Vacuum insulation board, preparation method and heat insulation equipment

Abstract

The invention discloses a vacuum heat preservation plate, a preparation method and heat insulation equipment, and belongs to the technical field of vacuum heat preservation materials. The core material is coated with the protective film; wherein the core material comprises a plurality of pieces of laminated fiber cloth, the raw material of the fiber cloth comprises organic fiber, the organic fiber has a non-circular cross section, and the surface density of the fiber cloth is 2g / m < 2 >-150g / m < 2 >. Through the synergistic effect of the low intrinsic heat conductivity coefficient of the organic fibers, the non-circular cross section and the fiber cloth cover density, the core material of the vacuum heat preservation plate supported by a three-dimensional network architecture and capable of infinitely increasing a heat conduction path can be built, and then the heat conductivity coefficient of the vacuum heat preservation plate in application is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vacuum thermal insulation materials, and particularly relates to a vacuum thermal insulation board and a preparation method and a thermal insulation equipment. BACKGROUND

[0002] In a thermal insulation equipment requiring a refrigeration or freezing function, a thermal insulation material is generally required to be used. A vacuum thermal insulation board has good thermal insulation performance and is increasingly advantageous in thermal insulation applications such as refrigeration or freezing. The structure of the vacuum thermal insulation board generally comprises a main core material, a getter / desiccant, and an outer protective film. The core material is the core material of the vacuum thermal insulation board, and the material, structure, and composition of the core material have a great influence on the thermal conductivity of the vacuum thermal insulation board.

[0003] At present, the core material of the vacuum thermal insulation board commonly used in the market mainly includes particulate fumed silica and glass fibers. However, in the aspect of desiring a lower thermal conductivity of the vacuum thermal insulation board at the present stage, the use of fumed silica and glass fibers as the core material also faces the technical dilemma that the thermal conductivity cannot be further reduced. SUMMARY

[0004] The embodiments of the present application at least solve the technical problem of a high thermal conductivity of a vacuum thermal insulation board in application in the related art to some extent. To this end, the embodiments of the present application provide a vacuum thermal insulation board, a preparation method, and a thermal insulation equipment.

[0005] In a first aspect, the embodiments of the present application provide a vacuum thermal insulation board, which comprises:

[0006] a core material, and

[0007] a protective film, the protective film covering the core material.

[0008] The core material comprises a plurality of fiber cloths stacked together, the raw material of the fiber cloth comprises organic fibers, the organic fibers have a non-circular cross section, and the areal density of the fiber cloth is 2 g / m 2 ~ 150 g / m 2 .

[0009] According to the technical solution, in the embodiment of the present application, the organic fiber with a non-circular cross section is used as the core material of the vacuum insulation board. The organic fiber has a relatively complex molecular structure, and the heat propagation speed in the organic fiber is slow, so the intrinsic thermal conductivity is low. In addition, the organic fiber has a non-circular cross section, which can increase the physical spacing between the organic fibers, reduce the contact area between the organic fibers, change the heat conduction path, and further reduce the thermal conductivity. In addition, the surface density of the fiber cloth can further help the organic fiber to achieve a low thermal conductivity when the film is formed. Finally, through the synergistic effect of the low intrinsic thermal conductivity of the organic fiber, the non-circular cross section, and the surface density of the fiber cloth, the three-dimensional network architecture supporting the core material of the vacuum insulation board is constructed, and the thermal conductivity of the vacuum insulation board in application is reduced.

[0010] In some embodiments, the shape of the non-circular cross section is one of a triangle, a trilobal shape, a cross shape, a T shape, a Y shape, a crescent shape, a dumbbell shape, a pentagram shape, a fan shape, and a quinofolium shape.

[0011] In some embodiments, the organic fiber includes at least one of the following:

[0012] PET, polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol.

[0013] In some embodiments, the fiber diameter of the organic fiber is 0.5um-50um.

[0014] In some embodiments, preferably, the fiber diameter of the organic fiber is 3um-15um.

[0015] In some embodiments, the fiber length of the organic fiber is 0.5mm-250mm.

[0016] In some embodiments, preferably, the surface density is 5g / m 2 -100g / m 2 .

[0017] In a second aspect, the present application provides a preparation method of the vacuum insulation board of any one of the first aspect. The method comprises:

[0018] dispersing the organic fiber in a liquid to obtain an organic fiber suspension;

[0019] wet-laying and controlling the water of the organic fiber suspension, and then baking to obtain a fiber cloth;

[0020] stacking and heat-treating a plurality of the fiber cloths to obtain a core material;

[0021] packing the core material into the protective film to obtain a bagged board; and

[0022] performing vacuumizing treatment on the bagged board, and when the vacuum degree of the bagged board reaches a set vacuum degree, performing hot-pressing sealing on the bagged board to obtain a vacuum insulation board.

[0023] In some embodiments, the weight of the organic fiber is 0.01% to 0.1% of the total weight of the organic fiber suspension.

[0024] In some embodiments, the dispersion method comprises mechanical stirring and microwave heating.

[0025] In some embodiments, the water control time is 5 min to 30 min; and / or, the baking temperature is 100℃ to 240℃.

[0026] In some embodiments, the multiple boards are 100 to 500 boards.

[0027] In some embodiments, the heat treatment temperature is 130℃ to 200℃.

[0028] In some embodiments, the set vacuum degree is 1.0*10 -4 Pa to 4.0*10 -3 Pa.

[0029] In some embodiments, the process parameters of the hot-pressing sealing comprise: voltage of 9V to 15V, and time of 15s to 25s.

[0030] In a third aspect, an embodiment of the present application provides a heat insulation device, which comprises the vacuum insulation board of any one of the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings required to be used in the embodiments or the prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0033] Figure 1 A structural schematic diagram of a vacuum insulation board according to an embodiment of the present application is shown in the figure.

[0034] Figure 2A flowchart of a preparation method of a vacuum insulation board according to an embodiment of the present application is shown in the figure;

[0035] Reference signs:

[0036] 1-polyacrylonitrile core material; 2-protection film; 3-getter. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0038] Unless otherwise specifically indicated, the terms used in the present application are understood as the meanings commonly used in the art. Therefore, unless otherwise defined, all the technical and scientific terms used in the present application have the same meanings as generally understood by those skilled in the art to which the present application belongs. If there is a conflict, the present specification takes priority. The various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by the existing methods.

[0039] Various embodiments of the present application can exist in the form of a range; it should be understood that the description in the form of a range is only for the convenience and brevity, and should not be understood as a hard limit on the scope of the present application; therefore, it should be considered that the described range has specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the described range, such as 1, 2, 3, 4, 5 and 6, which applies to any range. In addition, whenever a numerical range is indicated in the present application, it refers to any cited number (fraction or integer) within the indicated range.

[0040] In this document, the terms "upper" and "lower" are used to denote the orientation of the figures in the drawings. In addition, the terms "including", "containing" and similar terms are used broadly and are intended to be used in their broad sense. Also, the terms "including", "containing" or any other similar term is intended to be inclusive of the process, method, article, or apparatus that comprises a series of steps, operations, elements, and / or components, and is therefore intended to be inclusive of variations of such process, method, article, or apparatus that encompass additional steps, operations, elements, and / or components. In the absence of more specific terminology, the use of the term "comprise" or "comprises" to describe the relationship between the elements of the process, method, article, or apparatus is intended to encompass the recited elements, as well as additional elements, without excluding the recited elements. In this document, the terms "first" and "second" are used to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between the entities or operations. In this document, the term "and / or" describes the relationship between associated objects, and means that there can be three relationships, for example, A and / or B means that A exists alone, A and B exist together, and B exists alone. For the relationship between three or more associated objects described by "and / or", it means that any one of the three associated objects exists alone, or any two of the three associated objects exist together, for example, for A, and / or B, and / or C, it means that any one of A, B, and C exists alone, or any two of A, B, and C exist together. In this document, "one or more" means one or more, and "multiple" means two or more. "At least one", "at least one of the following" or the like means any combination of the items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", means a, b, c, a-b, i.e. a and b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0041] In addition, the present application can refer to the same reference numerals and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate a relationship between the various embodiments and / or arrangements being discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art can appreciate that other processes can be applied and / or other materials can be used.

[0042] Figure 1 A schematic structural diagram of a vacuum insulation board provided by an embodiment of the present application.

[0043] See Figure 1The embodiment of the present application provides a kind of vacuum insulation board, the vacuum insulation board includes:

[0044] protective film 2;And

[0045] core material 1, the protective film 2 is covered the core material 1;

[0046] Wherein, the core material 1 includes multiple layers of laminated fiber cloth, the raw material of the fiber cloth includes organic fiber, the organic fiber has non-circular cross section, the area density of the fiber cloth is 2g / m 2 ~ 150g / m 2 .

[0047] From the technical scheme, in the embodiment of the present application, organic fiber with non-circular cross section is used as the core material of vacuum insulation board, wherein, organic fiber has relatively complex molecular structure, and the heat propagation speed in organic fiber is slow, and the intrinsic thermal conductivity is low, and the organic fiber has non-circular cross section, which can improve the physical spacing between organic fibers, reduce the contact area between organic fibers, change the heat conduction path, and help to further reduce the heat transfer efficiency, thereby reducing the thermal conductivity. In addition, the area density of the fiber cloth can further facilitate the low thermal conductivity of the organic fiber during film formation. Finally, through the synergistic effect of the low intrinsic thermal conductivity of the organic fiber, the non-circular cross section and the area density of the fiber cloth, the core material of the vacuum insulation board material with infinite three-dimensional network architecture support for increasing the heat conduction path is constructed, thereby reducing the thermal conductivity of the vacuum insulation board material in application. For example, the area density of the fiber cloth includes but is not limited to 2g / m 2 , 5g / m 2 , 10g / m 2 , 20g / m 2 , 30g / m 2 , 40g / m 2 , 50g / m 2 , 60g / m 2 , 70g / m 2 , 80g / m 2 , 90g / m 2 , 100g / m 2 , 120g / m 2 , 140g / m 2 , 150g / m 2 , etc.

[0048] It should be noted that the organic fibers have a relatively low intrinsic thermal conductivity, which is due to: (1) the thermal conduction properties of organic matter: organic materials generally have a lower thermal conductivity due to their weak intermolecular forces, and the transmission of thermal vibrations within the material is relatively difficult. Compared with metal materials, the thermal conduction performance of organic materials is poor, so the organic fibers also have a relatively low thermal conductivity accordingly. (2) The arrangement and structure of the fibers: the thermal conductivity of organic fibers is affected by their structure and arrangement. When the fibers are arranged parallel to the direction of heat radiation, the thermal conductivity is relatively strong; when the fibers are arranged perpendicular to the direction of heat radiation, the thermal conductivity is low. This is because the vertically arranged fiber layer can more effectively hold still air, and still air is a poor conductor of heat, thereby reducing the overall thermal conductivity.

[0049] Organic fibers with non-circular cross-sections have a relatively low thermal conductivity. This is due to: (1) Non-circular cross-section fibers have more complex cross-sectional shapes than traditional circular cross-section fibers, such as triangular, trilobal, cross-shaped, T-shaped, Y-shaped, crescent-shaped, dumbbell-shaped, five-pointed star-shaped, fan-shaped, and five-leaf-shaped, etc. This complex cross-sectional shape changes the heat conduction path within the fiber, making the heat transfer in the fiber more complex and tortuous. Therefore, non-circular cross-section fibers generally have a lower thermal conductivity, which is beneficial to their application in thermal insulation fields. (2) The cross-sectional shape of the non-circular cross-section fiber also affects its arrangement and gap size in the fiber layer. When the fibers are arranged parallel to the direction of heat radiation, the thermal conductivity is relatively strong; when the fibers are arranged perpendicular to the direction of heat radiation, i.e. the fibers are arranged parallel to the fiber layer, the thermal conductivity is low. Due to the complex cross-sectional shape of the non-circular cross-section fiber, it is more likely to form a complex arrangement, thereby reducing its thermal conductivity to some extent. In addition, the gap of the non-circular cross-section fiber may also be relatively small, which also helps to reduce heat transfer.

[0050] In some embodiments, the fiber cloth has a three-dimensional network architecture.

[0051] The three-dimensional network architecture belongs to the microstructure of the fiber cloth, mainly including the arrangement of the fibers, the interweaving density, and the porosity, etc. These microstructure characteristics directly affect the thermal insulation, heat preservation, and air permeability of the fiber cloth. The lap joint structure between the fibers of the fiber cloth in the present application is a disordered three-dimensional network shape in a microscopic case, heat is transferred in the lapped fibers, and heat transfer between the fibers occurs through contact points, which increases the difficulty of heat transfer. Thus, it is beneficial to reduce the thermal conductivity.

[0052] In some embodiments, the shape of the non-circular cross-section is one of triangular, trilobal, cross-shaped, T-shaped, Y-shaped, crescent-shaped, dumbbell-shaped, five-pointed star-shaped, fan-shaped, and five-leaf-shaped.

[0053] It should be noted that the non-circular cross-sections listed in this embodiment are only partial typical representatives, and the triangle, trilobal, pentagram, and pentaphyllos are one type; the cross, T-shaped, Y-shaped are one type; the crescent, dumbbell, and fan are one type. The fiber with a non-circular cross-section is an organic special-shaped fiber, which has better dispersion effect in water than conventional circular fibers, and the physical spacing between the fibers is larger.

[0054] In some embodiments, the organic fiber comprises at least one of:

[0055] PET, polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol.

[0056] The intrinsic thermal conductivity of the organic material is lower than that of glass fiber or other inorganic non-metallic materials. By selecting an organic material, the thermal conductivity of the core material of the vacuum insulation board in application is reduced. In addition, the good chemical stability of the organic fiber resists the erosion of the external environment and maintains the long-term stability of the suspension.

[0057] It should be noted that PET is short for polyethylene terephthalate, which is a thermoplastic polyester material. PET is a polycondensate of terephthalic acid and ethylene glycol, with a highly symmetrical molecular structure and a certain crystallization orientation ability, thus having high film-forming and molding properties. PET is a highly crystalline polymer with a milky white or light yellow color, smooth and glossy surface, good creep resistance, fatigue resistance, abrasion resistance, and dimensional stability, high hardness, and good toughness. PET is resistant to oil, fat, dilute acid, dilute alkali, and most solvents, but not resistant to hot water immersion and alkali. At the same time, PET has excellent weather resistance and chemical stability, and low water absorption.

[0058] Polypropylene, abbreviated as PP, is a polymer formed by the addition polymerization of propylene. It is a white waxy material with transparent appearance and light weight. The chemical formula is (C3H6) n , the density is 0.89g / cm 3 ~0.91g / cm 3 , flammable, melting point is 164℃~170℃, softens at about 155℃, and the use temperature range is -30℃~140℃. It can resist acid, alkali, salt solution and various organic solvents below 80℃, and can be decomposed under high temperature and oxidation. Polypropylene is a kind of excellent thermoplastic synthetic resin, which is colorless and translucent, thermoplastic and light weight general plastic, with chemical resistance, heat resistance, electrical insulation, high strength mechanical properties and good high wear resistance processing performance, etc.

[0059] Polyethylene, PE for short, is a thermoplastic resin prepared by polymerization of ethylene monomer. In industry, it also includes copolymers of ethylene and a small amount of α-olefins. Polyethylene is odorless, nontoxic, and has a waxy feel. It has excellent low-temperature resistance (minimum service temperature -100℃ to -70℃). It is chemically stable because the polymer molecules are linked by carbon-carbon single bonds, and it can resist attack by most acids and bases. It is insoluble in most solvents at room temperature, has low water absorption, and excellent electrical insulation.

[0060] Polyesters are polymers obtained by polycondensation of polyols and polyacids. The main polyester is polyethylene terephthalate, PET for short. It has excellent physical and mechanical properties in a wide temperature range, and can be used at temperatures up to 120℃. It has excellent electrical insulation, even at high temperatures and high frequencies. However, it has poor resistance to corona, and good resistance to creep, fatigue, abrasion, and dimensional stability.

[0061] Polyamides, PA for short, are high polymers containing polar amide groups (-CO-NH-) in the main chain. They can be prepared by ring-opening polymerization of internal amine, or by polycondensation of diamin and diacid. Initially used as a raw material for manufacturing fibers, PA has become a widely used engineering plastic in industry due to its strong, wear-resistant, self-lubricating, and wide temperature range of use.

[0062] Polyacrylonitrile, chemical formula (C3H3N) n is a high molecular compound obtained by free radical polymerization of monomer acrylonitrile. The acrylonitrile units in the macromolecular chain are connected in a head-to-tail manner. Polyacrylonitrile has good weather resistance and solarization resistance, and can maintain 77% of its original strength after being placed outdoors for 18 months. It is also resistant to chemical reagents, especially inorganic acids, bleaching powder, hydrogen peroxide, and general organic reagents.

[0063] Polyvinyl alcohol, PVA for short, is a white, powdery, stable, nontoxic water-soluble polymer prepared by alcoholysis and polymerization of vinyl acetate. It can quickly dissolve in water at room temperature to form a stable colloid, and water is a good solvent for polyvinyl alcohol. Polyvinyl alcohol has good film-forming properties, and the formed film has excellent adhesion, solvent resistance, abrasion resistance, tensile strength, and oxygen barrier properties. Polyvinyl alcohol has both hydrophilic and hydrophobic functional groups, so it is an interfacially active substance. Therefore, polyvinyl alcohol can be used as a protective colloid in high molecular emulsion and suspension polymerization.

[0064] In some embodiments, the organic fiber has a fiber diameter of 0.5um to 50um.

[0065] Fiber diameter refers to the cross-sectional diameter of a single fiber. The fiber diameter is limited to 0.5 um to 50 um, which can satisfy the fiber film-forming property and low thermal conductivity, and also can satisfy the softness, strength, elasticity and moisture absorption of the fiber, etc. Meanwhile, the fiber diameter in this range can ensure good contact between fibers and avoid the flowability problem of the suspension caused by too large diameter. The fiber diameter larger than 50 um can result in poor fiber film-forming property to some extent, and the heat propagation route is shortened, which is not conducive to achieving low thermal conductivity. Exemplary fiber diameters of the organic fiber include, but are not limited to, 0.5 um, 1 um, 5 um, 8 um, 10 um, 15 um, 20 um, 25 um, 28 um, 30 um, 35 um, 40 um, 45 um, 50 um, etc.

[0066] In some embodiments, preferably, the fiber diameter of the organic fiber is 3 um to 15 um.

[0067] Preferably, the fiber diameter of the organic fiber is limited to 3 um to 15 um, which can further satisfy the fiber film-forming property and low thermal conductivity, and also can satisfy the softness, strength, elasticity and moisture absorption of the fiber, etc. Meanwhile, the fiber diameter in this range can ensure good contact between fibers and avoid the flowability problem of the suspension caused by too large diameter.

[0068] In some embodiments, the organic fiber includes at least one of the following:

[0069] Long filament fiber, short fiber and ultra-short fiber;

[0070] The fiber length of the organic fiber is 0.5 mm to 250 mm.

[0071] It should be noted that the long filament fiber is also called continuous long filament fiber, which is a type of chemical fiber form. The long filament is a filament with very long length. The short fiber is also called cut fiber, and the chemical fiber bundle is cut or broken into fibers with length equivalent to that of various natural fibers. The ultra-short fiber is shorter than the cut length of the conventional fiber, and has high dispersibility in the medium. The length of the organic fiber is an important factor affecting its physical properties and performance, and different lengths of fibers have different behaviors and effects in the suspension. The long fiber usually has high tensile strength and better hand feeling; the medium fiber is usually soft, wear-resistant and elastic; the short fiber is usually soft and has good air permeability; the ultra-short fiber is usually soft and fluffy; in the suspension, fibers of different lengths can be mixed to adjust the physical properties and performance of the suspension.

[0072] In some embodiments, the fiber length of the short fiber is 25 mm to 150 mm, and the fiber length of the ultra-short fiber is 1 mm to 12 mm.

[0073] The fiber length of the short fiber is limited to 25mm-150mm, and the fiber length of the ultra-short fiber is limited to 1mm-12mm, which improves the dispersion effect of the organic profiled fiber in the organic fiber suspension, thereby being conducive to improving the film-forming property of the organic fiber suspension and being conducive to achieving a low thermal conductivity of the organic fiber suspension during film formation. The fiber length of the short fiber is 25mm-150mm to ensure good softness and air permeability. The fiber length of the ultra-short fiber is 1mm-12mm to provide an extreme soft and fluffy feeling. Exemplarily, the fiber length of the short fiber includes but is not limited to 25mm, 30mm, 40mm, 50mm, 60mm, 70mm, 75mm, 80mm, 90mm, 100mm, 125mm, 150mm, etc.; and the fiber length of the ultra-short fiber includes but is not limited to 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, etc.

[0074] In some embodiments, preferably, the areal density is 5g / m 2 ~100g / m 2 .

[0075] The areal density is the mass per unit area of the fabric, which is expressed by 1m 2 g of the dry fabric. The weight per unit area is an index for evaluating the quality and cost of the fabric. The greater the value, the denser and thicker the knitted fabric is, but the more raw materials are consumed, and the cost of the fabric will increase. Theoretically, the smaller the areal density of the fiber cloth is, the simpler the overlapping between fibers is, and the fewer the contact points between multiple fibers are, which is conducive to achieving an ultra-low thermal conductivity. Preferably, the areal density of the fiber cloth is limited to 5g / m 2 ~100g / m 2 On the one hand, this can further meet the quality requirements of the fiber cloth, so that it can be used to prepare the inner core of the vacuum insulation panel; on the other hand, it can be more conducive to achieving an ultra-low thermal conductivity.

[0076] Please refer to Figure 1 In some embodiments, the vacuum insulation panel further comprises a getter 3.

[0077] As a high-efficiency energy-saving insulation material, the vacuum insulation panel has excellent thermal insulation performance due to its unique structure and material composition. In addition to the core material 1 and the protective film 2, the vacuum insulation panel also includes the protective film 2 and the getter 3, which work together to achieve excellent insulation effect. The protective film 2 is the outer protective layer of the vacuum insulation panel, which mainly functions to isolate the external environment from the internal vacuum environment, preventing gas permeation and heat transfer. The common outer film of the vacuum insulation panel on the market mainly includes gas barrier film. The getter 3 is an indispensable part of the vacuum insulation panel, which mainly functions to adsorb excess gas generated by permeation or material outgassing, thereby maintaining the stability of the internal vacuum environment. The selection of the getter 3 is crucial to the performance of the vacuum insulation panel. In some specific applications, additional desiccants may be used to further reduce internal humidity and improve the performance of the vacuum insulation panel. In summary, the vacuum insulation panel can be composed of the core material 1, the protective film 2 and the getter 3, which work together to form the unique structure and excellent thermal insulation performance of the vacuum insulation panel.

[0078] Figure 2 A flowchart of a preparation method of a vacuum insulation panel provided by an embodiment of the present application.

[0079] See Figure 2 Based on a general inventive concept, the preparation method of the vacuum insulation panel according to any one of the above embodiments provided by the embodiments of the present application comprises:

[0080] S1, dispersing organic fibers in a liquid to obtain an organic fiber suspension;

[0081] S2, wet-laying and controlling the water of the organic fiber suspension, and then baking to obtain a fiber cloth;

[0082] S3, stacking and heat-treating a plurality of the fiber cloths to obtain a core material 1;

[0083] S4, bagging the core material 1 into the protective film 2 to obtain a bagged panel; and

[0084] S5, vacuumizing the bagged panel, and when the vacuum degree of the bagged panel reaches a set vacuum degree, heat-sealing the bagged panel to obtain a vacuum insulation panel.

[0085] In some embodiments, the weight of the organic fibers is 0.01% to 0.1% of the total weight of the organic fiber suspension.

[0086] The present application uses organic irregular fibers with non-circular cross-section as the core material of vacuum insulation board. The special interface morphology of organic irregular fibers and the limited weight ratio of organic fibers in the total weight of the suspension improve the dispersion effect of organic irregular fibers in the organic fiber suspension and the physical spacing between fibers, and reduce the contact area between fibers, which is conducive to improving the film-forming property of the organic fiber suspension and effectively blocking the heat transfer efficiency. It is beneficial for the organic fiber suspension to achieve low thermal conductivity during film formation. At the same time, the low intrinsic thermal conductivity of organic irregular fibers helps to build a three-dimensional network architecture supported by the core material of the vacuum insulation board, which further reduces the thermal conductivity of the core material of the vacuum insulation board in application. The cross-section of the fibers in the organic fiber suspension can be any non-circular shape, which helps to increase the contact area between fibers and improve the stability and performance of the suspension. The weight ratio of organic fibers in the suspension is a key factor that directly affects the physical properties and performance of the suspension. Generally, the weight ratio of fibers is 0.01% to 0.1%, which can be adjusted according to specific application requirements to achieve the best thermal insulation, insulation or strength effect. For example, the weight of the organic fiber is a value of the total weight of the suspension, including but not limited to 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, etc.

[0087] In some embodiments, the dispersion method includes mechanical stirring and microwave heating.

[0088] Dispersing organic fibers in a liquid has significant advantages for subsequent processes of preparing fiber cloth and the fiber cloth itself. Uniformly dispersed fibers are easy to handle and process in a liquid, reducing fiber entanglement and knotting, thereby improving the flow of fibers during weaving or molding. At the same time, well-dispersed fibers can form a more uniform and dense fiber network during molding, which helps to improve the density and uniformity of the fiber cloth. Mechanical stirring is a strong turbulent motion that helps to break the mutual attraction and entanglement between fibers, allowing the fibers to achieve better dispersion in the solution. Microwave heating can use microwave radiation to heat materials non-contact, generating heat by inducing vibration and friction of polar molecules inside the material. In an aqueous solution of organic fibers, water molecules are the main polar molecules that quickly heat up after absorbing microwave energy, thereby promoting the dispersion of fibers. Through the dispersion effect of mechanical stirring or microwave heating, organic fibers are more easily dispersed in an aqueous solution, reducing the occurrence of fiber parallelism and increasing single fiber dispersion. This improvement has a positive impact on achieving low thermal conductivity of the organic fiber suspension during the subsequent film-forming process.

[0089] It should be noted that the wet-laid process is a process of making a fiber web in a wet state by a specific device (such as a wet-laid machine), and the fibers are dispersed in water containing chemical additives to form a suspension, and the water in the suspension is filtered out by a papermaking felt or screen, and the deposited fibers form a fiber web.

[0090] In some embodiments, the water control time is 5 min to 30 min; and / or

[0091] The baking temperature is 100°C to 240°C.

[0092] Preferably, the baking temperature is 140°C to 200°C.

[0093] Water control is specifically to remove excess liquid in the fiber web by methods such as extrusion and vacuum water absorption, reducing energy consumption and time in the subsequent baking process. By controlling water, the water content in the fiber web can be reduced, and at the same time, the structure damage caused by excessive compression between fibers can be avoided, so that a PET fiber cloth with excellent performance and specific cross-sectional shape can be produced. At the same time, limiting the water control time to 5 min to 30 min helps to improve the efficiency of water removal in the later baking. Exemplarily, the water control time includes but is not limited to 5 min, 7 min, 9 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min, 30 min, etc.

[0094] Baking is specifically to send the water-controlled fiber web into a baking oven for baking, and heat it by hot air or infrared rays, etc. to form stable bonding between fibers, and finally obtain a fiber cloth. Through baking, the bonding strength between fibers and the consistency of the product can be ensured, so that a fiber cloth with excellent performance and specific cross-sectional shape can be produced. Limiting the baking temperature to 100°C to 240°C can improve the water removal efficiency and effect of the fiber cloth. If the baking temperature is too low and lower than 100°C, the water removal efficiency and effect will be low to some extent; if the baking temperature is too high and higher than 240°C, the organic fibers will be fused and adhered to some extent. Exemplarily, the baking temperature includes but is not limited to 100°C, 120°C, 140°C, 150°C, 160°C, 170°C, 180°C, 200°C, 220°C, 230°C, 240°C, etc. Preferably, limiting the baking temperature to 140°C to 200°C can further improve the water removal efficiency and effect of the fiber cloth.

[0095] In some embodiments, the number of sheets is 100 to 500.

[0096] By stacking multiple fiber cloths, a multi-layer structure with a certain thickness and size is formed, so that the thickness and density of the core material can be significantly increased, thereby further improving the overall strength and stability. At the same time, the three-dimensional network structure of multiple fiber cloths can interweave and fuse with each other during the stacking process, forming a more complex and stable overall structure, which helps to improve the compression resistance, shear resistance and bending resistance of the polyacrylonitrile core material. Exemplarily, the number of stacked polyacrylonitrile fiber cloths includes but is not limited to 100, 200, 300, 320, 340, 350, 370, 390, 400, 420, 440, 460, 480, 500, etc.

[0097] In some embodiments, the temperature of the heat treatment is 130-200°C. Preferably, the temperature of the heat treatment is 160-180°C.

[0098] By heat treatment, not only can the further cross-linking and fusion between fibers be promoted, the overall strength and stability of the core material can be enhanced, but also the thermal performance and chemical stability of the core material can be improved to some extent, so that the internal structure and performance of the core material can be further optimized. At the same time, by limiting the temperature of the heat treatment to 130-200°C, the water removal and drying effect of the core material can be further accelerated, and the absorption of moisture in the air can be reduced. If the temperature of the heat treatment is too low and lower than 130°C, the water removal efficiency is low to some extent, and the water removal effect is poor. If the temperature of the heat treatment is too high and higher than 200°C, the organic fibers are prone to melt and stick to some extent. Exemplarily, the temperature of the heat treatment includes but is not limited to 130°C, 135°C, 140°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 200°C, etc. Preferably, the temperature of the heat treatment is limited to 160-180°C, which can further accelerate the water removal and drying effect of the core material and reduce the absorption of moisture in the air.

[0099] In some embodiments, the set vacuum degree is 1.0*10 -4 Pa-4.0*10 -3 Pa.

[0100] In the preparation process of the vacuum insulation board, the vacuum treatment is a crucial step, which directly affects the thermal insulation performance and service life of the vacuum insulation board. By limiting the vacuum degree of the vacuum treatment to 1.0*10 -4 Pa-4.0*10 -3 Pa, the heat loss through gas molecule heat conduction can be reduced, and the thermal insulation performance of the vacuum insulation board can be significantly improved. Exemplarily, the vacuum degree of the vacuum treatment includes but is not limited to 1.0*10 -4 Pa, 1.2*10 -4 Pa, 1.5*10-4 Pa, 1.8*10 -4 Pa, 2.0*10 -4 Pa, 2.2*10 -4 Pa, 2.5*10 -4 Pa, 2.8*10 -4 Pa, 3.0*10 -4 Pa, 3.2*10 -4 Pa, 3.5*10 - 4 Pa, 3.8*10 -4 Pa, 4.0*10 -3 Pa, etc.

[0101] In some embodiments, the process parameters of the heat sealing include: voltage of 9V-15V, time of 15s-25s.

[0102] In the preparation process of the vacuum insulation board, the heat sealing is a crucial process step, which has a decisive influence on the sealing and final performance of the product. The heat sealing can effectively improve the hot melt bonding effect of the inner layer of the film bag by limiting the voltage to 9V-15V and the time to 15s-25s, thereby ensuring the sealing and thermal insulation performance of the vacuum insulation board. Exemplarily, the voltage of the heat sealing includes but is not limited to 9V, 9.5V, 10V, 10.5V, 11V, 11.5V, 12V, 12.5V, 13V, 13.5V, 14V, 14.5V, 15V, etc., and the time of the heat sealing includes but is not limited to 15s, 16s, 17s, 18s, 19s, 20s, 21s, 22s, 23s, 24s, 25s, etc.

[0103] In a third aspect, the embodiments of the present application provide a heat insulation device, which contains the vacuum insulation board according to any one of the above embodiments. The heat insulation device includes but is not limited to a refrigerator, a freezer, a refrigerated vehicle, a refrigerated car, and a freezing car.

[0104] Meanwhile, the application of the vacuum insulation board provided by the present application includes but is not limited to heat insulation devices, and can also be used for building external wall insulation, motor home insulation, spacecraft heat protection and insulation, etc.

[0105] The present application will be further described in conjunction with specific examples and experimental data. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application. The experimental methods not specified in the following examples are generally determined according to the national standards. If there is no corresponding national standard, the general international standard, the conventional condition, or the condition suggested by the manufacturer is used.

[0106] Example 1

[0107] The embodiment provides a vacuum insulation board, and a preparation method thereof.

[0108] S101, organic fibers are dispersed in water to obtain an organic fiber suspension; wherein the organic fibers are cross-section triangular PET fibers with a diameter of 7 um and a length of 5 mm, and the weight of the PET fibers accounts for 0.05% of the total weight of the suspension;

[0109] S102, the organic fiber suspension is subjected to wet laying and water control for 5 min, and then is placed in an oven at 180 DEG C for baking for 2 h to obtain a fiber cloth with a surface density of 15 g / m 2 ;

[0110] S103, a plurality of the fiber cloth is stacked and then is placed in a baking channel for baking at 200 DEG C again for 2 h to obtain a core material;

[0111] S104, the core material is bagged in the protective film to obtain a bagged board; and

[0112] S105, the bagged board is placed in a vacuum packaging machine, the bagged board is subjected to vacuumizing treatment, when the vacuum degree of the bagged board reaches 3.5*10 -3 Pa, the bagged board is subjected to heat sealing and sealing, the heat sealing time is 15 s, the heat sealing voltage is 13 V, then the adsorbent shell is pressed and pierced, the internal pressure is further reduced, and a vacuum insulation board is obtained.

[0113] Example 2

[0114] The embodiment differs from the embodiment 1 in that the organic fibers are cross-section clover-shaped PET fibers with a diameter of 7 um and a length of 5 mm.

[0115] Example 3

[0116] The embodiment differs from the embodiment 1 in that the organic fibers are cross-section clover-shaped PET fibers with a diameter of 7 um and a length of 5 mm.

[0117] Example 4

[0118] The embodiment differs from the embodiment 1 in that the organic fibers are cross-section clover-shaped PET fibers with a diameter of 7 um and a length of 5 mm.

[0119] Example 5

[0120] The embodiment differs from the embodiment 1 in that the organic fibers are cross-section clover-shaped PET fibers with a diameter of 7 um and a length of 5 mm.

[0121] Example 6

[0122] The difference between this example and Example 1 is that the organic fiber is a cross-section crescent-shaped PET fiber with a diameter of 7 um and a length of 5 mm.

[0123] Example 7

[0124] The difference between this example and Example 1 is that the organic fiber is a cross-section dumbbell-shaped PET fiber with a diameter of 7 um and a length of 5 mm.

[0125] Example 8

[0126] The difference between this example and Example 1 is that the organic fiber is a cross-section five-pointed star-shaped PET fiber with a diameter of 7 um and a length of 5 mm.

[0127] Example 9

[0128] The difference between this example and Example 1 is that the organic fiber is a cross-section fan-shaped PET fiber with a diameter of 7 um and a length of 5 mm.

[0129] Example 10

[0130] The difference between this example and Example 1 is that the organic fiber is a cross-section five-leaf-shaped PET fiber with a diameter of 7 um and a length of 5 mm.

[0131] Example 11

[0132] The difference between this example and Example 1 is that the organic fiber is a cross-section triangular-shaped polyamide fiber with a diameter of 7 um and a length of 5 mm, and the weight of the polyamide fiber is 0.05% of the total weight of the suspension.

[0133] Example 12

[0134] The difference between this example and Example 1 is that the organic fiber is a cross-section cross-shaped polyamide fiber with a diameter of 7 um and a length of 5 mm, and the weight of the polyamide fiber is 0.05% of the total weight of the suspension.

[0135] Example 13

[0136] The difference between this example and Example 1 is that the organic fiber is a cross-section triangular-shaped polyacrylonitrile fiber with a diameter of 7 um and a length of 5 mm, and the weight of the polyacrylonitrile fiber is 0.05% of the total weight of the suspension.

[0137] Example 14

[0138] The difference between this example and Example 1 is that the organic fiber is a cross-sectionally cruciform polyacrylonitrile fiber having a diameter of 7 um and a length of 5 mm, and the weight of the polyacrylonitrile fiber is 0.05% of the total weight of the suspension.

[0139] Example 15

[0140] The difference between this example and Example 1 is that the weight of the PET fiber is 0.01% of the total weight of the suspension.

[0141] Example 16

[0142] The difference between this example and Example 1 is that the weight of the PET fiber is 0.1% of the total weight of the suspension.

[0143] Example 17

[0144] The difference between this example and Example 1 is that the fiber diameter of the PET fiber is 3 um.

[0145] Example 18

[0146] The difference between this example and Example 1 is that the fiber diameter of the PET fiber is 15 um.

[0147] Example 19

[0148] The difference between this example and Example 1 is that the fiber length of the PET fiber is 25 mm.

[0149] Example 20

[0150] The difference between this example and Example 1 is that the fiber length of the PET fiber is 1 mm.

[0151] Example 21

[0152] The difference between this example and Example 1 is that the fiber length of the PET fiber is 50 mm.

[0153] Example 22

[0154] The difference between this example and Example 1 is that the areal density of the fiber cloth is 5 g / m 2 .

[0155] Example 23

[0156] The difference between this example and Example 1 is that the areal density of the fiber cloth is 100 g / m 2 .

[0157] Example 24

[0158] The difference between this embodiment and embodiment 1 is that the baking temperature for preparing the fiber cloth is 100℃.

[0159] Example 25

[0160] The difference between this embodiment and embodiment 1 is that the baking temperature for preparing the fiber cloth is 240℃.

[0161] Comparative Example 1

[0162] This comparative example provides a vacuum insulation board, and a preparation method thereof comprises:

[0163] S111, dispersing glass fibers in water to obtain a glass fiber suspension; wherein the glass fibers are cross-sectional circular glass fibers with a diameter of 7um and a length of 5mm, and the weight of the glass fibers is 0.05% of the total weight of the suspension;

[0164] S112, wet-laying the glass fiber suspension and controlling water for 5min, and then placing it in a 180℃ oven for baking for 2h to obtain a glass fiber felt with an area density of 25g / m 2 ;

[0165] S113, stacking multiple pieces of the glass fiber felt and placing them in an oven for 200℃ baking for 2h to obtain a core material;

[0166] S114, bagging the core material in the protective film to obtain a bagged board; and

[0167] S115, placing the bagged board in a vacuum packaging machine, and performing vacuumizing treatment on the bagged board; when the vacuum degree of the bagged board reaches 3.5*10 -3 Pa, heat sealing the bagged board, heat sealing time 15s, heat sealing voltage 13V, and then pressing and piercing the getter shell to further reduce the internal pressure, to obtain a vacuum insulation board.

[0168] Comparative Example 2

[0169] The difference between this embodiment and embodiment 1 is that the organic fiber is cross-sectional circular PET fiber with a diameter of 7um and a length of 5mm.

[0170] Comparative Example 3

[0171] The difference between this comparative example and embodiment 1 is that the weight of the PET fiber is 2% of the total weight of the suspension.

[0172] Comparative Example 4

[0173] The difference between the present comparative example and Example 1 is that the weight of the PET fiber is 0.001% of the total weight of the suspension.

[0174] Comparative Example 5

[0175] The difference between the present comparative example and Example 1 is that the fiber diameter of the organic fiber is 0.1 um.

[0176] Comparative Example 6

[0177] The difference between the present comparative example and Example 1 is that the fiber diameter of the organic fiber is 60 um.

[0178] Comparative Example 7

[0179] The difference between the present comparative example and Example 1 is that the baking temperature for preparing the fiber cloth is 300℃.

[0180] Experimental Testing

[0181] In order to better illustrate the heat insulation performance of the vacuum insulation panel provided by the present application, the vacuum insulation panels obtained in Examples 1-25 and Comparative Examples 1-7 are subjected to experimental testing of the thermal conductivity, and the results are shown in Table 1.

[0182] Table 1 Thermal conductivity of the vacuum insulation panels obtained in Examples 1-25 and Comparative Examples 1-7

[0183]

[0184]

[0185] As can be seen from Table 1, compared with the vacuum insulation panels with glass fiber and organic round fiber core material, the vacuum insulation panel with organic profiled fiber core material provided by the present application has lower thermal conductivity and better heat preservation effect. Meanwhile, as can be seen from Examples 1-25, the thermal conductivity of the vacuum insulation panel with organic profiled fiber core material has strong correlation with the fiber type and fiber cross-sectional morphology. The thermal conductivity of the vacuum insulation panel with PET fiber core material is lower than that with polyamide and polyacrylonitrile, and the thermal conductivity of the vacuum insulation panel with cross-sectional fiber core material is lower than that with other non-circular cross-sectional material, so in actual application, the vacuum insulation panel with cross-sectional PET fiber core material can be selectively prepared. In addition, as can be seen from Comparative Example 1, the thermal conductivity of the vacuum insulation panel prepared from organic fiber is significantly better than that prepared from glass fiber, and as can be seen from Comparative Example 2, the thermal conductivity of the vacuum insulation panel prepared from non-circular cross-sectional organic fiber is significantly better than that prepared from circular cross-sectional organic fiber.

[0186] In addition, one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0187] In the embodiment of the present application, the organic profiled fiber material is used to replace fumed silica or glass fiber, and is applied to the main body material of the vacuum insulation board core material, so that the problems of cost, environmental hazards and inability to realize ultra-low thermal conductivity are overcome.

[0188] In the embodiment of the present application, the high-efficiency suspension dispersion of the organic profiled fiber creates conditions for the low gram weight of the fiber cloth after wet laying, and the high rigidity characteristics of the organic profiled fiber material provide support for the three-dimensional network structure of the vacuum insulation board core material. Heat transfer is carried out in the three-dimensional network architecture of the fiber, which fully utilizes the low intrinsic thermal conductivity of the organic profiled fiber, the profiled cross section and the three-dimensional structure to increase the heat conduction path, and finally prepares the vacuum insulation board with ultra-low thermal conductivity.

[0189] In the embodiment of the present application, the initial thermal conductivity of the vacuum insulation board is less than 1.46 mW*(m K) -1 .

[0190] In the embodiment of the present application, the intrinsic thermal conductivity of the glass fiber is much higher than that of the organic polymer material, so the use of organic fiber instead of glass fiber for the development of ultra-low thermal conductivity VIP board has certain advantages, and the characteristic morphology of the cross section of the organic profiled fiber greatly reduces the contact area between the fibers, effectively blocks the heat transfer efficiency, and provides favorable conditions for ultra-low thermal conductivity.

[0191] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification.

Claims

1. A vacuum insulation panel, characterized in that, The vacuum insulation board comprises: a core material, and a protective film covering the core material; The core material includes a plurality of fiber cloths stacked together, the fiber cloths are made of organic fibers, the organic fibers have a non-circular cross section, and the fiber cloths have a surface density of 2 g / m 2 ~ 150 g / m 2 .

2. The vacuum thermal panel according to claim 1, characterized in that, The fiber cloth has a three-dimensional network structure.

3. The vacuum thermal panel according to claim 1, characterized in that, The non-circular cross section has a shape selected from the group consisting of triangle, trilobal, cross, T, Y, crescent, dumbbell, pentagram, fan, and pentalobal.

4. The vacuum thermal panel according to claim 1, characterized in that, The organic fiber comprises at least one of: PET, polypropylene, polyethylene, polyester, polyamide, polyacrylonitrile, and polyvinyl alcohol.

5. The vacuum thermal panel according to claim 4, characterized in that, The fiber diameter of the organic fiber is 0.5 um to 50 um.

6. The vacuum thermal panel according to claim 5, characterized in that, Preferably, the fiber diameter of the organic fiber is 3 um to 15 um.

7. The vacuum thermal panel according to claim 4, characterized in that, The fiber length of the organic fiber is 0.5 mm to 250 mm.

8. The vacuum thermal panel according to claim 1, characterized in that, Preferably, the areal density is 5 g / m 2 ~ 100 g / m 2 .

9. A method of producing the vacuum thermal insulation panel according to any one of claims 1 to 8, characterized in that, The method comprises: dispersing the organic fiber in a liquid to obtain an organic fiber suspension; wet-laying and controlling the water content of the organic fiber suspension, and then baking to obtain a fiber cloth; stacking and heat-treating a plurality of the fiber cloths to obtain a core material; bagging the core material in the protective film to obtain a bagged board; and performing vacuumizing treatment on the bagged board, and when the vacuum degree of the bagged board reaches a set vacuum degree, performing hot-pressing sealing on the bagged board to obtain a vacuum insulation board.

10. The method of claim 9, wherein, The weight of the organic fiber is 0.01% to 0.1% of the total weight of the organic fiber suspension.

11. The method of claim 9, wherein, The dispersion method comprises mechanical stirring and microwave heating.

12. The method of claim 9, wherein, The water content control time is 5 min to 30 min; and / or the baking temperature is 100°C to 240°C.

13. The method of claim 9, wherein, The plurality is 100 to 500.

14. The method of claim 9, wherein, The heat treatment temperature is 130°C to 200°C.

15. The method of claim 9, wherein, The set vacuum degree is 1.0*10 -4 Pa~4.0*10 - 3 Pa.

16. The method of claim 9, wherein, The hot-pressing sealing process parameters include: voltage of 9V to 15V, and time of 15s to 25s.

17. A thermal insulation device, characterized by The heat insulation equipment contains the vacuum insulation board according to any one of claims 1 to 8.

Images