US20130115407A1

US20130115407A1 - Vacuum insulation material and insulation structure for refrigerator cabinet having the same

Info

Publication number: US20130115407A1
Application number: US13/805,271
Authority: US
Inventors: Jaehyun SOH; Ilseob Yoon; Youngbae Kim
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2010-09-29
Filing date: 2011-09-02
Publication date: 2013-05-09
Also published as: WO2012043990A2; KR20120033165A; WO2012043990A3; EP2622291A2

Abstract

A vacuum insulation material includes a core material, and a wrapping member configured to cover the core material, the wrapping member provided with an outermost layer externally exposed, a barrier layer laminated beneath the outermost layer, and a thermal bonding layer disposed beneath the barrier layer and contacting the core material, wherein the barrier layer comprises at least one polyimide film, on which an inorganic layer is laminated. With the configuration, the wrapping member of the vacuum insulation material can be more resistant to high temperature such that the vacuum insulation material can be safe from the risk of deformation, resulting in enhancing reliability of insulation efficiency.

Description

TECHNICAL FIELD

The present disclosure relates to a vacuum insulation material and an insulation structure of a refrigerator cabinet having the same, and more particularly, a vacuum insulation material capable of enhancing reliability of insulation efficiency of a refrigerator cabinet by making a wrapping member of the vacuum insulation material used in the refrigerator more resistant to high temperature so as to protect the vacuum insulation material from a risk of deformation upon installed in the refrigerator.

BACKGROUND ART

In general, a refrigerator is an apparatus for storing foods at low temperature, and includes a cabinet defining storage spaces, such as a refrigerating chamber, a freezing chamber or the like for storing foods, doors for opening or closing the refrigerating chamber and the freezing chamber, and a machine part having a refrigerant compression cycle.
Here, the cabinet, referring to FIG. 1, is generally configured such that an insulation material is filled between an outer surface 10 defining its appearance and an inner surface 20 defining the storage spaces to enhance cooling efficiency. To this end, a polyurethane foam 30 is injected and foamed between the inner surface 20 and the outer surface 10 in an assembled state as shown in FIG. 2.
The polyurethane foam 30 contains air therein, which causes limitation in view of improving its insulation efficiency. Hence, referring to FIG. 3, an insulation structure having an improved insulation function is employed. Namely, a vacuum insulation material 40 as well as the portion formed by the polyurethane foam 30 are employed between the outer surface 10 and the inner surface 20 of the cabinet. In other words, the polyurethane foam and the vacuum insulation material are positioned sequentially from the inner surface.
The vacuum insulation material is shown in FIG. 4. As shown in FIG. 4, the vacuum insulation material 40 includes a core material 41 formed by laminating (stacking, depositing) panels formed of glass fibers or silica, and present in a vacuum state, and a wrapping member 42 for wrapping the core material 41 to maintain the vacuum state of the core material 41. In the meantime, when the core material 41 is formed of glass fibers, getters 43 is often included in the wrapping member 42 to remove gas components introduced into the wrapping member 42. Here the getter is not required when the silica is used as the core material 41.
The wrapping member 42 is a constituting element in a shape of envelope, which is formed by laminating (depositing) various materials, and accommodates the core material 41 therein. In general, referring to FIG. 5, the wrapping member 42 has a structure of interposing (coupling) an aluminum foil 42 b between polymer films 42 a and 42 c to prevent permeation of humidity and gas.
When the vacuum insulation material is mounted in the cabinet of the refrigerator, the vacuum insulation material is first situated in the cabinet and the polyurethane foam is filled therein. When the polyurethane is injected to become a polyurethane foam, reaction heat is generally generated. The reaction heat heats up the polyurethane foam in the range of 70° C. to 100° C.
Such increased heat (temperature) is transferred to the vacuum insulation material contacting the polyurethane foam, accordingly, the wrapping member of the vacuum insulation material may be deformed due to the transferred heat. Consequently, insulation efficiency of the vacuum insulation material may be lowered.

DISCLOSURE OF INVENTION

Technical Problem

Therefore, to obviate those problems, an aspect of the detailed description is to provide a vacuum insulation material having excellent thermal endurance without being thermally deformed by reaction heat even though polyurethane foam is filled in a cabinet of a refrigerator.
Another aspect of the detailed description is to provide a vacuum insulation material capable of exhibiting reliable insulation efficiency by reducing a risk for deformation by ensuring excellent thermal endurance.
Another aspect of the detailed description is to provide an insulation structure for a refrigerator cabinet, capable of exhibiting excellent insulation efficiency by virtue of the use of a vacuum insulation material obtaining reliable insulation performance by reduction of a risk for deformation in response to enhanced thermal endurance.

Solution to Problem

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a vacuum insulation material includes a core material, and a wrapping member configured to cover the core material, the wrapping member provided with an outermost layer externally exposed, a barrier layer laminated beneath the outermost layer, and a thermal bonding layer disposed beneath the barrier layer and contacting the core material, wherein the barrier layer comprises at least one polyimide film, on which an inorganic layer is laminated.
With the configuration, as the polyimide film having the metalized inorganic layer is laminated between the outermost layer and the thermal bonding layer of the wrapping member, thermal endurance of the wrapping member can be enhanced and accordingly the risk of deformation of the vacuum insulation material can be reduced, thereby allowing for the use in a high temperature state. Consequently, reliability of insulation efficiency of the vacuum insulation material can be enhanced.
The inorganic layer may be configured by laminating an aluminum foil on the polyimide film or laminating aluminum on the polyimide film through vacuum-Al metalizing. Such configuration may derive more improved functions of the vacuum insulation material in view of insulation and humidity shielding.
The barrier layer may include at least one polyimide film having a laminated aluminum foil, and at least one polyimide film having a vacuum-metalized aluminum. With the configuration, several sheets of polyimide films each having an inorganic layer can be laminated one another, thereby allowing for designing of the vacuum insulation material to have desired moisture vapor permeability and air permeability.
In accordance with one exemplary embodiment, an insulation structure for a refrigerator cabinet may include an outer surface and an inner surface of the refrigerator main body, and an insulating unit formed between the outer and inner surfaces of the refrigerator cabinet, wherein the insulating unit comprises a polyurethane foam layer, and a vacuum insulation material having the features.
With the configuration, the vacuum insulation material having the wrapping member, which has excellent thermal endurance to be useable at high temperature, can be applied to the refrigerator cabinet, thereby implementing a refrigerant cabinet having high insulation efficiency and high reliability of insulation performance.

Advantageous Effects of Invention

As the polyimide film having the metalized inorganic layer is laminated between the outermost layer and the thermal bonding layer of the wrapping member, thermal endurance of the wrapping member can be enhanced and the risk of deformation of the vacuum insulation material can be reduced, thereby allowing for the use in a high temperature state. Consequently, reliability of insulation efficiency of the vacuum insulation material can be enhanced.
In addition to improvement of insulation and humidity shielding function of the vacuum insulation material, several sheets of polyimide films each having the inorganic layer laminated thereon are laminated, so as to allow for designing of the wrapping member of the vacuum insulation material to have desired moisture vapor permeability and air permeability.
Also, the vacuum insulation material having the wrapping member, which has high thermal endurance to be useable at high temperature, can be applied to the insulation structure of the refrigerator cabinet, thus to implement a refrigerator cabinet having high insulation efficiency and high reliability of insulation performance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a general refrigerator;

FIGS. 2 and 3 are sectional views showing an outer wall of the general refrigerator;

FIG. 4 is a sectional view of a vacuum insulation material according to the related art;

FIG. 5 is a partial perspective view of a wrapping member according to the related art; and

FIGS. 6 to 8 are partial sectional views showing exemplary embodiments of a wrapping member for a vacuum insulation material in accordance with the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a vacuum insulation material includes a core material, and a wrapping member configured to cover the core material, the wrapping member provided with an outermost layer externally exposed, a barrier layer laminated beneath the outermost layer, and a thermal bonding layer disposed beneath the barrier layer and contacting the core material, wherein the barrier layer comprises at least one polyimide film, on which an inorganic layer is laminated.

MODE FOR THE INVENTION

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings where those components are rendered the same reference number that are the same or are in correspondence, regardless of the figure number, and redundant explanations are omitted. In describing the present invention, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the gist of the present invention, such explanation has been omitted but would be understood by those skilled in the art. The accompanying drawings are used to help easily understood the technical idea of the present invention and it should be understood that the idea of the present invention is not limited by the accompanying drawings. The idea of the present invention should be construed to extend to any alterations, equivalents and substitutes besides the accompanying drawings.
FIGS. 6 to 8 are partial sectional views showing exemplary embodiments of a wrapping member for a vacuum insulation material in accordance with the present disclosure.
A vacuum insulation material according to this specification may include a core material 200, and a wrapping member 100 for covering the core material 200. The wrapping member 100 may include an outermost layer 110 exposed to the exterior, a barrier layer 120 laminated beneath the outermost layer 110, and a thermal bonding layer 130 located beneath the barrier layer 120 and contacting the core material 200. The barrier layer 120 may include one or more polyimide films 121 a and 121 b, on which inorganic layers 122 a and 122 b are laminated, respectively.
The core material 200 may be made of glass fiber, which is well-known as a material having an excellent insulation characteristic. The core material 200 may be formed by laminating (stacking) panels woven from the glass fibers so as to obtain a high insulation effect. The core material 200 may alternatively employ silica. The silica is superior to the glass fiber in the aspect of long-term reliability, by virtue of less change in performance even after extended use.
The wrapping member 100 may include the outermost layer 110, the barrier layer 120 and the thermal bonding layer 130. The wrapping member 100 may maintain a vacuum state of the core material 200 and function to protect the core material 200.
The outermost layer 110 may be exposed to an outer surface of the vacuum insulation material. In this specification, the outermost layer 110 may be formed of nylon. The nylon is a material having high elasticity, accordingly, use of the nylon may prevent the vacuum insulation material from being destroyed even due to an external impact, which may be generated during assembly or installation of the vacuum insulation material. Especially, in regard of the fact that the vacuum insulation material for a refrigerator is fabricated with a considerable size for improving efficiency, it may be possible to prevent in advance the vacuum insulation material from being defective during work or destroyed or damaged due to an external impact or scratch, by virtue of the outermost layer 120 formed of nylon.
The thermal bonding layer 130 is a portion where edge portions of the wrapping member 100 without the core material 200 are thermally bonded (welded) after accommodating the core material 200 therein to shield the inside of the wrapping member 100.
The thermal bonding layer 130 may be made of linear low density polyethylene (LLDPE). The LLDPE may be medium-pressure polyethylene or low-pressure polyethylene. Its molecular structure is similar to high density polyethylene and its density is similar to low density polyethylene, generally 0.915 to 0.965. Upon employing such LLDPE as the thermal bonding layer 140, the LLDPE exhibits relatively high melt viscosity, and rigidity or environmental stress crack resistance and tear strength about twice higher than those of the low-density polyethylene, so it may be suitable to form the thermal bonding layer 130.
Meanwhile, the barrier layer 120 may be formed between the outermost layer 110 and the thermal bonding layer 130. The barrier layer 120, as shown in FIG. 6, may include at least one of the polyimide film 121 a having the laminated inorganic layer 122 a.
The barrier layer 120 may function to block permeation of humidity and air and heat transfer into the wrapping member 100. Hence, a plurality of polymer films may be laminated to have a desired (expected) effect as the barrier layer 120. Especially, inorganic layers may be interposed between the polymer films so as to enhance insulation effect and effectively block permeation of humidity and air.
The polyimide (PI) film has a melting point higher than 700° C. and is used as a plastic material, which is usable for a long term of time. Particularly, it exhibits high thermal endurance in spite of the plastic material. This specification uses this polyimide film to improve the thermal endurance of the wrapping member 100.
That is, referring to FIG. 6, the polyimide film 121 a, on which the inorganic layer 122 a is metalized, is laminated between the outermost layer 110 and the thermal bonding layer 130 of the wrapping member 100 so as to give the wrapping member 100 of the vacuum insulation material high thermal endurance and reduce a risk of deformation of the vacuum insulation material. Accordingly, the vacuum insulation material may be allowed for use at high temperature, thereby enhancing reliability of insulation efficiency.
In the meantime, the inorganic layer 122 a may be configured by laminating an aluminum foil on the polyimide film or metalizing aluminum on the polyimide film through vacuum-Al metalizing. Such configuration may derive more improved functions of the vacuum insulation material in view of insulation and humidity shielding, as compared to the use of only the polyimide film.
The barrier layer 120 may include at least one polyimide film having a laminated aluminum foil and at least one polyimide film having a vacuum-metalized aluminum.
FIG. 7 shows an exemplary embodiment of a wrapping member having a barrier layer, which includes a polyimide film 121 a having one aluminum metalized film 122 a, and a polyimide film 121 b having one laminated aluminum foil 122 b.
Also, FIG. 8 shows an exemplary embodiment of a wrapping member having a barrier layer, which includes two polyimide films 121 a each having an aluminum metalized layer 122 a.
However, the present disclosure may not be limited to those laminated structures. Alternatively, two or more polyimide films each having an inorganic layer laminated thereon may be stacked one another.
With the configuration, as several sheets of polyimide films each having the inorganic layer laminated thereon are laminated one another, it is able to design a wrapping member of the vacuum insulation material with excellent thermal endurance and a desired performance of shielding humidity and air.
The barrier layer 120 may further include one or more polymer films 123 and 124 in addition to the inorganic layer-laminated polyimide film. FIGS. 6 to 8 show examples including a plurality of polymer films laminated one another.
The polymer films 123 and 124 may be made of ethylene vinylalcohol (EVOH) or polyester (PET). However, the present invention may alternatively employ any polymer film if it has a similar function or effect, without limit to EVOH or PET.
Since the EVOH has an alcohol group with strong polarity, it has a high intermolecular force and accordingly can have low oxygen permeability. However, the EVOH is hydrophilic, thus it is sensitive to water. The PET has a relatively good permeability. Also, the PET is excellent in view of moisture vapor permeability and relatively cheap cost, compared to the EVOH. Therefore, upon using both EVOH and PET, the effect of shielding humidity and air can be improved more.
In addition, an aluminum layer may be metalized at least one or each of the polymer films 123 and 124. With this configuration, more improved insulation efficiency can be exhibited and desired moisture permeability and air permeability can be conveniently set.
The present disclosure may not be limited to the foregoing exemplary embodiments. Alternatively, a plurality of polymer films may be laminated one another.
Meantime, an insulation structure for a refrigerator cabinet may include outer surface and inner surface of the refrigerator cabinet, and an insulating unit disposed between the outer and inner surfaces of the refrigerator cabinet, and the insulating unit may include a polyurethane foam layer, and a vacuum insulation material having the aforementioned features.
That is, the polyurethane foam layer and the vacuum insulation material may be laminated sequentially between the inner surface and the outer surface of the refrigerator cabinet. The vacuum insulation material may include a core material, and a wrapping member to cover the core material. The wrapping member may include an outermost layer, a barrier layer laminated beneath the outermost layer, and a thermal bonding layer located beneath the barrier layer and contacting the core material. The barrier layer may include at least one polyimide film, on which an inorganic layer is laminated. Also, the inorganic layer may be a laminated aluminum foil. The inorganic layer may be configured by laminating aluminum on the polyimide film through vacuum-Al metalizing. In addition, the barrier layer may include at least one polyimide film having a laminated aluminum foil and at least one polyimide film having a vacuum-metlized aluminum. This configuration will be understood by the foregoing description, so detailed description will be omitted.
With the configuration, a vacuum insulation material, which includes a wrapping member having excellent thermal endurance so as to be usable at high temperature, can be applied to an insulation structure of a refrigerator cabinet. Consequently, the refrigerator cabinet can exhibit excellent insulation efficiency and reliable insulation performance.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.

Claims

1. A vacuum insulation material comprising: a core material; and a wrapping member configured to cover the core material, the wrapping member comprising an outermost layer externally exposed, a barrier layer laminated beneath the outermost layer, and a thermal bonding layer disposed beneath the barrier layer and contacting the core material, wherein the barrier layer comprises at least one polyimide film, on which an inorganic layer is laminated.

2. The material of claim 1, wherein the inorganic layer is a laminated aluminum foil.

3. The material of claim 1, wherein the inorganic layer is that aluminum is laminated on the polyimide film through vacuum-Al metalizing.

4. The material of claim 1, wherein the barrier layer comprises at least one polyimide film having a laminated aluminum foil, and at least one polyimide film having a vacuum-metalized aluminum.

5. An insulation structure for a refrigerator cabinet comprising: an outer surface and an inner surface of the refrigerator main body; and an insulating unit formed between the outer and inner surfaces of the refrigerator cabinet, wherein the insulating unit comprises a polyurethane foam layer, and a vacuum insulation material according to claim 1.

6. An insulation structure for a refrigerator cabinet comprising: an outer surface and an inner surface of the refrigerator main body; and an insulating unit formed between the outer and inner surfaces of the refrigerator cabinet, wherein the insulating unit comprises a polyurethane foam layer, and a vacuum insulation material according to claim 2.

7. An insulation structure for a refrigerator cabinet comprising: an outer surface and an inner surface of the refrigerator main body; and an insulating unit formed between the outer and inner surfaces of the refrigerator cabinet, wherein the insulating unit comprises a polyurethane foam layer, and a vacuum insulation material according to claim 3.

8. An insulation structure for a refrigerator cabinet comprising: an outer surface and an inner surface of the refrigerator main body; and an insulating unit formed between the outer and inner surfaces of the refrigerator cabinet, wherein the insulating unit comprises a polyurethane foam layer, and a vacuum insulation material according to claim 4.