JP3190200B2 - Method and apparatus for widening water flow during running of vinyl alcohol polymer film in water - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment process for a vinyl alcohol-based polymer film, which uses a non-smoothing phenomenon in which both sides of the film curl inward and the film undulates during running in water. The present invention relates to a method for effectively preventing the occurrence by a method, and an apparatus for performing the method.

[0002]

2. Description of the Related Art Vinyl alcohol polymer films such as polyvinyl alcohol films and ethylene-vinyl alcohol copolymer films are widely used as raw films for optical films such as polarizing element films. In the production of, a step of washing the raw film with water is required prior to a dyeing step (a dyeing step using iodine or a dichroic dye) and a stretching step (a uniaxial stretching step). Further, the vinyl alcohol-based polymer film may be run in water for washing or water treatment without being limited to the use of the optical film.

[0003] However, the vinyl alcohol-based polymer film absorbs water when running underwater and swells, and is prevented from curling in a cylindrical shape with both edges of the film and generating wavy called vertical wrinkles. I can't. FIG. 5 is an explanatory diagram showing a curled state of both edges of the vinyl alcohol-based polymer film during running in water. Although FIG. 5 shows a case where both edges of the film curl downward, the film may curl upward, depending on the habit of the film.

[0004] When the film is curled or undulated, the subsequent handling becomes extremely difficult. In particular, when the curl is generated, the curled portion causes blocking and the film is damaged. Sometimes.

Conventionally, in order to prevent such non-smoothing phenomenon such as curling and waving, a method of expanding a film with an expander roll has been adopted. An expander roll is a “c” that spreads out in the roll rotation direction.
With a groove in the shape of.

[0006]

However, when a vinyl alcohol-based polymer film that has absorbed water is spread with an expander roll, the expander roll is originally used in a dry state, so that a so-called hydroplaning phenomenon (under water adhesion) occurs. In this case, a phenomenon in which the film slips and idles), and smooth expansion of the film may not be achieved.

[0007] The width by the expander roll is
The limitation is that it can be applied to films that produce curls up to about 2 cm wide per edge, but not to films that produce 4-20 cm wide per edge.

Further, the expansion by the expander roll causes the roll to come into direct contact with the water-absorbed vinyl alcohol-based polymer film, which causes uneven stretching when the film is stretched in a subsequent step. Or when the film is used for optical applications, the optical properties may be degraded.

Under such a background, the present invention provides a non-smoothing phenomenon in which both edges of a film curl inward and the film undulates in a water treatment process of a vinyl alcohol-based polymer film during running in water. It is an object of the present invention to provide a method for effectively preventing the occurrence of water by a water injection method, and to provide an apparatus therefor.

[0010]

SUMMARY OF THE INVENTION The method of widening water flow of a vinyl alcohol-based polymer film during running in water according to the present invention relates to a method of spreading a vinyl alcohol-based polymer film (F) which is caused when running underwater. A counter-nozzle (11) for the left end comprising a front side nozzle (a) and a back side nozzle (b), and a front side nozzle (a) and a back side nozzle (b) A pair of nozzles (12) for the right end provided with a film (F) running in water is intermittently arranged along both sides of the film (F), and the nozzles (a) of these paired nozzles (11) and (12) ) and (b), characterized in that water is sprayed from the center of the front and back of the film (F) toward the edge.

The water flow spreading device for running a vinyl alcohol polymer film underwater according to the present invention comprises a front side nozzle at both edges of a vinyl alcohol polymer film (F) running in water in a water tank (3). (a) and the left end pair nozzle (11) having the back side nozzle (b) and the right side counter nozzle (12) also having the front side nozzle (a) and the back side nozzle (b). The nozzles (a) and (b) of the paired nozzles (11) and (12) are arranged so that water can be jetted from the center of the front and back sides of the film (F) to the edge side. (11), (12) is provided with a water pipe (2) for pressure-feeding water.

Hereinafter, the present invention will be described in detail.

Examples of the vinyl alcohol polymer film (F) include a polyvinyl alcohol film and an ethylene-vinyl alcohol copolymer film. Here, the vinyl alcohol polymer film is a copolymer modified product,
It may be a graft modified product, a polymer alloy, etc.
Also, two vinyl alcohol polymer films or a vinyl alcohol polymer film and another film may be used.
It may be a laminate of more than one layer.

The vinyl alcohol polymer film (F) is washed or treated with water by passing the film (F) through water in a water tank (3). The film (F) often travels in the horizontal direction in the water tank (3), but sometimes travels diagonally upward or downward, and can travel vertically in a short distance.

In the present invention, the front side nozzle is intermittently provided along both sides of the film (F) running in water.
(a) and counter-nozzle for left end with back side nozzle (b)
(11), front side nozzle (a) and back side nozzle
and a pair of nozzles (12) for the right end provided with (b).

The front side nozzle (a) and the back side nozzle (b) may be provided independently of each other.
The branch pipe (21) is divided into upper and lower pipes (24, 24) using a T-shaped pipe (22) and an elbow pipe (23), and each pipe (2
It is more advantageous to provide a front side nozzle (a) and a back side nozzle (b) at the tip of 4). In this case, it is desirable that the pipe constituting the pipe (24) is a freely bending pipe so that the direction of the nozzle can be adjusted.

The front side nozzle (a) and the back side nozzle (b)
The injection pressure of water to be sprayed is 1.5 to 10 kg / cm ²
It is desirable to set to. When the injection pressure is too low, the effect of preventing the film (F) from curling at both ends and the effect of preventing the film from waving are not sufficiently exhibited.On the other hand, when the injection pressure is too high, both ends of the film (F) vibrate and the film (F) ) May be impaired. The injection pressure of water injected from both nozzles (a) and (b) is a pair of nozzles.
In principle, (11) and (12) should be the same, but the injection pressure of both nozzles (a) and (b) may be slightly changed.

Front side nozzle (a) and back side nozzle (b)
The flow rate of water to be injected per unit time is 50
It is desirable to set to ~ 500 kg / hr. When the flow rate is too small, the effect of preventing the curl of the film (F) at both ends and the effect of preventing the film from waving are not sufficiently exhibited. Smooth running may be impaired.
In this case as well, the flow rate of the water jetted from both nozzles (a) and (b) is basically the same for the pair of nozzles (11) and (12). , (b) may be slightly changed.

The nozzles (11) and (12) are intermittently arranged along both sides of the film (F). The interval at this time is 20 to 100 cm when the film (F) width is around 1 meter.
Often. Intermittently arranged nozzles (11), (1
The water jet pressure and flow rate per unit time of the nozzles (a) and (b) in 2) may be set to be the same throughout the running direction of the film (F), and may be changed so as to gradually increase or decrease. Is also good.

A water pipe (2) is installed between the pair of nozzles (11), (12) and the pump (6) in order to pump water to the pair of nozzles (11), (12).

In the present invention, the nozzles (a) and (b) of the paired nozzles (11) and (12) for the left end and the right end are directed from the center to the edge from the front and back of the film (F). And spray water. Spray direction is film (F) width direction (film (F)
(A direction perpendicular to the traveling direction of the vehicle), but may be set to a direction slightly oblique to the width direction. By such water jetting, curling on both sides of the film (F) running in water and waving of the film (F) are effectively prevented.

[0022]

According to the present invention, since the water stream is sprayed toward both the front and back edges of the vinyl alcohol polymer film (F) running in water, both edges of the film (F) having a tendency to curl or undulate. Is stretched by the water flow, and non-smoothing phenomena such as curling and waving are effectively prevented. Moreover, at this time, even if the film (F) normally curls in water with a width of 4 to 20 cm or more per edge, both edges are stretched without any problem.

In addition, according to the present invention, the pair of nozzles (11), (1)
Since the water flow ejected from 2) becomes a laminar flow and supports both edges of the film (F) from above and below, there is no damage even if the film (F) is in a water-absorbed and swollen state.

[0024]

The present invention will be further described with reference to the following examples.

Embodiment 1 FIG. 1 is an explanatory view of an embodiment of a method and an apparatus for widening water flow according to the present invention as viewed from above, FIG. 2 is an explanatory view of the embodiment of the present invention as viewed from the front, and FIG. FIG. 4 is a partial view of FIG. 1 as viewed from the AA direction, and FIG. 4 is a detailed view of FIG.

A thickness of a polyvinyl alcohol film having an average degree of polymerization of 3800 and an average degree of saponification of 99.5 mol%
A vinyl alcohol-based polymer film (F) for producing a polarizing element film having a width of 100 μm and a width of 100 cm is continuously fed out from a roll,
Guided to the water tank (3) via the guide roll (4), washed by running in water at a temperature of 20 ° C, pulled out of the water tank (3) via the guide roll (5), and then dried for drying. I drove for the zone.

In the above-mentioned water tank (3), a pair of nozzles (11) for the left end and a pair of nozzles (12) for the right end are arranged at both sides of the film (F) running in water at intervals of 50 cm. It was arranged as follows.

As shown in detail in FIG. 4, these paired nozzles (11) and (12) are provided at the tips of conduits (24) and (24) made of a stainless steel freely bending tube. To front side nozzle (a)
And the back side nozzle (b), the elbow pipe (23),
It has the shape of a crab scissors connected by a T-tube (22) via (23). The T-tube (22) is connected via a distribution pipe (21) to a water pipe (2) for pumping water from a pump (6).

The front side nozzle (a) and the back side nozzle (b) at the tip of the pair of nozzles (11) and (12) are both films.
(F) It is adjusted so that water can be sprayed from the center side of the front and back to the edge side.

The jet pressure of water jetted from the front side nozzle (a) and the back side nozzle (b) of each pair of nozzles (11) and (12) is set to 3 kg / cm ² , and these nozzles (a) , (b), the flow rate of water per unit time was set to 200 kg / hr. The film (F) used here usually causes a curl of about 10 cm in width at one edge in water, but if the film (F) is run in water under the above conditions, there is no problem at both edges. Is stretched to prevent curling and waving.

[0031]

According to the present invention, as described in the paragraph of action, a water stream is blown toward both front and back edges of the vinyl alcohol polymer film (F) running in water, so that curl tendency or Both edges of the film (F) having a tendency to undulate are stretched by water flow, and non-smoothing phenomena such as curling and waving are effectively prevented.

In addition, according to the present invention, the pair of nozzles (11), (1)
Since the water jet ejected from 2) supports both edges of the film (F) from above and below, there is no damage even if the film (F) is in a water-absorbing and swollen state.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of a method and an apparatus for widening a water flow according to the present invention as viewed from above.

FIG. 2 is an explanatory view of an embodiment of a method and an apparatus for widening water flow according to the present invention as viewed from the front side.

FIG. 3 is a partial view of an embodiment of the method and apparatus for spreading a water flow according to the present invention, as viewed from a direction AA in FIG. 1;

FIG. 4 is a detailed view of FIG. 3;

FIG. 5 is an explanatory diagram showing a curled state of both edges of a vinyl alcohol-based polymer film during traveling in water.

[Explanation of symbols]

(11)… Nozzle for left end, (12)… Nozzle for right end,
(a) ... front side nozzle, (b) ... back side nozzle, (2) ... water pipe, (21) ... distribution pipe, (22) ... T pipe, (23) ... elbow pipe, (2)
4) ... conduit, (3) ... water tank, (4), (5) ... guide roll, (6)
… Pump, (F)… film

Claims (8)

(57) [Claims] 1. A method for preventing a non-smoothing phenomenon of a vinyl alcohol-based polymer film (F) which occurs when the film (F) runs in water, comprising: a front side nozzle (a) and a back side nozzle (b); A pair of nozzles (11) for the left end provided with a pair of nozzles (11) for the right end also provided with a front side nozzle (a) and a back side nozzle (b), and a film (F) running underwater on both sides. The nozzles (a) and (b) of the paired nozzles (11) and (12) intermittently distribute water from the center of the front and back of the film (F) to the edge. A method for widening a water flow of a vinyl alcohol-based polymer film during running in water, characterized by spraying. 2. The method according to claim 1, wherein the pair of nozzles (11) and (12) are arranged at intervals of 20 to 100 cm along both sides of the film (F). . 3. The method according to claim 1, wherein the jet pressure of the water jetted from the nozzles (a) and (b) is 1.5 to 10 kg / cm ² , respectively. 4. The method according to claim 1, wherein the flow rate of water jetted from the nozzles (a) and (b) per unit time is 50 to 500 kg / hr. 5. A front side nozzle is provided on both sides of a vinyl alcohol polymer film (F) running in water in a water tank (3).
(a) and counter-nozzle for left end with back side nozzle (b)
(11), front side nozzle (a) and back side nozzle
(b) and a pair of nozzles (12) for the right end from the nozzles (a) and (b) of these paired nozzles (11) and (12) from the center to the edge of the front and back of the film (F). A water pipe that is installed so that water can be jetted toward it, and that pumps water to these pair nozzles (11) and (12).
(2) A water flow spreading device for running a vinyl alcohol-based polymer film in water, having a configuration in which (2) is installed. 6. An apparatus according to claim 5, wherein the pair of nozzles (11) and (12) are arranged at intervals of 20 to 100 cm along both sides of the film (F). 7. A distribution pipe (21) from a water pipe (2) is connected to a T-shaped pipe (22).
6. The method according to claim 5, further comprising branching into upper and lower conduits (24), (24) using an elbow pipe (23), and nozzles (a), (b) provided at the end of each of the conduits (24). Water flow spreading device. 8. The water flow spreading device according to claim 7, wherein the pipe constituting the pipe (24) is a freely bending pipe.