JPH02635Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a resin foaming furnace for manufacturing, for example, vinyl leather for wall materials by foaming a foamable resin by heating, and more specifically, to an improvement of heating equipment. .

[Prior art]

Conventionally, hot air is supplied into the furnace, and the temperature required for foaming the resin by convection heating by the hot air is e.g. 200 to 230℃.
It was designed to heat up to a certain degree.

[Problem that the invention attempts to solve]

However, since there is an upper limit to the amount of heat transfer in convection heating using hot air, resin foaming requires a long time, for example, about 1 minute, which may reduce the processing capacity of the furnace or cause large continuous It had the disadvantage of requiring a processing furnace.

In addition, in order to efficiently perform convective heat transfer, circulation of hot air is required, and the amount of heat dissipated due to the circulation increases, resulting in a disadvantage that the thermal efficiency is considerably reduced.

The purpose of the present invention is to sufficiently shorten the heating time required for resin foaming, to sufficiently improve thermal efficiency, and to obtain foamed resin of good quality.

[Means for solving problems]

The characteristic configuration of the present invention is that a device is provided between the preheating area and the foaming area in the furnace to form a hot air curtain that prevents gas flow between the two areas, and a hot air discharge path is provided on the foaming area side. A far-infrared heater for heating the resin is provided in each of the preheating area and the foaming area, and its effects are as follows.

[Effect]

In other words, both preheating and heating foaming of the resin
Since radiation heat transfer is mainly performed using a far-infrared heater, the resin can be preheated and heated to foam with a sufficiently large amount of heat transfer as required, the heating time required for resin foaming can be sufficiently shortened, and the efficiency is high. Thermal energy loss can be sufficiently reduced by good radiation heat transfer.

By the way, preheating and foaming the resin using radiation heat transfer using near infrared rays can shorten the heating time and improve thermal efficiency, but only the surface of the resin foams.
Derived defects that make the product feel bad to the touch.

However, when far infrared rays are used as in the present invention, the entire resin foams uniformly, making it possible to reliably obtain a product with a good texture.

Further, since the hot air discharge path is connected to the foaming region side, the hot air forming the catene can be mainly flowed to the foaming region side, and not much to the preheating region side. Therefore, the ambient temperature only in the foaming region can be equalized by the action of hot air, the entire resin can be foamed evenly, and the texture can be made even better, and the preheating region does not require strict atmospheric temperature equalization. Thermal energy loss caused by hot air supply can be almost eliminated, further improving thermal efficiency.

[Effect of idea]

As a result, heating time can be significantly shortened compared to conventional methods, improving the processing capacity of resin foaming furnaces, and making it possible to process large quantities continuously with a small furnace, reducing the space and cost required to install a furnace. Now we can save enough.

In addition, thermal efficiency can be greatly improved compared to conventional methods, and energy savings and operating cost savings can be achieved.
Furthermore, it is now possible to reliably obtain a high-quality product with an excellent tactile feel, and to provide a resin foaming furnace that is excellent in terms of both economy and performance as a whole.

〔Example〕

Next, an example will be shown with reference to FIGS. 1 and 2.
A heating chamber 2 is formed in the tunnel-type furnace body 1 from an inlet 2a to an outlet 2b, and is sloped so that the height becomes higher toward the outlet 2b, and receives and guides the belt-shaped resin 4 extending from the feed roll 3a to the take-up roll 3b. Guide rolls 5 are provided at the heating chamber 2 and its entrance and exit, and the resin 4, which is continuously moved at a constant speed, is guided through the preheating area 2.
A resin foaming furnace is formed in which the resin is heated to around the foaming temperature in the foaming region 2d and maintained at the foaming temperature in the foaming region 2d.

A far-infrared heater 6 equipped with a large number of tubes 6a whose surfaces are coated with a radiator such as zirconia that emits far-infrared rays, and a gas burner that supplies high-temperature gas to the tubes 6a is connected to the resin transfer path in the preheating area 2c and the foaming area 2d. The resin 4 is placed above and below the heater 6, and is configured to heat the resin 4 from both sides by radiant heat transfer from the heater 6.

A nozzle 7 for forming a hot air curtain is provided between the preheating area 2c and the foaming area 2d, and a hot air generator 8 is connected to the nozzle 7 to generate air between the preheating area 2c and the foaming area 2d on both upper and lower sides of the resin transfer path. It is configured to block gas flow with a hot air curtain.

The suction port of the hot air return passage 10 with the fan 9 is connected to the foaming area 2.
d, the discharge port is connected to the hot air generator 8, the suction port of the hot air discharge passage 12 with the fan 11 is connected to the exit side of the bubbling region 2d, and the discharge port is connected to the deodorizing machine 13.
In other words, all of the hot air from nozzle 7 is in the foaming area 2.
d side so that the atmospheric temperature in the foaming area 2d is equalized by the hot air, energy consumption in the hot air generator 8 can be reduced by hot air circulation through the reflux path 10, and as the resin foams. The generated vapor of plasticizer, etc. is assisted by the slope of the heating chamber 2,
It is configured to be quickly sent to the deodorizing machine 13.

Sensor 14, sensor 1 that detects hot air temperature
In order to maintain the temperature detected by the foaming area 2 within the set range, a controller 16 is provided to automatically operate the input regulating valve 15 for the burner 8a of the hot air generator 8.
It is configured to keep the ambient temperature of d constant.

A nozzle 17 for forming a hot air curtain is provided on the entrance side of the preheating area 2c, and the exhaust gas path 6b of the heater 6 and the fan 18 of the preheating area 2c are connected to the nozzle 17.
The hot air curtain is configured to prevent outside air from flowing into the preheating area 2c.

A recovery path 19 with a suction port arranged on the inlet side of the preheating area 2c, and an exhaust gas path 6 of the heater 6 in the bubbling area 2d.
b is connected to the fan 9 for the hot air generator 8,
It is constructed to recover heat.

[Another example]

Next, another embodiment will be explained.

The equipment for forming a hot air curtain between the preheating area 2c and the foaming area 2d can be appropriately modified in terms of specific configuration, heat source, etc., and they are collectively referred to as devices 7 and 8 for forming a hot air curtain.

The far-infrared heater 6 can also be changed as appropriate in its specific configuration, heat source, and other aspects.

The overall configuration of the resin foaming furnace can be modified in various ways, such as making the resin 4 transfer method intermittent,
It is possible to omit the hot air circulation structure, or to form the heating chamber 2 substantially horizontally.

The type and purpose of the foamable resin are not limited.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, with FIG. 1 being a schematic longitudinal sectional view and FIG. 2 being a schematic cross-sectional view. 2c... Preheating area, 2d... Foaming area, 6... Far infrared heater, 7, 8... Hot air curtain forming device, 12... Hot air discharge path.

Claims (1)

[Scope of utility model registration request] Devices 7 and 8 are provided between the preheating zone 2c and the foaming zone 2d in the furnace to form a hot air curtain that prevents gas flow between the two zones.
A hot air discharge path 12 is connected to the d side, and the preheating area 2c
and a resin foaming furnace in which far-infrared heaters 6 for heating the resin are provided in each of the foaming regions 2d.