in a direction perpendicular to the direction of film travel. te plural/number. Individual:
The heaters are arranged so that each heater can be controlled independently, and the thermoplastic resin is compressed into a film. After being stretched, widened, and cooled, it is rolled up in the winding zone, and the winding is completed. Later film low? 1. A method for manufacturing a film, comprising: detecting a diameter distribution of the film, and adjusting electric power applied to the heater in accordance with the detected diameter distribution.