JPH05275159A - Infrared ray heating device - Google Patents

Abstract

PURPOSE:To generate a maximum efficiency of energy by forming an infrared ray heating device, which is to heat an object by means of irradiating it with infrared rays, from a near-infrared ray lamp and/or media infrared ray lamp and reflex boards installed on both sides thereof. CONSTITUTION:A coating. film is formed on the surface of an object to be dried W, wherein the base boards is made of copper, aluminum, iron, or plastics while the coating consists of a resin of acrylic, urethane, epoxy, or meramine type. The coating is dried by an infrared ray lamp emitting a wavelength peak under 3.0mum with a high infrared ray transmissivity and high absorptiveness of base board, preferably a lamp 11 emitting near or medium infrared rays between 1.2-1.5mum, and a stainless steel plate 13 is used to make surrounding while the undersurface is situated opposite the object W, wherein an angle of 45 deg. is generated so that the rays spread toward the object W. Thereby the temp. of not only the object but also the base board is raised.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an infrared heating device. More specifically, the present invention relates to a heating device that heats an irradiation target by irradiating infrared rays, and further relates to an infrared heating device that can be used for drying a coating film applied to the irradiation target as a result of heating.

[0002]

2. Description of the Related Art Heretofore, an apparatus using far infrared rays has been known as an infrared heating apparatus for drying a coating film applied to the surface of an object to be irradiated by using infrared rays.

[0003]

In the same apparatus used in the drying furnace, the far-infrared lamp is fixed to the furnace surface, and therefore, when the size of the irradiation target conveyed in the furnace changes, the far-infrared lamp and the The distance to the illuminated object changes. However, since far-infrared rays have a low energy density and thus have a large attenuation with respect to distance, there is a problem that the drying efficiency decreases when the distance between the irradiation object and the far-infrared lamp increases. Further, when the surface of the object to be irradiated has irregularities, there is a problem that the degree of heating varies depending on the surface and the degree of drying also varies.

Further, an infrared heating device has been proposed in which a bank provided with a plurality of far-infrared lamps is movable and is moved in the direction of an object to be irradiated, but the amount of movement is limited when the object to be irradiated has irregularities. Since far infrared rays have a large attenuation rate with respect to distance, there is a problem related to the drying time when there is a limit to the distance to approach the irradiated object.

On the other hand, "near-infrared liquid, powder, coating, stove" (actual flat 1-151873), "light plate for paint baking oven" (real flat 2-43217), USP 4,863,375 "BA
KINGMETHOD FOR USE WITH LIQUID OR POWDER VARNISHIN
G FURNACE "(Baking Method for Youth
With liquid or powder varnishing
Furnace) and the like are known. In these conventional examples,
There is a description about "a kind of near-infrared liquid, powder, coating, stove baking method", "Using the fast high temperature and strong penetrating power of near-infrared rays, improving the method of baking products of stove, paint Is an invention for rapidly drying and enhancing its adhesive force ", that is," so-called liquid, powder, powder powder in the liquid state, liquid paint, gas or fluid is adhered to the surface of the object as a transportation medium, as it is. Then, the method of coating the coat uniformly by heating and melting ”is described.

Alternatively, "drying oven using near infrared rays,
Or, a drying method in which a high temperature part and a low temperature part are sequentially formed in a drying oven and dried, or a ceramic reflector is provided behind the near infrared lamp, and a heater is provided in the ceramic reflector. " There is a description.

In the October issue of the coating technology special issue, there is a description about "medium wavelength infrared radiator" (October 20, 1990, Riko Publishing Co., Ltd., pages 211-213). That is, "The radiant energy that reaches the coating film is partially absorbed, partially reflected, and partially transmitted. The absorbed energy is converted into heat to heat and dry the coating film. In the case of 1, since there is a base material and a body, the radiant energy transmitted through the coating film heats the base material, and the coating film is heated from the inside by heat conduction.

Near-infrared: Temperature 2000 to 2200 ° C. Maximum energy wavelength about 1.2 μm, large energy density, large reflected and transmitted energy, fast rising speed (1 to 2 seconds), and short life of about 5000 hours.

Mid-infrared: temperature 850-900 ° C, maximum energy wavelength about 2.5 μm, absorption in energy density. The transmitted energy is balanced, the energy penetrates into the coating film, and the life is long.

Far-infrared: temperature 500 to 600 ° C., maximum energy wavelength about 3.5 μm, small energy density, well absorbed but tends to be absorbed and heated on the surface of the coating film, long rise time (5 to 15 minutes), convection The loss is large. It is said that.

Further, in order to "2. Maximum efficiency medium wavelength infrared ray""dry faster and obtain better coating quality", that is, in order to heat and dry at maximum efficiency, the following two conditions are simultaneously satisfied. Need to be

The radiant energy with high temperature of the infrared radiator is proportional to the fourth power of the absolute temperature (T) of the radiator.

Eb ∝ T ⁴

The higher the temperature, the greater the radiant energy.

The maximum energy wavelength is slightly shorter than the peak absorption of the coating

The maximum peak wavelength that can be used for industrial infrared heating of paint is around 3 μm without exception. Therefore, the infrared radiator, which has the maximum energy wavelength around 2.5 μm, is well absorbed and transmitted, and the base material can be heated and heated from the inside.

The above relationship, the Vienna displacement law, which represents the relationship between the temperature (T) of the infrared radiator and the maximum energy wavelength (λm),

From λm = 2897 / T

T = (t + 273) = 2897 / 2.5

T = 880 ° C.

The medium-wavelength infrared ray satisfies this condition, has a large effective energy, and has maximum efficiency. It is said that.

However, actual Kaihei 1-151873, actual Kaihei 2
-43217, USP 4,863,375, etc. have a description that the coating film is dried using near infrared rays, but the nature of the near infrared rays used is not generally described and it is applied to the metal surface. There is no description about the optimum range and selection of the infrared rays to be irradiated due to the relationship between the coating film and the near infrared rays.

[0023] In the description of "Painting Technology Special Issue October issue",
Selection of infrared rays based on the relationship between infrared rays and the absorption rate of the base material,
Alternatively, there is no description about selection of infrared rays based on the cause of pinhole generation, and in coating drying, it is "2.5 μm.
The infrared radiator, which has the maximum energy wavelength in the front and back, has good absorption and transmission, and the base material can also be heated and heated from the inside. Is concluded.

[0024]

Means for Solving the Problems

An infrared heating device comprising a near-infrared lamp and / or a mid-infrared lamp and reflecting plates provided on at least both sides of the lamp,

Providing

[0027]

The irradiation light of the near-infrared lamp and / or the mid-infrared lamp is reflected by the reflection plate and is irradiated to the object to be irradiated.

[0028]

[Example] When a metal plate is used as a base material on which a coating film for a material to be dried W is formed, examples of the metal plate include iron, aluminum, copper, brass, gold, beryllium, molybdenum, nickel, lead, rhodium, and silver. , Tankel, antimony, cadmium, chromium, iridium, cobalt, magnesium, tungsten and other metals, with copper, aluminum and iron being particularly preferred. Plastics can also be used as the base material. Acrylic resin paints, urethane resin paints, epoxy resin paints, melamine resin paints, and other paints can be used as the paint that forms the coating film applied to the surface of metal or the like. The coating film may be a coating film obtained by melting a so-called powder coating film (polyester type, epoxy type, acrylic type, etc.).

25 to 28 show the reflectance of each metal at each wavelength (AMERICAN INSTITUTE OF PHYSICS HAND).
BOOK, American Institute of Physics Handbook 6-120). The higher the reflectance, the lower the absorptivity, and the lower the reflectance, the higher the absorptance.

FIG. 1 is an infrared absorption curve of butylated urea-butylated melamine resin. Figure 2 shows bisphenol A
It is an infrared absorption curve of a type epoxy resin. Figure 3 shows MMA
It is an infrared absorption curve of a homopolymer (acrylic type). FIG. 4 is an EMA homopolymer (acrylic) infrared absorption curve. FIG. 5 is an infrared absorption curve of unsaturated polyester resin. FIG. 6 shows the characteristic curve of the near-infrared lamp and the characteristic curve of the far-infrared lamp used in this example.
The peak wavelength of the near infrared lamp is 1.4 μm, and the peak wavelength of the far infrared lamp is 3.5 μm.

As the base metal plate of the material to be dried W, iron, aluminum, copper, brass, gold, beryllium, molybdenum, nickel, lead, rhodium, silver, tanker, antimony, cadmium, chromium, iridium, cobalt, magnesium are used. In case of using acrylic resin paint, urethane resin paint, epoxy resin paint, melamine resin paint as the paint, using a metal plate made of tungsten, infrared rays to the coating film of the paint applied to the base material surface An infrared lamp having a wavelength peak of 3.0 μm or less, preferably a so-called near-infrared lamp having a wavelength peak of 3.0 μm or less is used as the infrared ray for generating infrared rays in a region having a high transmittance and a high absorptance of the base material. It is desirable to do.

A plan sectional view is shown in FIG. 10 and a front sectional view is shown in FIG. 11. The near-infrared lamp 11 (5.0 kw) having a peak wavelength of 1.4 μm is vertically arranged on the wall surface inside the drying oven 12. It is the installed Example b. In this embodiment, the left and right SUS304 stainless steel plates of the near-infrared lamp 11 are used as the reflection plates 13 and are spread by 45 degrees so that the object W side is expanded.

A plan sectional view is shown in FIG. 12 and a front sectional view is shown in FIG.
w) up and down 5 are installed on the wall surface in the drying furnace 12, and the left and right SUS304 stainless steel plates of the near infrared lamp 11 are spread to 45 degrees so that the irradiation target W side spreads, and the stainless steel plates are also on the ceiling surface and the floor surface. It is the embodiment d in which the reflection plate 13 consisting of is installed.

A plan sectional view is shown in FIG. 14 and a front sectional view is shown in FIG.
w) is an example d in which five reflectors 13 made of SUS304 stainless steel plates on the left and right of the near-infrared lamp 11 are installed in parallel on the wall surface inside the drying oven 12.

FIG. 16 shows a plan sectional view, and FIG. 17 shows a front sectional view. Five near-infrared lamps (5.0 kw) are arranged above and below the near-infrared lamp 11 installed on the wall surface in the drying oven 12. Left and right SUS304 stainless steel plates are parallel and
This is an example e in which the reflector 13 made of the same stainless plate is installed so that the upper and lower surfaces also surround the near infrared lamp 11.

A plan sectional view is shown in FIG. 20 and a front sectional view is shown in FIG. 21. The five mid-infrared lamps 21 (5.0 kW) having a peak wavelength of 2.5 μm are vertically arranged on the wall surface in the drying furnace 12. This is an example in which the left and right SUS304 stainless steel plates of the middle infrared lamp are installed in parallel, and the reflectors made of the same stainless steel plate are installed so that the upper and lower surfaces also surround the periphery of the near infrared lamp.

As the lamp, the near infrared lamp 11 and the mid infrared lamp 21 may be mixed.

In Examples e and g, the reflecting plate 13 made of a stainless steel plate is extended to the irradiation object W when the thickness is 1000 mm. As shown in FIG. 22, which shows a central cross-sectional view, the movement of the reflection plate 13 causes the near-infrared lamp 11 to move.
Alternatively, the reflector 13 installed around the mid-infrared lamp 21 includes an inner reflector 14 and an outer reflector 15,
The outer reflector 15 is guided by the rails 22 and the like and moved by a motor. Alternatively, as shown in FIG. 23, the reflection plate 13 is formed of a rectangular parallelepiped whose both sides are open, and moves around the fixed infrared lamp 11 according to the rail 22.

The movement of the hood 16 composed of the reflector 13 is as follows.
When irradiating the non-irradiation object W having the uneven surface,
You may detect the uneven | corrugated shape of the surface with a sensor, and it may move away from the non-irradiation object W with a micromotor. Alternatively, a rectangular parallelepiped hood-shaped reflecting plate 13 corresponding to the length may be prepared and replaced according to the length. Further, the bellows-shaped hood 16 may be used to make it extendable. By narrowing the tip of the hood 16 on the irradiation target W side, it becomes possible to concentrate infrared rays.

Then, as shown in FIG. 32, the hood 16 may be installed so as to surround each infrared lamp. In this case, since it is not necessary to store the object W to be irradiated in a drying furnace to dry it, it is suitable for drying the coating of a large construction machine such as a bulldozer. In that case, even if the surface of the irradiation target W has irregularities, the distance from the tip of the reflector 13 to the surface of the irradiation target W can be set to be equal at any point. Therefore, it becomes possible to make each surface constant without distinction, and to heat and dry on average.

Further, by adjusting the distance from the tip of each hood 16 to the object W to be irradiated, it becomes possible to heat each dry portion at an arbitrary temperature, which is suitable when the coating film thickness is partially different.

In the case of Examples b and d, since the ceiling surface is open, it is effective to use it together with the hot air stove.

FIG. 24 is an explanatory view of an embodiment of a gun type infrared heating device. In the gun type infrared heating device, a cylindrical hood 16 having a reflecting surface on the inner surface, which is different in length or a shape in which the tip is opened, is prepared as an attachment as needed, and the hood 1 is irradiated by the irradiation target W.
Select 6 and mount it in front of the infrared lamp 11. In this case, it is effective to heat and dry the inner part.

FIG. 33 is an enlarged view of a main part of an embodiment of an infrared heating apparatus suitable for drying an object W to be irradiated having a partially thick portion W1. In this embodiment, a cylindrical hood 1 whose inner surface is a reflector 13 from the front of the near-infrared lamp 11 at the position of the thick portion W1 toward the irradiated object W
6 is projected. Conventionally, when an object to be irradiated having a thick portion W1 partially provided as shown in FIG. 33 is heated to dry the coating film, heating is performed in accordance with the thick portion W1 There is a problem that heating is insufficient in the thick portion, and if the heating is performed in accordance with the non-thick portion, the thick portion W1 is overbaked. However, in this embodiment, even if each near-infrared lamp 11 is heated in accordance with the non-thick portion, since the thick portion W1 is given more energy than the non-thick portion, the thick portion W1 is insufficiently heated. It never becomes.

34 and 35 are explanatory views of an embodiment of an infrared heating device for intensively heating the bottom portion, which is apt to lack infrared irradiation. In this embodiment, the tip of the hood 16 is bent and opened at the bottom of the irradiation object W.

In the embodiment shown in FIGS. 36 and 37, which is an enlarged view of FIG. 36, between the lamp housings 31 in which a plurality of near-infrared lamps 11 or mid-infrared lamps 21 are installed on the wall surface of the drying furnace 12. A guide 32 such as a rail is installed in parallel with. 33 is a lamp holder, 2
A near-infrared lamp 11 or a mid-infrared lamp of a book is attached, and it can move up and down along a guide 32 and can be positioned by a stopper (not shown). At the tip of the lamp, a cylindrical hood 16 facing the irradiated object W direction
Is attached. Therefore, the position of the lamp housing 31 is moved to match the shape of the irradiation target W with the hood 1.
It is possible to heat part of the irradiation object W intensively by replacing 6.

FIG. 38 is a partially enlarged view of an infrared heating device for draining and drying when washing with water is performed as a chemical conversion treatment before coating, for example. If the water adhered to the object W to be irradiated remains in the next coating step, a coating film defect will occur, so it is necessary to remove the water. However, a pool of water is likely to be formed inside the bent portion at the lower end of the irradiation target W in FIG. 38, a recessed portion, and the like, and if the heating device is heated to an excessively high temperature in order to dry this, adhesion to the irradiation target W will be increased. Also, the chemical conversion film applied to improve rust prevention will be damaged. In this embodiment, the lower end of the irradiation target W is damaged at the tip of the hood 16. In this example, the hood 1
6 By directing the tip toward the lower end of the irradiated object W,
It partially gives high energy to dry the water accumulated in the bent part and does not damage the chemical conversion film in other parts.

33, 34, 35, 36 and 3
7 and the embodiment shown in FIG. 38, a mid-infrared lamp 21 may be used instead of the near-infrared lamp 11.

The surface of the base material of the material to be dried W on which the coating film is formed is irradiated with infrared rays and its reflected light which generate infrared rays in a region having a high infrared transmittance with respect to the coating film and a high absorption rate of the base material. In this case, the irradiated infrared rays pass through the coating film, are absorbed by the base material having the coating film formed on the surface thereof, and the surface of the base material is heated. Therefore, the coating film is heated and solidified from the back surface of the coating film close to the surface of the base material. Therefore, even if the solvent in the coating film evaporates, the solidified coating film surface will not be broken and pinholes will not be formed.

(Examples and Comparative Examples)

A plan sectional view is shown in FIG. 8 and a front sectional view is shown in FIG. 9. The near-infrared lamp 11 (5.0 kw) having a peak wavelength of 1.4 μm is installed on the wall surface in the upper and lower five drying ovens 12. The comparative example a is shown. In this comparative example, the reflector 13 is not provided around the near infrared lamp 11. A 2.3 mm thick iron plate is sequentially installed at a position of 600 mm and 1000 mm from the near-infrared lamp 11, and a contact thermometer (TAKARA type A-600) is brought into contact with and fixed to each iron plate. FIG. 30 shows a change in temperature rise at 600 mm. FIG. 31 shows a temperature rise change when the distance is 1000 mm. Further, both are shown in FIG.

The plan sectional view is shown in FIG. 10 and the front sectional view is shown in FIG. 11, in which five near infrared lamps 11 (5.0 kw) having a peak wavelength of 1.4 μm are vertically arranged on the wall surface in the drying furnace 12. It represents the installed example b. In this embodiment, the left and right SUS304 stainless steel plates of the near-infrared lamp 11 are set at 45 degrees so that the object W side is widened.
FIGS. 30 and 31 show the temperature change of the same iron plate as in Comparative Example a installed at 600 mm and 1000 mm from the lamp surface. Further, both are shown in FIG.

A plan sectional view is shown in FIG. 12, and a front sectional view is shown in FIG. 13. The near-infrared lamp 11 (5.0 kw) having a peak wavelength of 1.4 μm is vertically arranged on the wall surface in the drying furnace 12. It represents the installed example c. In this embodiment, the left and right SUS304 stainless steel plates of the near-infrared lamp 11 are expanded to 45 degrees so that the irradiation target W side is expanded, and the stainless steel plates are also installed on the ceiling surface and the floor surface. Comparative example a installed 600 mm and 1000 mm from the lamp surface
The temperature change of the iron plate similar to that is shown in FIGS. 30 and 31.
Further, both are shown in FIG.

A plan sectional view is shown in FIG. 14 and a front sectional view is shown in FIG. 15. The near-infrared lamp 11 (5.0 kw) having a peak wavelength of 1.4 μm is vertically arranged on the wall surface inside the drying oven 12. It represents the installed example d. In this embodiment, the left and right SUS304 stainless steel plates of the near infrared lamp 11 are installed in parallel. 600 mm and 100 from the lamp surface
The temperature change of the same iron plate as the comparative example a set at 0 mm is shown in FIGS. 30 and 31. Further, both are shown in FIG.

FIG. 16 shows a plan sectional view and FIG. 17 shows a front sectional view. Five near infrared lamps 11 (5.0 kw) having a peak wavelength of 1.4 μm are vertically arranged on the wall surface in the drying furnace 12. It represents the installed example e. In this embodiment, the left and right SUS304 stainless steel plates of the near-infrared lamp 11 are installed in parallel with each other so that the upper and lower surfaces also surround the near-infrared lamp 11. 600m from the lamp surface
FIGS. 30 and 31 show the temperature changes of the iron plate similar to Comparative Example a installed at m and 1000 mm. 1000m
In the case of m, the stainless steel plate is extended to the irradiation object W. Further, both are shown in FIG. In the case of 1000, when the reflection plate 13 was not extended, it is as follows. 0 minutes, 14 degrees C, 1.0 minutes, 22 degrees C, 2.0
Minutes, 32 degrees C, 3.0 minutes, 39 degrees C, 4.0 minutes, 47 degrees C, 5.0 minutes, 55 degrees C, 6.0 minutes, 61 degrees C, 7.0
Minutes, 66 degrees C, 8.0 minutes, 70 degrees C, 9.0 minutes, 74 degrees C, 10.0 minutes, 76 degrees C.

A plan sectional view is shown in FIG. 18 and a front sectional view is shown in FIG. 19. Five mid-infrared lamps 21 (5.0 kw) having a peak wavelength of 2.5 μm are installed vertically on the wall surface in the drying furnace 12. The comparative example f is shown. In this comparative example, the reflector 13 is not provided around the mid-infrared lamp 21.
FIGS. 30 and 31 show the temperature change of the same iron plate as in Comparative Example a installed at 600 mm and 1000 mm from the lamp surface. Further, both are shown in FIG.

A plan sectional view is shown in FIG. 20 and a front sectional view is shown in FIG. 21. The five mid-infrared lamps 21 (5.0 kW) having a peak wavelength of 2.5 μm are vertically arranged on the wall surface in the drying furnace 12. Represents installed Example g. In this embodiment, the left and right SUS304 stainless steel plates of the mid-infrared lamp 21 are installed in parallel with each other so that the upper and lower surfaces also surround the near-infrared lamp 11. 600m from the lamp surface
FIGS. 30 and 31 show the temperature changes of the iron plate similar to Comparative Example a installed at m and 1000 mm. 1000m
In the case of m, the stainless steel plate is extended to the irradiation object W. Further, both are shown in FIG.

As shown in FIGS. 29, 30, and 31, a near infrared lamp 11 is used, and the periphery of the lamp is surrounded by a stainless steel reflector 13 and the object W to be irradiated is reflected by the reflector 1.
It is most effective to increase the temperature in Example e in which 3 is extended.

[0059]

Therefore, according to the present invention, the object to be irradiated is effectively irradiated with infrared rays regardless of the unevenness of the surface of the object to be irradiated.

[Brief description of drawings]

[Figure 1] Infrared absorption curve of each resin

[Figure 2] Infrared absorption curve of each resin

[Figure 3] Infrared absorption curve of each resin

[Figure 4] Infrared absorption curve of each resin

FIG. 5: Infrared absorption curve of each resin

FIG. 6 is a characteristic curve diagram of an infrared lamp.

FIG. 7 is a plane center sectional view of a drying furnace according to an embodiment of the present invention.

FIG. 8 is a plan sectional view of a comparative example.

FIG. 9 is a front sectional view of a comparative example.

FIG. 10 is a plan sectional view of an embodiment of the present invention.

FIG. 11 is a front sectional view of an embodiment of the present invention.

FIG. 12 is a plan sectional view of an embodiment of the present invention.

FIG. 13 is a front sectional view of an embodiment of the present invention.

FIG. 14 is a plan sectional view of an embodiment of the present invention.

FIG. 15 is a front sectional view of an embodiment of the present invention.

FIG. 16 is a plan sectional view of an embodiment of the present invention.

FIG. 17 is a front sectional view of an embodiment of the present invention.

FIG. 18 is a plan sectional view of a comparative example.

FIG. 19 is a front sectional view of a comparative example.

FIG. 20 is a plan sectional view of an embodiment of the present invention.

FIG. 21 is a front sectional view of an embodiment of the present invention.

FIG. 22 is a plan sectional view of the hood of the embodiment of the present invention.

FIG. 23 is a plan sectional view of the hood of the embodiment of the present invention.

FIG. 24 is a front view of the embodiment of the present invention.

FIG. 25 is a reflectance diagram of metal at each wavelength.

FIG. 26 is a reflectance diagram of metal at each wavelength.

FIG. 27 is a reflectance diagram of metal at each wavelength.

FIG. 28 is a reflectance diagram of metal at each wavelength.

FIG. 29: Temperature rise diagram

FIG. 30: Temperature rise diagram

FIG. 31 Temperature rising diagram

FIG. 32 is a front view of the embodiment of the present invention.

FIG. 33 is an enlarged view of a main part of the embodiment of the present invention.

FIG. 34 is an enlarged view of a main part of the embodiment of the present invention.

FIG. 35 is an enlarged view of a main part of the embodiment of the present invention.

FIG. 36 is a perspective view of an embodiment of the present invention.

37 is an enlarged view of the embodiment of the present invention shown in FIG.

FIG. 38 is an enlarged view of a main part of the embodiment of the present invention.

[Explanation of symbols]

 11 Infrared lamp 13 Reflector

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[Procedure amendment]

[Submission date] May 21, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction content]

FIG. 33 is an enlarged view of a main part of an embodiment of an infrared heating apparatus suitable for drying an object W to be irradiated having a partially thick portion W1. In this embodiment, a cylindrical hood 1 whose inner surface is a reflector 13 from the front of the near-infrared lamp 11 at the position of the thick portion W1 toward the irradiated object W
6 is projected. Conventionally, when an object to be irradiated having a thick portion W1 partially provided as shown in FIG. 33 is heated to dry the coating film, heating is performed in accordance with the thick portion W1 Overbake in the thick part,
If heating is performed in accordance with the non-thick portion, the thick portion W1 has a problem of insufficient heating. However, in this embodiment, even if each near-infrared lamp 11 is heated in accordance with the non-thick portion, since the thick portion W1 is given more energy than the non-thick portion, the thick portion W1 is insufficiently heated. It never becomes.

Claims (1)

[Claims] 1. An infrared heating device comprising a near-infrared lamp and / or a mid-infrared lamp and reflecting plates installed on at least both sides of the lamp.