JPH03235219A - Method and device for drying long-sized film - Google Patents

Abstract

PURPOSE:To make improvement in productivity and quality by ejecting hot wind radially from the center of a curvilinear orbit. CONSTITUTION:A film 4 receives an approximately uniform wind pressure when the hot wind is radially ejected from the central part of the curvilinear orbit in the curvilinear traveling part a of a long-sized film 4. Since the film travels curvilinearly in nearly the arc-shaped orbit where the tension and wind pressure exactly match and, therefore, the smooth traveling is assured and the local drying of the coating compd. on the surface does not arise. Many hot wind blow-out holes are uniformly distributed and provided on the peripheral surface of a hot wind nozzle body 7 to uniformly blow out the hot wind. A nozzle body 7 is disposed apart in the direction orthogonal with a virtual line from the center of the virtual line connecting guide rollers 6, 6. The hot wind falls onto the film 4 and dries the surface thereof in a drying chamber 5. The stability of the traveling is enhanced in this way and the uniform drying is executed. The improvement in the productivity and quality is thus made.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for drying a long film,
In particular, the present invention relates to a drying method and apparatus suitable for the drying process of magnetic paint when producing magnetic tape.

[Prior art] Magnetic tapes such as video tapes and audio tapes are made by applying magnetic paint to the surface of a thin base film such as a polyester film, drying it, and going through a process that includes smoothing the surface. It is manufactured by making a long magnetic tape material and cutting it into a predetermined width.

In the manufacturing process of the original magnetic tape, the above-mentioned steps are continuously carried out between 10,000 rolls while winding the long film onto the other roll.

In this manufacturing process, various drying methods are used to dry the magnetic paint applied to the surface of the base film, but the main method is to blow warm air onto the surface of the moving base film. , 6A air drying is used to dry the paint on the surface.

In the manufacturing process of such magnetic tapes, it is required to increase the running speed of the base film in order to improve productivity. However, as the film travels at higher speeds, the time it is exposed to hot air during the drying process becomes shorter (and there is no longer enough time to dry the paint applied to the base film. In other words, the time it takes to dry the paint In order to expose the film to hot air for a sufficient period of time, the faster the film travels, the longer it must travel, which necessitates larger equipment.

Therefore, as a countermeasure against this problem, a drying device as shown in FIG. 4 has been adopted. In this drying device, one roll 1
A paint is applied to the surface of the long film 4 fed out from the coating unit 2, and the long film 4 is passed through the guide roller 3.8 and the surface treatment roller 9 and wound onto the other roll 10. Pass through drying room 5.5...

In this drying chamber 5.5..., between a pair of guide rollers 6.6 that guide the long film 4, a nozzle 7 is moved in a direction perpendicular to an imaginary line connecting the guide rollers 6.6.
Hot air is blown onto the long film 4 from ', and one pressure of the hot air causes the long film 7 to run in an Ω-shape to the side of the imaginary line connecting the guide rollers 6.6.

In this method, since the long film 4 travels in a curved manner, the travel distance of the long film 40 can be increased by this amount, and the long film 4 can be exposed to hot air for a correspondingly long time.

[Problems to be Solved by the Invention] In the conventional apparatus described above, since the nozzle 7' blows hot air onto the long film 4 in a direction perpendicular to the imaginary line connecting the guide rollers 6.6, the long film 4 The wind pressure exerted by the warm air on the guide roller 6.6 is particularly high in the center of the guide roller 6.6, and is considerably lower on both sides thereof. For this reason, the long film 4
does not curve properly in an Ω-shape, but actually curves while drawing an approximate elliptical arc trajectory, as shown in FIG.

However, when a long film runs in a curved manner on such a track, the running becomes unstable and the running track becomes unstable.
Running may be disrupted.

Moreover, because the hot air blows strongly locally, rapid drying occurs in some areas, causing only the surface layer of the resin contained in the paint to condense, leaving the paint film uneven without being completely dry inside. Problems such as the occurrence of problems are likely to occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a drying method and apparatus capable of solving the above-mentioned conventional problems and capable of stabilizing the running of a long film and uniformly blowing hot air.

Means for Solving Problem C] That is, in order to solve the ff1 problem, in the present invention,
While running the long film 4, the long film 4
Warm air is blown onto the long film 4 between a pair of guide rollers 6 and 60 that guide the long film 4.
In the method of drying a long film in which the long film runs curved to the side of an imaginary line connecting the idle rollers 6.6, warm air is radially ejected from the center of the curved trajectory at the curved running portion a of the long film 4. To provide a method for drying a long film.

Further, the long film drying device includes a pair of guide rollers 6.6 for guiding the traveling long film 4, and means for blowing hot air onto the surface of the long film 4 traveling between the guide rollers 6.6. , the guide roller 6
．． The means for blowing hot air onto the long film 4 traveling between the rollers 6 and 6 is a hot air nozzle body 7 that blows out hot air radially, and the hot air nozzle body 7 is connected to the pair of idle rollers 6 and 6. To provide a long film drying device disposed on the side of a line.

[Function] In the drying method according to the present invention, the long film 4 blows hot air radially from the center of the curved trajectory at the curved running portion a of the long film 4.
The area receives approximately uniform warm air pressure. In addition, since the long film 4 is subjected to approximately uniform wind pressure, the long film 4 curves in a substantially arc-shaped trajectory at a point where its tension and the wind pressure are balanced. This allows the long film 40 to run smoothly and prevents the paint from drying locally on its surface.

Further, in the drying device according to the present invention, the hot air nozzle body 7 that blows out hot air radially is connected to the pair of guide rollers 6.
．． 6, the curved traveling portion a of the long film 4 can blow out hot air radially from the center of the curved trajectory, and the method described above can be carried out reliably. can.

[Example of implementation] Examples of the present invention will be described in detail below.

FIG. 1 shows a magnetic tape manufacturing scheme with a drying device according to an embodiment of the invention. First, a long film 4, which serves as the base of the magnetic tape, is pulled out from the roll 1, and a magnetic paint is applied to its surface in the coating section 2. Thereafter, the drying device is placed between the guide rollers 3 and 8.

This drying device consists of five drying chambers 5.5... arranged in series, and each drying chamber 5.5... has a pair of idle rollers 6.6 and a hot air nozzle. It has a body 7. To explain this with reference to FIGS. 2 and 3, the hot air nozzle body 7 is provided with a large number of hot air blowing holes uniformly distributed on the circumferential surface 7a of a cylindrical main body. The warm air supplied from the ducts 7b, 7b uniformly blows out from the hot air outlet. Therefore, hot air is uniformly radially blown out from the hot air nozzle body 7 as shown by the arrows in FIG. The hot air nozzle body 7 is located at a distance ζ from the center of an imaginary line connecting the pair of idle rollers 6.6 in a direction perpendicular to the imaginary line.

The hot air nozzle body 7 may be one having a slit in a cylindrical surface or a cylindrical body formed of a porous material, in addition to the one described above, as long as it blows hot air radially and uniformly. . Furthermore, instead of having a cylindrical shape, it may be an assembly of nozzles, for example, in which a plurality of fine nozzles with their tips oriented radially are arranged vertically.

The long film 4 guided by the pair of guide rollers 6.6 runs on a curved trajectory surrounding the hot air nozzle body 7. Since the hot air is uniformly radially blown out from the hot air nozzle body 7, the curved trajectory of the long film 4 depends on the wind pressure of the hot air jetted from the hot air nozzle body 7,
At the point where the tension of the long film 4 that opposes this is balanced, it is formed as a substantially circular arc trajectory. Therefore,
The center of the hot air nozzle body 7 is placed at the center of this planned arcuate trajectory, and the tension applied to the elongated film 4 is adjusted so that the actual curved trajectory of the long film 4 follows the planned arcuate trajectory. In relation to this, the volume and speed of the hot air injected from the hot air nozzle body 7 are determined and controlled.

In this way, the long film 4 is dried in the drying chamber 5.5...
By being exposed to hot air, the magnetic paint applied to the surface of the film 4 dries.

Subsequently, the long film 4 that has passed through the drying chambers 5, 5, . Thereafter, this is heat-treated for a while to polymerize the resin component of the magnetic paint, thereby completing the original magnetic tape.

[Effects of the Invention] As explained above, according to the present invention, when hot air is applied to the long film 4 to dry the paint on the surface thereof, an arcuate trajectory of the long film 4 is reliably formed, and the arc trajectory of the long film 4 is reliably formed. Uniform hot air can be applied to the long film 4 inside the arcuate trajectory.

As a result, the running stability of the long film 4 is increased, and the drying is performed uniformly, thereby achieving the effect of improving productivity and quality.

[Brief explanation of drawings]

FIG. 1 is a plan view of a running system for a long film including a drying device according to an embodiment of the present invention, FIG. 2 is a plan view of the main parts of the same drying device, and FIG. FIG. 4 is a perspective view showing an example of a hot air nozzle body, and FIG. 4 is a plan view of a long film running system including a conventional drying device.

Claims (2)

[Claims] (1) While running the long film 4, hot air is blown onto the long film 4 between a pair of guide rollers 6, 6 that guide the long film 4, and the wind pressure of the hot air is applied to the long film 4. In the long film drying method in which the long film 4 is run curved to the side of the imaginary line connecting the guide rollers 6, 6, hot air is radiated from the center of the curved trajectory at the curved run portion a of the long film 4. A long film drying method characterized by: (2) Long film drying comprising a pair of guide rollers 6, 6 for guiding the running long film 4, and means for blowing hot air onto the surface of the long film 4 running between the guide rollers 6, 6. In the device, the guide roller 6;
The means for blowing hot air onto the long film 4 traveling between the hot air nozzle bodies 7 that blow hot air radially,
A long film drying apparatus characterized in that the hot air nozzle body 7 is arranged on the side of an imaginary line connecting the pair of guide rollers 6, 6.