JPH0868592A - Manufacture of vacuum heat-insulating panel - Google Patents

Abstract

PURPOSE: To provide manufacture of a vacuum heat-insulating panel which is constituted to reduce the occurrence of an uneven surface during vacuum exhaust. CONSTITUTION: Manufacture of a vacuum heat-insulating panel is such that a core material 24 formed in such a manner to fill breathable bag with powdery filler is contained in an outer wrapping bag 22 having gas barrier properties and thereafter, gas is exhausted so that the interior of the outer wrapping bag 22 is forced into a vacuum state, and the outer wrapping bag 22 is sealed to a vacuum heat-insulating panel 14. During exhaust, gas is simultaneously exhausted through two opening parts 22a and 22b, positioned facing each other, of the outer wrapping bag 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vacuum heat insulating panel used in a refrigerator or the like.

[0002]

2. Description of the Related Art Conventionally, vacuum insulation panels are
It is designed to be installed in a heat insulating box such as a refrigerator or a freezer to exhibit heat insulating performance.

As shown in FIG. 5, a vacuum heat insulating panel generally has a predetermined shape in which a powder having heat insulating properties such as perlite powder and fine silica powder is stored in a bag having air permeability such as paper or nonwoven fabric. It is composed of a core material preliminarily molded in and a non-breathable synthetic resin outer bag for accommodating the core material, and is formed into a rectangular plate shape 100 as shown in FIG. 5 (a). And the inside is in a vacuum state,
This provides heat insulation.

When manufacturing this vacuum insulation panel, for example, the heat seal layer 102 and the aluminum vapor deposition layer 10 are used.
Rectangular three-layer film 1 composed of 3 and synthetic resin layer 104
Two sheets of 05 are stacked and one side 108 thereof is left, and the other three sides 109 are joined by heat fusion to form a bag-like outer bag 105. Then, the core material in which the powder 107 is filled in the breathable bag 106 is housed in the outer bag 105, and the opening 108 is formed.
Evacuate the inside more. After that, the opening 10
The vacuum heat insulating panel 100 is manufactured by bonding 8 by means of heat fusion or the like and sealing the outer bag 105.

[0005]

However, in such a manufacturing method, when the outer bag 105 is evacuated, the movement of the air in the outer bag 105 is disturbed, and the opening 108 is formed.
Exhaust conditions are different in the vicinity and in the back, and core material fine powder 10
7 is distorted in the laminated form, and the panel surface 100a is
Uneven irregularities 110 as shown in FIGS. 5A and 5B are generated. That is, the core material powder 107 becomes a resistance at the time of evacuation, the movement of the exhausted air is hindered, and the outer bag 10
Since the air flow from the inner part of 5 becomes unstable, the core material powder 107 is largely moved, and the panel surface 100a
The uneven deformation 110 is generated.

[0006] Normally, the above-mentioned exhaust is carried out by placing the outer packaging bag 105 on a flat table, so that the lower surface of the outer packaging bag 105 is pressed by this table to be flat, but uneven deformation 110 occurs on the upper surface. It's easy to do.

When uneven unevenness 110 is generated on the panel surface 100a as described above, the following problems as described with reference to FIG. 6 occur.

FIG. 6 shows a heat insulating box 12 used in a refrigerator.
0 is a schematic longitudinal cross-sectional view of the inner box 11 of the heat insulating box 120.
2 and the outer box 114, a plurality of vacuum insulation panels 100.
Is attached. In this figure, four types of mounting states 100A to 100D are shown.

In the above vacuum heat insulation panel 100, the surface with the unevenness is covered with the inner box 112 and the outer box 1 of the heat insulation box 120.
Since it cannot be mounted in contact with 14, it is not possible to mount it on both sides of the panel 100 and the box 12 like 100A, for example.
The space 122 between 0 and 0 must be filled with polyurethane foam or the like.

Alternatively, as in 100B and 100C, the surfaces having no unevenness are brought into close contact with the inner box 112 and the outer box 114, respectively, and the space 12 between the unevenness generating surface and the box 120 is formed.
2 must be filled with foamed polyurethane.

That is, as shown in 100D, since it cannot be attached to both inner walls of the box 120 so as to be in close contact with each other, it is necessary to fill the foamed polyurethane, and the thickness of the heat insulating box 120 cannot be reduced. There is. In addition, since extra foamed polyurethane is required as a filler, there is a problem in that it is not preferable in terms of CFC measures.

Therefore, in view of the above points, an object of the present invention is to provide a method for manufacturing a vacuum heat insulating panel capable of reducing the occurrence of surface irregularities during vacuum evacuation.

[0013]

According to a first aspect of the present invention, there is provided a vacuum insulating panel manufacturing method, wherein a core material obtained by filling a breathable bag with a powdery filler is contained in an outer bag having gas barrier properties. Then, the inside of the outer bag is evacuated to a vacuum state, and a method for manufacturing a vacuum heat-insulating panel, in which the outer bag is sealed to produce a vacuum heat-insulating panel, wherein the outer bag is opposed to the outer bag when the gas is exhausted. This is a method of simultaneously exhausting air from two openings.

A method of manufacturing a vacuum heat insulating panel according to claim 2 is
A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, then the inside of the outer bag is evacuated to a vacuum state, and the outer bag is sealed. A method of manufacturing a vacuum heat insulating panel, comprising: pressing a molding member from both sides of the outer bag when the gas is exhausted.

A method of manufacturing a vacuum heat insulating panel according to claim 3 is
A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, then the inside of the outer bag is evacuated to a vacuum state, and the outer bag is sealed. A method for manufacturing a vacuum heat insulating panel for manufacturing a vacuum heat insulating panel according to claim 1, wherein after the evacuation, before returning to atmospheric pressure, the outer bag is pressed by a molding member from both sides to flatten the outer bag. is there.

A method of manufacturing a vacuum heat insulating panel according to claim 4 is
A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, then the inside of the outer bag is evacuated to a vacuum state, and the outer bag is sealed. A method for manufacturing a vacuum heat insulating panel, comprising: a step of roughly evacuating air from the inside of the outer bag and a step of rough evacuation of the vacuum heat insulating panel. Up to a high vacuum stage for exhausting air from the inside of the outer bag, and the exhaust amount per unit time in the rough evacuation stage is
This is a method of reducing the exhaust amount per unit time in the high vacuum stage.

[0017]

In the method of manufacturing a vacuum insulation panel according to claim 1, when the inside of the outer bag is evacuated, it is simultaneously evacuated from the two openings of the outer bag facing each other. The flow of air sucked between the materials is smooth, and the deformation of the core material due to the movement of the filler is small.

In the method of manufacturing the vacuum heat insulating panel according to the second aspect, when the inside of the outer bag is evacuated, the molding material is pressed from both sides of the outer bag, so that the core material housed in the outer bag is formed. The movement of the powdered filling material is restricted.

In the method for manufacturing a vacuum heat insulating panel according to claim 3, after the inside of the outer bag is evacuated and before returning to atmospheric pressure, the outer surface of the outer bag is pressed by a molding member from both sides of the outer bag to obtain a desired surface. Shape to shape.

In the method of manufacturing a vacuum heat insulating panel according to claim 4, when exhausting the inside of the outer bag, the exhaust amount per unit time in the roughing stage is smaller than the exhaust amount per unit time in the high vacuum stage, that is, The deformation of the core material is small because the exhaust is performed slowly and slowly in the rough evacuation stage where the air flow moves violently.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.
2 will be described.

FIG. 1A is a vertical sectional view of the evacuation device 10 in a state where the vacuum heat insulating panel 14 is exhausted, and FIG. 1B is a transverse sectional view thereof.

The vacuuming apparatus 10 is provided with a table 16 on which the vacuum heat insulating panel 14 is placed, and a table 16 provided on the table 16.
And a container 12 that forms a vacuum space, a heat sealer 18 that is provided at an appropriate position in the container 12 and heat seals one side of the vacuum heat insulating panel 14, and is attached to the container 12 and connected to a vacuum pump (not shown). Exhaust hose 2
It consists of 0.

The upper surface of the base 16 is formed in a rectangular shape,
It has a smooth surface. And two heat sealing machines 1
One of the heat sealing machines 18 is disposed inside the two opposite sides of the base 16, and each heat sealing machine 18 is provided with a receiving portion 18a fixed on the base 16 and arranged above and below the receiving portion 18a. It is composed of a movable pressing portion 18b.

Two films having a heat-sealing property are inserted between the receiving portion 18a and the holding portion 18b of the heat sealing machine 18 and the heated holding portion 18b is moved downward to move the receiving portion 18a. By pressing against, the two films can be heat-sealed.

Next, a method of manufacturing the vacuum heat insulating panel 14 using the vacuum evacuation device 10 will be described. In addition,
The vacuum heat insulation panel 14 is composed of the outer bag 22 and the core material 24 as in the conventional vacuum heat insulation panel described above.
2 is a synthetic resin film having a gas barrier property, a core material 2
4 is formed by filling a bag having air permeability with a powdery filler such as silica fine powder.

Two rectangular gas barrier films are superposed on each other, the ends of the two opposite sides 22c and 22d are heat-sealed, and the tubular outer bag 22 having the other two opposite sides 22a and 22b is opened. Form. Into the outer bag 22, a core material 24 preformed in a plate shape is provided in the opening 22 of the outer bag 22.
Insert from a.

As shown in FIGS. 1 (a) and 1 (b),
It is placed in the vacuum device 10. At this time, the outer bag 22
Of the vacuum heat insulating panel 14 such that the two open side portions 22a and 22b of the vacuum heat insulating machine 18 are located between the receiving portion 18a and the holding portion 18b of the heat sealing machine 18, respectively.
It is placed on the table 16.

Then, after covering the container 12, a vacuum pump (not shown) is driven so that the container 12 is pulled through the exhaust hose 20.
Evacuate the air inside and evacuate. At this time, the air is simultaneously exhausted from the two facing openings 22a, 22a of the outer bag 22.

This evacuation is composed of two steps, a rough evacuation step and a high evacuation step, so that the exhaust amount per unit time in the rough evacuation step is smaller than the exhaust amount per unit time in the high evacuation step. Also, it is desirable that the evacuation time in the rough evacuation stage be longer than that in the high vacuum stage.

Here, the roughing stage is a stage in which most of the air is exhausted from the inside of the outer bag 22, that is, for example, the internal pressure of the outer bag 22 is the atmospheric pressure (760 Torr) at the start of exhaust.
To about 10 Torr.

The high vacuum stage is a stage in which air is exhausted from the inside of the outer bag 22 so that the vacuum heat insulating material 14 has a sufficient heat insulating effect from the roughing stage, that is, for example, the outer bag 22. Internal pressure is about 10 Torr to 1 Torr
Or it is a stage until it becomes less than that.

As described above, FIG. 2 shows an example in which the rough evacuation step takes time, that is, the evacuation rate is slowed, and the high vacuum step takes a short time, that is, the evacuation rate is fast. .

FIG. 2 shows the dimensions of the vacuum insulation panel 14 (length x length).
(Width x thickness) is 500 mm x 500 mm x 20 mm,
The degree of vacuum (Tor) in the container 12 with respect to the evacuation time (minutes)
It is a semi-logarithmic graph which shows an example of r).

The pressure in the container 12 is set to the atmospheric pressure (76
Evacuation is performed from 0 Torr) to 10 Torr, and then the exhaust speed is increased to exhaust from 10 Torr to 0.1 Torr in 1 minute. In the case of the vacuum heat insulating panel 14 of this size, when exhausting is completed in about 3 minutes, the rough evacuation step takes 1 minute or more, for example, 2 minutes, and then the exhaust speed is changed to 0.1 To.
It is desirable to quickly evacuate to rr.

After evacuation to 0.1 Torr, the two heat-sealing machines 18 and 18 heat-seal the two opposing opening sides 22a and 22b of the outer bag 22, respectively, and the core material 24 is attached to the outer bag 22. The inside is sealed in a vacuum state. As a result, the vacuum heat insulating panel 14 is manufactured. Then, the pressure in the container 12 is returned to atmospheric pressure, and the vacuum heat insulating panel 14 is taken out from the vacuuming device 10.

As described above, since the air is exhausted from the two opening portions 22a and 22b of the outer bag 22 which face each other at the same time, the flow of the air flowing between the powders of the core material 24 becomes smooth,
It is possible to reduce the occurrence of irregularities on the surface of the vacuum heat insulating panel 14 due to the deformation of the core material 24.

The specific evacuation time in the above vacuum evacuation depends on the volume of the heat insulating panel 14 and the like, but as described above, it takes time in the rough evacuation stage and quick evacuation in the high vacuum stage. As a result, it is possible to slowly exhaust the rough evacuation stage in which the air flow of the exhaust gas is intense. Therefore, the heat insulating panel 1 due to the deformation of the core material 24
(4) It is possible to reduce the occurrence of irregularities on the surface, and, in the high vacuum stage, since the gas is quickly evacuated, the total evacuation time does not become long.

FIG. 3 is a vertical sectional view of an evacuation device 30 showing the vacuum evacuation method of the second embodiment.

The evacuation device 30 has the same structure as the evacuation device 10 of FIG. 1 except that the molding members 16 and 32 for pressing both surfaces of the vacuum heat insulating panel 14 are provided.

The forming members 16 and 32 are composed of a smooth base 16 on which the vacuum heat insulating panel 14 is placed and a holding plate 32 which moves up and down in the container 12. This holding plate 32 is
The upper surface of at least the portion of the vacuum heat insulating panel 14 in which the core material 24 is housed can be pushed.

In this embodiment, the vacuum insulating panel 14 is placed on the base 16 and the lower surface of the outer bag 22 is supported smoothly, and the pressing plate 32 is moved downward to move the upper surface of the outer bag 22. Exhaust while pressing. The vacuum heat insulating panel 14 placed on the table 16 has only one side 22a open, and the other three sides 22b, 22c, 22d are heat-sealed in advance. That is, the air is exhausted only from the opening 22a on one side.

In this embodiment, the core material 24 at the time of exhausting
It is possible to prevent the above deformation by the pressing plate 32, and to reduce the occurrence of unevenness on the surface of the heat insulating panel 14.

FIG. 4 is a vertical sectional view of an evacuation device 30 showing the vacuum evacuation method of the third embodiment. However, the evacuation device 30 is the same as that of FIG.

In this method, first, one side 22 is placed on the stand 16.
The vacuum heat insulating panel 14 having only a opened is placed to perform vacuuming.

After the evacuation, before the pressure inside the container 12 is returned to the atmospheric pressure, the pressing plate 32 presses the surface of the vacuum heat insulating panel 14 with a static load to correct the uneven unevenness on the surface of the heat insulating panel.

After the pressing, the heat sealing machine 18
To heat seal the opening 22a.

In this method, after the evacuation, before the pressure is returned to the atmospheric pressure, the pressure plate 32 presses and corrects the heat insulation panel 14, so that the heat insulating panel 14 having a smooth surface can be obtained. The pressing by the pressing plate 32 must be performed before returning to atmospheric pressure, that is, in a vacuum atmosphere. This is because after returning to atmospheric pressure, the pressure causes the core material 24 to solidify, making shape correction impossible.

Also in the second and third embodiments, as described above, it is preferable that the roughing stage is slowly exhausted over time and the high vacuum stage is exhausted in a short time. It is possible to further reduce the occurrence of uneven unevenness on the surface.

Further, in the second and third embodiments, the case where the outer bag 22 is evacuated to the heat insulating material 14 whose one side 22a is open has been described, but like the first embodiment, the outer bag is sealed. The bag 22 having two opposite sides 22a and 22b opened may be vacuumed. In this case, the flow of exhausted air becomes smoother as described above,
It is desirable because the uneven deformation of the surface of the heat insulating material 14 can be further reduced.

The method of pressing the vacuum insulation panel 14 is as follows.
The configuration is not limited to the above, and for example, the panel 14 may be sandwiched between the molding members facing each other on the left and right, and the panel 14 may be pressed in an upright state. In this case, in particular, in the second embodiment, the two opposite sides 22
When using the outer bag 22 that opens at a and 22b, it is preferable to insert the outer bag 22 so that the opening sides 22a and 22b are oriented in the lateral direction and to exhaust air from the lateral direction instead of the vertical direction.

In all of the above-mentioned three embodiments, since the core material 24 of the vacuum heat insulating panel 14 is formed by filling the air-permeable bag with powder, the exhaust time does not become extremely long, It can be performed in the same exhaust time as the conventional one.

Since the vacuum heat insulating panel 14 manufactured as described above is smooth with almost no unevenness on the upper and lower surfaces, the outer box 1 of the heat insulating box 120 of the refrigerator shown in FIG.
14 and the inner box 112 can be mounted in close contact with each other (100D state). Therefore, it is not necessary to use the polyurethane foam together to form the heat insulating box 120, and the thickness of the heat insulating box 120 can be effectively reduced.

In the above embodiments, the method for manufacturing the rectangular vacuum heat insulating panel 14 has been described, but the present invention is not limited to the rectangular panel, and if it is a plate-like shape, for example, It can also be applied to circles and pentagons. In that case, when exhausting air from two openings facing each other, the other opening may be provided so as to be located farthest from one opening.

In the second and third embodiments, the molding members 16 and 32 do not necessarily have smooth surfaces, and the surface of the heat insulating panel 14 can be molded into a desired shape. It is also possible to use a member having an appropriate shape. That is, for example, in order to avoid a partition wall in the refrigerator inner box, a predetermined convex portion may be provided on the molding member to form a groove or a recess in a part of the panel 14.

[0056]

According to the method of manufacturing a vacuum heat insulating panel of the first or fourth aspect of the present invention, when the inside of the outer bag is evacuated, the deformation of the core material is small. Can be reduced, and a vacuum insulating panel having a smooth surface can be manufactured.

According to the manufacturing method of the vacuum heat insulating panel of the second or third aspect, the surface of the vacuum heat insulating panel can be formed into a desired shape by using the molding member having a predetermined shape. Therefore, if a molded member with a smooth surface is used,
It is possible to manufacture a vacuum insulating panel having a smooth surface.

As described above, when the vacuum heat insulating panel having a smooth surface is obtained, it can be mounted in a state in which it is in close contact with both the outer and inner walls of a heat insulating box such as a refrigerator. Therefore, the thickness of the heat insulation box can be reduced, and
It is not necessary to use it in combination with foamed polyurethane to form a heat insulating box.

[Brief description of drawings]

1A and 1B are a vacuum evacuation device showing a state during vacuum evacuation of a first embodiment of the present invention, in which FIG. 1A is a vertical sectional view and FIG.

FIG. 2 is a graph showing the relationship between the evacuation time and the degree of vacuum during evacuation.

FIG. 3 is a vertical cross-sectional view of an evacuation device showing a state during evacuation of a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view of an evacuation device showing a state during evacuation of a third embodiment of the present invention.

FIG. 5 is a vacuum heat insulation panel manufactured by a conventional manufacturing method, in which (a) is a perspective view and (b) is A- of (a).
It is a vertical sectional view taken along line A.

FIG. 6 is a schematic vertical cross-sectional view of a heat insulating box showing an example of a mounted state of a vacuum heat insulating panel.

[Explanation of symbols]

 14 ... Vacuum insulation panel 16 ... Stand 22 ... Outer bag 22a, 22a ... Opening of outer bag 24 ... Core material 32 ... Holding plate

Claims (4)

[Claims] 1. A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, and then the inside of the outer bag is evacuated to a vacuum state, and A method for manufacturing a vacuum heat insulating panel, which comprises sealing an outer bag and manufacturing a vacuum heat insulating panel, wherein at the time of the evacuation, air is simultaneously evacuated from two opposing openings of the outer bag. Production method. 2. A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, after which the inside of the outer bag is evacuated to a vacuum state, and It is a manufacturing method of a vacuum heat insulation panel which seals an outer bag and manufactures a vacuum heat insulation panel, Comprising: Pressing from both sides of the above-mentioned outer bag with a molding member at the time of evacuation, The manufacturing method of a vacuum heat insulation panel characterized by things. 3. A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, after which the inside of the outer bag is evacuated to a vacuum state, and A method of manufacturing a vacuum heat insulating panel for sealing a vacuum heat insulating panel to seal a vacuum heat insulating panel, wherein after the evacuation, before returning to atmospheric pressure, the outer bag is pressed by a molding member from both sides of the outer bag, A method for manufacturing a vacuum insulation panel, which comprises flattening. 4. A core material obtained by filling a breathable bag with a powdery filler is housed in an outer bag having a gas barrier property, after which the inside of the outer bag is evacuated to a vacuum state, and A method for manufacturing a vacuum heat insulation panel, which comprises sealing an outer bag and manufacturing a vacuum heat insulation panel, wherein the evacuation includes a rough evacuation step of almost exhausting air from inside the outer bag, and the vacuum heat insulation panel from the rough evacuation step. Until it has an adiabatic effect, further comprising a high vacuum step of exhausting air from the inside of the outer packaging bag, the exhaust amount per unit time in the rough evacuation step, from the exhaust amount per unit time in the high vacuum stage A method for manufacturing a vacuum insulation panel, which is characterized in that the number is reduced.