JP2003251691A - Heating device for foamable resin sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating device of a foamable resin sheet whereby the whole of the foamable resin sheet of which one surface is provided with a pattern or a color and the other with nothing can be foamed sufficiently to be in an optimum state. <P>SOLUTION: The heating device of the foamable resin sheet heats, by infrared rays, the foamable resin sheet in one surface A of which values of a color system are nonuniform and in the other surface B of which the values are uniform. On the opposite sides of the foamable resin sheet 1, a first heater 2 is disposed at a position opposite to one surface A wherein the values of the color system are nonuniform and a second heater 3 is disposed at a position opposite to the other surface B wherein the values are uniform. The value of the peak wavelength of the infrared rays radiated from the first heater 2 is larger than that of the peak wavelength from the second heater 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed resin sheet heating device for heating a foamed resin sheet which serves as a container for packaging meat, sashimi, bento and fruits.

[0002]

2. Description of the Related Art Conventionally, containers for packaging meat, sashimi, bento and fruits are made of foamed resin sheets such as expanded polystyrene sheets and expanded polypropylene sheets, and these expanded resin sheets are radiated from a ceramic heater. A container having a predetermined shape is formed by heating with infrared rays and performing heat forming such as vacuum forming or pressure forming.

Further, the foamed resin sheet has pores inside the sheet due to heating, and the pores have a heat insulating effect and can increase the thickness of the sheet itself, and have flexibility. It is possible to protect the food contained in the container from the shock during transportation and the shock during display.

However, the infrared rays radiated from the ceramic heater are infrared rays having a peak wavelength value of 2.5 μm or more.

When the foamed resin sheet is irradiated with such infrared rays, the polymer compound forming the foamed resin sheet has an absorption band of stretching vibration and bending frequency of its constituent molecules of about 2.5 μm or more. Many exist in the wavelength range,
As a result, when infrared rays having a peak wavelength are irradiated in the vicinity of this absorption band, the irradiation energy becomes heat at the extreme surface of the sheet, and the heat is mainly transferred to the inside by conduction. However, since the foamed resin sheet in the heated portion foams during heating to generate pores, the pores further hinder the transfer of heat to the inside, and as a result, the foamed resin sheet is sufficiently foamed to the inside. I couldn't.

In order to solve such a problem, recently, infrared rays having a peak wavelength value of less than 2.5 μm are used to heat a foamed resin sheet to the inside so as to cause sufficient foaming in the inside. The technology is known.

However, even in the method of heating the foamed resin sheet to the inside by utilizing infrared rays having a peak wavelength value of less than 2.5 μm, if the foamed resin sheet is heated only from one side, the surface irradiated with the infrared rays is The difference between the temperature and the temperature on the surface not irradiated with infrared rays becomes large, and the degree of foaming differs between the front and back surfaces of the foamed resin sheet.If the foamed sheet is formed in such a state, the foamed sheet does not deform into a predetermined shape However, there was a problem that variations occurred.

Therefore, the inside of the foamed resin sheet is sufficiently foamed by irradiating both sides of the foamed resin sheet with infrared rays having a peak wavelength value of less than 2.5 μm to heat the foamed resin sheet. The degree of foaming on both sides was made equal.

[0009]

On the other hand, from the viewpoint of a container, recently, as represented by a sashimi container, a wave pattern or chrysanthemum is used for the purpose of creating beauty on the surface of the container on which the sashimi is placed. A variety of patterns and decorations in various colors have been developed, such as the ones and gold leaf colors.

The foamed resin sheet which is the base for forming such a sashimi container has a pattern or color on only one side, and has no pattern or color on the other side. There is no such thing. This is because the back surface of the container becomes a blind spot for the observer, and it is not necessary to decorate the back surface.

As described above, the foamed resin sheet was considered to be best heated by irradiating infrared rays having a peak wavelength value of less than 2.5 μm from both sides. It has been found that the following problems occur when a foamed resin sheet having a pattern or color on only one surface and no pattern or color on the other surface is thermoformed.

More specifically, the peak wavelength value is 2.5 μm depending on the pattern and color applied to the foamed resin sheet.
The degree of absorption of infrared rays of less than less than 100 μm is different, and the temperature increases in a part of the region of the foamed resin sheet that is colored with the infrared ray having the peak wavelength value of less than 2.5 μm.
The temperature does not rise in some areas of the foamed resin sheet that has a color that does not absorb much infrared rays with a peak wavelength value of less than 2.5 μm, and the foamed resin sheet on the surface with a pattern or color has a peak wavelength. When heated with infrared rays having a value of less than 2.5 μm, the temperature rise of the sheet was uneven, and the foamed resin sheet could not be foamed in a sufficiently optimal state.

This results from the fact that infrared rays having a peak wavelength value of less than 2.5 μm have the property of being absorbed differently by colors. The color can be defined by the value of the color system, and there are various color systems as follows, and the L * a * b * color system specified by the International Commission on Illumination (CIE). System (also called CIELAB system), L * C * h color system, Hunter Lab color system, XYZ
There is a Munsell color system including (Yxy) color system, hue (H), lightness (V), and saturation (C). Any color system may be used, but if the values of the color system are different, The colors will be different.

That is, when the surface of the foamed resin sheet having non-uniform colorimetric values is heated with infrared rays having a peak wavelength value of less than 2.5 μm, unevenness occurs in the temperature rise of the sheet and the foamed resin sheet. There is a problem that the sheet cannot be uniformly foamed.

The object of the present invention has been made based on the above circumstances, in which one surface is provided with a pattern or color and the value of the color system is non-uniform, and the other surface is a pattern. Provided is a foamed resin sheet heating device capable of foaming the entire foamed resin sheet to a sufficiently optimal state even inside the foamed resin sheet that is not colored or colored and has a uniform color system value. Especially.

[0016]

In the foamed resin sheet heating device according to claim 1, one surface has non-uniform colorimetric values and the other surface has uniform colorimetric values. A foamed resin sheet heating device for heating a foamed resin sheet with infrared rays, comprising: a first heater that radiates infrared rays to a position facing one surface having a nonuniform colorimetric value across the foamed resin sheet. A second heater that emits infrared rays is arranged at a position facing another surface having a uniform color system value, and the peak wavelength value of the infrared rays emitted from the first heater is It is characterized in that it is larger than the value of the peak wavelength of infrared rays radiated from the second heater.

A foamed resin sheet heating apparatus according to a second aspect of the present invention is the foamed resin sheet heating apparatus according to the first aspect, in particular, the peak wavelength value of the first heater is 2.5 μm.
It is characterized by being m or more.

The foamed resin sheet heating device according to claim 3 is the foamed resin sheet heating device according to claim 1 or 2, wherein the first heater is a ceramics heater or a transparent heater. An incandescent lamp having an infrared radiation film formed on a surface of a bulb, wherein the second heater is a transparent bulb incandescent lamp.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a foamed resin sheet. The foamed resin sheet 1 is a foamed polystyrene sheet, and in order to decorate one surface A, a checkered pattern is formed. In the figure, 10 is a colored portion and 11 is a non-colored portion which is not colored and the surface of the expanded polystyrene sheet is exposed as it is. Then, on the other surface B of the expanded polystyrene sheet, the entire surface of the expanded polystyrene sheet is exposed as it is. In such a foamed resin sheet 1, one surface A has nonuniform colorimetric values, and the other surface B has uniform colorimetric values.

In FIG. 1, the foamed resin sheet 1 is wound in a roll shape, but is made flat and fed into the heating area, and one surface A and the other surface B are fed by a foamed resin sheet heating device described later. Both are simultaneously irradiated with infrared rays and heated.

FIG. 2 is an explanatory view of the foamed resin sheet heating device of the present invention. In the foamed resin sheet heating device, the first heater 2 is arranged at a position facing one surface A of the foamed resin sheet 1 with the foamed resin sheet 1 interposed therebetween, and the second heater 3 is positioned at a position facing the other surface B. Are arranged.

The first heater 2 is a ceramic heater 20 as a heat source for radiating infrared rays, and eight ceramic heaters 20 are arranged along the foamed resin sheet 1. This ceramic-based heater 20 has a ceramic radiating portion 21 that radiates infrared rays, and a heating wire such as a nichrome wire is molded in the radiating portion 21. Is heated and infrared rays are emitted from the emission section 21. The infrared rays emitted from the emission section 21 emit infrared rays having a peak wavelength value of 4 to 5 μm, which is larger than 2.5 μm, due to the characteristics of ceramics. The peak wavelength is a wavelength that shows the maximum value of the spectral radiance.

The second heater 3 is an incandescent lamp 30 in which a filament is arranged in a transparent bulb 31 as a heat source for emitting infrared rays, and eight incandescent lamps 30 are arranged along the foamed resin sheet 1. . This incandescent lamp 30
Since the bulb 31 is transparent, the light emitted from the filament passes through the bulb 31 and radiates infrared rays having a peak wavelength value of 1 to 1.5 μm smaller than 2.5 μm. Although the reflection mirror M is arranged behind the incandescent lamp 30 in FIG. 2, it is provided as necessary. That is, the value of the peak wavelength of infrared rays emitted from the first heater 2 is larger than the value of the peak wavelength of infrared rays emitted from the second heater 3.

As described above, the foamed resin sheet 1 is heated by infrared rays having a peak wavelength value of 4 to 5 μm radiated from the first heater 2 on one surface A having a nonuniform colorimetric value. And the value of the peak wavelength radiated from the second heater 3 is 1 to 1.5 on the other surface B having a uniform color system value.
It is heated with infrared rays of μm.

The reason why one surface A of the foamed resin sheet 1 having a non-uniform color system is heated with infrared rays having a peak wavelength value of 2.5 μm or more will be explained. Infrared rays of 5 μm or more have different colors, that is, even if the values of the color system are different, the extent to which they are absorbed by each color and the rate of temperature rise are almost the same. Explaining with reference to FIG. 1, the colored portion 10 and the uncolored portion 11 having different color system values have almost the same degree of absorption of infrared rays having a peak wavelength value of 2.5 μm or more. As a result, the temperature rising rates of the temperatures of the colored portion 10 and the non-colored portion 11 are almost the same, and the peak wavelength of the entire one surface A is 2.5 μm or more, and the infrared absorption is uniform. In addition, the heating rate does not vary.

The one surface B of the foamed resin sheet 1 is
Since the value of the color system is uniform and it is necessary to sufficiently heat the inside of the foamed resin sheet 1, the peak wavelength value is 2.
Heat with infrared radiation that is less than 5 μm.

That is, if the foamed resin sheet heating device of the present invention is used, the foamed resin sheet 1 can simultaneously heat its respective surfaces with infrared rays having different peak wavelengths. Can be heated to the optimum state. Therefore, even if the foamed resin sheet 1 after heating is molded into a container having a predetermined shape, there is a problem in that the thickness also varies.

FIG. 3 is an explanatory view of another foamed resin sheet heating device of the invention. The difference from the foamed resin sheet heating device shown in FIG. 2 is the structure of the first heater. In FIG. 3, the first heater 4 uses the incandescent lamp 40 in which the filament is arranged in the transparent bulb 41 and the far-infrared radiation film 42 is formed on the surface of the transparent bulb 41 as a heat source. The first heater 4 is arranged at a position facing one surface A of the foamed resin sheet 1 on which the value of the color system is not uniform, and eight incandescent lamps 40 are arranged along the foamed resin sheet 1. It is lined up. 2 shows the incandescent lamp 4.
A reflecting mirror M is arranged behind 0, but is provided as necessary.

The far-infrared radiation film 42 is mainly made of SiO ₂ , and the far-infrared radiation film 42 is heated by the light emitted from the filament to emit infrared rays having a peak wavelength value of about 3 μm. It is a thing. Second heater 3
Is the same as that of the second heater 3 shown in FIG. 1, the description of the structure will be omitted, but it is arranged at a position facing the other surface B of the foamed resin sheet 1 having a uniform color system value. There is. The value of the peak wavelength is smaller than 2.5 μm.
It radiates infrared rays of 5 μm well. That is,
The peak wavelength value of infrared rays emitted from the first heater 4 is larger than the peak wavelength value of infrared rays emitted from the second heater 3.

As described above, the far-infrared radiation film 42 radiates infrared rays having a peak wavelength value of about 3 μm. Therefore, the entire surface A of the foamed resin sheet 1 having a nonuniform colorimetric system value. Infrared rays are absorbed evenly, and the temperature rising rate can be made uniform over the entire surface A.

As described above, according to the foamed resin sheet heating device shown in FIG. 3, the foamed resin sheet 1 has the one surface A having the nonuniform colorimetric values radiated from the first heater 4. The surface B is heated by infrared rays having a peak wavelength value of about 3 μm, and the other surface B having a uniform color system has a peak wavelength value of 1 to 1.5 μm emitted from the second heater 3. It is heated by infrared rays.

Therefore, since the foamed resin sheet 1 can simultaneously heat its respective surfaces with infrared rays having different peak wavelength values, the entire foamed resin sheet 1 can be fully heated to the optimum state. Therefore, even if the foamed resin sheet 1 after heating is molded into a container having a predetermined shape, there is a problem in that the thickness also varies.

As shown in FIGS. 2 and 3, in the foamed resin sheet heating apparatus of the present invention, the first heater for heating one surface of the foamed resin sheet having non-uniform colorimetric values has a peak wavelength. Is larger than the peak wavelength of the second heater, and it is particularly preferable to emit infrared rays having a value of 2.5 μm or more. The reason is that when the emission wavelength of infrared rays is less than 2.5 μm, the degree of infrared rays absorbed by each color is different, and when heating the surface of the foamed resin sheet with non-uniform colorimetric values. To
This is because the temperature rise rate of the foamed resin sheet becomes uneven, and it becomes impossible to foam the entire foamed resin sheet to the inside in a sufficiently optimal state.

Further, the second heater for heating the other surface of the foamed resin sheet having a uniform color system has a peak wavelength value smaller than that of the first heater. It is preferable to emit infrared rays whose value is less than 2.5 μm. The reason is that if the emission wavelength of infrared rays is 2.5 μm or more, the infrared rays do not reach the inside of the foamed resin sheet, and it is impossible to foam the inside of the foamed resin sheet in a sufficiently optimal state.

[0035]

According to the foamed resin sheet heating apparatus of the present invention, one surface of the foamed resin sheet having non-uniform colorimetric values is heated by the infrared rays emitted from the first heater. , The other surface having a uniform color system value is heated by the infrared rays emitted from the second heater, and the peak wavelength value of the infrared rays emitted from the first heater is equal to that of the infrared rays emitted from the second heater. Since it is larger than the value of the peak wavelength, the inside of the foamed resin sheet can be heated, and furthermore, the entire sheet can be foamed to the inside in a sufficiently optimal state.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a foamed resin sheet.

FIG. 2 is an explanatory diagram of a foamed resin sheet heating device of the present invention.

FIG. 3 is an explanatory view of another foamed resin sheet heating device of the present invention.

[Explanation of symbols]

1 Foamed resin sheet 10 colored part 11 Uncolored part 2 First heater 20 Ceramics heater 21 Radiator 3 Second heater 30 incandescent lamps 31 Transparent valve 4 First heater 40 incandescent lamps 41 transparent valve 42 Far infrared radiation film

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3K058 AA86 BA00 CE02 CE04 CE18                       CE19 CE32                 4F208 AC03 AG20 AH52 AK08 AK09                       MA01 MA02 MH06                 4K063 AA01 CA03 FA81

Claims (3)

[Claims] 1. One surface has non-uniform color system values,
A foamed resin sheet heating device that heats a foamed resin sheet whose infrared color is uniform on the other side, wherein the foamed resin sheet is sandwiched and the colorimetric values are non-uniform A first heater that radiates infrared rays is arranged at a position facing the other side, and a second heater that radiates infrared rays is arranged at a position facing the other surface having a uniform colorimetric value. The foamed resin sheet heating device is characterized in that the value of the peak wavelength of infrared rays radiated from is larger than the value of the peak wavelength of infrared rays radiated from the second heater. 2. The peak wavelength value of the first heater is 2.
It is 5 micrometers or more, The foaming resin sheet heating apparatus of Claim 1 characterized by the above-mentioned. 3. The first heater is a ceramics-based heater or an incandescent lamp having an infrared radiation film formed on a surface of a transparent bulb, and the second heater is an incandescent lamp of a transparent bulb. The foamed resin sheet heating device according to claim 1 or 2, which is characterized in that.