JP7272658B2 - Drying equipment and drying method - Google Patents

Description

The present invention relates to a drying apparatus and a drying method, and in particular, effectively irradiates infrared rays (including mid-infrared rays and far-infrared rays; the same shall apply hereinafter) without being disturbed by the aqueous solvent or organic solvent to be dried. It relates to a drying apparatus and a drying method capable of drying efficiently in a short time.

Conventionally, when forming a coating layer or the like on the surface of a glass bottle or the like as an object to be coated, after applying an inorganic paint or inorganic ink, it is heated to 300 to 600 ° C. A method of heating and curing under heating conditions of 15 minutes to 60 minutes is often used (see, for example, Patent Documents 1 and 2).

For example, the drying device 109 disclosed in Patent Document 1 includes a predetermined air device 103 and an infrared heater device for irradiating near-infrared rays or middle-infrared rays toward the article to be coated 101, as shown in FIG. 11(a). 105 and a high-frequency induction heating device 107 that heats the object 101 to be coated by high-frequency induction.
An air device 103 for heating the paint applied to the object 101 with hot air includes a circulation air outlet 103a, a circulation air inlet 103b, a circulation duct 103c, a heater 103d and a circulation fan 103e.

According to the drying device 109, the entire paint is heated by circulating hot air and near-infrared rays or middle-infrared rays, and the temperature of the deep part of the paint is raised by high-frequency induction without excessively increasing the temperature of the paint surface. be able to.
Therefore, the coating film quality can be maintained and the paint can be dried in a short time.

Further, the drying apparatus disclosed in Patent Document 2, as shown in FIG. and a drying device 117 provided on the upper surface of the coating film 111 and including an infrared radiation device 115 for radiating infrared rays to the coating film.

According to the drying device 117, the convective electric heat from the lower surface of the web 111 (the back surface of the coating film surface) and the radiant electric heat from the upper surface (coating surface) promote drying from the inside of the coating film. The coating film can be dried in a short time without causing unevenness or skinning (formation of dry film on the surface of the coating film).

Japanese Patent Application Laid-Open No. 8-332434 (Claims etc.) JP 2015-66519 A (Claims etc.)

However, in the case of the drying apparatus disclosed in Patent Document 1, even if it can be applied to a glass container or the like as an item to be dried, it has relatively low heat resistance such as a direct blow PET bottle (heat resistant temperature: about 60 to 80 ° C.). The problem of inapplicability was observed for articles to be dried having poor substrates.
That is, since the suitable heating condition adjustment range is extremely narrow for the types of various substrates (substrates) of the article to be dried, in the case of the drying apparatus disclosed in Patent Document 1, suitable There was a problem that the heating conditions could not be changed.
In addition, since a high-frequency induction heating device is required, not only is the cost of the device increased, but the principle of high-frequency induction heating is such that the object to be dried is limited to a coating film that causes high-frequency induction.
Furthermore, although the hot air is circulated around the object to be dried to equalize the heating temperature, the moisture and organic solvent contained in the hot air absorb the infrared rays used for heating, resulting in the coating being unusable. A problem was observed in that the film formation was adversely affected.

In addition, in the case of the drying device 117 disclosed in Patent Document 2, hot air is applied from the lower surface of the web 111 to heat the coating film from below. When the specific heat of the material itself is large, the problem is that the heat of the hot air is difficult to reach the coating film. Therefore, there is a problem that the coating film cannot be dried uniformly and efficiently.
In addition, since the hot air is applied only from the lower surface of the web and is not applied to the infrared ray emitting surface side, there is a problem that the interaction between the hot air and the infrared rays cannot be actively utilized.

Therefore, the inventors of the present invention, as a result of conventional earnest efforts, have provided a predetermined first heating device and a second heating device, and have made it possible to prevent absorption of infrared rays by the second heating device. The inventors have found that infrared rays can be effectively irradiated without being disturbed by the dried aqueous solvent or organic solvent by controlling the direction of the airflow after drying in a fixed direction, and have completed the present invention.
That is, the present invention can be easily applied to various articles to be dried, and actively utilizes the mutual effect of hot air and infrared rays to dry and form a coating film efficiently in a short time. It is an object of the present invention to provide a drying apparatus capable of drying and a drying method using the same.

According to the present invention, a housing having an introduction part for introducing an airflow, and heating the airflow to generate a heated airflow having a predetermined temperature are applied to the article to be dried from the first direction as the predetermined direction. a first heating device for blowing, a heated airflow discharge section for discharging the heated airflow blown by the first heating device to the outside of the housing from a second direction as a predetermined direction, and an article to be dried, and a second heating device for heating by irradiating infrared rays, wherein the first direction is different from the second direction, and the heated airflow advances and is discharged in a fixed direction. There is provided a drying apparatus characterized in that the above problems can be solved.

That is, a heated airflow introduced from the outside of the housing and heated is applied to the article to be dried from a first direction, and the heated airflow is directed from a second direction different from the first direction to the housing. It can be discharged outside the body as a unidirectional flow.
Therefore, the moisture and solvent that evaporates from the paint applied to the article to be dried does not circulate around the article to be dried. and effectively eliminated.
Therefore, the mutual effect of hot air and infrared rays is positively utilized for the infrared irradiation of the item to be dried. It becomes possible to carry out in an atmosphere (eg, about 1/2 to 1/10).
Therefore, such infrared rays effectively reach the article to be dried without being absorbed or blocked by the scattering moisture or solvent, and the absorption efficiency of the infrared rays in the coating film on the article to be dried is extremely high (for example, about 2-10 times).

In addition, the heating of the inside of the paint is also promoted, that is, the combined effect of the heated airflow and the infrared rays is exhibited, so the drying conditions can be adjusted simply by changing the heating conditions such as the heated airflow (temperature, wind speed, irradiation time, etc.). It can be widely changed, and can be formed by drying efficiently in a wide temperature range in a short time according to the substrate (substrate) of various articles to be dried and the type of coating film.
It should be noted that the fact that the heated air travels in a certain direction means, for example, that a cylindrical flow path with a cross-sectional area of 100 cm ² and a length of 1 m, which may have bends and curves, is assumed in the flow path of the drying device (Fig. C), which means that the heated air moves unidirectionally and is exhausted along its cylindrical channel without backflow or circulation.

Thus, for example, if an envisioned cylindrical channel is provided with multiple (e.g., five) streamers in the middle of an equally envisioned channel, and all streamers flow in the same direction, the heated air It can be said that they are moving in the same direction.
In addition, as another guideline, measure the air volume and wind pressure using an anemometer and an anemometer near the start point and end point of the cylindrical flow path assumed in the same way, and for example, the difference is 50% or less. If it is 80% or less, it can be said that the heated air is proceeding in the same direction more appropriately.

Further, in constructing the drying apparatus of the present invention, it is preferable that the introduction section for taking in the airflow is provided below the heated airflow discharge section along the vertical direction.
With such a positional relationship, the heated airflow introduced from the outside of the housing is effectively applied to the article to be dried from the first direction, and the heated airflow applied to the article to be dried is , in a state containing moisture and solvent, it is effectively discharged in the shortest distance as a unidirectional flow to the outside of the housing from a second direction different from the first direction without returning to the surroundings of the dried product. be.

Further, in constructing the drying apparatus of the present invention, it is preferable that the first heating device is an electric heater that generates a heated airflow at 50 to less than 100.degree.
By using a heated airflow in such a temperature range, direct blow PET bottles (heat resistant temperature: about 60 to 80 ° C), PP resin plates (heat resistant temperature: about 90 ° C), ABS resin plates (heat resistant temperature: about 100 ° C) ° C.), PC resin plates (heat resistant temperature: about 120 ° C.), and other substrates with relatively poor heat resistance can be widely applied simply by changing the heating conditions of the heated air flow. can.

Further, in configuring the drying apparatus of the present invention, the second heating device is an infrared heating device (sometimes referred to as a mid-infrared heating device) equipped with a reflecting device, and the radiance of the infrared heating device is It is preferable to set the peak wavelength to a value within the range of 2 to 5 μm.
The use of infrared rays in such a wavelength range is preferable for quick drying of coating films of various paints, because absorption by water and solvents is further reduced.
In addition, since the infrared heating device is provided with a reflector on the back side, it is possible to efficiently use infrared rays, and it is also possible to easily control the directionality of the heating airflow.

Further, in constructing the drying apparatus of the present invention, it is preferable that a hollow portion is provided inside the housing, and a transfer means for moving the article to be dried at a predetermined speed along the hollow portion is provided. .
Due to the provision of such transfer means, the number of dryings performed by the drying apparatus per unit time can be significantly increased.

Further, in constructing the drying apparatus of the present invention, a temperature control member is provided inside the housing, in which at least the sides and the periphery of the ceiling are shielded with an aluminum plate, and the ceiling of the temperature control member , a vent for emitting the heated airflow from said second direction.
With such a configuration, the air flow inside the drying device is further stabilized in a predetermined direction (first direction to second direction) by the temperature adjustment member having a predetermined structure, and the ventilation port or the like stabilizes the air flow inside the drying device. Excessive temperature rise inside the device can be prevented.
In addition, since the internal temperature of the drying device does not rise excessively, even aluminum plates, which are slightly inferior to stainless steel in terms of chemical resistance (water resistance, solvent resistance) and mechanical properties, can be used for a long period of time. It can function as a very good infrared reflector, especially a mid-infrared reflector.

Further, in configuring the drying apparatus of the present invention, the aluminum plate in the ceiling portion of the temperature adjustment member is formed of a plurality of aluminum plates, a first aluminum plate and a second aluminum plate. It is preferable that the first aluminum plate and the second aluminum plate overlap when viewed from above.
With such a configuration, the overlap width of the first aluminum plate and the second aluminum plate can be made variable, and the width of the ventilation opening can be adjusted to efficiently adjust the internal temperature. can be done.
Also, by making the overlap width variable, the predetermined dimension of the temperature control member can be shortened or, conversely, lengthened. Therefore, the drying apparatus of the present invention can be easily adapted to the size and amount of the material to be dried.
In order to easily change the overlapping width of the first aluminum plate and the second aluminum plate, a slide mechanism (for example, a linear slider with bearings) is used for the first aluminum plate and the second aluminum plate. are preferably provided between both ends of the housing.

Another aspect of the present invention is a housing provided with an introduction part for taking in an airflow, heating the airflow to generate a heated airflow having a predetermined temperature, and directing the article to be dried in a predetermined direction in the second direction. a first heating device that blows from one direction; a heated airflow discharge section that discharges the heated airflow blown by the first heating device to the outside of the housing from a second direction as a predetermined direction; This is a drying method using a drying device including a second heating device for heating the dried product by irradiating it with infrared rays.
The first direction and the second direction are different from each other, and in a drying method using a drying device in which the heated airflow does not actually circulate and is discharged after advancing in a fixed direction. a step of preparing an article to be dried having a coating film on a substrate as an article to be dried; A drying step of heating by irradiating infrared rays with a second heating device while spraying the product, and a discharging step of discharging the airflow after drying the article to be dried from the second direction to the outside of the housing; A drying method characterized by comprising

That is, according to the drying method of the present invention, the heated airflow introduced from the outside of the housing is applied to the article to be dried from the first direction without circulating around the article to be dried, The heated airflow can be quickly and effectively discharged in the shortest distance from the second direction, which is different from the first direction, to the outside of the housing as a unidirectional flow.
Therefore, unlike the conventional circulating heating method, the infrared irradiation to the article to be dried is performed in an atmosphere with a low concentration of moisture or solvent that easily absorbs the infrared rays, especially the middle infrared rays of a predetermined wavelength (for example, about 1/2 to 1 /10). As a result, the amount of infrared rays that reach and are absorbed by the coating film or the like of the article to be dried is correspondingly increased (for example, about 2 to 10 times).
Therefore, the heating of the inside of the paint is also promoted, that is, the combined effect of the heated airflow and the infrared rays is exhibited, so the drying conditions can be changed widely, depending on the substrate of various articles to be dried and the type of coating film. , can be dried (formed) efficiently in a short time in a wide temperature range.

Further, in carrying out the drying method of the present invention, it is possible that a cavity is provided inside the housing, and the article to be dried is dried while being moved at a predetermined speed by a transporting means along the cavity. preferable.
Such transport means make it possible to significantly increase the number of dryings performed per unit of time by carrying out the drying method.

Further, in carrying out the drying method of the present invention, in the drying step, as the first heating device, an electric heater that generates a heated air flow of less than 50 to 100 ° C. is used, and as the second heating device, a reflector is used. It is preferable to heat the article to be dried to a temperature of 100° C. or higher using an infrared heating device having a radiance peak wavelength in the range of 2 to 5 μm.
First, by using the first heating device that heats to a predetermined temperature, even for articles to be dried having relatively poor heat resistance substrates such as direct blow PET bottles (heat resistant temperature: about 60 to 80 ° C.), Widely applicable.
In addition, when infrared rays in such a wavelength range, particularly mid-infrared rays contained therein, are mainly used, absorption by moisture and solvents is further reduced, which is preferable for quick drying of coating films of various paints.
Moreover, since the infrared heating device having the reflector on the back side is used, the infrared rays can be used efficiently, and the directivity of the heating airflow can be easily controlled.

Further, in carrying out the drying method of the present invention, a temperature control member having at least the sides and the periphery of the ceiling portion shielded with an aluminum plate and having a ventilation opening in the ceiling portion is provided inside the housing. It is preferable that the drying is performed while discharging the heated airflow from the second direction to the outside of the housing via the ventilation opening.
By carrying out in this manner, the air flow inside the drying apparatus is further stabilized in a predetermined direction (first direction to second direction) by the temperature adjustment member having the predetermined structure, and the ventilation port or the like stabilizes the drying apparatus. Excessive temperature rise inside the can be prevented.
In addition, since the internal temperature of the drying device does not rise excessively, even aluminum plates, which are slightly inferior to stainless steel in terms of chemical resistance (water resistance, solvent resistance) and mechanical properties, can be used for a long period of time. It can function as a very good reflector for infrared rays, especially mid-infrared rays.

FIGS. 1(a) to 1(e) are diagrams provided for explaining the drying apparatus of the first embodiment, and FIG. 1(a) in particular is an external perspective view of the drying apparatus of the first embodiment, FIG. 1(b) is a view of the inside of the drying device viewed from the side of the device, FIG. 1(c) is a view of the inside of the drying device viewed from the front of the device, FIGS. 1(d) and ( e) is a diagram showing an example of the belt of the transfer means. FIG. 2 is a diagram for explaining the radiance characteristics of an infrared lamp suitable for use in the present invention. FIGS. 3(a) to 3(c) are diagrams provided for explaining the drying apparatus of the second embodiment, in particular, FIG. 3(a) is an external perspective view of the drying apparatus, and FIG. FIG. 3(c) is a view of the inside of the drying device as seen from the side of the device, and FIG. 3(c) is a view of the inside of the drying device as seen from the front of the device. FIGS. 4(a) to 4(c) are diagrams provided for explaining the drying apparatus of the third embodiment, in particular, FIG. 4(a) is an external perspective view of the drying apparatus, and FIG. FIG. 4C is a view of the inside of the drying device as seen from the side of the device, and FIG. 4C is a view of the inside of the drying device as seen from the front of the device. FIGS. 5(a) and 5(b) are diagrams provided for explaining the drying apparatus of the fourth embodiment, and are diagrams particularly showing the vicinity of another form of the heated airflow outlet. FIGS. 6(a) to 6(c) are diagrams provided for explaining the drying apparatus of the fifth embodiment, in particular, FIG. 6(a) is an external perspective view of the drying apparatus, and FIG. It is the figure which looked at the inside of the drying apparatus from the side of the said apparatus. FIGS. 7(a) to 7(c) are diagrams provided for schematically explaining the flow of air in the drying device. FIG. 8 is a diagram for explaining the drying apparatus of the sixth embodiment, and is a perspective view for explaining the temperature adjusting member in particular. 9(a) and 9(b) serve to explain the width and overlapping state of the temperature adjusting member when the cut plane taken along the line AA' in FIG. 8 is viewed in the direction of the arrow. It is a diagram. FIG. 10 is a diagram for explaining changes in surface temperature when an aluminum plate, a mirror surface aluminum plate, and a stainless steel plate are irradiated with infrared rays. FIG. 11(a) is a diagram for explaining a conventional drying apparatus, and FIG. 11(b) is a diagram for explaining another conventional drying apparatus.

Hereinafter, embodiments of the present invention will be specifically described.
Also, the shapes, materials, numerical ranges, etc. described in the following description are merely preferred examples within the scope of the present invention. Therefore, the present invention is limited only to the following embodiments without any particular reason. isn't it.

[First embodiment]
As shown in FIG. 1, the drying apparatus 10 of the first embodiment includes a housing 11 having an introduction portion 21 for introducing an airflow, and heating the airflow to generate a heated airflow having a predetermined temperature. A first heating device 23 that blows against the dried product W from a first direction (for example, see arrow A in FIG. 1) as a predetermined direction, and a heated airflow that is blown by the first heating device 23 to the outside of the housing 11 from a second direction (see, for example, the arrow B in FIG. 1) as a predetermined direction. The drying device 10 includes a second heating device 15 for heating, and the first direction is different from the second direction, and the heated airflow advances in a fixed direction and is discharged. The drying apparatus 10 is characterized by:
In addition, a transfer means 13 for transferring the material to be dried W coated with paint at a predetermined speed in a predetermined direction (see, for example, the symbol D in FIG. 1) within the housing 11, and the drying apparatus 10 as a whole. and a control device (particularly not shown) that controls the operation of.
The first heating device 23 includes a hot air generator 17 that generates a heated airflow, and a heated airflow supply unit 19x that blows the generated heated airflow onto the article to be dried from a predetermined direction during infrared irradiation.
Furthermore, the drying apparatus 10 preferably has a form in which the heated airflow is supplied to the article to be dried from below the transfer means 13 and discharged above the transfer means 13 .
Hereinafter, each configuration of the drying apparatus 10 in the first embodiment will be specifically described.

1. Housing A housing 11 provided with an introduction portion 21 for taking in an airflow (air) from the outside of the housing 11 includes a transfer means 13, an infrared irradiation device as a second heating device 15, and a first heating device 23. and a configuration for efficiently discharging the article W to be dried to the outside of the housing 11 from a predetermined direction without circulating the article W after drying.
The housing 11 is constructed of a structure having a shape suitable for enclosing the transfer means 13 and the like using, for example, a metal frame, a metal plate, a heat-resistant resin plate, or the like.
Further, in the case of the case 11 illustrated in FIG. 1, it has a substantially rectangular outer diameter of 10 m or more, contains the transfer means 13, and one end of the rectangle is the entrance 10a for the article W to be dried. , and the other end of the housing 11 serves as an outlet 10b.

As the material for the metal frame and metal plate, aluminum, nickel, stainless steel, tungsten, or a combination thereof can be used, and aluminum is particularly preferred.
The reason for this is that aluminum is relatively easy to be mirror-polished, for example, the surface roughness Ra is 0.1 μm or less, more preferably the surface roughness Ra is in the range of 0.005 to 0.1 μm. This is because it is easy to adjust to the value of
Therefore, a mirror-polished aluminum plate can more efficiently totally reflect mid-infrared rays with a specific wavelength of 2 to 5 μm contained in infrared rays.

Here, it is necessary to heat the airflow taken in from the introduction part 21 and blow the heated airflow onto the article to be dried W from the first direction. A fan 19a (also used as the fan 17b of the hot air generating device 17 in this example) that sends the heated airflow generated in 17 toward the belt conveyor 13a, a duct 19b that guides the heated airflow sent by the fan 19a to the belt conveyor 13a, It consists of

The duct 19b is provided with a heating airflow blowing surface having a length and width substantially the same as the length and width of the infrared irradiation device as the second heating device 15, facing the lower surface of the belt conveyor 13a. It is preferable that the structure is
In addition, it is preferable that a large number of opening holes or opening slits for blowing out the heated airflow are provided at appropriate positions on the blowing surface.

2. Transporting Means The transporting means 13 is contained inside the housing 11 and moves in a substantially horizontal direction to move the article to be dried W from the inlet 10a of the drying device 10 toward the outlet 10b and then to the first The material is transferred through a heating airflow area by the heating device 23 and an infrared irradiation area by the second heating device 15 .
The transfer means 13 includes a belt conveyor 13a that rotates along the longitudinal direction of the housing 11, a motor 13b that drives the belt conveyor 13a, and a rotating roller 13c that smoothly moves the belt conveyor 13a. but preferably a plurality of intermediate rollers.

In the drying apparatus 10 of this embodiment, the transfer means 13 is a belt conveyor 13a having an opening 13d through which the heated airflow can pass from below to above the belt conveyor 13a.
Therefore, the belt conveyor 13a having the openings 13d may be of any suitable type. Preferably, a conveyor 13a is used.

Alternatively, it is possible to use a belt conveyor 13a having a lattice shape as shown in FIG. 1(e) and using the gaps between the lattices as openings 13d.
Therefore, considering heat resistance and infrared resistance, stainless steel and carbon fiber are suitable for the constituent material of the belt conveyor 13a.

In addition, the moving speed of the belt conveyor 13a is determined by judging the type of paint to be used, the type of solvent, and the drying property thereof, but is usually a value within the range of 0.1 to 20 m/min. , more preferably in the range of 0.5 to 10 m/min, and even more preferably in the range of 1 to 8 m/min.

3. First heating device The first heating device 23 is used to dry the coating film (see symbol W1 in FIG. 7) applied to the substrate of the article to be dried W (see symbol W2 in FIG. 7). It is a part that generates a heated airflow at a temperature (for example, 50 to 100° C. or less) based on an airflow (air) taken in from the outside.
Then, the first heating device 23 blows the heated airflow as the first airflow onto the article to be dried W from the first direction (see arrow A in FIG. 1) as the predetermined direction, and furthermore, It is a part for quickly moving the heated airflow after the heating as a second airflow in a predetermined direction in cooperation with other constituent parts.
Here, it is preferable to set the temperature of the heated airflow blown by the first heating device 23 to a value within the range of 50 to less than 100.degree. The reason for this is that by setting this temperature range, for example, even for a direct blow PET bottle with a relatively low heat resistance temperature (heat resistance temperature: about 60 to 80 ° C.), etc., it is effective without causing problems such as deformation. This is because it can be applied

In addition, the first heating device 23 takes in the outside air from the introduction part 21, and the hot air generating device 17 that sends hot air, and the hot air sent by the hot air generating device 17 as a first air flow in a predetermined direction. It is preferable to include a heated airflow supply section 19x for blowing a heated airflow onto the article to be dried W from one direction.
The hot air generator 17 includes a heater 17a as a heat source for heating the outside air (air) taken in from the introduction part 21, and a fan 17b for guiding the outside air to the heat source and sending it as a heated airflow. It is preferable to be
The reason for this is that, by adopting such a configuration, it is possible to efficiently generate hot air at a predetermined temperature, and to blow a stable heated airflow in a predetermined direction onto the article W to be dried.
It should be noted that the first heating device 23 is preferably designed to be explosion-proof, as required, assuming that a highly flammable organic paint or the like may be used in forming the coating film.

4. Second heating device The second heating device 15 is, as shown in FIG. It is preferable to heat the article W to be dried to a temperature of 100° C. or higher while setting the wavelength of the radiance peak mainly in the mid-infrared rays to a value within the range of 2 to 5 μm.
In addition, the infrared irradiation device, which is an example of the second heating device 15, has an infrared lamp 15a (sometimes referred to as a mid-infrared lamp) having a predetermined length provided in the transfer path of the transfer means 13 along the transfer direction. ) 15a and a reflector 15b provided behind (above) the infrared lamp 15a.
At this time, in order to prevent deformation of the article W to be dried when the article W to be dried has a low heat resistance temperature, the transfer speed of the transfer means 13 and the irradiation time and intensity of the infrared lamp 15a are appropriately adjusted.

Moreover, it is preferable to provide a plurality of such infrared lamps 15a along the width direction of the transfer means 13, for example, at a rate of 2 to 10 lamps/m (see FIG. 1(c)).
When a plurality of infrared lamps 15a are provided in the width direction of the transfer means 13, they may be provided not only directly above the transfer means 13 but also obliquely upward (see FIG. 1(c)).
In addition, the distance (linear distance) between the infrared lamp 15a and the belt conveyor 13a of the transfer means 13 is determined by the efficiency of infrared rays reaching the article W to be dried without the infrared lamp 15a coming into contact with the article W to be dried. preferably determined in favor of
Here, such a linear distance is assumed to be a relatively short distance of about 10 to 50 cm, for example.
This is because with such a configuration, the article to be dried W can be dried more efficiently in a shorter period of time.

Here, as the infrared lamp 15a, any suitable lamp can be used, but as an example, it is preferable to use a commercially available mid-infrared lamp (model number S-08R manufactured by Yuten Co., Ltd.).
FIG. 2 shows the radiance characteristics of this commercially available mid-infrared lamp, with wavelength on the horizontal axis and radiance on the vertical axis.
This mid-infrared lamp has a radiance peak wavelength of around 3 μm, and even in a wavelength band of 2 to 5 μm, the radiance at the peak wavelength is attenuated only to about 1/2 to 1/2. It does not.
According to another experiment conducted by the inventor, this mid-infrared lamp is separately found to be easy to obtain desired drying characteristics by applying the present invention.

5. Heated Airflow Supply Portion The heated airflow supply portion 19x is a portion that blows the hot air generated by the hot air generation device 17 from below the belt conveyor 13a as the transfer means 13. As shown in FIG.
More specifically, the hot air sent by the hot air generating device 17 is rectified in the first direction as the predetermined direction by passing through the heated airflow supply unit 19x, and the heated airflow is generated. is sprayed onto the article W to be dried.
Therefore, the heated airflow supply section 19x preferably includes a fan 19a for stably supplying hot air as a heated airflow and a duct 19b for rectifying the hot air in a predetermined direction.
That is, with such a configuration, the heated airflow can be efficiently supplied to the articles W to be dried even if the articles W to be dried are placed on the belt conveyor 13a in various shapes.

6. Heated Airflow Discharge Portion The heated airflow discharge portion 19y ejects the heated airflow, which is blown by the heated airflow supply portion 19x and has passed through the opening 13d of the belt conveyor 13a, from above the belt conveyor 13a into a second direction different from the first direction. It is a part that transfers as a unidirectional flow in the direction of . It is also a part for discharging the transferred heated airflow to the outside of the housing 11 .
Therefore, the heated airflow discharge part 19y includes, for example, a duct 19c that receives the heated airflow and straightens it in a second direction, which is a predetermined direction, and a duct 19c connected to the duct 19c that sucks the heated airflow sent to the duct 19c. and a fan 19d that
That is, by adopting such a configuration, the blown heated airflow can be discharged to the outside in the shortest distance as a flow in a certain direction without actually circulating, and efficiently inside the housing 11. This is because the air remaining in the air can be ventilated.

Here, it is preferable that the duct 19c generally have a length and width substantially the same as the length and width of the infrared radiation device as an example of the second heating device 15 .
Further, the fan 19 d is preferably provided on the top surface of the housing 11 , for example, and configured to discharge the heated airflow to the outside of the housing 11 .
In addition, it is also preferable that the heated airflow discharge part 19y is provided with a scrubber for capturing the aqueous component and the solvent component.
The reason for this is that with such a configuration, the air remaining in the housing 11 can be more efficiently ventilated.

7. Control Device The control device (hereinafter not particularly illustrated) comprises transfer means 13, an infrared irradiation device as an example of the second heating device 15, a hot air generator 17, a heated airflow supply unit 19x, a heated airflow These parts are controlled to predetermined conditions while considering the relationship with the discharge part 19y.
Specifically, the control device controls the speed of the belt conveyor 13a, the output of the infrared rays emitted by the infrared irradiation device as the second heating device 15 (or the surface temperature), and the temperature of the heated airflow generated by the hot air generation device 17. , the flow rate, the amount and flow rate of the heated airflow supplied by the heated airflow supply unit 19x, and the discharge speed of the heated airflow discharge unit 19y.
This control device can be configured by a conventionally known control circuit, for example, a programmed microcomputer.

8. Accessory Parts As will be described with reference to FIGS. 8 and 9, as accessory parts, an aluminum plate ( 41a, 41b, 41c, 41d, 43) is preferably provided.
At least one pair of infrared lamps 45 are provided on both lateral sides of the temperature adjusting member 40, and a ventilation port 42 for discharging the heated air current is provided in the ceiling of the temperature adjusting member 40. is also preferred.
With such a temperature adjustment member 40, the temperature profile as shown in FIG. 10 facilitates temperature adjustment. This is because it can be carried out very economically.

[Second embodiment]
In the second embodiment, as shown in FIGS. 3(a) to 3(c), the heated airflow is directed from the first end 13e at both lateral ends of the belt conveyor 13a toward the second end 13f, and It is characterized by comprising a heated airflow supply part 31x that supplies the heated airflow in parallel with the transfer surface of the belt conveyor 13a, and a heated airflow discharge part 31y that receives and discharges the supplied heated airflow on the second end 13f side. It is a drying device 30 for drying.
In this embodiment, the first direction is the direction in which the heated airflow supply section 31x supplies (see arrow A in FIG. 3), and the second direction is the direction in which the heated airflow discharge section 19y discharges (see the arrow A in FIG. 3). 3, arrow B).
At this time, since the first direction (arrow A) and the second direction (arrow B) have different angles, either one of the arrows A and B is inclined with respect to the transfer surface of the belt conveyor 13a. I wish I could. Moreover, when both the arrow A and the arrow B are parallel to the transfer surface of the belt conveyor 13a, either one can be tilted upstream or downstream with respect to the traveling direction of the article W to be dried. .

The heated airflow supply section 31x in this embodiment is preferably configured by a duct 31a having the same length as the infrared irradiation device along the first end 13e of the belt conveyor 13a.
In addition, the duct 31a has a plurality of opening holes along the length direction of the infrared irradiation device as the second heating device 15 or a length of about the same length as the infrared irradiation device for blowing out the heated airflow. It is preferable to have a configuration with a narrow opening. This duct 31 a is connected to the hot air generator 17 of the first heating device 25 .

On the other hand, the heated airflow discharge part 31y can be composed of a duct 31b having the same length as the infrared irradiation device along the second end 13f of the belt conveyor 13a.
In addition, the duct 31b has a plurality of opening holes along the length direction of the infrared irradiation device as the second heating device 15 or a long length about the same as the length of the infrared irradiation device for sucking the heated airflow. It is preferable to have a configuration with a wide opening. This duct 31b is connected to the fan 19d.
With such a configuration, even if a flat article to be dried is placed on the belt, the heated airflow can be supplied and discharged as desired.

[Third embodiment]
In the third embodiment, as shown in FIGS. 4(a) to 4(c), the heated airflow is directed from the first end 13e and the second end 13f, which are both lateral ends of the belt conveyor 13a, to the belt conveyor. 13a toward the center and in parallel with the transfer surface of the belt conveyor 13a; The drying device 50 is characterized in that
In this embodiment, the first direction is the direction in which the heated airflow supply section 51x supplies (see arrow A in FIG. 4), and the second direction is the direction in which the heated airflow discharge section 19y discharges (see the arrow A in FIG. 4). 4, arrow B).
In addition, in the drying device 30 of the second embodiment described above, the heated airflow generated by the hot air generation device 17 is supplied from the first end 13e of the belt conveyor 13a toward the second end 13f in the horizontal direction, It is different from the third embodiment in that it is configured to receive and discharge at the end side.

Further, in the drying device 50 of the third embodiment, the heated airflow supply unit 51x is the same as the infrared irradiation device as the second heating device 15 along the first end 13e and the second end 13f of the belt conveyor 13a. It is preferable to construct the duct 51a having a length.
The duct 51a has a plurality of opening holes along the length direction of the infrared irradiation device as the second heating device 15, or a length of about the same length as the infrared irradiation device, for blowing out the heated airflow. It is preferable to have a configuration with a narrow opening.

Here, this duct 51a is connected to the hot air generator 17 of the first heating device 27, while the heated airflow discharge part 19y may be the same as that used in the drying device 10 of the first embodiment. .
With such a configuration, even if a flat article to be dried is placed on the belt conveyor 13a, it is possible to supply and discharge the heated air current as desired.
Moreover, since the heated airflow is discharged above the belt conveyor 13a, the second heating device 15 is used to irradiate the three-dimensional article W to be dried with the heated airflow in an atmosphere having a low solvent concentration. It can be performed.

[Fourth embodiment]
As shown in FIGS. 5A and 5B, the fourth embodiment includes a heating airflow supply mechanism in the drying device 10 of the first embodiment, a drying device 30 of the second embodiment, and a Drying devices 60 and 60' are combined with the heated airflow supply mechanism of the drying device 50 of the third embodiment.
That is, in the drying device 30 of the second embodiment and the drying device 50 of the third embodiment, the heated airflow is supplied parallel to the transfer surface of the belt conveyor 13a from one end or both ends of the belt conveyor 13a in the horizontal direction. It is different from the fourth embodiment in that
In this regard, in the fourth embodiment, in addition to supplying the heating airflow from the lateral direction, the heating airflow may be supplied from below the belt conveyor 13a.

Specifically, as shown in FIG. 5A, a heated airflow outlet 71 is provided in a region of the heated airflow duct of the heated airflow supply unit 32x facing the lower surface of the belt conveyor 13a. It is preferable that the drying device 60 has a structure in which the heated airflow is supplied to the lower surface of the belt conveyor 13a.
In this embodiment, the first direction is the direction in which the heated airflow supply portion 32x supplies (see arrows A1 and A2 in FIG. 5A), and the second direction is the direction in which the heated airflow discharge portion 31y is the discharge direction (see arrow B in FIG. 5(a)). At this time, there are two first directions, but it is sufficient if each of the arrows A1 and A2 satisfies a predetermined relationship with the arrow B.
With this configuration, the article to be dried W can be sufficiently exposed to the heated airflow from the lateral direction and from below.

Further, as shown in FIG. 5B, a heated airflow outlet 71 is provided in a region of the heated airflow duct of the heated airflow supply unit 52x facing the lower surface of the belt conveyor 13a to supply the heated airflow. It is also preferable to use a drying device 60' having a structure for supplying to the lower surface of the belt conveyor 13a.
In this embodiment, the first direction is the direction in which the heated airflow supply portion 51x supplies (see arrows A1 and A2 in FIG. 5B), and the second direction is the direction in which the heated airflow discharge portion 19y is supplied. is the discharge direction (see arrow B in FIG. 5(b)). Also at this time, it is sufficient that each of the arrows A1 and A2 satisfies the predetermined relationship with the arrow B as described above.
With this configuration, the heated airflow hits the article to be dried W from both lateral sides and from below, and is then discharged upward, so that the heated airflow can be applied from more directions.

[Fifth embodiment]
In the fifth embodiment, as shown in FIGS. 6A and 6B, a heated airflow is applied to the article to be dried W in the front stage of the infrared irradiation device as the second heating device 15, and the article to be dried is heated. It is a drying device 90 provided with a second heated airflow supply device 91 for temporarily drying the coating film of the product W.
In the case of this drying device 90, the overall length of the housing 11 is slightly longer than that of the first embodiment, and the infrared irradiation device as the second heating device 15 is provided near the center of the housing 11, and the entrance 10a is provided. and the infrared irradiation device as the second heating device 15, a second heating airflow supply device 91 is provided.
The second heated airflow supply device 91 is provided between the infrared irradiation device as the second heating device 15 and the second heated airflow supply device 91 as the duct 93 a of the first heating device 29 . A heated airflow is supplied to the transfer means 13 by using a duct 93a having an extended length so as to straddle.
Therefore, according to the drying apparatus 90 of the fifth embodiment, it is possible to further shorten the drying time of the articles to be dried by the amount of provisional drying of the articles to be dried.
The temperature of the heated airflow used for this temporary drying is preferably in the range of, for example, 50 to less than 100.degree. The reason for this is that, like the first embodiment, by setting such a temperature range, for example, it can be effectively applied even to the article to be dried W having a relatively low heat resistance temperature.

[Sixth embodiment]
Although part of the sixth embodiment has been described above, as shown in FIG. 8, the inside of a rectangular housing (not particularly shown) has an aluminum plate around at least the sides and the ceiling. (41a, 41b, 41c, 41d, 43) is provided, and ventilation openings 42 (42a, 42b) for discharging heated airflow are provided in the ceiling of the temperature adjustment member 40. It is a drying device equipped with
Further, as such a preferred embodiment, the ceiling portion of the temperature adjustment member 40 is formed of a plurality of aluminum plates, namely a first aluminum plate 43a and a second aluminum plate 43b, and the edges of the ends of each aluminum plate are A sliding mechanism for varying the width of the overlap is provided along the line.
In the sixth embodiment, the first heating device, the second heating device, the heated airflow discharge section, the transfer means, etc., which are other configurations described in the first embodiment, are the same as those in the first embodiment. It can have the same or similar configuration as the form.

(1) Temperature adjustment member The temperature adjustment member is a frame member that should be recognized as a part of the housing of the drying apparatus made of an aluminum plate or the like. It is a functional member that efficiently guides the hot air of the second heating device to the article to be dried and reflects the infrared rays of the second heating device to suppress the outflow of energy to the outside.
That is, it is preferable to have a rectangular parallelepiped tunnel shape so as to cover a belt conveyor as a transport means for transporting the article to be dried, and to have an aluminum plate covering the periphery.
The reason for this is that by installing the first heating devices facing each other along the belt conveyor inside the temperature adjusting member, the reflection of the aluminum plate is also used as appropriate, and the product to be dried is extremely efficiently heated. This is because the infrared ray can be applied to the target.

In addition, the aluminum plate covering the periphery can effectively totally reflect infrared rays, particularly mid-infrared rays of a predetermined wavelength, so that the drying efficiency can be enhanced and the drying time can be significantly shortened.
Specifically, compared to the case where no predetermined temperature adjustment member is provided inside the housing, for example, the desired temperature range is set to less than 180 to 300 ° C., and the drying time is shortened by 20 to 90%. and, better yet, the desired temperature range can be less than 40-180° C. and the drying time can be reduced by 50-90%.
On the other hand, the drying time can be reduced by 20 to 70% compared to the case where the inside of the housing is covered with a stainless steel plate, and the aluminum plate, especially the mirror surface with a surface roughness Ra of 0.1 μm or less. Covering with an aluminum plate is preferred.

Therefore, the length of the temperature adjusting member in the direction along the direction of flow of the belt conveyor is determined by the type of dried product and the speed of the belt conveyor, but is preferably within the range of 30 to 400 cm.
The reason for this is that with such a length, it is possible to secure a sufficient time for drying even when the belt conveyor is constantly moving, but on the other hand, excessive drying may cause poor drying of the article to be dried. This is because it is possible to prevent it from occurring.
Therefore, the length of the temperature adjusting member is more preferably in the range of 80-300 cm, more preferably in the range of 100-200 cm.

Also, the width of the temperature control member can be adjusted by the overlap width of the aluminum plate of the ceiling, and is preferably within the range of 20 to 300 cm. Moreover, the height of the temperature adjusting member is preferably within the range of 50 to 250 cm.
The reason for this is that the articles to be dried can pass through the inside without interfering with each other, and it is possible to prevent the temperature distribution inside from becoming uneven due to excessively large size.
Therefore, the width of the temperature adjusting member is more preferably a value within the range of 40-250 cm, more preferably a value within the range of 50-200 cm.
Further, the height of the temperature adjusting member is more preferably in the range of 80 to 200 cm, more preferably in the range of 100 to 180 cm.

(2) Aluminum Plate In addition, the surface of the aluminum plate is often subjected to an oxidation treatment (alumite treatment) or a non-oxidation treatment, but either treatment may be used.
Further, the aluminum plate of the temperature control member is preferably an aluminum plate whose surface is polished and has a predetermined surface roughness, and is highly reflective and has an average surface roughness (Ra) of 0.005. A value within the range of ˜0.1 μm is preferred.
The reason for this is that if the surface roughness is within this range, the infrared rays emitted from the second heating device can be prevented from being diffusely reflected, and the total reflection can be used to further shorten the drying time. is.
Therefore, it is more preferable to set the average surface roughness (Ra) of the aluminum plate to a value within the range of 0.01 to 0.05 μm, and more preferably to a value within the range of 0.015 to 0.025 μm. preferable.

Further, it is preferable to set the regular reflectance as surface glossiness to a value within the range of 80 to 99.9%.
The reason for this is that with such a reflectance, the infrared rays emitted from the second heating device are efficiently reflected, and the drying time can be significantly shortened.
Therefore, the regular reflectance of the aluminum plate is preferably within the range of 85 to 99.5%, more preferably within the range of 90 to 99%.

Further, the thickness of the aluminum plate (including the mirror-finished aluminum plate) is preferably determined in consideration of the temperature characteristics of the drying device, corrosion resistance, discoloration resistance, workability, etc., but it is usually 0.5 mm. A value within the range of 01 to 5 mm is preferred.
The reason for this is that if the thickness of the aluminum plate is less than 0.01 mm, it may be difficult to adjust the surface roughness to a desired level or to laminate the plate on a base material or the like.
On the other hand, if the thickness exceeds 5 mm, the weight of the drying apparatus including the temperature control member may be excessively increased, or the processability may be significantly deteriorated.
Since the temperature characteristics, corrosion resistance, and discoloration resistance of the drying device are relatively good, and workability is good, the thickness of the aluminum plate can be set to a value within the range of 0.1 to 3 mm. More preferably, the value is in the range of 0.5 to 2 mm.

(3) Ventilation Port The ventilation port is a structural part for discharging high-temperature air accumulated inside the temperature control member to the outside of the temperature control member.
That is, it is preferable that the ceiling portion of the temperature control member is provided with a ventilation port for discharging the heated airflow blown from the first heating device from the second direction and leading it to the heated airflow discharge portion.
The reason for this is that by providing the ventilation opening, the temperature inside the temperature control member does not become excessively high, and even if the article to be dried is vulnerable to heat, only the outer paint part is dried and deformed. This is because it can be dried without
And, for example, by immediately releasing the acidic or alkaline atmosphere that is generated when drying an object to be dried that has been coated with solvent-based paint, even an aluminum plate with relatively low chemical resistance can be dried. This is because it can be dried while suppressing corrosion and discoloration.

The shape of the ventilation port may be any shape as long as it can efficiently discharge the high-temperature air that has accumulated inside the temperature control member. A mesh shape with a plurality of holes is preferable.
The reason for this is that the internal air can be discharged without variation regardless of the position of the article to be dried during transfer.
Therefore, in particular, from the viewpoint of ease of manufacture, it is preferable to dispose the aluminum plate of the ceiling portion of the temperature control member closer to the center in the width direction and use the gap formed on the side surface as the ventilation port.
If the ceiling of the temperature control member is made up of a plurality of aluminum plates and has an overlap mechanism, which will be described later, the gap in the center where the aluminum plates are stacked can be used as a ventilation port. It is preferable (see reference numeral 42c in FIG. 9(a)).

Also, as shown in FIGS. 9A and 9B, the ventilation opening 67 has a width (L1, L2) between the frame 49 on the side of the temperature adjusting member 40 and the aluminum plate 43 on the ceiling. is preferably adjustable by means of a slide mechanism 44 of .
The reason for this is that the set temperature can be easily adjusted according to the article to be dried, and even an article that is deformed at a relatively low temperature can be effectively dried.
Here, as shown in FIGS. 9A and 9B, the width between the side frame 49a and the first aluminum plate 43a of the ceiling is L1, and the side frame 49b and the ceiling are The width from the second aluminum plate 43b is L2.
Therefore, the width of the ventilation opening (L1, L2) is preferably a value within the range of 1 to 200 mm, more preferably a value within the range of 5 to 150 mm, and a value within the range of 10 to 100 mm. is preferably

Further, it is preferable that the opening area of the ventilation opening is within the range of 1 to 50% of the total area of the ceiling and the ventilation opening.
The reason for this is that such an opening area can efficiently discharge an acidic or alkaline atmosphere generated when the article to be dried is dried to the outside of the temperature control member without excessively releasing heat. is.
Therefore, it is more preferable that the opening area of the ventilation opening is in the range of 5 to 40%, and more preferably in the range of 10 to 30%.

(4) Overlap Mechanism In addition, as shown in FIG. 8, the overlap mechanism includes the first aluminum plate 43a and the second is a mechanism in which the aluminum plates 43b of are stacked vertically.
That is, as shown in FIGS. 9A and 9B, the first aluminum plate 43a and the second aluminum plate 43b are slid in the width direction by a slide mechanism 44, which will be described later, and arranged near the center. It is preferable to have a configuration in which they are overlapped with an overlap width (L3).
The reason for this is that the overlap width of the first aluminum plate and the second aluminum plate can be made variable, and the width of the ventilation opening can be adjusted to efficiently adjust the internal temperature. .
By making the overlap width variable, the frame 49 on the side of the temperature adjustment member 40 can be arranged closer to the center, and the dimension (L4) in the width direction of the temperature adjustment member can be increased. or smaller. Therefore, the drying apparatus of the present invention can be easily adapted to the size and amount of the material to be dried.

Moreover, it is preferable that the overlap width (L3) is a value within the range of 10 to 1500 mm.
The reason for this is that if the overlap width is less than 10 mm, excessive heat escapes through the gaps between the overlapping portions of the aluminum plates, making it impossible to effectively control the temperature. Moreover, if the overlap width exceeds 1500 mm, the weight of the overlapped portion becomes heavy, and the aluminum plate may be distorted.
Therefore, the overlap width is more preferably a value within the range of 20-1000 mm, more preferably a value within the range of 30-500 mm.

(5) Slide Mechanism The slide mechanism is a mechanism for sliding the aluminum plate on the ceiling of the temperature adjustment member in the width direction of the temperature adjustment member (see mechanisms P and Q in FIG. 8).
That is, it is preferable that the ceiling portion of the temperature control member is formed of a plurality of aluminum plates, and the mechanism slides along the edges of the aluminum plates.
The reason for this is that since the ceiling is made up of a plurality of aluminum plates, they can be partially overlapped and the width of the ceiling can be adjusted.
In addition, as shown in FIGS. 9(a) and 9(b), the slide mechanism 44 can move along the edge of each aluminum plate of the ceiling, so the width (L1, L2) of the ventilation opening can be adjusted. At the same time, by moving the side frames 49 (49a, 49b), the width (L4) of the temperature control member can also be adjusted.

Specifically, as shown in FIGS. 9(a) and 9(b), the slide mechanism has a slide mechanism 44 on a frame 48 in the width direction, and a plurality of aluminum plates (43a, 43a, 43b) can be moved independently.
As a result, the widths (L1, L2) of the ventilation openings can be adjusted, and the lateral frames can be moved along the frames in the width direction, so the width of the temperature control member can also be adjusted. can.

The slide mechanism can be composed of, for example, slide rails provided on the frames 48 (48a, 48b) in the width direction and sliders attached to aluminum plates that slide on the slide rails.
As a simpler structure, the slide mechanism can be configured by providing grooves in the frame in the width direction and screwing the grooves through holes for screwing drilled in the edge of the aluminum plate.

[Seventh embodiment]
Although not shown in particular, the seventh embodiment includes a housing provided with an introduction part for taking in an airflow, and heating the airflow to generate a heated airflow having a predetermined temperature, and directing the article to be dried in a predetermined direction. a first heating device that blows from a first direction; a heated airflow discharge section that discharges the heated airflow blown by the first heating device to the outside of the housing from a second direction as a predetermined direction; The present invention relates to a drying method using a drying device including a second heating device for heating a dried product by irradiating it with infrared rays.
The first direction and the second direction are different from each other, and the drying method uses a drying apparatus configured to advance and discharge the heated airflow in a fixed direction without circulating it. That is, a step of preparing an article to be dried having a coating film on a substrate as an article to be dried, and applying a heated air current having a predetermined temperature to the article to be dried from a first direction by a first heating device. a drying step of heating by irradiating infrared rays with a second heating device while spraying; A drying method characterized by comprising:

Therefore, unlike the conventional circulating heating method, the infrared irradiation to the article to be dried is performed in an atmosphere with a low concentration of water or solvent that easily absorbs the infrared rays (mid-infrared rays) (for example, about 1/2 to 1/10). can be carried out, resulting in a corresponding increase (eg, about 2-10 times) in the absorption efficiency of infrared radiation in the coating on the article to be dried.
In addition, the heating of the inside of the paint is also promoted, that is, the combined effect of the heated airflow and the infrared rays is exhibited, so the drying conditions can be changed widely, depending on the substrate of various articles to be dried and the type of coating film. , can be dried (formed) efficiently in a short time in a wide temperature range.
Each step will be described in more detail below.

(1) Step of preparing an article to be dried having a coating film temperature: about 100°C), PC molded product (heat resistant temperature: about 120°C), etc. are prepared.
Next, these molded products are attached to a spindle rod or placed flat, and a coating is sprayed onto the surface of the substrate by spray coating, bar coater coating, brush coating, or the like to form a coating film. .

Here, the type of paint is preferably determined in consideration of the type of substrate, decorative effect, coloring effect, etc. In the case of thermosetting resin paint, as an example, urethane acrylate polymer as the main agent, It is preferable to mix an isocyanate compound, a carboxyl group-containing compound, etc. as a cross-linking agent, and further mix a coloring agent, a filler, an antioxidant, an ultraviolet inhibitor, etc. as additives.

In addition, when the paint is a thermoplastic resin, this is also an example, but at least one of acrylic resin, polyolefin resin, polyester resin, urethane resin, rubber resin, carboxyl group-containing compound, etc. as the main agent, and It is preferable to add coloring agents, fillers, antioxidants, UV inhibitors, tackifiers, etc. as additives.
Considering the ease of application of these thermosetting resin paints and thermoplastic resin paints, the uniformity of the coating film formed, etc., it is preferable to further add a predetermined amount of an aqueous solvent or an organic solvent.

(2) Simultaneous execution of the step of spraying a heated air stream by the first heating device/the step of irradiating infrared rays by the second heating device. A drying step in which the second heating device irradiates and heats the article to be dried while blowing the airflow against the article to be dried, and the airflow after drying the article to be dried is blown from the second direction to the outside of the housing. and the discharging step of discharging to and are carried out virtually simultaneously.
That is, the heated airflow introduced from the outside of the housing is applied to the article to be dried from the first direction without circulating around the article to be dried, and the heated airflow is applied to the article to be dried in the first direction. It is a step of quickly and effectively discharging in the shortest distance from the second direction to the outside of the housing as a unidirectional flow.

Of course, the step of blowing the heated airflow by the first heating device and the step of irradiating the infrared rays by the second heating device may be slightly deviated. It can be said that it is more effective to dry the article to be dried if the application step is performed 1 to 5 seconds earlier and then the infrared irradiation step by the second heating device is performed.
Furthermore, even if the step of blowing the heated airflow by the first heating device and the step of irradiating the infrared rays by the second heating device are started at the same time, the first heating device blows the heated airflow first. It is also preferable to perform the infrared ray irradiation step by the second heating device after finishing the attaching step and with a delay of 1 to 5 seconds.

(3) Ejecting step In the ejecting step, the heated airflow applied to the article to be dried from the first direction is discharged from the housing from the second direction, which is a different direction, so as not to be entangled with the first direction. It is a process that discharges quickly and effectively in the shortest distance as a unidirectional flow.
Here, the angle formed by the first direction and the second direction of the heating airflow can usually be set to a value within the range of 20° to 150°, including when they are opposed to each other and when they are not opposed to each other. preferable.
The reason for this is that if the angle is less than 20°, the heated airflow in the first direction and the heated airflow in the second direction are likely to partially mix, and the heatability of the article to be dried is significantly reduced. This is because there are cases.
On the other hand, if the angle exceeds 150°, it may become difficult to determine the positions of the first direction and the second direction in the heated airflow, and the drying apparatus may become complicated and large. .
Therefore, the angle between the first direction and the second direction of the heating airflow is preferably set to a value within the range of 30 to 120°, more preferably within the range of 45 to 90°. .
The angle formed by the first direction and the second direction of the heated airflow is such that only the second heating device is stopped and the first heating device and other intake fans, discharge fans, etc. are operated, It can be determined by visually confirming air volume and air pressure according to the anemometer at each relevant position, or by a streamer, and at the same time, it can be determined that the inside of the housing is not circulating.

(4) Other process 1
In addition, it is preferable that a hollow portion is provided inside the housing, and the article to be dried is dried while being moved at a predetermined speed along the hollow portion by a transport means.
Such transport means make it possible to significantly increase the number of dryings performed per unit of time by carrying out the drying method.

(5) Other process 2
In the drying step, an electric heater that generates a heated airflow at 50 to less than 100 ° C. is used as the first heating device, and a reflector is used as the second heating device. It is preferable to heat the article to be dried to a temperature of 100° C. or higher using an infrared heating device (sometimes referred to as a mid-infrared heating device) having a value within the range of ˜5 μm.
First, by using the first heating device that heats to a predetermined temperature, the direct blow pet (heat resistant temperature: about 60 to 80 ° C.) and the PC resin plate (heat resistant temperature: about 120 ° C.) are relatively heat resistant. It can be widely applied to dried goods with poor substrate.
In addition, the use of mid-infrared rays in such a wavelength range is preferable for short-time drying of coating films of various paints because absorption by moisture and solvents is further reduced.
Moreover, the use of the mid-infrared heating device equipped with the reflecting device provides the advantage of being able to efficiently utilize the mid-infrared rays and to easily control the directionality of the heated airflow.

(6) Air Flow in Drying Apparatus Here, the air flow in the drying apparatus will be schematically described with reference to FIGS. 7(a) to (c).
First, as shown in FIG. 7A, an infrared ray L is irradiated onto a material to be dried W having a coating film W1 on a substrate W2. Then, as shown in FIG. 7(b), water and solvent are scattered from the coating film W1, and the surface of the article to be dried W is filled with the air S1 with high humidity and solvent concentration inside the housing.
Then, this air S1 is sprayed with non-circulating fresh air S3 (heated airflow) from a first direction (see arrow A in FIG. 7), and is blown in a second direction (see FIG. 7), which is a different direction. ), the air S1 with high humidity and high solvent concentration is discharged to the outside of the housing as a unidirectional flow.
By carrying out in this manner, the air existing between the second heating device 15 and the article W to be dried is appropriately replaced with the air S2 having low humidity and solvent concentration, and the air close to the surface of the article W to be dried is replaced. An area (eg 5-50 cm from the surface of the article to be dried W) is replaced with fresh air S3.
As a result, the article W to be dried can be effectively irradiated with the infrared rays L.
In addition, as described above, the spraying of the heated airflow by the heated airflow supply unit 19x, the irradiation of the infrared rays L by the second heating device 15, and the discharge by the heated airflow discharge unit 19y are superimposed. Alternatively, each may be performed independently in order.

1. Preparatory Step Example 1 of the present invention and Comparative Examples 1 to 5 were performed as follows.
That is, using a stirring device, the main agent is a mixture of urethane acrylate polymer / urethane acrylate oligomer (weight ratio: 50/50) at 80% by weight, and an isocyanate compound (TDI) as a curing agent. 20% by weight and 1% by weight of a coloring agent were uniformly dissolved in a predetermined amount of ethyl acetate as a solvent to prepare a thermosetting paint (solid concentration: 25% by weight).

2. Creation process The created paint is applied to the following four types of substrates (direct blow pet container (thickness 1mm), ABS resin plate (thickness 1mm), PC resin plate (thickness 1mm), glass plate (thickness 1mm)) On the other hand, a thermosetting resin paint film was formed by spray coating so that the film thickness was 20 μm, and dried articles for several examples and comparative examples were prepared.
Then, using the drying apparatus 10 shown in FIG. 1, the article to be dried having the uncured coating film was dried (heat cured) according to the drying conditions of Examples and Comparative Examples shown in Table 1 below.
A container containing the solvent was placed inside the drying apparatus 10 for the purpose of increasing the degree of influence of the solvent. Due to this solvent placed inside the dryer 10, the VCO (volatile organic compound) concentration inside the dryer 10 was around 100 ppm.

3. Evaluation method Next, in order to verify the curing of the coating films of the dried products of Examples and Comparative Examples that were dried under the conditions shown in Table 1, a rubbing test was performed using IPA (isopropyl alcohol) and Kanakin No. 3 cotton cloth. carried out.
In addition, as deformation verification, the degree of deformation with respect to the desired shape was visually determined and evaluated.
In Example 1 and the like, the amount of the organic solvent around the dried product was a low value of at least less than 10 ppm when the heated air stream was blown from at least the first direction.
Then, in the drying apparatus of FIG. 1, assuming a predetermined assumed cylindrical flow path, the flow rate of the heated air indicated by arrows A and B was measured with a flow meter. A value of 80% or more was confirmed.

(1) Rubbing test IPA is sprayed on the surface of the coating film of the article to be dried (10 pieces), and the surface of the coating film is rubbed (10 times reciprocatingly) with Kanakin No. 3 cotton cloth. was evaluated.
⊚: Rubbing can be performed without catching the cotton cloth, and the gloss of the coating film is maintained.
◯: Rubbing can be performed without the cotton cloth being caught, but a phenomenon of lowering the gloss of the coating film occurs.
Δ: A phenomenon occurs in which the coating film is caught on the cotton cloth and partially peeled off.
x: A phenomenon occurs in which the coating film is caught on the cotton cloth, the coating film is completely peeled off, and the base is visible.

(2) Verification of Deformation The degree of deformation of the articles to be dried (10 pieces) was visually evaluated according to the following criteria and evaluated in four stages.
(double-circle): The desired form is maintained.
◯: almost retains the desired form.
Δ: Slightly deformed from the desired form.
x: Remarkably deformed from the desired form.

4. Evaluation Results As Example 1 and Comparative Examples 1 to 5, Tables 1 to 4 show the rubbing test (coating film formability) and deformation verification results for the following four types of substrates (parts, containers).

5. Evaluation Results From the evaluation results based on Example 1 and Comparative Examples 1 to 5 shown in Tables 1 to 4, the following points are considered.
That is, as shown in Example 1, when the heating airflow (non-circulating and fresh heating airflow) from the first heating device and the infrared irradiation from the second heating device are used together, regardless of the type of substrate, At an irradiation time of 5 minutes, both the rubbing test and the deformation verification gave an evaluation of "A".

On the other hand, as shown in Comparative Examples 1 to 3, on the premise of using a predetermined thermosetting resin paint, when the coating film is dried only by spraying the heated airflow from the first heating device, the temperature of the heated airflow is increased. It is understood that even if spraying is performed at 80° C. for 20 minutes, the rubbing test does not give an evaluation of “O” or higher.

In addition, as shown in Comparative Example 4, on the premise of using a constant thermosetting resin paint, when a heated air stream from the first heating device is blown at a temperature of 80 ° C. for 30 minutes, the substrate is vulnerable to heat. It can be understood that the direct blow pet has a "△" evaluation for deformation verification.

Further, as shown in Comparative Example 5, infrared irradiation was performed by the second heating device (infrared irradiation time was 5 minutes, infrared irradiation power was 50% (300° C. in terms of the surface temperature of the infrared lamp)). ) alone, it can be understood that direct blow pet and ABS resin, which are vulnerable to heat, have a deformation verification value of “Δ” or less.
Although the details are omitted, in a separate test, the infrared irradiation power of the second heating device was set to 40%, 50%, 60%, and 85% (in terms of the surface temperature of the infrared lamp, 240°C, 300°C, and 360°C). , 510° C.), the deformation verification results tend to deteriorate.

On the other hand, in the drying method of the present invention, by using both the heated airflow (non-circulating and fresh heated airflow) from the first heating device and the infrared irradiation from the second heating device, the drying process can be performed in an extremely short time of 5 minutes. That is, it was found that the desired drying could be performed more excellently in a time such as one-sixth that of Comparative Examples 4, 5, and the like. Moreover, similar effects are obtained for four kinds of materials.
That is, according to the drying apparatus and drying method of the present invention, from a direct blow pet container that requires relatively low temperature heating to a glass plate that can be heated to a considerably high temperature, the first heating device and the second heating device conditions can be easily changed to dry coating films applied to various materials at low cost and in high quality in a short period of time.

[Example 2]
In addition, as Example 2, the temperature control member according to the sixth embodiment was placed inside the housing of the drying device, and the direct blow pet was dried, and the rubbing test and the like were performed in the same manner as in Example 1. made an evaluation.
Specifically, an aluminum plate (FS003, stock (manufactured by the company UACJ) was evaluated by inserting a temperature control member that constituted the surroundings.
In addition, the ceiling part of the temperature control member is made by overlapping two aluminum plates so that the overlap width (L3) is 150 mm, and between the side frame and the aluminum plate, each of the ventilation openings is provided. A ventilation opening with a width (L1, L2) of 100 mm is provided.
As a result, it was confirmed that both evaluations of the rubbing test and deformation verification were "⊚".

[Example 3, Example 4, Comparative Example 6]
Further, FIG. 10 shows a mirror surface aluminum plate (A) with a thickness of 0.6 mm as Example 3, an aluminum plate (B) with a thickness of 0.6 mm as Example 4, and a thickness of 0.6 mm as Comparative Example 6. When a 0.6 mm stainless steel plate (C) was irradiated with mid-infrared rays from an infrared irradiation device having a luminance peak at a wavelength of 2 to 5 μm, the surface temperature on the irradiation side was evaluated.
Specifically, at a set temperature of 200 ° C., the distance between the heater and each plate is 300 mm. was stopped and measured after an additional 3 minutes.
According to FIG. 10, with the stainless steel plate (C), after 20 minutes, the temperature was about half of the heater setting temperature, and the initial temperature increased by 60 ° C. or more, while the aluminum plate (B) For example, the temperature rise is only about 30° C. from the initial temperature.
In addition, the specular aluminum plate (A) is about 10° C. lower than the aluminum plate (B), and it can be understood that the mid-infrared rays can be reflected more effectively.
Therefore, it can be understood that if the periphery of the temperature control member is made of an aluminum plate, the mid-infrared rays can be reflected, the energy can be prevented from escaping to the outside, and the products to be dried can be efficiently irradiated with the mid-infrared rays. .

In Example 3, Example 4, and Comparative Example 6, evaluations such as a rubbing test were performed in the same manner as in Example 1, but the irradiation time was set as short as 3 minutes.
As a result, the evaluations of the rubbing test and the deformation verification in Example 3 were "⊚", respectively, but in Example 4, the evaluation of the deformation verification was "⊚", but the evaluation of the rubbing test was "◯". rice field.
Furthermore, in Comparative Example 6, the evaluation of deformation verification was “⊚”, but the evaluation of rubbing test was “×”.

As described above, according to the present invention, the heated airflow from the first heating device and the infrared rays (including mid-infrared rays) from the second heating device are applied to the article to be dried that has been coated with paint. At the same time, the supplied heated air stream can be discharged in a predetermined direction after irradiating the article to be dried, and can be discharged to the outside of the housing without actually being circulated.
For this reason, since the infrared rays hit the article to be dried in an atmosphere with an extremely low solvent concentration, the infrared rays are efficiently absorbed by the coating film, and the heating of the inside of the coating film can also be accelerated.
That is, according to the present invention, it is possible to remarkably enhance the combined effect of the heated airflow and the infrared irradiation.

Therefore, when a predetermined thermosetting resin is used, for example, the heating time is 5 minutes (1/12) at a heating temperature of 80 ° C., which is extremely short compared to the circulating heated airflow drying (about 60 minutes). It became possible to dry the coating film (formation of the coating film) in a short period of time.
Moreover, according to the present invention, the temperature adjustment of the heated airflow by the first heating device and the temperature adjustment by infrared rays by the second heating device are extremely easy, and the It can be easily applied to drying coatings on various substrates.

In addition, by providing a temperature control member inside the housing, the periphery of which is covered with an aluminum plate, particularly an aluminum plate having a surface roughness Ra of 0.1 μm or less, and a ventilation opening in the ceiling, The energy consumption of infrared lamps and the like attached to the side surface of the temperature control member is reduced, and the following unexpected effects can be obtained.

1) Direct blow molded products with relatively poor heat resistance, etc., drying and heating of coating on polypropylene films, polycarbonate molded products with excellent heat resistance, drying and heating of coating on polyester molded products, or printing on polyester films, etc. By simply changing the shape of the temperature control member (e.g., length, width, shape, overlap width, etc.), it is possible to handle various product drying and form a good coating surface, etc. in a short time. It became possible.
2) In addition, if it is normal, the surface of the aluminum plate, etc. will melt and corrode, so the solvent that creates an acidic or alkaline atmosphere, or a paint that uses a water-based solvent is applied. Even under these conditions, the properties of the aluminum plate constituting the temperature control member can be maintained for a long period of one year or longer.

3) Furthermore, by providing a predetermined temperature adjustment member, energy consumption can be reduced, product drying can be done in a short time, and the life of the infrared lamp can be extended (assuming the same heating energy irradiation (2 to 10 times)).
4) In addition, the width of the ventilation opening in a given temperature control member can be adjusted by, for example, a slide mechanism, so that various sizes, dimensions, etc., can be changed simply by widening the width of the temperature control member. It is now possible to easily respond to products, etc.

As can be understood from the above description, according to the present invention, the drying time of the coating film can be shortened, and the throughput of the drying process can be shortened. expected to be effective.
Therefore, the present invention can contribute to various fields in which drying of coating films is required, and thus has a very high degree of industrial contribution.

10: Drying device (first embodiment)
11: Case 13: Transfer Means 13a: Belt Conveyor 13d: Opening 15: Second Heating Device (Infrared Irradiation Device)
17: Hot air generator 17a: Heaters 19x, 31x, 51x: Heated airflow supply units 19y, 31y: Heated airflow discharge units 23, 25, 27, 29: First heating device 30: Drying device (second embodiment)
50: Drying device (third embodiment)
60, 60': combined drying device (fourth embodiment)
71: Blowout port for heated airflow 90: Drying device (fifth embodiment)
W: Product to be dried W1: Substrate W2: Coating film

Claims (11)

A drying apparatus characterized by having the following configurations (a1) to (a8).
(a1) A configuration including a housing provided with an introduction portion for taking in an airflow.
(a2) A configuration comprising a first heating device that heats the airflow to generate a heated airflow having a predetermined temperature and blows the airflow onto the article to be dried from a first direction as a predetermined direction.
(a3) by emitting the heated airflow blown by the first heating device to the outside of the housing from a second direction different from the first direction as a predetermined direction, A configuration comprising a heated airflow exhaust that allows the heated airflow to travel and exit .
(a4) A configuration comprising a second heating device for heating the article to be dried by irradiating it with infrared rays.
(a5) A configuration in which a hollow portion is provided inside the housing, and transport means for moving the article to be dried at a predetermined speed along the hollow portion is provided.
(a6) A configuration in which the transfer means has an opening for allowing the heated airflow to pass from below to above.
(a7) The first heating device takes in outside air from the introduction part, and a hot air generating device for sending hot air, and a part to which the hot air generated by the hot air generating device is blown from below the transfer means. A configuration having a heating airflow supply part of
(a8) A configuration in which an introduction section for introducing the airflow is provided below the heated airflow discharge section in the vertical direction. 2. The drying apparatus according to claim 1 , wherein said first heating device is an electric heater that generates a heating airflow of 50 to less than 100.degree. The second heating device is an infrared heating device equipped with a reflector, and the wavelength of the radiance peak of the infrared heating device is set to a value within the range of 2 to 5 μm. 2. The drying device according to 2 . A temperature control member is provided inside the housing, the temperature control member being shielded by an aluminum plate at least on the sides and the periphery of the ceiling, and the heated airflow is directed to the ceiling of the temperature control member from the second direction. 4. Drying device according to any one of the preceding claims, characterized in that it is provided with a vent for discharging. The drying apparatus according to any one of claims 1 to 4, wherein the transfer means is a mesh or lattice belt conveyor. A drying apparatus characterized by having the following configurations (b1) to (b6).
(b1) A configuration including a housing provided with an introduction portion for taking in an airflow.
(b2) A configuration comprising a first heating device that heats the airflow to generate a heated airflow having a predetermined temperature and blows the airflow onto the article to be dried from a first direction as a predetermined direction.
(b3) The heated airflow blown by the first heating device is emitted to the outside of the housing from a second direction different from the first direction as a predetermined direction , so that A configuration comprising a heated airflow exhaust that allows the heated airflow to travel and exit .
(b4) A configuration comprising a second heating device for heating the article to be dried by irradiating it with infrared rays.
(b5) A temperature control member is provided inside the housing, in which at least the sides and the periphery of the ceiling are shielded by an aluminum plate, and the heated airflow is directed to the ceiling of the temperature control member. A configuration with ventilation openings for emission from the direction of
(b6) The aluminum plate in the ceiling portion of the temperature adjustment member is formed from a first aluminum plate and a second aluminum plate, which are a plurality of aluminum plates, and the first aluminum plate and the second aluminum plate are formed from a plurality of aluminum plates. A configuration in which the ends of the aluminum plates overlap when viewed from above. A drying method using a drying apparatus having the following configurations (a1′) to (a8′) ,
a step of preparing, as the article to be dried, an article to be dried having a coating film derived from a coating containing a thermosetting resin or a thermoplastic resin on a substrate;
a drying step in which the first heating device blows a heated airflow having a predetermined temperature onto the article to be dried from the first direction, while the second heating device irradiates and heats the article to be dried; ,
a discharge step of discharging the airflow after drying the article to be dried from the second direction to the outside of the housing;
A drying method comprising:
(a1') A configuration including a housing provided with an introduction portion for taking in an airflow.
(a2') A configuration comprising a first heating device that heats the airflow to generate a heated airflow having a predetermined temperature and blows the airflow onto the article to be dried from a first direction as a predetermined direction.
(a3') by emitting the heated airflow blown by the first heating device to the outside of the housing from a second direction different from the first direction as a predetermined direction , A configuration comprising a heated airflow discharge portion for allowing the heated airflow to advance and be discharged .
(a4') A configuration comprising a second heating device for heating the article to be dried by irradiating it with infrared rays.
(a5') A configuration in which a hollow portion is provided inside the housing, and transport means for moving the article to be dried at a predetermined speed along the hollow portion is provided.
(a6') A configuration in which the transfer means has an opening through which the heated airflow passes from below to above.
(a7') A portion in which the first heating device takes in outside air from the introduction portion and blows the hot air generated by a hot air generation device for sending hot air from below the transfer means. A configuration having a heating airflow supply unit as.
(a8') A configuration in which an introduction portion for taking in the airflow is provided below the heated airflow discharge portion along the vertical direction. 8. The drying method according to claim 7 , wherein a hollow portion is provided inside the housing, and the article to be dried is dried while being moved at a predetermined speed by a transporting means along the hollow portion. Method. In the drying step, as the first heating device, an electric heater that generates a heated airflow at 50 to less than 100 ° C. is used, and as the second heating device, the wavelength of the radiance peak is in the range of 2 to 5 μm. 9. The drying method according to claim 7 or 8, wherein the article to be dried is heated to a temperature of 100[deg.] C. or higher using an infrared heating device having a value within. Inside the housing, at least the sides and the periphery of the ceiling are shielded with an aluminum plate, and a temperature control member having a ventilation opening in the ceiling is provided, and through the ventilation opening, the 10. The drying method according to any one of claims 7 to 9, wherein drying is performed while a heated airflow is discharged from the second direction to the outside of the housing. A drying method using a drying apparatus having the following configurations (b1′) to (b6′) ,
a step of preparing, as the article to be dried, an article to be dried having a coating film derived from a coating containing a thermosetting resin or a thermoplastic resin on a substrate;
a drying step in which the first heating device blows a heated airflow having a predetermined temperature onto the article to be dried from the first direction, while the second heating device irradiates and heats the article to be dried; ,
a discharge step of discharging the airflow after drying the article to be dried from the second direction to the outside of the housing;
A drying method comprising:
(b1′) A configuration including a housing provided with an introduction portion for taking in an airflow.
(b2') A configuration comprising a first heating device that heats the airflow to generate a heated airflow having a predetermined temperature and blows the airflow onto the article to be dried from a first direction as a predetermined direction.
(b3′) by emitting the heated airflow blown by the first heating device to the outside of the housing from a second direction different from the first direction as a predetermined direction ; A configuration comprising a heated airflow discharge portion for allowing the heated airflow to advance and be discharged .
(b4') A configuration comprising a second heating device for heating the article to be dried by irradiating it with infrared rays.
(b5') A temperature control member is provided inside the housing, the temperature control member having an aluminum plate shielding at least the sides and the periphery of the ceiling, and the heated airflow is directed to the ceiling of the temperature control member. Configuration with vents for emission from two directions.
(b6') The aluminum plate in the ceiling portion of the temperature adjustment member is formed from a first aluminum plate and a second aluminum plate, which are a plurality of aluminum plates, and the first aluminum plate and the second aluminum plate are formed from a plurality of aluminum plates. A configuration in which the ends of the two aluminum plates overlap when viewed from above.

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