JPH038473B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention mainly involves forming a desired resin coating by drying a workpiece whose surface is coated with a resin material, such as aluminum sash, while passing through a furnace. This relates to a hot air dryer used for.

[Conventional technology]

Generally, resin coatings formed on the surface of aluminum sash etc. are often acrylic melamine-based or urethane-based.
These are dried in an atmosphere at a furnace temperature as shown in FIG. In other words, when temperature H is set on the vertical axis and drying time T is set on the horizontal axis, the acrylic melamine drying temperature A is 180°C ± 10°C.
Urethane drying temperature B is 150°C ± 10°C. At that time, the temperature rise time R from when the workpiece is introduced into the furnace until it reaches the above atmosphere
are aluminum plates with a thickness of about 5 mm and are all 14 to 15
It takes about a minute.

As a result of the above, conventional hot air dryers of this type uniformly spread the entire area inside the furnace to the above temperatures (150°C, 180°C).
The system was configured so that only a single type of hot air could be supplied within the range of 30°C.

[Problem that the invention seeks to solve]

Due to the above configuration, the conventional hot air dryer has the following problems.

Conventionally, the resin film formed on the surface of aluminum sash, etc., has been made of acrylic melamine, urethane, etc., but in recent years, resin films using resins with superior weather resistance and chemical resistance, such as futsuo resin, have been used. There is a growing demand for

The above-mentioned furnace for acrylic melamine and urethane resins can only dry within a uniform temperature range of 180℃ and 150℃, but we have changed this to allow drying at a temperature of 240℃±10℃ for fluorocarbon resins. However, it takes 14 to 15 minutes to heat up an aluminum plate with a thickness of about 5 mm.

However, if the temperature of this soft resin is gradually increased over 14 to 15 minutes instead of rapidly increasing the temperature for about 5 minutes, cracks will occur in the resin film and cause baking failure. There was a difficult point.

[Means for solving problems]

This invention solves the above-mentioned problems of the prior art, and shortens the drying zone in the furnace at a specified temperature for each single type, which is necessary for baking conventional resins including futuristic resins, and the workpiece. It is an object of the present invention to provide a hot air dryer which can expand the baking range in the same furnace and improve economic efficiency by forming a composite body with a high temperature zone whose temperature increases within a certain period of time. The present invention is characterized by a hot air dryer in which a conveyor is disposed in the furnace, a hot air supply port is provided on the bottom side of the furnace, and a hot air discharge port is provided on the top side. The high-temperature heating device with a large number of high-temperature injection holes on the starting end side is housed in a complex manner, and when the interior of this furnace is formed in an ascending and descending manner, the above-mentioned high-temperature heating device is formed into a trapezoidal shape. .

[Effect]

When using a hot air dryer with the above configuration to dry a resin material applied to the surface of an aluminum sash or the like to form a desired resin film, the applied resin material may be acrylic melamine or urethane. standards for uniformly generating the specified temperature throughout the entire area of the furnace using a single type specified for each system type, without requiring the participation of the high-temperature heating device installed at the beginning of the furnace. Using a hot air atmosphere, baking drying can be carried out optimally for each system. In this case, the workpiece introduced into the atmosphere can reach the desired drying temperature for each system while gradually advancing inside the furnace from the starting end side. Furthermore, if the resin material applied to the surface of the workpiece is a fluorine-based resin material, a high-temperature heating device installed at the starting end of the furnace will be involved. In other words, when this high-temperature heating device participates, it is possible to create a composite temperature atmosphere in which the drying temperature at the starting end of the furnace is significantly higher than that at the rear of this position, so that the workpiece introduced into the furnace is heated in proportion to the advancing speed. It is possible to quickly reach the desired drying temperature required by the soft material within a short period of time (rapid temperature rise time) without drying, making it possible to dry several types of materials at different temperatures with high efficiency using the same drying oven. can be done.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show a first embodiment of a hot air dryer according to the present invention. This hot air dryer is constructed as follows. That is, in this hot air dryer, a drying oven 1 whose four circumferences are covered with a heat insulating material or the like is formed into a flat shape with no undulations. Although the overall plan view of the drying oven 1 is not shown, the first
The entrance is on the left side of the figure, and the exit is on the right side.

A series of rails 2 are installed at the upper center of the entire area inside the furnace, and a hanging comparer 3 is suspended from the rails 2 so as to be able to circulate at regular intervals. A hot air supply port 4 is provided at the bottom of the entire area inside the furnace for introducing hot air from a burner 8 (described later) into the furnace through a hot air circulation path 6. The hot air fed into the furnace from the hot air supply port 4 is discharged to the outside of the furnace from a hot air discharge port 5 provided in the ceiling. A series of hot air circulation paths 6 communicating with the hot air supply port 4 and the hot air discharge port 5 are installed at an external position of the drying oven 1 according to this aspect, and a blower 7 is connected to a midway position of this circulation path 6. has been done. The above hot air circulation path 6 and burner 8
A hot air return path 10 with an air blower 11 is provided between them to reheat the hot air from the hot air outlet 5. The burner 8 described above is connected to an oil tank 12 via an oil supply pump 13. Furthermore, the reheated hot air is passed through the hot air supply path 9 connected between the burner 8 and the hot air circulation path 6 to the drying oven 1 again.
By supplying the drying material to the inside, the drying device is constructed into a single type drying device that can circulately supply desired temperatures depending on the system, such as the above-mentioned acrylic melamine drying temperature A, urethane drying temperature B, etc.

The following high-temperature heating device 14 is housed on the starting end side of the drying oven 1 (located on both sides of the interior near the left entrance in FIG. 1). This high temperature heating device 14 is constructed as follows. That is, this high-temperature heating device 14 is provided with a large number of high-temperature injection holes 15 on the longitudinal face plate, and these high-temperature injection holes 15
From is a high heat supply furnace 1 connected to the burner 8 described above.
8. The furnace is configured so that high-temperature hot air of about 270°C to 350°C is supplied to the starting end side of the furnace through the high-temperature circulation path 16. Note that a blower 17 is connected to a midway position of the high-temperature circulation path 16. Air curtains 1 are placed at the start and end positions of the front half of the furnace in this state.
9 are installed respectively to prevent leakage of hot air inside the furnace. The high temperature heating device 14 of the above embodiment is housed and arranged in such a manner that it is combined into the single type drying device described above. Reference numeral 20 denotes a workpiece such as an aluminum sash, which is transported through the furnace using the hanging conveyor 3 described above.

When drying the resin material applied to the surface of the workpiece 20 made of aluminum sash or the like using the hot air dryer having the above configuration to form a desired resin coating,
When the applied resin material is acrylic melamine type or urethane type, the high temperature heating device 14 installed at the beginning of the drying furnace 1 can be installed in the entire area of the furnace without requiring participation. A single drying device with
180℃±10℃, 150℃± for urethane drying temperature B
Using a standard hot air atmosphere that uniformly generates a drying temperature of 10°C, it is possible to perform the optimal baking drying for each system. At that time, the workpiece 20 introduced into the above-mentioned atmosphere in the furnace with a hanging conveyor 3
can reach the above-mentioned desired drying temperature for each system while gradually advancing inside the furnace from the starting end side (14 to 15 minutes depending on the heating time R).

Further, when the resin material applied to the surface of the workpiece 20 is a fluorine-based resin material, the high temperature heating device 14 installed at the starting end of the furnace is used. In this case, the above high temperature heating device 1
4 participates, the drying temperature at the starting end of the furnace is controlled by the specified temperature (240°C ± 10°C for the drying temperature C of the futsu system) from the large number of high-temperature injection holes 15 provided in the device 14 to the single-type drying device at the rear. Since a large amount of hot air is supplied at a composite temperature (approximately 20°C ± 350°C) that is significantly higher than the drying temperature (drying temperature in °C), an atmosphere at this composite temperature can be rapidly created at the starting end of the furnace. Therefore, the workpiece 20 introduced into the furnace is made to quickly reach the desired drying temperature required by the fusible system within a short period of time (about 5 minutes due to the rapid heating time P) without being proportional to the advancing speed. As a result, a resin film can be formed smoothly and easily under a state in which the heat zone temperature of the workpiece 20 immediately after being introduced into the furnace is raised to a specified temperature.

3 and 4 show a second embodiment of the hot air dryer according to the invention. This hot air dryer is constructed as follows. That is, this hot air dryer has a drying oven 1 similar to the first embodiment described above.
is covered on all four sides with heat insulating material, etc.
It is a low-lying dry zone 1A with a low starting and ending end.
In addition, the middle area is formed in an elevating type to become a higher dry zone 1B.

The entire area of the furnace other than the starting end is constructed as a single drying device as in the first embodiment. Therefore, a description of the configuration of this single type drying device will be omitted. Note that 7a is a filter box attached to the blower 7 in the above device.

The starting end side in the drying oven 1 described above (positions on both sides in the high drying zone 1B near the left low entrance in Fig. 3)
A high-temperature heating device 14 shown below is housed inside. This high-temperature heating device 14 is provided with a large number of high-heat injection holes 15 in a trapezoidal face plate. It is configured so that high-temperature hot air near ℃ is supplied to the high drying zone 1B on the starting end side of the furnace. Incidentally, a blower 17 equipped with a filter box 17a is connected to a midway position of the high-temperature circulation path 16. In this case, the high temperature heating device 14 is housed in the high drying zone 1B in the front half of the furnace, so that leakage of high temperature is physically prevented only at the bottom of the high drying zone 1B. High temperature heating device 14 according to this embodiment
are housed and arranged in a combined manner in the single type drying device described above.

When drying the resin material applied to the surface of the workpiece 20 made of aluminum sash or the like using the hot air dryer configured as described above to form a desired resin film,
When the applied resin material is an acrylic melamine type or urethane type, please refer to the above 1.
As in the embodiment, the participation of the high temperature heating device 14 installed at the starting end in the drying oven 1 is not required. Therefore, a single type of drying device installed throughout the furnace is used to maintain the specified temperature for each system (180°C ± 10°C for acrylic melamine drying temperature A, 150°C for urethane drying temperature B). ℃±10℃ drying temperature)
By creating a standard hot air atmosphere that evenly generates the following conditions, it is possible to carry out baking drying that is optimal for each system. At this time, the workpiece 20 introduced into the above-mentioned atmosphere in the furnace by the hanging conveyor 3 is heated for 14 to 15 seconds depending on the temperature rise time R while gradually advancing inside the furnace from the starting end side.
The above desired drying temperature for each system can be easily reached within minutes.

In addition, when the resin material applied to the surface of the workpiece 20 is a soft type, the high temperature heating device 14 installed at the beginning of the high drying zone 1B in the furnace is used. It turns out. At this time, when the above-mentioned high-temperature heating device 14 participates, the drying temperature at the starting end side of the high-altitude drying zone 1B is set to a specified temperature by the single-type drying device on the rear side from the large number of high-temperature injection holes 15 provided in the above-mentioned device 14. (Drying temperature of 240°C ± 10°C in the case of drying temperature C for drying systems) Since a large amount of hot air is supplied at a composite temperature (nearly 270°C to 350°C), the starting end of the furnace is heated to this composite temperature. An atmosphere can be created quickly. In this case, the workpiece 20 rising from the low drying zone 1A on the entrance side while being suspended on the hanging conveyor 3 is first introduced into the high drying zone 1B from the upper side, and then at this position. A specified high temperature (270
The lower part of the workpiece 20 will be exposed to high temperature after the conveyor 3 has risen, and the heating start time will be different for the upper and lower parts of the workpiece. It turns out. However, since the above-mentioned high-temperature heating device 14 is formed into a trapezoid, the heating from this device is quickly released from the upper part of the workpiece at the rear of the high-temperature heating device.
The lower part will be heated for a long time, and the upper and lower parts will be heated at high temperature for approximately the same amount of time in total, and the workpiece 20 will be heated for a short period of time (due to the rapid temperature rise time P), without being proportional to the advancing speed. It is possible to quickly reach the desired drying temperature required by the soft material within a few minutes), and it is possible to smoothly and easily form a resin film while the heat zone temperature of the workpiece 20 is raised to a specified temperature. can.

〔Effect of the invention〕

This invention provides a hot air dryer in which a conveyor is arranged in a furnace, a hot air supply port is provided at the bottom of the furnace, and a hot air discharge port is provided at the top of the furnace. A high-temperature heating device provided with high-temperature injection holes is housed in a composite manner, and when the interior of the furnace is formed in an ascending and descending manner, the above-mentioned high-temperature heating device is formed in a trapezoidal shape. It is. Therefore, the inside of the drying oven has a drying zone with a specified temperature for each single type necessary for baking conventional resins including futsuo-based resins (acrylic melamine resin, urethane-based resin, etc.), and a drying zone with a specified temperature for each single type, which is necessary for baking conventional resins including futsuo-based resins (acrylic melamine-based resins, urethane-based resins, etc.). Because it is formed with a complex of high temperature heat that raises the temperature of the processed material within a short time, it is possible to perform multiple drying processes using various systems in the same furnace, making it possible to form resin films such as aluminum sash. This has the effect of widening the range of burning and greatly increasing the economic efficiency of this type of industry.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing the main parts of a flat hot air dryer according to a first embodiment of the present invention, and FIG.
A vertical sectional front view taken along the - line in Figures and Figure 3;
Fig. 3 is a vertical side view showing the main parts of the elevating type hot air dryer according to the second embodiment, Fig. 4 is a detailed side view of Fig. 3, and Fig. 5 is the baking temperature of each resin and its temperature. It is an explanatory diagram showing the time required to reach. 1...Drying oven, 2...Rail, 3...Hanging conveyor, 4...Hot air supply port, 5...Hot air discharge port,
14...High temperature heating device, 15...High temperature injection hole.

Claims (1)

[Claims] 1. A hot air dryer in which a conveyor is disposed at the top of the furnace, a hot air supply port is provided at the bottom of the furnace, and a hot air discharge port is provided at the top of the furnace. A hot air dryer characterized by having a high-temperature heating device housed in a complex manner on the starting end side. 2. The hot air dryer according to claim 1, wherein the high temperature heating device is provided with a large number of high heat injection holes. 3. When the inside of the drying furnace is formed in an ascending and descending manner, the high-temperature heating device housed at the starting end side of the drying furnace is formed in a trapezoidal shape. Hot air dryer.