KR20230036630A - Vacuum insulator and method of manufacturing the same - Google Patents

Abstract

Disclosed are a vacuum insulator and a manufacturing method thereof. The disclosed vacuum insulator comprises: an outer skin material defining an inner space; a core material filling the inner space of the outer skin material; and an absorption material disposed in the inner space of the outer skin material together with the core material. The core material may include a multilayer structure in which a plurality of unit sheets are stacked. Each of the unit sheets may include glass fibers. The multilayer structure may include 10 or more unit sheets. The inner space of the outer skin material in which the core material and the absorption material are disposed may be in a vacuum state. The weight per unit area of the glass fibers in each of the unit sheets may be less than 100 g/m^2. The weight per unit area of the glass fiber in each of the unit sheets may be about 50-70 g/m^. The average diameter of the glass fibers may be about 13 μm or less. Therefore, the vacuum insulator can have low thermal conductivity of a predetermined level or lower and excellent insulation performance.

Description

Vacuum insulator and method of manufacturing the same {Vacuum insulator and method of manufacturing the same}

The present invention relates to a heat insulating material and a manufacturing method thereof, and more particularly, to a vacuum insulating material and a manufacturing method thereof.

Demand for energy conservation and environmental protection is increasing worldwide, and regulations and systems are being strengthened in this regard. In relation to energy saving, improvement of insulation performance is required in order to reduce heat loss in various products, structures or buildings.

In the case of existing heat insulating materials, the thickness must be increased in order to increase the heat insulating performance. In this case, the thickness of the heat insulating layer of the product or structure increases, causing problems in terms of space efficiency and the like. For example, conventional insulation materials such as polyurethane have a thermal conductivity of about 20 mW/(m·K), and when this is used, the outer wall of the refrigerator becomes thicker, reducing the storage capacity of the refrigerator, that is, the internal volume. will do Therefore, in order to solve this problem, the use of a high-efficiency insulator capable of exhibiting excellent thermal insulation performance even with a relatively thin thickness is required.

The vacuum insulator is a high-efficiency insulator, and by minimizing the convection effect of air using a vacuum state, excellent insulation performance can be implemented even with a relatively thin thickness. Vacuum insulators have about 5 to 10 times better insulation performance than conventional insulators, and when applied to home appliances, energy savings of about 20% to 30% are possible. Energy savings of up to 50% or more can be achieved. In addition, since the thickness of the heat insulation layer can be reduced due to high efficiency as well as energy saving, there is an advantage in that the usable space increases.

In recent years, as energy standards in each country have been strengthened, the demand for improving the performance of vacuum insulators has also increased. Accordingly, research and development for lowering the initial thermal conductivity of the vacuum insulator to a predetermined level, for example, about 1.5 mW/mk or less and further improving the insulation performance are required. In addition, there is a need to secure a vacuum insulator that can reduce the manufacturing cost of the vacuum insulator and can easily adjust the thickness according to the application and its manufacturing process.

A technical problem to be achieved by the present invention is to provide a vacuum insulator having a low thermal conductivity of a predetermined level or less and excellent thermal insulation performance, and a manufacturing method thereof.

In addition, a technical problem to be achieved by the present invention is to provide a vacuum insulator and a method for manufacturing the same, which are easy to manufacture, can reduce manufacturing costs, and can easily adjust the thickness according to the application.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to embodiments of the present invention for achieving the above object, the outer shell material defining the inner space; a core material filled in the inner space of the shell material; and an absorbent disposed in the inner space of the shell material together with the core material, wherein the core material includes a multilayer structure in which a plurality of unit sheets are stacked, and each of the unit sheets is configured to include glass fibers, , The multi-layered structure includes 10 or more unit sheets, and the inner space of the shell material in which the core material and the absorbent material are disposed has a vacuum state.

A weight per unit area of the glass fibers in each of the unit sheets may be less than about 100 g/m ² .

A weight per unit area of the glass fiber in each of the unit sheets may be about 10 g/m ² to about 70 g/m ² .

An average diameter of the glass fibers may be about 13 μm or less.

An average diameter of the glass fibers may be about 6 μm or more.

The average length of the glass fibers may be about 1 to 50 mm.

The unit sheet may have a thickness of about 5 mm or less.

The vacuum insulator may have a thermal conductivity of about 1.5 mW/(m·K) or less.

The envelope material may include a multi-film structure, and the multi-film structure is sequentially stacked L-LDPE (linear low density polyethylene) layer or CPP (cast polypropylene) layer / Al layer or VM-EVOH (vacuum metallized ethylene vinyl) -alcohol copolymer) layer / nylon layer and VM-PET (vacuum metalized polyethylene terephthalate) layer may be included.

The adsorbent may include a moisture absorbent and a gas absorbent.

According to other embodiments of the present invention, providing the shell material, the core material and the absorbent material defining the inner space, respectively; disposing the core material and the absorbent material in the inner space of the shell material; and making an internal space of the shell material in which the core material and the absorbent material are disposed in a vacuum state, wherein the preparing of the core material comprises forming a plurality of unit sheets including glass fibers; and forming a multilayer structure by laminating the plurality of unit sheets and pressing them, wherein the multilayer structure includes 10 or more unit sheets.

Forming the multi-layer structure may include performing a thermal compression bonding process on the laminate in which the plurality of unit sheets are stacked.

The forming of the multilayer structure may include performing a needling process on the laminate in which the plurality of unit sheets are stacked, and performing a thermal compression bonding process on the laminate.

The needling process may be performed on a partial thickness of the laminate from one side of the laminate.

A weight per unit area of the glass fibers in each of the unit sheets may be less than about 100 g/m ² .

A weight per unit area of the glass fiber in each of the unit sheets may be about 50 g/m ² to about 70 g/m ² .

An average diameter of the glass fibers may be about 13 μm or less.

The average length of the glass fibers may be about 1 to 50 mm.

In the vacuum insulator, the unit sheet may have a thickness of about 5 mm or less.

The vacuum insulator may have a thermal conductivity of about 1.5 mW/(m·K) or less.

According to other embodiments of the present invention, the outer shell material defining the inner space; a core material filled in the inner space of the shell material; and an absorbent disposed in the inner space of the shell material together with the core material, wherein the core material includes a multilayer structure in which a plurality of unit sheets are stacked, and each of the unit sheets is configured to include glass fibers, , The glass fiber contains Na ₂ O, the total content of the Na ₂ O in the glass fiber is 0.3 wt% or less, and the inner space of the outer shell in which the core material and the adsorbent are disposed is a vacuum insulator having a vacuum state is provided.

The multilayer structure may include 10 or more unit sheets.

A weight per unit area of the glass fibers in each of the unit sheets may be less than about 100 g/m ² .

A weight per unit area of the glass fiber in each of the unit sheets may be about 50 g/m ² to about 70 g/m ² .

An average diameter of the glass fibers may be about 13 μm or less.

An average diameter of the glass fibers may be about 6 μm or more.

An average length of the glass fibers may be about 1 mm to about 50 mm.

The unit sheet may have a thickness of about 5 mm or less.

The vacuum insulator may have a thermal conductivity of about 1.5 mW/(m·K) or less.

The envelope material may include a multi-film structure, and the multi-film structure is sequentially stacked L-LDPE (linear low density polyethylene) layer or CPP (cast polypropylene) layer / Al layer or VM-EVOH (vacuum metallized ethylene vinyl) -alcohol copolymer) layer / nylon layer and VM-PET (vacuum metalized polyethylene terephthalate) layer may be included.

The adsorbent may include a moisture absorbent and a gas absorbent.

According to embodiments of the present invention, a vacuum insulator having a low thermal conductivity of a predetermined level or less and excellent thermal insulation performance may be implemented. For example, according to an embodiment of the present invention, a vacuum insulator having a thermal conductivity (initial thermal conductivity) of about 1.5 mW/(m·K) or less and correspondingly excellent thermal insulation performance may be implemented. When using such a vacuum insulator, it is possible to improve energy efficiency by reducing heat loss while reducing the thickness of the insulating layer.

In addition, according to the embodiments of the present invention, it is possible to implement a vacuum insulator that is easy to manufacture, can reduce manufacturing cost, is easy to adjust the thickness according to the application, and has an excellent surface condition of the core material and a method for manufacturing the same. there is.

In addition, according to embodiments of the present invention, it is possible to provide an eco-friendly vacuum insulator and a manufacturing method capable of minimizing environmental pollution by utilizing glass fibers harmless to the human body.

1 is a cross-sectional view for explaining a vacuum insulator according to an embodiment of the present invention.
2 is a cross-sectional view for explaining the configuration of a core material that can be applied to a vacuum insulator according to an embodiment of the present invention.
3 is a cross-sectional view for explaining the configuration of a core material applied to a vacuum insulator in a comparative example.
4 is an image showing a microstructure of glass fibers included in a core material applied to a vacuum insulator according to an embodiment of the present invention.
5A and 5B are cross-sectional views illustrating a process of forming a core material applied to a vacuum insulator according to an embodiment of the present invention.
6A to 6D are views for explaining a process of forming a core material applied to a vacuum insulator according to an embodiment of the present invention.
7 is a view for explaining a method of forming a core material applied to a vacuum insulator according to another embodiment of the present invention.
8 is a cross-sectional view showing the configuration of a shell material applicable to a vacuum insulator according to an embodiment of the present invention.
9 is a cross-sectional view showing a modified form of a vacuum insulator according to an embodiment of the present invention.
10 is a perspective view exemplarily showing the overall shape of a vacuum insulator according to an embodiment of the present invention.
11 is a photographic image exemplarily showing a vacuum insulator manufactured according to an embodiment of the present invention.
12 to 16 are photographic images showing various structures that a vacuum insulator according to an embodiment of the present invention may have.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Embodiments of the present invention to be described below are provided to more clearly explain the present invention to those skilled in the art, and the scope of the present invention is not limited by the following examples, Embodiments may be modified in many different forms.

Terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. Terms in the singular form used herein may include plural forms unless the context clearly indicates otherwise. Also, as used herein, the terms "comprise" and/or "comprising" specify the presence of the stated shape, step, number, operation, member, element, and/or group thereof. and does not exclude the presence or addition of one or more other shapes, steps, numbers, operations, elements, elements and/or groups thereof. In addition, the term “connection” used in this specification means not only direct connection of certain members, but also a concept including indirect connection by intervening other members between the members.

In addition, when a member is said to be located “on” another member in the present specification, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members. As used herein, the term “and/or” includes any one and all combinations of one or more of the listed items. In addition, terms of degree such as "about" and "substantially" used in the present specification are used in a range of values or degrees or meanings close thereto, taking into account inherent manufacturing and material tolerances, and are used to help the understanding of the present application. Exact or absolute figures provided for this purpose are used to prevent undue exploitation by infringers of the stated disclosure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The size or thickness of areas or parts shown in the accompanying drawings may be slightly exaggerated for clarity of the specification and convenience of description. Like reference numbers indicate like elements throughout the detailed description.

1 is a cross-sectional view for explaining a vacuum insulator 200 according to an embodiment of the present invention.

Referring to FIG. 1, the vacuum insulator 200 according to an embodiment of the present invention includes an outer shell 100 defining an inner space SP1 (ie, an accommodation space), and an inner space SP1 of the outer shell 100. It may include a core material 150 filled in the core material 150 and an absorbent material 170 disposed in the inner space SP1 of the shell material 100 together with the core material 150 .

The outer covering material 100 may include a first outer covering material 110 and a second outer covering material 120 facing the first outer covering material 110 . Edges of the first envelope 110 and the second envelope 120 may be joined, and an internal space SP1 may be defined between the first envelope 110 and the second envelope 120. there is. In FIG. 1 , a portion indicated by reference number E10 represents an edge portion where the first envelope material 110 and the second envelope material 120 are joined, that is, 'wings'. The wing portion E10 may be referred to as a kind of extension or expansion portion. A specific configuration that the envelope 100 may have will be described in more detail later with reference to FIG. 8 .

The core material 150 may include an inorganic material having a high porosity, for example, a porosity of 50% or more or 70% or more (porosity measured by mercury porosimetry) based on the total volume of the core material 150 . The inorganic material may include glass fibers and may have a porous structure in which pores are defined between adjacent glass fibers. A specific configuration that the core material 150 may have will be described in more detail with reference to FIG. 2 below.

The absorbent 170 may be a member for adsorbing moisture and/or gas. Although only one absorbent 170 is shown in FIG. 1 for convenience, in practice, the absorbent 170 may include a moisture absorbent and a gas absorbent provided separately therefrom. One or more moisture absorbents and one or more air absorbing agents may be disposed in the inner space SP1 of the cover material 100 .

The moisture absorbent may include, for example, calcium oxide, and may further include a metal oxide together with the calcium oxide. The absorbent may have a thin pack or pouch form. However, the material and form of the absorbent are not limited to the above and may be variously changed.

The intake agent may serve to adsorb gases such as oxygen, nitrogen, and carbon dioxide (CO ₂ ). The intake agent may include, for example, a metal oxide such as silver (Ag) oxide or copper (Cu) oxide, and a small amount of calcium oxide and a metal such as cobalt (Co) together with the metal oxide , barium (Ba), or lithium (Li) may be further included. The intake may have a coin shape. However, the material and shape of the air intake is not limited to the above and may be variously changed.

In addition, the position of the absorbent 170 shown in FIG. 1 is only exemplary, and the position may be variously changed. At least one of the moisture absorbent and the air intake may be disposed in a predetermined area, such as the middle of the inner space SP1, spaced apart from the first envelope material 110 and the second envelope material 120. By providing the moisture absorbent and/or the air intake, moisture and gas in the inner space SP1 can be easily removed, and as a result, the insulation performance of the vacuum insulator 200 can be improved.

The inner space SP1 of the shell material 100 in which the core material 150 and the absorbent material 170 are disposed may have a vacuum state. The interior space SP1 may be made into a vacuum state by substantially removing air in pores defined between the interior space SP1 and the core material and between the glass fibers constituting the core material. The degree of vacuum in the inner space SP1 may be reduced to, for example, about 10 Pa or less compared to atmospheric pressure of about 10 ⁵ Pa. By minimizing the convection effect of air using a vacuum state, excellent insulation performance can be implemented even with a thin thickness. The vacuum insulator 200 according to the embodiment of the present invention may have excellent insulation performance (low thermal conductivity) that is about 12 times or more than that of a conventional polyurethane foam insulator. In addition, when comparing the thickness required to implement the same insulation performance, the conventional polyurethane foam requires a thickness of about 125 mm, whereas the vacuum insulator 200 according to an embodiment of the present invention has a thickness of about 10 mm or less. of thickness may be required. The vacuum insulation material 200 described in FIG. 1 may be a vacuum insulation panel (VIP). However, in some cases, the vacuum insulator 200 may have a shape other than a panel shape.

2 is a cross-sectional view for explaining the configuration of a core material that can be applied to a vacuum insulator according to an embodiment of the present invention.

Referring to FIG. 2 , a core material applied to a vacuum insulator according to an embodiment of the present invention may include a multilayer structure MS11 in which a plurality of unit sheets S11 are stacked. The multilayer structure MS11 may be a kind of 'glass fiber board'. Here, each of the unit sheets S11 may be configured to include glass fibers. In each of the unit sheets S11, the basis weight or area density based on a single layer of the glass fiber is less than about 160 g/m ² , and more preferably less than 100 g/m ² there is. The areal density of the glass fibers in each unit sheet S11 may mean the total weight per unit area of the glass fibers when it is assumed that the unit sheet S11 is composed of a single layer of glass fibers. The low area density of the glass fibers in each unit sheet S11 may mean that the thickness of the unit sheet S11 is thin or that the diameter of the glass fibers used in the unit sheet S11 is small.

In one embodiment, the area density of the glass fibers in each unit sheet S11 may be, for example, about 10 to about 70 g/m ² . Also, the glass fibers may have an average diameter of about 13 μm or less. For example, the average diameter of the glass fibers may be greater than or equal to about 6 μm and less than or equal to about 13 μm. In the vacuum insulator, each unit sheet S11 may have a thickness of about 5 mm or less. In addition, the multilayer structure MS11 may include a large number of unit sheets S11, for example, about 10 or more unit sheets S11, preferably about 15 or more unit sheets S11. The number of unit sheets S11 constituting the multilayer structure MS11 may be about 10 or more and about 100 or less. As the number of stacked unit sheets S11 increases while maintaining the thickness of the entire core material constant, the thickness of each unit sheet S11 decreases.

In one embodiment, the horizontal arrangement characteristics of the glass fibers throughout the multi-layered structure MS11 in which 15 or more unit sheets are stacked may be greatly improved. Specifically, the glass fibers in each unit sheet (S11) have a randomly arranged nonwoven fabric characteristic, but in each unit sheet (S11) having an areal density of 50 to 70 g/m ² , the glass fibers are horizontally arranged rather than vertically arranged components. The arrangement component may be larger, and accordingly, the arrangement density of the glass fibers in the horizontal direction within the micro-thickness unit sheet S11 is maximized. As a result, the vertical connection of the glass fibers between the plurality of unit sheets S11 can be minimized. Since a large number of unit sheets S11 are stacked and the glass fibers are arranged in a substantially horizontal direction in each unit sheet S11, the connection between the glass fibers between two adjacent unit sheets S11 is a point ) contact, and the continuity of the connection in the vertical direction can be minimized or effectively suppressed. Accordingly, conduction of heat through the glass fibers can be mainly performed in a horizontal direction along the plane of the unit sheet S11, and conduction of heat between the unit sheets S11 in a vertical direction can be effectively blocked. As a result, the vacuum insulator according to the embodiment of the present invention not only blocks thermal shear due to radiation by vacuum, but also thermal shear between unit sheets S11, so that the heat between the two main surfaces facing each other of the vacuum insulator is blocked. Conduction is suppressed, and very excellent thermal insulation performance can be obtained. For example, the vacuum insulator according to an embodiment of the present invention may have a very low thermal conductivity (initial thermal conductivity) of about 1.5 mW/(m·K) or less. However, the limiting thermal conductivity of the vacuum insulator may be greater than about 0.5 mW/(m·K), for example.

The weight per unit area of the glass fibers in each unit sheet S11 is less than about 100 g/m ² , for example, about 50 g/m ² to about 70 g/m ² , and the average diameter of the glass fibers is about 13 μm. Hereinafter, for example, in the case of about 6 μm to about 13 μm, it may be advantageous to improve the horizontal arrangement characteristics of the glass fibers in each unit sheet S11 in the multilayer structure MS11 and to minimize the heat transfer path. In particular, when the weight per unit area of the glass fibers in each unit sheet S11 is controlled to about 50 g/m ² to 70 g/m ² and the number of stacked unit sheets S11 is increased, arrangement in the horizontal direction Directivity and arrangement density can be improved, and when a glass fiber having a low diameter of about 13 μm or less or about 8.5 μm or less is used, an effect of minimizing a heat transfer path can be obtained. When the weight per unit area of the glass fibers in each unit sheet S11 is 100 g/m ² or more or the average diameter of the glass fibers is greater than 13 μm, the unit sheet S11 has a thick thickness and can be used. Since the number of sheets S11 decreases and the vertical arrangement of glass fibers in each unit sheet S11 can be increased (heat transfer is proportional to the diameter and inversely proportional to the length, accordingly, as the diameter increases, the cross-section of the glass fibers decreases). Because of the large amount of heat transferred through the material), it may be difficult to secure a low thermal conductivity. On the other hand, when the weight per unit area of the glass fibers in each unit sheet S11 is less than about 50 g/m ² or the average diameter of the glass fibers is less than about 6 μm, the thickness of the unit sheet S11 is too large. It may be difficult to manufacture the unit sheet S11 itself due to thinness or low strength. Therefore, according to an embodiment of the present invention, the unit area weight of the glass fibers in each unit sheet S11 is about 50 to 100 g/m ² or about 50 g/m ² to 70 g/m ² , and the The average diameter of the glass fibers may be about 6 to 13 μm, preferably about 6 to 8.5 μm.

Meanwhile, the average length of the glass fibers may be about 1 to 50 mm. The glass fiber used in the embodiment of the present invention may be a type of long fiber. The glass fiber may be 'chopped glass fiber'. In this case, the horizontal arrangement characteristics of the glass fibers in each unit sheet S11 may be further improved. Therefore, it may be more advantageous to lower the thermal conductivity (initial thermal conductivity) of the vacuum insulator according to the embodiment to about 1.5 mW/(m·K) or less.

In the vacuum insulator according to an embodiment of the present invention, the thickness of the multilayer structure MS11 compressed by vacuum may be about 0.5 cm to about 5 cm, for example, about 0.8 cm to about 1 cm. However, this thickness range is only exemplary, and the appropriate thickness of the multi-layer structure MS11 may be variously changed according to the application of the vacuum insulator.

Additionally, according to an embodiment of the present invention, the unit sheet S11 may be composed of only glass fibers or may be composed of glass fibers as a main component, and in some cases, silica powder (with glass fibers) It may have a structure including porous powder or organic materials such as silica powder) and organic fibers (PP, PET fibers).

3 is a cross-sectional view for explaining the configuration of a core material applied to a vacuum insulator in a comparative example.

Referring to FIG. 3 , the core material applied to the vacuum insulator according to the comparative example may include a multilayer structure (MS22) in which a plurality of unit sheets (S22) are stacked. Here, each of the unit sheets S22 may be configured to include glass fibers. A weight per unit area of the glass fiber in each unit sheet S22, that is, an areal density, may be about 100 g/m ² to about 145 g/m ² . In addition, the average diameter of the glass fibers may be about 13 μm to 12 μm. In addition, the number of unit sheets S22 constituting the multi-layer structure MS22 is the total thickness of the multi-layer structure MS22 of the comparative example compared to the multi-layer structure MS11 according to the embodiment described in FIG. 2. When based on the same case as the total thickness. may be half or close to half

As in the comparative example of FIG. 3, the weight per unit area of the glass fibers in each unit sheet S22 is about 100 g/m ² to about 145 g/m ² , and the average diameter of the glass fibers is about 13 to 12 μm. , and when the number of unit sheets (S22) stacked is relatively small, the thermal conductivity (initial thermal conductivity) of the vacuum insulator according to the comparative example including the multilayer structure (MS22) to which the unit sheets (S22) are applied is about 1.75 mW/(m). . Therefore, the vacuum insulator according to the embodiment to which the multi-layer structure (MS11) shown in FIG. 2 is applied can exhibit significantly improved insulation performance compared to the vacuum insulator according to the comparative example to which the multi-layer structure (MS22) shown in FIG. 3 is applied.

4 is an image showing a microstructure of glass fibers included in a core material applied to a vacuum insulator according to an embodiment of the present invention.

Referring to FIG. 4, the glass fibers included in the core material applied to the vacuum insulator according to an embodiment of the present invention have a horizontal direction substantially parallel to the main surface of the multi-layer structure within the unit sheet, even throughout the multi-layer structure in which the unit sheets are laminated. Arrayed to form a network structure. The glass fiber may have a fiber structure similar to a kind of non-woven fabric. However, the microstructure of the glass fiber shown in FIG. 4 is only exemplary and may be variously changed.

A method of manufacturing a vacuum insulator according to an embodiment of the present invention includes providing an outer shell material, a core material, and an absorbent material defining an inner space, disposing the core material and the absorbent material in the inner space of the outer shell material, and the core material and A step of making the inner space of the outer shell in which the absorbent is disposed in a vacuum state may be included. The outer cover material may be formed to have the above-described inner space between them by arranging the first outer cover material and the second outer cover material having a corresponding shape so as to face each other, and bonding the edges thereof by a thermal fusion method. Some of the edge portions of the first envelope material and the second envelope material may be left in an unbonded state and used as an opening (entrance) accessible to the internal space from the outside. Through the opening, the core material and the absorbent material may be disposed in the inner space defined by the shell material. Thereafter, air in the inner space may be removed through the opening by an adsorption method to create a vacuum state, and the opening may be sealed by a thermal fusion method. Here, the core material and the absorbent material may correspond to the core material 150 and the absorbent material 170 described with reference to FIGS. 1 and 2 . However, the specific method of manufacturing the vacuum insulator described above is exemplary and known techniques in the art may be referred to.

In the manufacturing method of the vacuum insulator according to the embodiment, the step of preparing the core material is the step of forming a plurality of unit sheets containing glass fibers and laminating the plurality of unit sheets and hot pressing them to form a multilayer structure A weight per unit area of the glass fibers in each of the unit sheets may be less than about 100 g/m ² .

5A and 5B are cross-sectional views illustrating a process of forming a core material applied to a vacuum insulator according to an embodiment of the present invention.

Referring to FIG. 5A , preparing a core material may include forming a plurality of unit sheets S10 including glass fibers.

Referring to FIG. 5B , preparing the core material may include forming a multilayer structure MS10 by stacking a plurality of unit sheets S10 and compressing them.

A multi-layered structure (MS10) as shown in FIG. 5B may be put into the inner space of the shell material together with the adsorbent, and the inner space may be vacuumed. As the inner space is made into a vacuum state, the multilayer structure MS10 may be further compressed in its thickness direction. The 'multi-layer structure' of the core material disposed inside the vacuum insulator manufactured in this way may correspond to the multi-layer structure MS11 described with reference to FIG. 2 .

The weight per unit area of the glass fibers in each unit sheet S10 may be less than about 100 g/m ² , for example, about 50 g/m ² to about 70 g/m ² . The glass fibers may have an average diameter of about 13 μm or less, for example, about 6 μm to about 13 μm. An average length of the glass fibers may be about 1 mm to about 50 mm. The multilayer structure MS10 may include 15 or more unit sheets S10. After manufacturing the vacuum insulator, the thickness of the unit sheet (ie, corresponding to S11 in FIG. 2 ) in a state included in the vacuum insulator may be about 5 mm or less. These conditions and technical effects thereof may be the same as those described with reference to FIG. 2 . As a result, according to an embodiment of the present invention, a vacuum insulator with excellent performance having a very low thermal conductivity (initial thermal conductivity) of about 1.5 mW/(m·K) or less can be manufactured. When using such a vacuum insulator, it is possible to significantly improve energy efficiency by reducing heat loss while reducing the thickness of the insulating layer.

6A to 6D are views for explaining a process of forming a core material applied to a vacuum insulator according to an embodiment of the present invention.

Referring to Figure 6a, it shows a glass fiber that can be used for the manufacture of the core material. The glass fibers may have an average diameter of about 13 μm or less or about 8.5 μm or less. In addition, the average length of the glass fibers may be about 1 to 50 mm.

6B shows equipment (thinning equipment) for thinning the glass fiber. By using this equipment, the glass fibers are dispersed on the surface of the roller to form a unit sheet formed by randomly arranging the glass fibers mainly in a horizontal direction. The unit sheet may have a predetermined thickness. A weight per unit area of the glass fibers in each of the unit sheets may be less than about 100 g/m ² , for example, about 50 to about 70 g/m ² . The unit sheet may be manufactured, for example, in a manner similar to that of nonwoven fabric. In this way, a plurality of unit sheets can be manufactured.

Referring to FIG. 6C , one laminate may be formed by stacking a plurality of unit sheets. This laminate is designated by the reference number MS10a.

Referring to FIG. 6D , a multilayer structure in which the plurality of unit sheets are compressed (bonded) may be formed by performing a thermal compression bonding process on the laminate MS10a in which the plurality of unit sheets are stacked. At this time, a predetermined thermocompression bonding equipment HP1 may be used. The thermocompression bonding equipment HP1 may include a hot press. In the thermocompression bonding process, the thermocompression temperature may be, for example, about 600° C. or higher. In the thermocompression bonding process, the laminate MS10a may be heated to, for example, about 500 °C to 750 °C. In this way, a multilayer structure MS10 as shown in FIG. 5B may be formed.

In some cases, a preliminary bonding step of performing a needling process on the multilayer body MS10a in which a plurality of unit sheets are stacked may be further included before performing the thermocompression bonding process. In other words, the step of forming the multilayer structure includes performing a needling process on the laminate MS10a in which a plurality of unit sheets are stacked, and performing a thermal compression bonding process on the laminate MS10a. steps may be included. The above needling process is exemplarily shown in FIG. 7 .

Referring to FIG. 7 , after disposing a needle mat NM1 including a plurality of needles N10 on a laminate MS10a in which a plurality of unit sheets are stacked, the needle mat NM1 is moved up and down. A needling process of moving and piercing the multilayer body MS10a with a plurality of needles N10 may be performed. An end of the needle N10 may have a structure bent in a predetermined shape. Accordingly, temporary joining is induced by bridging between adjacent unit sheets.

In one embodiment, the needling process is performed only for a partial thickness of the laminate MS10a from one side (upper surface in the drawing) of the laminate MS10a, or the horizontal orientation component of the glass fibers is greater than the vertical orientation component. It can be performed for a limited amount of time and frequency at a largely sustained level.

The needling process for a partial thickness means that the needle is not passed through the laminate MS10a in the thickness direction, and is performed only for a partial thickness of one surface portion (upper surface portion in the drawing) of the laminate MS10a. do. Performing this needling process for some thickness minimizes the orientation of the glass fibers in the thickness direction of the laminate, which induces bridging, so that the thermal conductivity between the principal surfaces facing each other is glass fibers having a vertical component mainly for bridging. It is to reduce what is increased by Through this needling process, a state in which a plurality of unit sheets are temporarily bonded to a certain extent may be formed while the glass fibers are woven in a vertical direction in a portion of the multilayer body MS10a. After performing such a needling process, a multilayer structure may be formed by performing a thermocompression bonding process as described in FIG. 6D. However, the needling process described in FIG. 7 is exemplary and may be optional.

According to an embodiment of the present invention, it is possible to easily form a core material having excellent horizontal arrangement characteristics of glass fibers and excellent surface conditions. In addition, by adjusting the number of stacked unit sheets, it is very easy to control the thickness of the core material according to the application. In addition, the manufacturing method of the vacuum insulator according to the embodiment has excellent workability and may be advantageous in reducing manufacturing cost.

8 is a cross-sectional view showing the configuration of a shell material applicable to a vacuum insulator according to an embodiment of the present invention.

Referring to FIG. 8 , an envelope material applicable to a vacuum insulator according to an embodiment of the present invention may include a multi-film structure. The multi-film structure, for example, L-LDPE (linear low density polyethylene) layer 10 or CPP (cast polypropylene) layer 10 / Al layer 20 or VM- A vacuum metallized ethylene vinyl-alcohol copolymer (EVOH) layer 20 / a nylon layer 30 and a vacuum metallized polyethylene terephthalate (VM-PET) layer 40 may be included. The Al layer 20 may be a kind of Al foil. In the multi-film structure, L-LDPE serves as an adhesive layer and is bonded by thermal fusion or ultrasonic fusion.

This multi-film structure may be applied to both the first envelope 110 and the second envelope 120 of FIG. 1 . The outer cover material having such a structure may serve to protect the core material and the adsorbent material while effectively blocking the permeation of gas and moisture. However, the configuration of the cover material described with reference to FIG. 8 is exemplary, and may be variously changed depending on the case.

9 is a cross-sectional view showing a modified form of a vacuum insulator 200 according to an embodiment of the present invention. FIG. 9 shows a form in which the wing portion E10 is folded and attached to the body portion of the vacuum insulator 200 in the structure of FIG. 1 . The wing part E10 may be attached to face the lower surface or the upper surface of the body. When attaching the wings E10, a predetermined adhesive member such as an adhesive tape may be used. By folding and attaching the wings E10, the vacuum insulator 200 may have a rectangular panel or a substantially hexahedron shape or a chamfered polyhedron with a portion of the corner cut off.

10 is a perspective view exemplarily showing the overall shape of a vacuum insulator 200 according to an embodiment of the present invention. As shown in FIG. 10 , the vacuum insulator 200 according to an embodiment of the present invention may have a rectangular panel or a substantially hexahedral shape. The structure of the vacuum insulator 200 of FIG. 10 may correspond to the case where the wings E10 are folded and attached to the body, as shown in FIG. 9 .

11 is a photographic image exemplarily showing a vacuum insulator manufactured according to an embodiment of the present invention. The vacuum insulator of FIG. 11 may have a structure corresponding to the vacuum insulator 200 of FIG. 10 .

However, the structure of the vacuum insulator according to the embodiment of the present invention is not limited to a flat plate structure and may be variously changed.

12 to 16 are photographic images showing various structures that a vacuum insulator according to an embodiment of the present invention may have.

12 shows a vacuum insulator with a flat structure, FIG. 13 shows a vacuum insulator with a dent structure having a recessed area, and FIG. 14 shows a vacuum insulator with a bending structure, 15 shows a vacuum insulator having a curved structure (ie, a curved structure), and FIG. 16 shows a vacuum insulator having a structure in which holes are formed. In addition, the vacuum insulator may have various deformable structures such as a cutting type, a slim type, a cylinder type, and a round type.

Vacuum insulators according to embodiments of the present invention can be usefully applied to various fields such as home appliances, industrial use, and construction use. For example, in the case of home appliances, it can be applied to various home appliances such as general refrigerators, kimchi refrigerators, water purifiers, and electric rice cookers. In the case of industrial use, it can be applied to refrigerated warehouses, refrigerated/refrigerated vehicles, refrigerated containers, and vending machines. In the case of construction, it can be applied to the interior/exterior insulation of buildings, front doors/fire doors, etc. In addition, it can be used as an insulator surrounding a fuel tank of a liquefied natural gas (LNG) fuel ship or an LNG storage tank, and the vacuum insulator according to an embodiment of the present invention can be applied to all fields to which the insulator is applied.

According to the embodiments of the present invention as described above, it is possible to implement a vacuum insulator having low thermal conductivity of a predetermined level or less and excellent thermal insulation performance. For example, according to an embodiment of the present invention, a vacuum insulator having a thermal conductivity (initial thermal conductivity) of about 1.5 mW/(m·K) or less and correspondingly excellent thermal insulation performance may be implemented. When using such a vacuum insulator, it is possible to improve energy efficiency by reducing heat loss while reducing the thickness of the insulating layer. In addition, according to the embodiments of the present invention, it is possible to implement a vacuum insulator that is easy to manufacture, can reduce manufacturing cost, is easy to adjust the thickness according to the use, and has an excellent surface condition of the core material and a manufacturing method thereof. In addition, according to embodiments of the present invention, it is possible to provide an eco-friendly vacuum insulator and a manufacturing method capable of minimizing environmental pollution by utilizing glass fibers harmless to the human body.

Additionally, the glass fibers applied to the vacuum insulator according to the embodiments described above may include SiO ₂ , Al ₂ O ₃ , and CaO as main components, and Na ₂ O of K ₂ O as a minor component. In the glass fiber, control of the total content ratio of K ₂ O and Na ₂ O is required to maintain thermal insulation performance, and the total content may be about 1.5 wt% or less. In the glass fiber, the content of K ₂ O may be, for example, about 0.2 to 1 wt%, and the content of Na ₂ O may be, for example, about 0.05 to 0.8 wt%. For example, in the glass fiber, the content of K ₂ O may be, for example, about 0.31 wt%, and the content of Na ₂ O may be, for example, about 0.28 wt%. For example, the content of K ₂ O may be about 0.71 wt%, and the content of Na ₂ O may be, for example, about 0.32 wt%. The content of K ₂ O may be about 0.096 wt%, and the content of Na ₂ O may be, for example, about 0.24 wt%. The K ₂ O content may be about 0.084 wt%, and the Na ₂ O content may be, for example, about 0.66 wt%.

A total amount of K ₂ O and Na ₂ O in the glass fiber may be about 0.25 wt% or more. When the total content of K ₂ O and Na ₂ O in the glass fiber exceeds about 1.5 wt%, the heat transfer rate and strength of the glass fiber may be difficult to apply to a multi-layer sheet, and it may not be easy to implement excellent thermal insulation performance. there is. Accordingly, the total amount of K ₂ O and Na ₂ O in the glass fiber may be about 1.5 wt% or less. Meanwhile, the glass fiber may further include additional metal oxides such as B ₂ O ₃ , MgO, and Fe ₂ O ₃ in addition to the K ₂ O and Na ₂ O.

In addition, the above-described vacuum insulator may be manufactured so that colors are identified according to differences in performance, and may be managed in a color identification method. For example, a vacuum insulator with a thermal conductivity of 1.5 mW/mk or less is black, a vacuum insulator with a thermal conductivity of 1.86 mW/mk or less is green, a vacuum insulator with a thermal conductivity of 2.3 mW/mk or less is yellow, and a vacuum insulator with a thermal conductivity of 2.9 mW/mk or less is colored yellow. A vacuum insulator having a thermal conductivity of mW/mk or less is red, and a vacuum insulator having a thermal conductivity of 4.0 mW/mk or less is an ivory color. Therefore, when disposing of a refrigerator or the like, the performance of the vacuum insulator applied thereto can be visually identified, and it can be easily recycled as a vacuum insulator for construction or other purposes.

In this specification, preferred embodiments of the present invention have been disclosed, and although specific terms have been used, they are only used in a general sense to easily explain the technical details of the present invention and help understanding of the present invention, and do not limit the scope of the present invention. It is not meant to be limiting. It is obvious to those skilled in the art that other modifications based on the technical idea of the present invention can be implemented in addition to the embodiments disclosed herein. For example, those skilled in the art will know that the vacuum insulator and its manufacturing method according to the embodiments described with reference to FIGS. 1 to 16 can be modified in various ways. Therefore, the scope of the invention should not be determined by the described embodiments, but by the technical idea described in the claims.

* Description of symbols for main parts of drawings *
100: outer covering material 110: first outer covering material
120: second outer cover material 150: core material
170: adsorbent 200: vacuum insulator
E10: wing part SP1: inner space
S10, S11: Unit sheet MS10, MS11: Multilayer structure
HP1 : Thermocompression equipment NM1 : Needle mat

Claims (21)

an outer covering material defining the inner space;
a core material filled in the inner space of the shell material; and
Including an absorbent disposed in the inner space of the shell material together with the core material,
The core material includes a multilayer structure in which a plurality of unit sheets are laminated, each of the unit sheets is configured to include glass fibers, and the multilayer structure includes 10 or more of the unit sheets,
The inner space of the shell material in which the core material and the absorbent material are disposed has a vacuum state. According to claim 1,
The weight per unit area of the glass fiber in each of the unit sheets is less than 100 g / m ² Vacuum insulator. According to claim 2,
A weight per unit area of the glass fiber in each of the unit sheets is 10 g/m ² to 70 g/m ² Vacuum insulator. According to claim 1,
The average diameter of the glass fiber is 13 ㎛ or less vacuum insulator. According to claim 4,
The average diameter of the glass fiber is 6 ㎛ or more vacuum insulator. According to claim 1,
The average length of the glass fiber is a vacuum insulator of 1 to 50 mm. According to claim 1,
A vacuum insulator having a thickness of the unit sheet of 5 mm or less. According to claim 1,
The vacuum insulator has a thermal conductivity of 1.5 mW / (m K) or less. According to claim 1,
The skin material includes a multi-film structure,
The multi-film structure is sequentially laminated L-LDPE (linear low density polyethylene) layer or CPP (cast polypropylene) layer / Al layer or VM-EVOH (vacuum metallized ethylene vinyl-alcohol copolymer) layer / nylon layer and VM-PET A vacuum insulator comprising a (vacuum metalized polyethylene terephthalate) layer. According to claim 1,
The absorbent is a vacuum insulator comprising a moisture absorbent and a gas absorbent. Providing an outer shell material, a core material, and an absorbent material defining an inner space, respectively;
disposing the core material and the absorbent material in the inner space of the shell material; and
Making the inner space of the shell material in which the core material and the absorbent material are disposed in a vacuum state,
The step of preparing the core material,
forming a plurality of unit sheets including glass fibers; and
Laminating the plurality of unit sheets and compressing them to form a multilayer structure,
The multi-layer structure is a method of manufacturing a vacuum insulator comprising 10 or more unit sheets. According to claim 11,
The forming of the multi-layer structure includes performing a thermal compression process on a laminate in which the plurality of unit sheets are stacked. According to claim 11,
The forming of the multi-layer structure may include performing a needling process on a laminate in which the plurality of unit sheets are stacked, and performing a thermal compression bonding process on the laminate. method. According to claim 13,
The needling process is a method of manufacturing a vacuum insulator performed on a partial thickness of the laminate from one side of the laminate. According to claim 11,
The weight per unit area of the glass fiber in each of the unit sheets is less than 100 g / m ² Method of manufacturing a vacuum insulator. According to claim 15,
The weight per unit area of the glass fiber in each of the unit sheets is 50 g / m ² to 70 g / m ² Manufacturing method of the vacuum insulator. According to claim 11,
The average diameter of the glass fiber is a method of manufacturing a vacuum insulator of 13 μm or less. According to claim 11,
The average length of the glass fiber is a method of manufacturing a vacuum insulator of 1 to 50 mm. According to claim 11,
The method of manufacturing a vacuum insulator in which the thickness of the unit sheet in the vacuum insulator is 5 mm or less. According to claim 11,
The method of manufacturing a vacuum insulator having a thermal conductivity of 1.5 mW / (m K) or less. an outer covering material defining the inner space;
a core material filled in the inner space of the shell material; and
Including an absorbent disposed in the inner space of the shell material together with the core material,
The core material includes a multilayer structure in which a plurality of unit sheets are stacked, each of the unit sheets is configured to include glass fibers, the glass fibers include K O and Na O, and in the glass fibers, the Na The total content of ₂ O is 1.5 wt% or less,
The inner space of the shell material in which the core material and the absorbent material are disposed has a vacuum state.

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