JPS63256166A - Method for drying band-shaped object - Google Patents

Abstract

PURPOSE:To uniformly dry the coated surfaces of a band-shaped object by moving heat shielding plates provided between heating plates and the band- shaped object in the transverse direction of the band-shaped object thereby adjusting the heat radiation from the heating plates. CONSTITUTION:While the band-shaped object 1 coated with a coating liquid is run in an oven 5 disposed with the heating plates 9, 10 above and below, said object is dried. The heat shielding plates 11-14 provided between the heating plates 9, 10 and the band-shaped object 1 are moved in the transverse direction of the band-shaped object 1 to adjust the heat radiation from the heating plates at this time. As a result, the radiation heat supplied from the heating plates to the band-shaped object is adjusted to an optimum state and the coated surfaces of the band-shaped object are uniformly dried.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention improves the drying process when manufacturing photographic materials, for example, by applying a coating liquid to a long plastic strip and drying it. It is something.

[Conventional technology]

Photographic light-sensitive materials and various other products in which various types of lamination or coating are applied to a long support such as a plastic sheet or paper are generally produced by coating a strip of material with a coating liquid in which predetermined components are dissolved or dispersed in an organic solvent. It is produced by drying.

Conventionally, this drying method involves blowing hot air onto a strip coated with a coating liquid. In this drying method, the strip-like material was dried uniformly by controlling the volume, temperature, and flow direction of the hot air.

There was also a method of drying the strip using radiant heat from heating plates placed above and below it (Japanese Unexamined Patent Publication No. 149871/1986).
In this drying method, the heating plate is divided in the width direction, and the heating temperature of each heating plate is adjusted independently to uniformly dry the strip.

[Problem that the invention seeks to solve]

However, with these methods of uniformly drying a strip, delicate temperature control in the width direction cannot be made sufficiently, and uneven drying occurs on the surface of the strip.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a method for drying a strip-shaped object, which can uniformly dry the coated surface of the strip-shaped object.

[Means for solving problems]

As a result of intensive studies to achieve such an objective, the inventor of the present invention provided a heat shield plate between the heating plate and the strip-shaped object, and moved this heat shield plate in the width direction to supply the heat shield to the strip-shaped object. The present invention was completed by discovering that by adjusting the radiant heat, it is possible to finely adjust the temperature in the width direction.

That is, the present invention provides a method for drying a strip coated with a coating liquid while running it in an oven in which heating plates are disposed above and below, in which a heat shield plate is provided between the heating plate and the strip. The present invention relates to a method for drying a strip-shaped object, which is characterized in that the coated surface of the strip-shaped object is uniformly dried by moving the strip in the width direction to adjust radiant heat from a heating plate.

The type of strip is not particularly limited, and a coating liquid in which the necessary components are dissolved or dispersed in a flammable organic solvent is applied to a support such as various plastic sheets, paper, or metal foil, depending on the purpose. It is something that

An appropriate flammable organic solvent is selected depending on the components to be dissolved or dispersed, and examples thereof include benzene, toluene, alcohol, acetone, methyl acetate, and methylene glycol.

A strip coated with a coating liquid containing a flammable organic solvent is dried by moving it through an oven in which heating plates are placed above and below the strip.

The heating plate heats the traveling strip, and the strip is dried exclusively by radiant heat transfer from the heating plate.

The temperature of the heating plate is, in short, set so as to dry the strip to a predetermined degree, and is appropriately set in consideration of the type, size and running speed of the strip, the type of organic solvent, etc.

Oil, molten metal, heated steam, etc. are used as a heat medium for the heating plate.

A heat shield is provided between the heating plate and the strip, and the heat shield is moved in the width direction of the strip to adjust the radiant heat supplied from the heating plate to the strip. This heat shield plate can block radiant heat from the heating plate and is only required to be provided so as to be movable in the width direction of the strip. It is provided in the shape of a flat plate near the side ends of the upper and lower heating plates.

In order to adjust the surface temperature of the strip to be uniform with this heat shield plate, consider the temperature of the heating plate, the width of the heating plate and the strip, and their relationship, and adjust the temperature near the side edges of the upper and lower heating plates. When the heating plates are provided at four locations, each heating plate is moved in the width direction so that the surface temperature of the strip becomes uniform. Then, in this state, the heat shield plate is fixed and the strip is dried.

The inside of the oven is preferably filled with an inert gas, a cover is provided around the oven, and the inlet and outlet of the strip are preferably kept to a minimum of slit-like openings.

The inert gas is a gas that can inhibit combustion in the atmosphere, such as nitrogen gas or carbon dioxide gas. The volume of inert gas blown into the oven is set to keep the solvent concentration of the gas exhausted from the oven at a constant value, taking into account the type, size and running speed of the strip, the type of organic solvent, etc. It is set as appropriate.

[Effect]

In the method of the present invention, the strip is dried by radiant heat from the heating plates by running it between heating plates provided in an oven. At this time, the heat shield plate is moved in the width direction to adjust the state of the radiant heat supplied from the heating plate to the strip, so that the surface of the strip has a uniform temperature distribution. As a result, the solvent on the surface of the strip evaporates uniformly, making the coated surface of the strip uniform.

〔Example〕

An embodiment of the method for drying a strip according to the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic diagram of a drying apparatus used in the method for drying a strip, viewed from the side in the direction of travel of the strip, and FIG. 2 is a schematic diagram of the same as seen from the direction of travel of the strip.

As shown in these figures, a strip 1 is unwound from a raw roll 2 and coated with a coating liquid 4 using a known coating device 3. Then, it is dried in an oven 5 and wound onto a winding roll 6. The oven 5 is a flat box-like sealed type, and a slit-shaped open lower 8 through which the strip 1 passes is provided on both longitudinal end faces.

Inside the oven 5, heating plates 9 and 10 are provided above and below the travel path of the strip 1. This heating plate 9.10 is formed of a radiant tube through which steam flows, fins that diffuse and radiate heat, a heat insulating material, and a frame.

Between the heating plate 9.10 and the strip 1, the heating plate 9.10
There are flat heat shield plates 11, 12, 13.
14 are arranged. This heat shield plate 11.12.13,
14 is a drive device 15, 16, 17, 18 from the outside direction
It is supported by and is movable in the width direction of the strip 1 by the operation of the drive device 15, 16, 17, 18.

Note that the reference numeral 19 is a supply side blower that supplies inert gas into the oven 5, and the reference numeral 20 is a discharge side blower that discharges the inert gas from the oven 5. And this blower 1
9 is connected to a heater, a gas supply device, etc. (not shown).

In such an apparatus, a strip 1 is unwound from a raw roll 2, coated with a coating liquid 4 by a coating device 3, and then entered into an oven 5. The inside of the oven 5 is filled with inert gas sent by a blower 19, and upper and lower heating plates 9.
The solvent of the coating liquid 4 applied to the strip 1 is evaporated by the radiant heat of 10. At this time, the drive device 15.16.17.18
is activated, and heat shield plates 11, 12, .
13.Move 14 in the width direction.

Therefore, the surface of the strip 1 has an extremely uniform temperature distribution, and the solvent evaporates in a uniform state.

In this way, the strip 1 gradually dries as it travels through the oven 5, leaves the oven 5 in a completely dry state, and is wound onto the take-up roll 6. The solvent evaporated by drying is discharged from the oven 5 by the blower 20 together with the inert gas.

Now, a strip 1 coated with a photosensitive liquid using aluminum as a support was dried by a method using such an apparatus.

The temperature of the supplied inert gas air is 90°C, the temperature of the upper and lower heating plates 9.10 is 100°C, and the upper and lower heating plates 9.10 from the strip 1
The distance between the heat shield plates 11, 12, 13, and
The drying condition was examined by moving it in the width direction. As a result, the interval between the inner edges of the upper two heat shield plates 11 and 13 is larger than the width of the strip 1, and the interval between the inner edges of the lower two heat shield plates 12 and 14 is equal to the width of the strip 1. When equal or narrow, the coated surface of Strip 1 after drying was the most homogeneous.

〔Effect of the invention〕

The method of the present invention moves the heat shield plate in the width direction and freely adjusts the supply state of radiant heat from the heating plate, so that the radiant heat supplied from the heating plate to the strip can be optimized. The coated surface of the strip can be dried uniformly.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a drying device used in the method of drying a strip according to the present invention, viewed from the side with respect to the traveling direction of the strip;
FIG. 2 is a schematic view of the same strip as seen from the traveling direction. 1... Band-shaped material 4... Coating liquid 5... Oven 9.10... Heating plate 11.12.13.14
... Heat shield plate 15, 16, 17, 18 ... Drive device Fig. 1 Fig. 2

Claims (1)

[Claims] In a method of drying a strip coated with a coating liquid while running it in an oven with heating plates arranged above and below, a heat shield plate provided between the heating plate and the strip is used to dry the strip in the width direction of the strip. A method for drying a strip, which is characterized by uniformly drying the coated surface of the strip by adjusting the radiant heat from the heating plate.