KR101585908B1 - Method and device for winding film and method for manufacturing film roll - Google Patents

Abstract

The winding information such as the thickness of the film, the total winding length, and the like is inputted to the winding information inputting section before starting winding of the film. The winding length specifying portion at switching specifies the winding length at the time of switching by collating the winding information inputted to the winding information input portion with the winding information stored in the LUT memory. The winding of the film starts from straight winding, in which the film is wound so that the side edges are aligned. When the winding length reaches the winding length at the time of switching, the oscillation winding is changed to winding the film while displacing the side edge within a range of a constant amplitude (Wo).

Winding method

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of winding a film,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winding method, an apparatus and a method of manufacturing a film roll for winding a film such as a polymer film.

A polymer film used for a protective film of a polarizing plate for a liquid crystal display (LCD) is generally manufactured by a solution casting method. In the solution film-forming method, first, a dope is prepared. Dope is prepared by dissolving a polymer such as cellulose acetate together with various additives such as a plasticizer, a UV absorber and a lubricant in a solvent. The prepared dope is flexible with an endless support such as a metal band to form a flexible film. The flexible film is peeled from the metal band in that it has self-supporting property. The separated flexible film is dried by hot air or the like to form a polymer film (hereinafter simply referred to as " film "). The film is wound by the winding device after embossing of the concave and convex portions is performed on both side ends (ear portions) by the knurling-imparting roller.

In the winding device, a film is wound by so-called straight winding, in which a film is wound around a core in order so that side edges of the film are generally aligned. The thickness of the ear portion becomes larger than the center portion in the width direction by the embossing process in the film roll wound by the straight winding. For this reason, the winding diameter of the ear portion is often larger than the winding diameter of the center portion. In this case, since the pressure of the surface of the film is concentrated on the nail portion, the embossing of the unevenness formed by the knurling-imparting roller collapses and a phenomenon called ear extension is caused in which the nail portion of the film is stretched in the width direction. In addition, the thinning of the film, the lengthening of the film, and the widening of the film, which are performed in accordance with the demand of the recent liquid crystal display apparatus, further elongate the ear portion.

The thickness of the center portion and the thickness of the ear portion are uneven in the film in which the ear extensions are generated. Therefore, when such a film is introduced into a liquid crystal display, the display performance is affected. When the film is pulled out from the film roll on which the ear was stretched, the width of the film wound on the outside of the winding roll of the film roll by the ear extension is larger than the width of the film wound on the inside of the winding core of the film roll. That is, the size of the film is not matched. For this reason, cutting or the like for adjusting the width of the film is separately required, which requires more processing and cost.

Japanese Unexamined Patent Application Publication No. 2002-28972 and Japanese Unexamined Patent Application Publication No. 2002-87690 disclose so-called oscillate winding in which a film is wound around a winding core so that side edges of the film are shaken in a certain range within a certain range To wind the film. By this winding, the winding diameter of both side edge portions (ear portions) and the winding diameter of the center portion are made almost equal. As a result, the occurrence of elongation at the ear is suppressed and the thickness of the film is prevented from becoming uneven.

However, when the film is wound by osylate winding as in Japanese Patent Application Laid-Open Nos. 2002-28972 and 2002-87690, a part of the film roll may have a winding slackness. If a winding looseness is generated in the film roll, a winding deviation occurs at a place where the winding looseness occurs due to vibration or the like when the film roll is transported. There is a fear that the film is subjected to friction damage due to occurrence of winding displacement. The winding displacement refers to a phenomenon in which a predetermined winding shape (roll shape) is not maintained and changes, that is, the phenomenon that the positions of both side edges of the film roll are displaced from a predetermined position.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a film winding method, an apparatus and a method of manufacturing a film roll which can wind a film so that elongation and winding displacement do not occur in the film roll after winding.

The film winding method of the present invention includes a first winding step and a second winding step. The second winding step is performed after the first winding step. The first winding step winds the film onto the core so that the side edges of the film are aligned. The second winding step periodically vibrates the film or the core in the width direction of the film to wind the film on the core. In this second winding step, the film or the core is periodically vibrated in the width direction of the film so that the side edge is periodically shifted in a certain range with respect to the width direction of the film.

It is preferable to switch from the first winding step to the second winding step when the winding length of the film reaches a predetermined winding length at the time of switching. The winding length at the time of switching is set within a range of 10% or more and 30% or less with respect to the entire winding length of the film.

The method of producing a film roll of the present invention includes a first winding step and a second winding step. The second winding step is performed after the first winding step. The first winding step winds the film onto the core so that the side edges of the film are aligned. The second winding step periodically vibrates the film or the core in the width direction of the film to wind the film on the core. In this second winding step, the film or the core is periodically vibrated in the width direction of the film so that the side edge is periodically shifted in a certain range with respect to the width direction of the film.

The manufacturing method of the film roll further includes a step of obtaining a switching timing. This switching timing is a timing for switching from the first winding step to the second winding step. The timing is obtained based on the entire winding length of the film. The total winding length is the length of the film to be wound. It is preferable that the switching timing is determined by a winding length within a range of 10% or more and 30% or less with respect to the entire winding length of the film.

Further, the winding device of the film of the present invention includes a film winding section, an oscillating section, and a switching section. The film winding portion rotates the winding core to wind the film on the winding core. The oscillation portion causes the film or the winding core to vibrate in the width direction of the film in conjunction with the winding of the film. This oscillation portion vibrates the film or the winding so that the film is an oscillate winding where the winding periodically shifts within a certain range in the width direction of the film on the winding. The switching unit switches the winding of the film from the straight winding to the oscillation winding when the winding length of the film reaches a predetermined winding length at the time of switching.

In the winding device of this film, the winding length at the time of switching is preferably within a range of 10% or more and 30% or less with respect to the entire winding length of the film.

According to the present invention, it is possible to wind the film so that elongation of the ear portion and winding displacement do not occur in the film roll after the winding.

As shown in Fig. 1, the film production line 10 is provided with a film production apparatus 11 and a winding device 12. The film production apparatus 11 manufactures the film 13 by, for example, a solution casting method. In the solution film-forming method, first, a dope is prepared by using the raw materials described in the following [raw materials]. Then, the prepared dope is softened on an endless support to form a flexible film. When the flexible film becomes self-supporting, the flexible film is peeled from the endless support. The film 13 is formed by drying the peeled flexible film by hot air or the like. The formed film 13 is conveyed to the winding device 12 through the nulling roller 15. The knurling-imparting roller 15 forms minute concavities and convexities on both side edge portions (ear portions) in the width direction of the film 13 by embossing or the like. The height of the concavities and convexities formed by the knurling-imparting rollers is preferably 5 占 퐉 or more and 20 占 퐉 or less.

1 and 2, the winding device 12 includes a winding shaft 19, a winding core holder 20, a winding core 21, a turret 22, guide rollers 23 and 24, A dancer roller 25, an encoder 27, an oscillator 29, a winding motor 30, a controller 31 and a dancer unit 32. [ The film size of the object to be wound in the winding device 12 is not particularly limited. For example, it is preferable that the film has a total winding length of 2000 m or more and 7000 m or less and a width of 500 mm or more and 2500 mm or less.

As shown in Fig. 2, the take-up shaft 19 is attached to the turret 22 by a cantilever support mechanism. The cantilever support mechanism is a mechanism for supporting only one end of the take-up shaft 19. A winding core (21) is attached to the winding shaft (19). Both ends of the winding core 21 are sandwiched by the winding core holder 20 of the winding shaft 19. The core holder 20 is slidable in the axial direction (Y direction) of the take-up shaft 19 and is attached to the take-up shaft 19 in a non-rotatable manner. A take-up motor 30 is connected to one end of the take-up shaft 19 so as to rotate the take-up shaft 19. By this rotation, the winding core 21 is also rotated, and the film 13 can be wound around the winding core 21. By winding the film 13, a film roll 38 in which the film 13 is wound in a roll shape is obtained.

A shift mechanism 28 is attached to the attachment end of the take-up shaft 19 in the turret 22. The shift mechanism 28 reciprocates the core holder 20 in the axial direction on the take-up shaft 19. The shift mechanism 28, the take-up shaft 19, and the core holder 20 constitute an oscillation portion 29. The oscillator portion 29 is operated to cause the winding holder 20 to reciprocate in the Y direction on the take-up shaft 19 by the shift mechanism 28 so that each time the film 13 is stacked, The position of the film 13 is shifted within the range of the amplitude W0, and the oscillation of the film 13 can be wound. In the case where the oscillation portion 29 is not operated, it is possible to straightly wind the film 13 in a state where both side edges of the film 13 are aligned. The switching of the straight winding and the oscillation winding is performed by the controller 31.

Here, the oscillation width Wo, which is the oscillation width, can be arbitrarily set, and the amplitude Wo is preferably within a range of 10 mm or more and 30 mm or less. When the oscillation width is within the above range, In addition to being fixed at a constant value, it may be gradually increased or decreased or decreased after the increase.

The guide rollers 23 and 24 and the dancer roller 25 guide the film 13 from the film producing apparatus 11 in the carrying direction (X direction). The dancer roller 25 adjusts the winding tension of the film 13 by moving the film 13 in the up and down direction (Z direction) by the shift mechanism 26. The shift mechanism 26 and the dancer roller 25 constitute the dancer portion 32. [ The encoder 27 transmits an encoder pulse signal to the controller 31 whenever the guide roller 24 rotates at a constant rotation angle. The guide roller 24 may be provided with a tension sensor for measuring the winding tension of the film 13.

The controller 31 controls the driving of the oscillation portion 29, the winding motor 30, and the dancer portion 32. The controller 31 includes a winding information input section 39, an LUT memory 40, a winding length specifying section 41 for switching, a winding length measuring section 42 and a switching judging section 43. Winding information such as the total winding length, thickness and width of the film 13, outer diameter of the winding core 21, and winding tension are input to the winding information inputting section 39.

The winding length (winding length at the time of switching) of the film 13 at the time of switching from straight winding to oscillatory winding is stored in the LUT memory 40 for each winding information. The winding length at the time of switching is preferably set within a range of 10% or more and 30% or less with respect to the total winding length of the film 13, more preferably 15% or more % ≪ / RTI >

The reason why the winding length at the time of switching is set in the above range is as follows. As shown in Fig. 3, the graph 50 shows the relationship between the stress generated in the film 13 in the circumferential direction of the core 21 and the winding length. The stress in the circumferential direction of the film 13 is obtained on the basis of the rotational torque of the winding core 21 and the tensile force by the dancer portion 32. The stress in the circumferential direction of the film 13 becomes positive when the rotation torque of the winding core 21 is greater than the tension by the dancer portion 32 and the rotation torque of the winding core 21 is greater than the tension by the dancer portion 32 It becomes negative when it becomes small. 4, when a force is applied from the point P1 to the outside in the circumferential direction in the film roll 38 on which the film 13 is wound on the winding core 21, The stress in the circumferential direction at the point P1 is positive. Further, when a force is applied in the peripheral direction toward the point P2, the stress in the circumferential direction at the point P2 of the film 13 is referred to as the negative.

The graph 50 of FIG. 3 is obtained in advance from known stress calculation equations based on the tension at the start of winding of the film 13 and the tension at the end of winding. The distribution pattern of the stress in the circumferential direction of the film 13 varies in various values and sound areas according to the parameters such as the thickness, width, winding length, outer diameter of the winding, and change situation of the winding tension pattern of each film. It can be seen that the film is substantially the same distribution pattern as in Fig. 3 from the film winding result of Fig.

The stress in the circumferential direction of the film 13 is positive in the portion where the winding length on the winding 21 side is small in the film roll 38 as shown in the graph 50. [ In Fig. 3, the reference numeral L1 is attached to the winding length whose stress decreases and becomes negative (-) from the portion where the winding length is zero. In the start of winding, the circumferential stress decreases sharply as the winding length becomes longer. Then, the stress in the circumferential direction is further reduced to enter the negative (-) region. In Fig. 3, the reference numeral LE is attached to the winding length corresponding to completion of winding. In the negative (-) region, the stress in the circumferential direction represents the minimum value (Smin). In Fig. 3, the symbol Lmin is added to the winding length indicating the minimum value (Smin) of the stress in the circumferential direction. In the portion where the winding length exceeds Lmin, the circumferential stress increases gradually as the winding length becomes longer, and enters the positive region. After the circumferential stress exhibits the minimum value (Smin), the symbol L2 is added to the winding length which increases and changes in the positive direction. Here, when the stress in the circumferential direction of the film 13 is in the negative region, the rotational torque of the winding core 21 becomes larger than the tensile force by the dancer portion 32, and the winding of the film 13 becomes loose The pressure (surface pressure) of the surface of the film 13 is lowered. The graph 51 of FIG. 5 shows the change of the surface pressure at both side ends of the film 13 when the winding was performed by straight winding, and the graph 52 of FIG. And the graph 53 shows the change in the surface pressure at the right end. As shown in Fig. As shown by these graphs 51 to 53, the lowering of the surface pressure when the film 13 is wound by the straight winding is relatively smaller than the lowering of the surface pressure when the film 13 is wound by the oscillatory winding. The left end of the film 13 is the left end toward the X direction and the right end is the right end toward the X direction.

The lowering of the surface pressure at the time of starting the winding of the film 13 causes the winding of the film roll 38 after winding to cause loosening or winding displacement. Thus, as described above, while the surface pressure is lowered at the start of winding of the film 13, that is, while the stress in the circumferential direction of the film 13 is in the negative region, straight winding is performed, When the length is within the range of 10% or more and 30% or less with respect to the length, it is switched to the oscillation winding. As a result, as shown by the graphs 54 and 55 in Fig. 7, the winding of the film 13 by the straight winding at the start of winding of the film 13 suppresses the reduction of the surface pressure and the stress in the circumferential direction of the film 13 It is possible to disperse the surface pressure in the transverse direction with respect to the width direction of the film 13 to reduce the occurrence of ear extensions. The timing for switching from the straight winding to the oscillation winding is more preferable when the winding length is in the range of 15% or more and 25% or less with respect to the total winding length.

Further, when the winding length is 10% or more of the total winding length, when switching from the straight winding to the oscillation winding, the surface pressure at the start of winding of the film 13 is sharply lowered More reliably. As a result, it is possible to more reliably prevent the film roll 38 from being wrapped or loosened. When the winding length exceeds 30% with respect to the total winding length, the winding in the circumferential direction of the film 13 is wound by straight winding even after the film 13 has passed through the negative region. The elongation of the ear is liable to occur in the film roll 38 as compared with the case of Fig. Therefore, when the winding length is 30% or less with respect to the total winding length, switching from the straight winding to the oscillation winding can be more reliably prevented from occurring than when switching is performed after exceeding 30%.

The winding length specifying unit 41 at the time of switching compares the wrapping information stored in the LUT memory 40 with the wrapping information input to the wrapping information input unit 39 to obtain the wrapping length at the time of switching corresponding to the inputted wrapping information Specify. The winding length measuring section 42 measures the winding length of the film 13 wound on the winding core 21 on the basis of the encoder pulse signal from the encoder 27.

The switching judging section 43 judges whether or not the winding length measured by the winding length measuring section 42 exceeds the winding length at the switching specified by the winding length specifying section 41 at the time of switching. When it is determined that the winding length exceeds the winding length at the time of switching, the oscillation-start-winding start signal is transmitted to the oscillation portion 29. The oscillating portion 29 receives the oscillation retracting start signal and outputs the position of the side edge 13a from the straight winding which winds the film 13 so that the side edge 13a of the film is aligned with the range of the amplitude Wo The winding of the film 13 is changed while the film 13 is being displaced.

Next, the operation of the winding device will be described with reference to a flowchart shown in Fig. First, the winding information of the film 13 to be wound is inputted to the winding information inputting section 39. [ The winding length specifying section 41 at the time of switching specifies the winding length at the time of switching corresponding to the input winding information by collating the winding information input to the winding information input section 39 with the winding information stored in the LUT memory 40 do.

Then, the winding of the film 13 is started by straight winding. At the time of winding, an encoder pulse signal is transmitted from the encoder 27 to the controller 31 every predetermined time each time the guide roller 24 is rotated at a constant rotation angle. The winding length of the film 13 is measured by the winding length measuring section 42 on the basis of the encoder pulse signal.

The switching judging section 43 sequentially judges whether or not the winding length measured by the winding length measuring section 42 exceeds the winding length at the time of switching. When it is determined that the winding length exceeds the winding length at the time of switching, the controller 31 transmits an oscillation winding start signal to the oscillation portion 29. The oscillator portion 29 receiving the oscillatory winding start signal causes the core 21 to vibrate at a constant amplitude Wo along the axial direction (Y direction). Whereby the winding of the film 13 is changed from the straight winding to the oscillation winding.

When the winding of the film 13 is completed, the film roll 38 is separated from the take-up shaft 19. The film roll 38 is transported to various factories by transport means such as a truck. At this time, since the inside of the winding core of the film roll 38 is a straight winding winding, there is no winding loosening, and there is no case where winding displacement occurs in the film roll 38 even if there is vibration during transportation. In addition, since the outer side of the winding of the film roll 38 is an osylate winding, the occurrence of ear extension is suppressed.

In the above embodiment, the core 21 is vibrated in the width direction of the film 13 to wind the film. However, the method of winding the oscillate is not limited to this method, and a well-known method may be used. For example, the winding core 21 may not move, and the film 13 itself may be vibrated in its width direction.

In the above embodiment, the present invention is applied to an on-line solution film-forming apparatus. However, the present invention is not limited to the above embodiment. For example, the present invention can be applied to an on-line melting-film-forming apparatus or an off-line roll-winding switching apparatus.

(Raw material)

In the present embodiment, cellulose acylate is used as the polymer, and triacetyl cellulose (TAC) is particularly preferable as the cellulose acylate. Among the cellulose acylates, it is more preferable that the substitution degree of the acyl group with respect to the hydrogen atom of the hydroxyl group of the cellulose satisfies all of the following formulas (I) to (III). In the following formulas (I) to (III), A and B represent substitution degree of an acyl group with respect to a hydrogen atom of a hydroxyl group of cellulose, A represents substitution degree of an acetyl group, 22 < / RTI > It is also preferable that 90% by weight or more of the TAC is particles of 0.1 mm to 4 mm.

(I) 2.5? A + B? 3.0

(II) 0? A? 3.0

(III) 0? B? 2.9

In addition, the polymer used in the present invention is not limited to cellulose acylate.

The glucose unit having? -1,4 bonding constituting cellulose has a free hydroxyl group at 2-position, 3-position and 6-position. The cellulose acylate is a polymer (polymer) in which some or all of these hydroxyl groups are esterified by acyl groups having two or more carbon atoms. The degree of acyl substitution means that the hydroxyl group of cellulose is esterified (100% esterification is substitution degree 1) for each of the 2-position, 3-position and 6-position.

The total degree of acylation substitution, that is, DS2 + DS3 + DS6 is preferably 2.00 to 3.00, more preferably 2.22 to 2.90, and particularly preferably 2.40 to 2.88. The DS6 / (DS2 + DS3 + DS6) is preferably 0.28 or more, more preferably 0.30 or more, particularly preferably 0.31 to 0.34. Here, DS2 is the degree of substitution of the hydroxyl group at the 2-position of the glucose unit by the acyl group (hereinafter also referred to as " 2-position acyl substitution degree ") and DS3 is the degree of substitution by the acyl group of the 3-position hydroxyl group Quot; 3-position acyl substitution degree "), and DS6 is the degree of substitution (hereinafter also referred to as " 6-position acyl substitution degree ") of an acyl group of a hydroxyl group at 6 position.

The acyl group used in the cellulose acylate of the present invention may be one kind or two or more kinds. When two or more kinds of acyl groups are used, one of them is preferably an acetyl group. When the sum of degree of substitution by hydroxyl groups at the 2-position, 3-position and 6-position is taken as DSA and the sum of degree of substitution by acyl groups other than the acetyl group of the hydroxyl group at 2-position, Is more preferably from 2.22 to 2.90, and particularly preferably from 2.40 to 2.88. The DSB is 0.30 or more, particularly preferably 0.7 or more. In the DSB, 20% or more of the DSB is a substituent of the 6-position hydroxyl group, more preferably 25% or more is a substituent of the 6-position hydroxyl group, more preferably 30% or more, particularly preferably 33% . A cellulose acylate having a degree of substitution at the 6-position of the cellulose acylate of 0.75 or more, more preferably 0.80 or more, and particularly 0.85 or more can be exemplified. A solution (dope) in which solubility is preferable by these cellulose acylates can be produced. In particular, it becomes possible to produce a good solution in a non-chlorine-based solvent. Further, it is possible to produce a solution having a low viscosity and a good filtration property.

The acyl group having 2 or more carbon atoms in the cellulose acylate of the present invention may be an aliphatic group or an aryl group and is not particularly limited. These may be, for example, alkylcarbonyl esters, alkenylcarbonyl esters or aromatic carbonyl esters of cellulose, aromatic alkylcarbonyl esters and the like, each of which may further have a substituted group. Preferable examples thereof include propionyl, butanoyl, pentanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, Nonyl, cyclohexanecarbonyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like. Among them, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are more preferable, and propionyl and butanoyl are particularly preferable.

Examples of the solvent for preparing the dope include aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as dichloromethane and chlorobenzene, alcohols such as methanol, ethanol, n-propanol, n-butanol Diethyleneglycol, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), esters (such as methyl acetate, ethyl acetate and propyl acetate), and ethers (e.g., tetrahydrofuran, Rosorb, etc.), and the like. In the present invention, "dope" means a polymer solution or dispersion obtained by dissolving or dispersing a polymer in a solvent.

Of these, halogenated hydrocarbons having 1 to 7 carbon atoms are preferably used, and dichloromethane is most preferably used. From the viewpoints of the solubility of TAC, the peelability of the flexible film from the support, the mechanical strength of the film, and the physical properties such as the optical properties of the film, it is preferable to mix one to several kinds of alcohols having 1 to 5 carbon atoms in addition to dichloromethane . The content of the alcohol is preferably 2% by weight to 25% by weight, more preferably 5% by weight to 20% by weight, based on the whole solvent. Specific examples of the alcohol include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like, but methanol, ethanol, n-butanol or a mixture thereof is preferably used.

However, in recent years, a solvent composition in the case of not using dichloromethane has been studied for the purpose of minimizing the influence on the environment. For this purpose, an ether having 4 to 12 carbon atoms, an ether having 3 to 12 carbon atoms, Ketones having 1 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and alcohols having 1 to 12 carbon atoms are preferably used. These can be used in an appropriate mixture. For example, a mixed solvent of methyl acetate, acetone, ethanol, and n-butanol. These ethers, ketones, esters and alcohols may have a cyclic structure. Furthermore, a compound having two or more functional groups of ether, ketone, ester and alcohol (i.e., -O-, -CO-, -COO- and -OH) can also be used as a solvent.

Details of the cellulose acylate are described in paragraphs [0140] to [0195] of Japanese Patent Laid-Open No. 2005-104148. These substrates are also applicable to the present invention. Further, additives such as a solvent and a plasticizer, an anti-deterioration agent, an ultraviolet absorber (UV agent), an optically anisotropic control agent, a retardation control agent, a dye, a matting agent, a stripping agent and a peeling accelerator are likewise used in JP 2005-104148 ] To [0516].

The present invention will be described in more detail with reference to Examples 1 to 7 below. Comparative Examples 1 to 3 were conducted as comparative experiments for the present invention. The present invention is not limited to the following examples.

[Example 1]

The film 13 was wound on the winding core 21 by using the winding device 12 shown in Figs. 1 and 2. At first, the film 13 was wound by straight winding, and when the winding length reached the winding length at the time of switching, the winding was switched from straight winding to oscillatory winding. The total winding length of the film 13 was 5400 m, and the winding length at the time of switching was set to 20% with respect to the total winding length.

[Example 2]

The film 13 was wound in the same manner as in Example 1 except that the winding length at the time of switching was set to 12% with respect to the total winding length.

[Example 3]

The total winding length of the film 13 was 1800 m. The winding length at the time of switching was set at 28% with respect to the entire winding length. Other than these, the film 13 was wound in the same manner as in Example 1. The stress in the circumferential direction of the film 13 with respect to the circumferential direction of the winding core was a negative region at the time of switching from the straight winding to the oscillatory winding.

[Example 4]

The film (13) was wound in the same manner as in Example 1, except that the winding length at the time of switching was 8% with respect to the total winding length. At the time of switching from the straight winding to the oscillation winding, the stress in the circumferential direction of the film 13 with respect to the circumferential direction of the winding core was a negative region.

[Example 5]

The total winding length of the film 13 was 1800 m. The winding length at the time of switching was set at 32% with respect to the total winding length. Other than these, the film 13 was wound in the same manner as in Example 1.

[Example 6]

The film 13 was wound in the same manner as in Example 1 except that the winding length at the time of switching was 10% of the total winding length. In the sixth embodiment, the straight winding is performed while the stress in the circumferential direction of the film 13 in the circumferential direction of the winding is in the negative region, and the stress in the circumferential direction of the film 13 in the circumferential direction of the winding is negative From the region to the positive region, from the straight winding to the oscillatory winding. That is, in the seventh embodiment, L 2 in FIG. 3 is 540 m (length corresponding to 10% of 5400 m), and when the winding length reaches 540 m, straight winding is switched to osilyte winding.

[Example 7]

The total winding length of the film 13 was 1800 m. The winding length at the time of switching was set to 30% with respect to the total winding length. Except for these, the film (13) was wound in the same manner as in Example 1. In the seventh embodiment, the straight winding is performed while the stress in the circumferential direction of the film 13 in the circumferential direction of the winding is in the negative region, and the stress in the circumferential direction of the film 13 in the circumferential direction of the winding And switched from the straight winding to the oscillatory winding at a time point from the negative region to the positive region. That is, in the seventh embodiment, L 2 in FIG. 3 is 540 m (length corresponding to 30% of 1800 m), and when the winding length reaches 540 m, the straight winding is switched to the oscillatory winding.

[Comparative Example 1]

The same procedure as in Example 1 was performed except that the film 13 was wound by straight winding.

[Comparative Example 2]

The same procedure as in Example 1 was carried out except that the film 13 was first wound by an oscillate winding and then the film 13 was wound by straight winding.

[Comparative Example 3]

The same procedure as in Example 1 was carried out except that the film 13 was wound with only an osylate roll.

[Winding displacement]

Winding deviation of the film rolls obtained in Examples 1 to 7 and the film rolls obtained in Comparative Examples 1 to 3 were evaluated by visual inspection by the operator as follows.

No: No winding displacement was observed on the film roll.

Oil: There was a problem in the product because the frequency of occurrence of the winding displacement was small in the film roll.

There are quite a few problems: There were many problems in the product because there were a lot of occurrences of winding deviation in the film roll.

[Ear ear height]

The ear extensions of the film rolls obtained in Examples 1 to 7 and the film rolls obtained in Comparative Examples 1 to 3 were evaluated as follows.

A: Lx / La x 100 < 100.1% (very desirable level as a product)

B: 100.1%? Lx / La 占 100 <100.4%

C: Lx / La 占 100? 100% (level at which the product is problematic)

Here, Lx is the width of the film wound on the film roll, and La is the width of the film before being wound on the film roll.

[Friction damage]

The frictional damage of the films of the film rolls 38 obtained in Examples 1 to 7 and the film rolls obtained in Comparative Examples 1 to 3 was evaluated by visual inspection by the operator as follows. In addition, even if winding displacement is not confirmed, friction damage may be slightly confirmed. This is caused by the creasing (friction) of the film in the film roll. The frictional damage in this case corresponds to &quot; B &quot; in the following evaluation.

A: Almost no friction damage was seen on the film.

B: Some frictional damage was seen on the film, but there was no problem with the product.

C: A lot of frictional damage was seen on the film, and there was a product problem.

[result]

The results of Examples 1 to 7 and Comparative Examples 1 to 3 are shown in Table 1 below.

In Examples 1 to 3, there was no case such as winding displacement, friction damage, elongation of ear, or the like occurred in the film roll 38 after winding.

In Example 4, while the circumferential stress of the film 13 with respect to the circumferential direction of the winding was in the negative region, it was switched from the straight winding to the oscillatory winding. However, when the stress in the circumferential direction is in the negative range, the length of the oscillatory reel winding is relatively short, so that the winding deviation does not occur. The resulting friction damage was also at a level that did not cause any problem on the product. Also, ear elongation was not confirmed. On the other hand, in Example 6, in the case where the stress in the circumferential direction of the film 13 in the circumferential direction of the winding was shifted from the negative region to the positive region, the winding was switched from straight winding to oscillatory winding. Therefore, there was no winding displacement and no frictional damage was confirmed. Also, ear extensions were not generated.

In Example 5, the circumferential stress of the film 13 with respect to the circumferential direction of the winding was changed from the negative winding region to the positive winding region, and then from the straight winding to the oscillatory winding. However, since the circumferential stress becomes a positive region and the length of straight winding is relatively short, the ear portion elongation was at a level at which there was no problem in the product. On the other hand, in Example 7, in the case where the circumferential stress of the film 13 with respect to the circumferential direction of the winding was shifted from the negative region to the positive region, the winding was switched from straight winding to oscillatory winding. Therefore, there was no winding displacement and no frictional damage was confirmed. Also, ear extensions were not generated.

Further, in Comparative Example 1, since all of the rolls from the start of winding to the end of winding were wound by straight winding, ear extensions were generated in the film rolls. Further, in Comparative Example 2, since winding was carried out by winding the osylate at the start of winding and winding by straight winding at the end of winding, winding displacement occurred in the film roll and frictional damage caused by the winding displacement occurred. Further, in Comparative Example 3, no ear elongation was generated, but since winding was carried out by winding of osylate from the start of winding to the end of winding, a large winding displacement occurred in the film roll and a large frictional damage due to the winding displacement occurred.

The above objects and advantages will be easily understood by those skilled in the art by reading the detailed description of the preferred embodiments with reference to the accompanying drawings.

1 is a schematic view of a film production line.

2 is a plan view of the winding device of the present invention.

3 is a graph showing the relationship between the film stress and the winding length in the circumferential direction of the winding core.

4 is an explanatory view of the stress of the film in the circumferential direction of the winding core.

5 is a graph showing the relationship between the surface pressure and the winding length when wound by straight winding.

Fig. 6 is a graph showing the relationship between the surface pressure and the winding length when winding by osylate winding. And the solid line shows a change in the surface pressure at the left side end portion with respect to the width direction of the film. And the broken line indicates a change in the surface pressure at the right side end.

Fig. 7 is a graph showing the relationship between the surface pressure and the winding length when wound by straight winding and osylate winding. And the solid line shows a change in the surface pressure at the left side end portion with respect to the width direction of the film. And the broken line indicates a change in the surface pressure at the right side end.

8 is a flow chart showing the operation of the winding device of the present invention.

Claims (6)

A method of winding a film, comprising the steps of: (A) winding the film onto a core so that the side edges of the film are aligned; And (B) periodically vibrating the film or the core in the width direction of the film such that the side edge is periodically shifted in a certain range with respect to the width direction of the film, thereby winding the film on the core Is performed after the step (A). The method as claimed in claim 1, wherein, when the winding length of the film reaches a winding length during switching determined within a range of 10% or more and 30% or less with respect to the entire winding length of the film, B). &Lt; / RTI &gt; A method of manufacturing a film roll, comprising the steps of: (A) winding the film onto a core so that the side edges of the film are aligned; And (B) periodically vibrating the film or the core in the width direction of the film such that the side edge is periodically shifted in a certain range with respect to the width direction of the film, thereby winding the film on the core Is performed after the step (A). The method according to claim 3, wherein a timing for switching from the step (A) to the step (B) is obtained, the timing being obtained on the basis of the total winding length of the film, Wherein the switching timing is determined by a winding length within a range of 10% or more and 30% or less with respect to the total winding length of the film. A film wound section for winding the film on the winding core by rotating the winding core; An oscillation portion for vibrating the film or the core in the width direction of the film so that the film is wound on the winding core in an oscillating manner in which the film is periodically shifted within a certain range in the width direction of the film in cooperation with the winding of the film; And And a switching unit for switching the winding of the film from the straight winding to the oscillatory winding when the winding length of the film reaches a pre-determined winding length at the time of switching. The film winding apparatus according to claim 5, wherein the winding length at the time of switching is within a range of 10% or more and 30% or less with respect to the total winding length of the film.

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