JPH04330960A - Heater - Google Patents

Abstract

PURPOSE:To obtain a heater capable of reducing the number of an installed infrared generator by which the inside of a furnace is irradiated and capable of more effectively utilizing the irradiated rays. CONSTITUTION:The material to be carried is carried into a tunnel furnace from the outside thereof and, furthermore, carried to the outside of this tunnel furnace from the inside thereof. Infrared lamps 12 described below are provided to one face of the inside of the furnace. These infrared lamps 12 generate infrared rays which are high in infrared transmittance for a coated film of coating applied to the surface of the base material of the material to be carried and have a region high in absorptivity for the base material. Mirror surfaces 32 are provided in the irradiation faces of infrared rays emitted from an infrared generator so that the reflection surfaces due to the infrared lamps 12 in the inside of the tunnel furnace pinch the carrier path of the material W to be carried.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to a heating device for drying a coating film of a material to be dried by irradiating infrared rays in a furnace and further reflecting the infrared rays.

0002

BACKGROUND ART Conventionally, as a method of drying objects to be dried coated with various paints, methods using a so-called hot air oven or a drying oven utilizing far infrared rays are known. The drying mechanisms of these drying methods are understood as follows.

That is, first, an object to be dried, such as a metal plate or the like, whose surface is coated with a paint made of a solvent or a resin such as acrylic resin, is carried into a furnace. Next, hot air is blown or far infrared rays are irradiated. Then, the solvent on the surface of the paint applied to the object to be dried is first evaporated, and the surface loses fluidity and solidifies. When heat such as hot air propagates inside, that is, to the base material side, the coating film solidifies due to heating. Then, the solvent inside the surface breaks through the already solidified coating surface and evaporates. This leaves traces of foaming on the surface and creates pinholes. Therefore, in conventional hot air ovens or drying ovens that use far infrared rays, the solvent is evaporated in a setting room without rapid heating, and then far infrared rays are irradiated with a small temperature gradient or hot air is blown to perform drying.

However, the conventional drying methods using these drying ovens have the problem that drying takes a long time because drying is carried out while maintaining a low temperature that does not cause foaming.

[0005] In particular, when heating for the purpose of short-term drying using a combination of a hot air oven and infrared rays, the surface of the coating film reaches a higher temperature, causing a temperature difference between the coating surface and the metal surface at the interface between the coating film and causing foaming. There were problems that could easily arise.

On the other hand, "Near-infrared liquids, powders, coatings, and stoves" (Utility Model Application Publication No. 1-151873), "Light plate exclusively for paint baking ovens" (Utility Model Application Publication No. 2-43217), US Pat.
P4,863,375 “BAKING METHOD F
OR USE WITH LIQUID OR POW
DER VARNISHING FURNACE” (Baking Method for Youth with
liquid or powder vanishing
Furnace) etc. are known. These conventional examples include “
There is a description of ``a type of near-infrared liquid, powder, coating, stove baking method'', and ``Using near-infrared rays' rapid high temperature and strong penetrating properties, the stove baking method has been improved and paints can be baked. A device that dries quickly and strengthens its adhesion, that is, ``
``A coating method in which powder, liquid paint, gas, or fluid in a powder-liquid state is applied as a transport medium to the surface of an object, and then heated and melted to coat it evenly, as in so-called liquid or powder-liquid coating.'' There is a description of.

Alternatively, “a drying oven using near-infrared rays,”
Alternatively, a drying method in which a high-temperature section and a low-temperature section are sequentially formed in a drying oven, or a ceramic reflector is installed behind the near-infrared lamp, and a heater is installed inside the ceramic reflector.'' There is a description of.

[0008] Also, in the October issue of Painting Technology Special Issue, there is a description about ``medium wavelength infrared radiator'' (October 1990).
Published by Riko Publishing Co., Ltd., pp. 211-213). In other words, ``Some of the radiant energy that reaches the paint film is absorbed, some of it is reflected, and some of it is transmitted.The absorbed energy turns into heat, heating and drying the paint film.Painting In the case of , there is a base material and a body, so the radiant energy that passes through the paint film heats the base material, and heat conduction heats the paint film from the inside.

■Near infrared: Temperature 2000-2200°C
Maximum energy wavelength approximately 1.2 μm, high energy density, large reflected and transmitted energy, fast rise speed (
(1 to 2 seconds), and the lifespan is short at about 5,000 hours.

■Mid-infrared: Temperature 850-900°C, maximum energy wavelength approximately 2.5 μm, energy density medium, absorption. The transmitted energy is balanced and the energy penetrates into the coating film, resulting in a long life.

■Far infrared rays: Temperature 500-600°C, maximum energy wavelength approximately 3.5 μm, energy density low, well absorbed but tends to be absorbed and heated on the coating surface, long rise time (5-15 minutes) , convection loss is large. ”.

Furthermore, "2. Maximum efficiency medium wavelength infrared rays"
In order to dry faster and obtain better paint film quality, that is, to heat and dry with maximum efficiency, the following two conditions must be met at the same time.

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

[0014]Eb∝T4

[0015] The higher the temperature, the greater the radiant energy.

■The maximum energy wavelength is somewhat shorter than the peak absorption rate of the paint.

The maximum peak wavelength that can be used for industrial infrared heating of paints is around 3 μm without exception. Therefore 2.5
The infrared radiator, which has a maximum energy wavelength around μm, has good absorption and transmission, heating the base material and heating it from within.

Related to the above, the temperature of the infrared radiator (T
) and the maximum energy wavelength (λm), Wien's displacement law,

From λm=2897/T

T=(t+273)=2897/2.5

[
t=880°C

[0022] Medium wavelength infrared rays satisfy this condition, have large effective energy, and have maximum efficiency. ”.

However, Utility Model Application Publication No. 1-151873,
Utility Model Application Publication No. 2-43217, US Pat. However, there is no description of the optimum range of infrared rays to be irradiated and selection based on the relationship between near-infrared rays and the coating film applied to the metal surface.

On the other hand, far-infrared rays and mid-infrared rays that have been conventionally used for drying paint films select and use areas where the paint film has a high absorption rate, that is, areas where the paint film has a good infrared absorption rate. This is for the purpose of heating the coating film surface. However, the use of infrared rays, which have a high absorption rate in coatings, inherently poses the problem of pinhole formation. Therefore, there was a problem in that it took a long time to dry because the temperature was maintained at a low temperature that did not cause foaming.

[0025] In addition, the above-mentioned "Painting Technology Special Issue October issue" describes the selection of infrared rays based on the relationship between infrared rays and the absorption rate of the base material, or the selection of infrared rays based on the cause of pinhole formation. In painting drying, the authors conclude that ``an infrared radiator with a maximum energy wavelength of around 2.5 μm has good absorption and transmission, and can heat the base material and heat it from within.''

On the other hand, in the process of drying the paint film applied to the surface of the base material using near infrared rays, the inventors discovered that rather than selecting a region where the applied paint film has a high infrared absorption rate, the infrared transmission of the paint film We found that selecting near-infrared rays in a highly sensitive region can suppress the generation of pinholes. It is speculated that this is because the paint film is dried not from the paint film surface, but by directly heating the base material surface located at the interface with the paint film on the coated object, and the paint film is dried from the base material surface. be done.

That is, in general, when a metal is used as a base material, the longer the wavelength of infrared rays, the higher the reflectance of the metal, and the shorter the wavelength, the higher the heat absorption rate of the metal. Regarding the paint film, when drying the paint film using near-infrared rays, it is rather difficult to dry the paint film by using near-infrared rays that have high transmittance to the paint film. It is assumed that the heat is generated without any formation of .

Therefore, the inventor first filed Japanese Patent Application No. 2-3109.
16 ``Method for drying a paint film'', ``Drying method for drying a paint film applied to the surface of a base material using infrared rays in a region where the infrared transmittance of the paint film applied to the surface of the base material is high and the absorption rate of the base material is high is used. A method for drying a paint film characterized by drying the paint film.

By the way, the inventor has discovered that the infrared rays in the region where the infrared transmittance of the coating film of the paint applied to the surface of the base material is high and the absorption rate of the base material is high is the areal density of the radiant energy emitted from the heating element. It was found that the light reflected by the mirror surface was also effective in drying the materials to be dried.

[0030]

Problems to be Solved by the Invention It has been desired to reduce the number of infrared ray generators installed to irradiate the inside of the furnace and to utilize the irradiated infrared rays more effectively.

[0031]

[Means for Solving the Problems] The present invention is based on the above findings, that is,

[0032]
The infrared rays in the region where the infrared transmittance of the coating film of the paint applied to the surface of the base material of the material to be dried, which is transported from outside the furnace to the inside of the furnace, and from the inside of the furnace to the outside of the furnace, are high and the absorption rate of the base material is high. An infrared ray generator is provided on one side of the furnace, and a mirror surface is provided on the surface opposite to the infrared ray generator across the conveyance path of the material to be dried. heating device,

The conventional problems are solved by providing the following.

[0034]

[Operation] The material to be dried is transported and carried into the furnace. Then, one surface of the base material on which the coating film of the object to be dried is formed is irradiated with infrared rays in a region where the infrared transmittance is high for the coating film and the absorption rate of the base material is high. . Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed on one side of the object to be dried, and one surface of the base material is heated.

Therefore, the coating film on one side of the object to be dried is
It is heated and solidified from the back side of the coating near the surface of the base material. Therefore, even if the solvent in the coating evaporates, it will not break through the solidified coating surface and form pinholes.

[0036] Then, the material to be dried is further moved. Then, on the surface of the base material on which the other coating film of the object to be dried is formed, the infrared transmittance of the coating film is high due to the reflected light from the infrared ray generator, which is reflected by the mirror surface, and the coating film is formed on the base material surface. Infrared rays in a region with high absorption rate are irradiated. Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed on the other side of the object to be dried, and the surface of the base material is heated.

[0037] Therefore, the coating film is heated and solidified from the back side of the coating film, which is close to the surface of the base material. Therefore, even if the solvent in the coating evaporates, it will not break through the solidified coating surface and form pinholes.

Therefore, as the material to be dried moves, both sides of the material to be dried are heated and dried.

[0039]

[Example] When a metal plate is used as the base material on which the coating film is formed, the metal plate may be iron, aluminum, copper, brass, gold, beryllium, molybdenum, nickel, lead,
It consists of rhodium, silver, tankel, antimony, cadmium, chromium, iridium, cobalt, magnesium, tungsten and other metals, with copper, aluminum and iron being particularly preferred. As the paint forming the coating film applied to the metal surface, acrylic resin paint, urethane resin paint, epoxy resin paint, melamine resin paint, and other paints can be used. The coating film may be a coating film obtained by melting a so-called powder coating (epoxy, polyester, acrylic, etc.).

Tables 1 to 4 show the reflectance of each metal at each wavelength (AMERICAN INSTITUTE
OF PHYSICS HANDBOOK, American Institute of Physics Handbook 6-120). The higher the reflectance, the lower the absorption, and the lower the reflectance, the higher the absorption.

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

[0042] As the metal plate, iron, aluminum, copper, brass, gold, beryllium, molybdenum, nickel, lead,
Metal plates made of rhodium, silver, tankel, antimony, cadmium, chromium, iridium, cobalt, magnesium, and tungsten are used, and acrylic resin paint, urethane resin paint, epoxy resin paint, and melamine resin paint are used as paints. If the wavelength peak is 2
An infrared lamp of 1.2 μm or less, preferably 1.2 μm to 1.5 μm.
It is preferable to use a so-called near-infrared lamp of 5 μm.

Example 1

[0044] Near-infrared lamp (output peak 1.4 μm)

Metal plate Bonded steel plate (plate thickness 1 mm,
Dimensions: 100mm x 100mm)

Paint: Melamine resin (Amilac No. 1531 manufactured by Kansai Paint Co., Ltd., white, alkyd melamine resin paint, viscosity 20 sec, Iwata Cup NK-2 viscometer)

Comparative example 1

[0048] Far-infrared lamp (output peak 3.5 μm)

Metal plate Bonded steel plate (plate thickness 1mm,
Dimensions: 100mm x 100mm)

Paint: Melamine resin (Amilac No. 1531 manufactured by Kansai Paint Co., Ltd., white, alkyd melamine resin paint, viscosity 20 sec, Iwata Cup NK-2 viscometer)

Example 2

Near-infrared lamp (output peak 1.4 μm)

Metal plate Bonded steel plate (plate thickness 1mm,
Dimensions: 100mm x 100mm)

Paint Acrylic resin (Magicron No. 1531 manufactured by Kansai Paint Co., Ltd., white, acrylic/melamine/epoxy resin paint, viscosity 20 sec, Iwata Cup NK-2 viscometer)

Comparative example 2

[0056] Far-infrared lamp (output peak 3.5 μm)

Metal plate Bonded steel plate (plate thickness 1 mm,
Dimensions: 100mm x 100mm)

Paint Acrylic resin (Magicron No. 1531 manufactured by Kansai Paint Co., Ltd., white, acrylic/melamine/epoxy resin paint, viscosity 20 sec, Iwata Cup NK-2 viscometer)

Example 1, Example 2, Comparative Example 1, Comparative Example 2
For each film thickness: 30 μm, 40 μm, 50 μm
The ambient temperature and irradiation time were 130°C x 12
min, 140°C x 10 min, 150°C x 8 min, 160°
Table 5 (Example 1), Table 6 (Comparative Example 1), Table 7 (Example 2) ), shown in Table 8 (Comparative Example 2).

FIG. 11 is a sectional plan view of the first embodiment of the present invention, and FIG. 12 is a sectional plan view of the second embodiment. 11 is a tunnel furnace, and W is a material to be dried whose surface is coated with paint. The material to be dried W is made of a metal plate as a base material, and the metal plates include iron, aluminum, copper, brass, gold, beryllium, molybdenum, nickel, lead, rhodium,
Consists of silver, tantalum, antimony, cadmium, chromium, iridium, cobalt, magnesium, and tungsten. On the base material of the material to be dried W, a paint such as an acrylic resin paint, a urethane resin paint, an epoxy resin paint, or a melamine resin paint is applied.

The tunnel furnace 11 has two openings: an inlet A for carrying in the material to be dried, and an outlet B for carrying out the material to be dried. Reference numeral 12 denotes an infrared generator, which in this embodiment consists of an infrared lamp. A condensing mirror may be installed on the back side of the infrared lamp. In this embodiment, the infrared generator 12 is an infrared lamp with a peak wavelength of 2 μm or less, preferably 1.2 μm.
A so-called near-infrared lamp with a wavelength of 1.5 μm to 1.5 μm is used. The infrared rays in the region where the infrared transmittance to the coating film of the paint applied to the surface of the base material of the material to be dried W is high and the absorbance of the base material is high are shown in Figures 1 to 6 and Table 1 according to the type of base material and paint. Select based on Tables 1 to 8 and install at the required location in the furnace. A conveyor 31 conveys the material to be dried W from outside the tunnel furnace 11 into the tunnel furnace, and from inside the tunnel to outside the tunnel furnace.

The infrared generator 12 is provided on one side of the furnace as shown in FIGS. 11 and 12. 32 is a reflecting mirror. The reflecting mirror 32 connects the tunnel furnace 11 of the infrared generator 12 with a conveyor 31 serving as a conveyance path for the dried material.
It is located on the opposite side of the inner surface and is provided on the surface that irradiates the infrared rays generated by the infrared ray generator.

Next, the operation of the embodiment will be explained. The material to be dried W is transported and carried into the tunnel furnace. Then, on the surface of the base material on which one of the coating films of the material to be dried W is formed,
The infrared ray generator irradiates the coating film with infrared rays in a region where the infrared transmittance is high and the base material has a high absorption rate. Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed on one side of the object W to be dried, and the surface of the base material is heated.

[0064] Therefore, the coating film on one side of the material to be dried W is heated and solidified from the back side of the coating film close to the surface of the base material. Therefore, even if the solvent in the coating evaporates, it will not break through the solidified coating surface and form pinholes.

[0065] Then, when the material to be dried W is further moved,
Then, on the surface of the base material on which the other coating film of the material to be dried W is formed, the infrared transmittance of the coating film is high due to the reflected light produced by reflecting the irradiation light from the infrared ray generator 12 on the mirror surface.
Infrared rays are irradiated in areas where the base material has a high absorption rate. Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed on the other side of the object W to be dried, and the surface of the base material is heated.

[0066] Therefore, the coating film is heated and solidified from the back surface of the coating film, which is close to the surface of the base material. Therefore, even if the solvent in the coating evaporates, it will not break through the solidified coating surface and form pinholes.

Therefore, as the material to be dried W moves, both surfaces of the material to be dried are heated and dried.

When a plurality of objects W to be dried are conveyed by the conveyor 32, the distance between the objects W to be dried is such that each of the objects W to be dried takes a position that does not interfere with the irradiation of the other object W to be dried; Convey at the conveyance speed.

FIG. 7 is a front sectional view of a third embodiment of the invention, FIG. 8 is a front sectional view of a fourth embodiment of the invention, FIG. 9 is a partially enlarged view of FIG. 7, and FIG. 10 is a front sectional view of a fourth embodiment of the invention. FIG. In these embodiments, an air curtain is attached to the embodiment shown in FIGS. 11 and 12, and five or more condensing mirrors 32 that sequentially reflect the infrared lamps 12 are installed. That is, 1
3 is an air curtain. The air curtains 13 are installed at an inlet A of the material to be dried and an outlet B of the material to be dried, respectively, of the tunnel furnace 11 . 14 is an air outlet of the air curtain, and 15 is an air inlet. 16 is a fan, and 17 is a circulation duct connecting the air outlet 14 and the air intake port 15. 18 is a filter installed closer to the air outlet 14 than the fan 16 of the circulation duct 17. 21 is a cooling device. The fan 16 circulates the air so that the air taken in through the air intake port 15 is blown out from the air outlet 14.

22 and 23 are modustrol motors, 2
4 is a damper installed upstream of the fan 16 in the circulation duct 17 and operated by the Modustrol motor 22; 25 is a damper driven by the Modustrol motor 23; 26 is an exhaust fan; 27 is the air outlet 14.
A modustrol motor 22 installed in the
This is a temperature controller that controls the operation of 23. These constitute an air curtain and also constitute a cooling device 21.

In the embodiment shown in FIG. 8, the infrared lamp 12 is also installed at the location where the air curtain 13 is installed. In FIG. 9, B is the effective irradiation range of the infrared lamp 12. In the effective irradiation range B, the material to be dried W is heated from the base material side using an infrared lamp to dry the coating film. A is the air blowing range. In this embodiment, the effective irradiation range B and the air blowing range A slightly overlap.

Next, the operation of the embodiment will be explained. In these embodiments, both surfaces are irradiated with infrared rays that are sequentially reflected, similar to the embodiments shown in FIGS. 11 and 12. Furthermore, the inventors believe that ``the paint film formed on the surface of the base material can be detected by using infrared rays in a region where the infrared transmittance of the paint film applied to the base material surface is high and the base material has a high absorption rate. A simple circulation type air curtain is installed at the opening to the outside air of the furnace, and the coating film applied to the base material is dried in the furnace. It was discovered that when the film was dried, many pinholes were generated.

Compared to conventional drying ovens such as hot air ovens, this method uses infrared rays in the region where the infrared transmittance of the paint film applied to the surface of the base material is high and the absorption rate of the base material is high. A method for drying a coating film formed on the surface of a material, characterized by drying the coating film formed on the surface of the material." Furnaces that use this method are highly efficient. Therefore, the heat radiation from the furnace opening is large, and the temperature of the air supplied to the air curtain is gradually raised. When sprayed on the material to be dried in advance, the hot air heats the surface of the coating film without heating it from the base material side, resulting in surface drying (surface hardening), a thin diaphragm is formed on the surface, and then the surface of the material is heated. When heated from the material side, the solvent inside the surface breaks through the already solidified diaphragm surface and evaporates. It is presumed that then, traces of foaming remain on the surface, causing pinholes. In other words, it has been found that outside the effective range of infrared irradiation, it is more effective not to allow the air heated by infrared irradiation to affect the material to be dried.

[0074] Therefore, the material to be dried W coated with paint is
The material to be dried is transported into the tunnel furnace 11 through the transport port A. Then, the air passes through the air curtain 13 and is blown at the air outlet 14, but the air supplied by the air curtain is cooled by the cooling device 21 and the temperature rise is suppressed, so that the air blows onto the material to be dried WW. Even if it comes into contact with a surface, it will not act on the surface of the coating film to form a coating film. That is, while using the air curtain, the air outlet 14
The temperature controller 27 detects the temperature as 110 degrees, for example.
For example, if the temperature inside the tunnel furnace 11 is 160 degrees and the set temperature of the air blown out from the air outlet 14 is 80 degrees,
Modustrol motor 22 to correct the 0 degree temperature difference
, 23 are activated. Note that in this state, air intake port 1
5, it is 130°C. Then, the modustrol motor 22 opens the damper 24 and introduces outside air into the circulation duct 17. The modustrol motor 23 opens the damper 25 and operates the exhaust fan 26 to exhaust the air inside the circulation duct 17 to the outside of the circulation duct 17. When the temperature controller 27 senses that the temperature of the air blown out from the air outlet 14 has fallen below the set temperature,
Each damper 24, 25 is maintained at its opening degree to maintain the temperature of the air curtain 13.

Next, in the tunnel furnace 11, the material to be dried W
The base material surface has a high infrared transmittance for the coating film,
An infrared lamp 12 that emits infrared rays in a region where the absorption rate of the base material is high is irradiated. Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed, 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, which is close to the surface of the base material. Since no surface coating film is formed by the air curtain 13, even if the solvent in the coating film evaporates, the solidified coating film surface will not be broken and pinholes will not be formed.

As shown in FIG. 8, the air curtain 1
If the infrared lamp 12 that irradiates infrared rays in a region where the infrared transmittance to the coating film of the paint applied to the surface of the base material is high and the absorption rate of the base material is high is installed at the installation location of 3, the air curtain 13 At the installation location, the surface of the base material on which the coating film is formed is irradiated with infrared rays in a region where the infrared transmittance is high for the coating film and the absorption rate of the base material is high. Then, the infrared rays that have passed through the coating film are absorbed by the base material on which the coating film is formed, 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, and the coating film is dried from the position where the air curtain 13 is installed.

Table 9 shows the example illustrated in FIG.
The figure shows the state of pinhole occurrence in the coating film at different air curtain wind speeds and temperatures in a comparative example using an air curtain without a cooling device. In order to prevent the occurrence of pinholes, it is desirable to maintain the temperature at approximately 80°C or less.

Setting conditions

0079 Paint Melamine resin

Object to be painted Bonded steel plate 1.2t

[0081] Coating film thickness: 30 microns

[0082] Indoor temperature 30°C

[0083] Furnace temperature 160°C

Air curtain height (air outlet to air intake) 2m

0085 Air curtain wind speed

When the air velocity is 10 m/s at the air outlet, the air intake velocity is 4 m/s, when the air velocity is 7 m/s at the air outlet, the air intake velocity is 2.8 m/s, and when the air velocity is 4 m/s at the air outlet, the air intake velocity is 4 m/s. At the mouth, it was 1.2 m/s.

[0087]

[Effects of the Invention] Therefore, in the present invention, the number of installed infrared ray generators that irradiate the inside of the furnace is reduced, and the irradiated infrared rays are utilized more effectively.

[Brief explanation of drawings]

[Figure 1] Infrared absorption curve diagram of each resin

[Figure 2] Infrared absorption curve diagram of each resin

[Figure 3] Infrared absorption curve diagram of each resin

[Figure 4] Infrared absorption curve diagram of each resin

[Figure 5] Infrared absorption curve diagram of each resin

[Figure 6] Characteristic curve diagram of infrared lamp

FIG. 7 is a central cross-sectional view of the third embodiment of the present invention.

FIG. 8 is a central sectional view of the fourth embodiment of the present invention.

[Figure 9] Partially enlarged view of Figure 7

[Fig. 10] Planar sectional view of Fig. 7

FIG. 11 is a central sectional view of the first embodiment of the present invention.

[Figure 12
] Central sectional view of the second embodiment of the invention

[Table 1] Reflectance of metal at each wavelength

[Table 2] Reflectance of metal at each wavelength

[Table 3] Reflectance of metal at each wavelength

[Table 4] Reflectance of metal at each wavelength

[Table 5] Number of pinholes in Example 1

[Table 6] Number of pinholes in Comparative Example 1

[Table 7] Number of pinholes in Example 2

[Table 8] Number of pinholes in Comparative Example 2

[Table 9] Pinhole occurrence state in the coating film at different air curtain wind speeds and temperatures in Examples and Comparative Examples using air curtains without a cooling device

[Explanation of symbols] 11 Furnace 12 Infrared generator 32 Mirror

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

[Table 6]

[Table 7]

[Table 8]

[Table 9]

Claims (1)

[Claims] Claim 1: The infrared transmittance of the paint applied to the surface of the base material of the material to be dried, which is transported from the outside of the furnace to the inside of the furnace and from the inside of the furnace to the outside of the furnace, has a high infrared transmittance and a low absorption rate of the base material. An infrared generator that generates infrared rays in a high range is installed on one side of the furnace, and a mirror surface is provided on the surface that is irradiated with the infrared rays generated by the infrared generator on the opposite side of the furnace, across the conveyance path of the material to be dried. A heating device characterized by: