JPH04309779A - Manufacture of vacuum heat insulating material - Google Patents

Abstract

PURPOSE:To inexpensively manufacture a vacuum heat insulating material in which wrinkles are scarcely formed and which has excellent shape retentivity. CONSTITUTION:An impermeable plastic material is blow-molded, and a hollow vessel 11 made of a body 12, a discharge port 15 and an opening 16 is formed. A pressure feed pump 19 is connected to the opening 16, and the air containing inorganic fine powder having low thermal conductivity is supplied. Simultaneously, an exhaust pump 19 is connected to the port 15 in which a filter 17 is mounted to evacuate it, and the powder is filled in the vessel 11. After a filter 20 is mounted in the opening 16 and the air is evacuated from the port 15 and the opening 16, the port 15 and the opening 16 are sealed. Thus, since its rigidity is large, wrinkles are scarcely generated, and a vacuum heat insulating material having excellent shape retentivity is inexpensively manufactured by a small amount of material in small number of steps.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a vacuum heat insulating material used for keeping heat and cold.

0002

BACKGROUND OF THE INVENTION Recently, powder vacuum insulation materials have been used as insulation materials for household refrigerators, replacing polyurethane foam, which has been widely used in the past. This powder vacuum insulation material is formed as follows. FIG. 5 is an external view of the powder vacuum insulation material, and FIG.
FIG. 7 is an enlarged view of section B in FIG. 5. FIG. In FIG. 6, an inner bag 2 made of air-permeable kraft paper is filled with inorganic fine powder 1 having low thermal conductivity. Furthermore, it is covered with an outer wrapping material 3 made of a polyethylene terephthalate film coated with a non-breathable metal. Then, after exhausting the internal air, seal the
This forms the powder vacuum insulation material.

0003

[Problems to be Solved by the Invention] As described above, in the method for forming a powder vacuum insulation material, the container filled with the inorganic fine powder 1 is made of a polyethylene terephthalate material coated with metal and an inner bag 2 made of kraft paper. - It is created by laminating the outer packaging material 3 made of film. That is, the container is made from multiple materials and through a complex manufacturing process. Therefore, the above method for forming a powder vacuum insulation material has a problem in that the powder vacuum insulation material cannot be manufactured at low cost.

Furthermore, in the powder vacuum insulation material formed as described above, the inner bag 2 and the outer packaging material 3 are made of kraft paper or polyethylene terephthalate film, which have low rigidity. Therefore, the dimensional stability of the inner bag 2 and the outer packaging material 3 is poor, and there is a slight difference in shape between the two. Due to this difference in shape and the difference in elongation rate of each material, wrinkles 4 (
(see FIG. 7) occurs. The occurrence of wrinkles 4 cannot be avoided even if the powder vacuum insulation material is formed with the utmost care. The wrinkles 4 that occur in the powder vacuum insulation material often occur at the corner portions of the powder vacuum insulation material, as shown in FIG. Stress is concentrated at wrinkle 4,
In many cases, it protrudes from the surface of the outer packaging material 3. Therefore, when handling the powder vacuum heat insulating material, there is a problem that the wrinkles 4 are destroyed or the metal vapor deposited film at the wrinkles 4 is cracked, reducing the reliability of air impermeability. Furthermore, as described above, the rigidity of the inner bag 2 and the outer packaging material 3 is low, so that shape retention is poor. Therefore, when attaching the powder vacuum heat insulating material to the wall of a refrigerator case, for example, there is a problem that it cannot be easily attached.

[0005] Accordingly, an object of the present invention is to provide a method for producing a vacuum heat insulating material that is less likely to wrinkle and has good shape retention, which can be produced at low cost using fewer materials and fewer steps.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the method for manufacturing a vacuum insulation material of the present invention includes forming a molded container having a chamber and an opening by molding a non-breathable thermoplastic material, Powder with low thermal conductivity is injected through the opening of the molded container, a filter is attached to the opening into which the powder is injected, air in the room is exhausted from the opening through the filter, and the opening is closed. It is characterized by being sealed and formed by heat fusion.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to illustrated embodiments. In the method for manufacturing a vacuum heat insulating material of this embodiment, first, a hollow container 11 as shown in FIG. 1 is created. This hollow container 11 is made by blow molding a non-breathable plastic material. The hollow container 11 thus created includes a main body 12 forming a thin box, and a cylindrical opening that protrudes from two opposing side walls 13 and 14 of the main body 12 and communicates a chamber provided in the main body 12 with the outside. It consists of parts 15 and 16. Since the hollow container 11 has great rigidity and is integrally formed, wrinkles do not occur at the corner portions. The opening 15 (hereinafter referred to as exhaust port 1
5) is equipped with a filter 17 as shown in FIG. This filter 17 has minute pores that do not allow the inorganic fine powder with low thermal conductivity filled in the interior of the hollow container 11 to pass through, as will be described later.

Using the hollow container 11 formed as described above, a vacuum heat insulating material is formed in the following manner. Figure 2
As shown in FIG. 2, an exhaust pump 18 is connected to the exhaust port 15 of the hollow container 11 to which the filter 17 is attached. On the other hand, a pressure pump 19 is connected to the opening 16 . Then, air containing fine inorganic powder with low thermal conductivity is supplied into the interior of the hollow container 11 via the pressure pump 19 . Then, the fine powder supplied into the chamber is blocked by the filter 17 and is deposited and filled in the chamber. At this time, when the exhaust pump 18 connected to the exhaust port 15 is driven, the rate at which the fine powder is deposited into the interior of the hollow container 11 is further accelerated.

In this way, when the chamber of the hollow container 11 is filled with a predetermined amount of fine powder, the exhaust port 1 is opened.
The evacuation pump 18 connected to 5 and the pressure pump 19 connected to opening 16 are removed. Then, as shown in FIG. 3, a filter 20 is also attached to the opening 16. This filter 20 has the same function as the filter 17 described above. After that, a vacuum pump (not shown) is connected to the exhaust port 15 and the opening 16, and the air inside the hollow container 11 is exhausted. and,
When the room reaches a predetermined degree of vacuum, the filters 17 and 20 at the exhaust port 15 and the opening 16
and the vacuum pump are sealed by a suitable method such as heat sealing or ultrasonic welding. By doing this, as shown in FIG. 4, a vacuum heat insulating material is formed in which the hollow container 11 integrally formed by blow molding is filled with fine powder 21 and evacuated.

As described above, the method for manufacturing the vacuum heat insulating material in this embodiment involves filling the hollow container 11 made of blow-molded non-porous plastic material with inorganic fine powder having low thermal conductivity, and then evacuating and sealing the hollow container 11. I'm trying to stop it. Therefore, the hollow container 11 filled with the inorganic fine powder can be made from a single material in one step. In other words, according to this embodiment, the materials and manufacturing steps for the vacuum insulation material are reduced, and
Vacuum insulation materials can be manufactured at low cost.

[0011] Furthermore, the vacuum heat insulating material made of the hollow container 11 manufactured by blow molding has high rigidity, and wrinkles do not easily form at the corner portions. In other words, the vacuum heat insulating material manufactured according to this example will not be damaged at the wrinkles or cracks will occur in the metal vapor deposited film, thereby reducing the reliability of air impermeability. Furthermore, since the vacuum heat insulating material has high rigidity, it has good shape retention and can be easily attached to the wall of a refrigerator case, for example. From the above, according to this embodiment, a vacuum insulation device that is easy to handle and install can be manufactured at low cost.

As the material for the hollow container 11, polyacrylonitrile, polyethylene terephthalate, polyolefin, polyvinyl alcohol, etc. are used singly or in combination. At that time, since the exhaust port 15 and the opening 16 are sealed by heat fusion, a material that can be heat fused is desirable. In addition, the inorganic fine powder with low thermal conductivity to be filled into the hollow container 11 has an average particle size of 1
Fine powders of pearlite, silicon oxide, calcium silicate, vershlite, etc. having a particle size of 0 μm or less and a specific volume of 100 m 2 /g or more are desirable.

In the above embodiment, the hollow container 11
is formed by blow molding, but it may also be formed by injection molding or the like. The shape of the hollow container 11 is not limited to the above embodiment, and may be appropriately set depending on the shape of the cold/warm retaining box used. The number and location of the openings 15 and 16 are not limited to those in the above embodiments, but should be set in consideration of the location where the vacuum insulation material is installed, the injection efficiency of the inorganic fine powder, the vacuum exhaust efficiency, etc. Bye.

[0014]

[Effects of the Invention] As is clear from the above, in the method for manufacturing a vacuum insulation material of the present invention, the vacuum insulation material is manufactured using a molded container made of a non-breathable thermoplastic material. The container into which the low conductivity powder is injected can be made from a single material in one step. Therefore, according to the present invention, a vacuum insulation material can be manufactured at low cost using fewer materials and fewer steps.

[0015] Furthermore, the vacuum heat insulating material produced according to the present invention has high rigidity and is resistant to wrinkles at the corner portions. Therefore, in the vacuum heat insulating material, there is no need to pay attention to destruction of the wrinkled areas or cracks occurring in the metal vapor deposited film at the wrinkled areas, and the handling becomes easy. Furthermore, since the vacuum heat insulating material has high rigidity, it retains its shape well and can be easily attached to the wall of the box.

[Brief explanation of the drawing]

FIG. 1 is an external view of a hollow container according to an embodiment of the vacuum heat insulating material of the present invention.

FIG. 2 is a diagram showing a state in which an exhaust pump and a pressure pump are connected to the hollow container in FIG. 1;

FIG. 3 is a diagram showing a state in which a filter is attached to the opening of the hollow container in FIG. 1;

FIG. 4 is a sectional view taken along the line CC in FIG. 3;

FIG. 5 is an external view of a conventional powder vacuum insulation material.

6 is a sectional view taken along the line AA in FIG. 5. FIG.

7 is an enlarged view of part B in FIG. 5. FIG.

[Explanation of symbols]

11...Hollow container,
12...Main body, 15...Exhaust port part,
16...Opening part, 17, 20...Filter, 18...Exhaust pump, 19...Pressure pump,
21...Fine powder.

Claims (1)

[Claims] Claim 1: A molded container having a chamber and an opening is created by molding a non-breathable thermoplastic material, a powder with low thermal conductivity is injected through the opening of the molded container, and the powder is injected. A method for producing a vacuum heat insulating material, comprising: attaching a filter to the opening, exhausting air from the room through the opening, and sealing the opening by heat fusion.