Core material and preparation method thereof, vacuum insulated panel and heat insulation device

Abstract

The invention relates to the technical field of heat insulation materials, and particularly provides a core material and a preparation method thereof, a vacuum insulation panel and a heat insulation device, the core material comprises a main base material, the main base material comprises not less than 90 wt% of PET fiber, and the core material is doped with not less than 15 wt% of viscose fiber. The viscose fiber is doped in the main base material, and the doping amount of the viscose fiber is controlled to be not lower than 15% of the mass of the core material, so that the function of the viscose fiber can be effectively played, the viscose fiber and the PET fiber are mutually cooperated to play a role, the problem that flying dust and floating wadding are generated in the cutting process or the preparation and baking process of the PET fiber core material is effectively solved, and the service life of the PET fiber core material is prolonged. The core material is also ensured to have a lower heat conductivity coefficient and better strength, and the heat insulation performance of the core material is remarkably improved. The vacuum insulated panel prepared from the core material has excellent heat insulation performance and long service life, and the vacuum insulated panel has huge application value in the fields of buildings, household appliances and aviation.

Description

Technical Field

[0001] The present invention relates to the technical field of heat insulation materials, and in particular to a core material and a preparation method thereof, a vacuum insulation panel and a heat insulation device. Background Art

[0002] Vacuum insulation panel is a kind of vacuum insulation material. It is widely used in many fields due to its advantages such as low thermal conductivity, thin insulation layer thickness, good insulation performance, and good construction performance. Vacuum insulation panel is based on the principle of vacuum insulation. It reduces the heat transfer caused by air convection by maximizing the vacuum degree in the panel. It is mainly composed of three parts: core material, barrier film and gas adsorption material. The core material has built-in gas adsorbent and desiccant. In the vacuum state, gas insulation material is used to seal the double sides to form a board. The selection and production method of the core material inside the vacuum insulation panel have a great influence on the performance of the vacuum insulation panel. The core material is generally made of porous medium materials, such as aerogel, microporous polyurethane, silica powder, stone fiber wool, glass fiber, etc.

[0003] The core material of the vacuum insulation board made of PET fiber has good thermal conductivity and application prospects, but PET fiber is generally in the size of millimeters. Therefore, the PET fiber core material will produce flying dust and floating fibers during the cutting process or the preparation and baking process, affecting the working environment. Summary of the invention

[0004] The present invention aims to solve the technical problems in the prior art at least to a certain extent. To this end, one object of the present invention is to provide a core material and a preparation method thereof, a vacuum insulation panel and a heat insulation device.

[0005] In a first aspect of the present invention, a core material is provided, comprising a main substrate, wherein the main substrate contains not less than 90 wt % of PET fibers, and the core material is mixed with not less than 15 wt % of viscose fibers.

[0006] According to the core material of the present invention, the core material prepared with not less than 90wt% of PET fiber as the main substrate has good thermal insulation effect, and by doping viscose fiber into the main substrate and controlling the amount of viscose fiber added to not less than 15% of the core material weight, the role of viscose fiber can be effectively exerted, so that the viscose fiber and PET fiber can work together, which not only effectively solves the problem of flying dust and floating fluff generated by the PET fiber core material during the cutting process or the preparation and baking process, but also ensures that the core material has a lower thermal conductivity and better strength, and significantly improves the thermal insulation performance of the core material.

[0007] According to the core material of the present invention, based on the total mass of the core material, the mass proportion of the viscose fiber is 20% to 30%.

[0008] According to the above-mentioned core material of the present invention, the porosity of the viscose fiber is not less than 60%, preferably 65% - 70%.

[0009] According to the above-mentioned core material of the present invention, the porosity of the PET fiber is not less than 60%, preferably 80% - 85%.

[0010] According to the above-mentioned core material of the present invention, the mass of the main substrate accounts for 65% - 80% of the mass of the core material.

[0011] According to the above-mentioned core material of the present invention, the main substrate is PET fiber.

[0012] According to the above-mentioned core material of the present invention, the core material comprises 65wt% - 80wt% of the PET fiber and 20wt% - 30wt% of the viscose fiber.

[0013] In the second aspect of the present invention, the present invention provides a method for preparing the above-mentioned core material, and the method comprises: Crushing and softening the PET fiber; Beating the softened PET fiber and viscose fiber in water to obtain a mixed slurry; Depositing the mixed slurry on a partition board to form a wet slurry layer and then drying.

[0014] According to the method for preparing the above-mentioned core material of the present invention, first, the PET fiber is crushed, soaked and cooked, and the texture of the PET fiber becomes soft to obtain soft PET fiber; then the softened PET fiber and viscose fiber are mixed and beaten in water, so that the fibers are dispersed, and the PET fiber and viscose fiber are suspended in water to form a uniform mixed slurry; finally, the above-mentioned mixed slurry is dehydrated and deposited on a partition board to form a wet slurry layer, and the wet slurry layer is further dried to remove water, thereby forming the core material. Because the PET fiber and viscose fiber are mixed and beaten, during the drying process of the wet slurry layer, the problems of flying dust and floating flocs generated by the PET fiber are effectively avoided. Even when the prepared core material is cut later, no flying dust and floating flocs will be generated, thereby improving the quality of the working environment. Therefore, the above method can be used to prepare a core material with stable performance, high strength and excellent heat insulation effect.

[0015] According to the above-mentioned method for preparing the core material of the present invention, before the softened PET fiber and viscose fiber are beaten in water, at least one of a defoaming agent and a dispersant is added to the water, and then beating treatment is carried out.

[0016] According to the above-mentioned method for preparing the core material of the present invention, the addition amount of the defoaming agent is 2% - 4% of the total mass of the core material.

[0017] According to the above-mentioned method for preparing the core material of the present invention, the addition amount of the dispersant is 1% - 2% of the total mass of the core material.

[0018] In the third aspect of the present invention, the present invention provides a vacuum insulation panel. The vacuum insulation panel includes the above-mentioned core material or the core material prepared by the above-mentioned method. Thus, the vacuum insulation panel has excellent heat insulation performance and a long service life.

[0019] In the fourth aspect of the present invention, the present invention provides a heat insulation device. The heat insulation device includes the above-mentioned vacuum insulation panel. Thus, the heat insulation device has excellent heat insulation performance, low production cost and a long service life. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a process display diagram of the core material preparation of the present invention. Detailed Embodiments

[0022] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention with reference to the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0023] The core material of the vacuum insulation panel prepared with PET fibers has good thermal conductivity and application prospects. However, dust and floating flocs will be generated during the cutting process or the preparation and baking process of the PET fiber core material. Therefore, the inventor adds an appropriate amount of conventional adhesive during the preparation of the PET fiber core material to fix it to overcome the above-mentioned dust and floating flocs problems. However, the inventor finds that the thermal conductivity of the core material prepared by adding the conventional adhesive is significantly reduced, and the tensile strength is also poor, which will undoubtedly have a significant impact on the heat insulation performance of the vacuum insulation panel.

[0024] In view of this, in the first aspect of the present invention, the present invention provides a core material, which includes a main substrate, the main substrate contains not less than 90 wt% of PET fibers, and not less than 15 wt% of viscose fibers are incorporated into the core material.

[0025] According to the above core material of the present invention, including the main substrate, the core material prepared with PET fibers not less than 90wt% as the main substrate has good heat insulation effect. By doping viscose fibers in the main substrate and controlling the doping amount of viscose fibers not less than 15% of the mass of the core material, the role of the adhesive fibers can be effectively exerted, enabling the adhesive fibers and PET fibers to play a synergistic role. This not only effectively solves the problems of dust and floating flocs generated during the cutting process or the preparation and baking process of the PET fiber core material, but also ensures that the core material has a low thermal conductivity and good strength, significantly improving the heat insulation performance of the core material.

[0026] According to an embodiment of the present invention, based on the total mass of the core material, the mass ratio of the viscose fibers is 20% - 30%. For example, the mass ratio of the viscose fibers is 20%, 22%, 24%, 26%, 28%, 30%, or the range between any two of the above values. By controlling the mass ratio of the viscose fibers within the above range, the bonding effect of the viscose fibers can be effectively exerted, and the core material is ensured to have a low thermal conductivity and excellent strength.

[0027] According to an embodiment of the present invention, the porosity of the viscose fibers is not less than 60%, preferably 65% - 70%. For example, the porosity is 60%, 62%, 64%, 66%, 68%, 70%, etc., or the range between any two of the above values.

[0028] According to an embodiment of the present invention, the viscose fibers are selected from one of ordinary viscose fibers, high wet modulus viscose fibers, and polynosic fibers.

[0029] Preferably, based on the total mass of the core material, the mass ratio of the viscose fibers is 20% - 30%, and the porosity of the viscose fibers is 65% - 70%.

[0030] According to an embodiment of the present invention, the porosity of the PET fibers is not less than 60%, preferably 80% - 85%. For example, the porosity is 60%, 70%, 80%, 82%, 85%, 90%, etc., or the range between any two of the above values. By controlling the porosity of the PET fibers within the above range, it can cooperate with the viscose fibers to play a role, improving the strength of the core material and reducing the thermal conductivity of the core material.

[0031] Preferably, the porosity of the PET fibers is 80% - 85%, and the porosity of the viscose fibers is 65% - 70%. By controlling the porosity of the PET fibers and the viscose fibers within the above range, the strength of the core material can be improved, the thermal conductivity of the core material can be reduced, and the generation of dust can be effectively prevented.

[0032] According to an embodiment of the present invention, the mass of the main substrate accounts for 65% - 80% of the mass of the core material.

[0033] According to an embodiment of the present invention, the mass of the main substrate accounts for 65% - 80% of the mass of the core material. The main substrate is PET fiber. For example, the mass of the main substrate accounts for 65%, 70%, 75%, 80%, etc. of the mass of the core material.

[0034] Preferably, the mass of the main substrate accounts for 65% - 80% of the mass of the core material. The main substrate is PET fiber, and the porosity of the PET fiber is 80% - 85%. By controlling the mass ratio of the PET fiber in the core material within the above range and the porosity of the PET fiber being 80% - 85%, the strength of the core material can be effectively improved, and the thermal conductivity of the core material can be reduced.

[0035] According to an embodiment of the present invention, the core material includes 65wt% - 80wt% of the PET fiber and 20wt% - 30wt% of the viscose fiber. By controlling the mass ratio of the PET fiber and the viscose fiber in the core material within the above range, the synergistic effect between the PET fiber and the viscose fiber can be effectively exerted, the strength and heat insulation performance of the core material can be significantly improved, and the generation of flying dust and floating flocs can be effectively avoided.

[0036] Preferably, the core material includes 65wt% - 80wt% of the PET fiber and 20wt% - 30wt% of the viscose fiber. The porosity of the viscose fiber is 65% - 70%, and the porosity of the PET fiber is 80% - 85%. This core material has excellent heat insulation performance and strength.

[0037] According to an embodiment of the present invention, the core material further includes other auxiliary materials. For example, the auxiliary materials include defoaming agents and / or dispersants. In order to ensure the strength and heat insulation performance of the core material, the content of other auxiliary materials is as small as possible, for example, not exceeding 5% of the total mass of the core material.

[0038] In the second aspect of the present invention, the present invention provides a method for preparing the above core material, and the method includes: S100: Crush and soften the PET fiber.

[0039] In this step, the PET fiber is crushed, soaked and steamed, and the texture of the PET fiber becomes soft, obtaining soft PET fiber. By crushing the PET fiber, it is convenient to better interact with the viscose fiber to improve the performance of the core material and is also convenient for softening. It should be noted that both soaking and steaming are conventional operations in the art, and the purpose of soaking and steaming is to soften the PET fiber, which is beneficial for the subsequent beating treatment. For example, soak at room temperature for 1h - 5h and steam for 20min - 60min.

[0040] According to an embodiment of the present invention, the fiber length of the crushed PET fiber is 3mm - 5mm. For example, the fiber length is 3mm, 4mm, 5mm, etc.

[0041] S200: Pulverize the softened PET fibers and viscose fibers in water.

[0042] In this step, referring to Figure 1 , mix the above-mentioned softened PET fibers and viscose fibers in water, and then pulverize them in a beater to disperse the fibers, making the PET fibers and viscose fibers suspended in water to form a uniform mixed slurry. The present invention does not particularly limit the specific pulverizing time, and those skilled in the art can select according to process requirements. In principle, the fibers should be dispersed as much as possible to form a uniform suspension solution.

[0043] According to an embodiment of the present invention, the solid content of the mixed slurry is 2% - 5%. For example, the solid content is 2%, 3%, 4%, 5%, etc., or the range between any two of the above values. By controlling the solid content of the mixed slurry within the above range, the fibers are more evenly dispersed, and the uniformity of the wet pulp layer prepared in the later process is improved.

[0044] According to an embodiment of the present invention, before pulverizing the softened PET fibers and viscose fibers in water, add at least one of an antifoaming agent and a dispersant to the water, and then perform pulverizing treatment. Adding an antifoaming agent reduces the amount of foam generated during pulverizing to ensure the quality of the prepared core material; adding a dispersant makes the fibers more evenly dispersed in the solution and improves the quality of the core material. It should be noted that the antifoaming agent and the dispersant are conventional reagents in the art, and those skilled in the art can select according to the actual situation, which will not be elaborated here.

[0045] According to an embodiment of the present invention, the addition amount of the antifoaming agent is 2% - 4% of the total mass of the core material, which can reduce the foam generated during pulverizing as much as possible while ensuring the quality of the core material.

[0046] According to an embodiment of the present invention, the addition amount of the dispersant is 1% - 2% of the total mass of the core material, which can improve the dispersibility of the fibers as much as possible while ensuring the quality of the core material.

[0047] S300: Deposit the mixed slurry on a separator to form a wet pulp layer and then dry it.

[0048] In this step, dehydrate and deposit the above-mentioned mixed slurry on a separator to form a wet pulp layer, and further dry the wet pulp layer to remove moisture, thereby forming a core material. Because the PET fibers and viscose fibers are mixed and pulverized, during the drying process of the wet pulp layer, the problems of flying dust and floating flocs generated by the PET fibers are effectively avoided. Even when the prepared core material is cut later, no flying dust and floating flocs will be generated, thus improving the quality of the working environment. Therefore, the above method can be used to prepare a core material with stable performance, high strength and excellent heat insulation effect.

[0049] As an example, pour the prepared mixed slurry into a trough, and use a paper fishing curtain (usually a bamboo curtain or a metal mesh) to fish in the mixed slurry. The paper fishing curtain is gently shaken in the water to evenly distribute the fibers on the curtain surface, forming a thin layer of fiber pulp layer.

[0050] As an example, place the fished fiber pulp layer together with the paper fishing curtain on the absorbent cloth, gently press out the excess water, then remove the fiber pulp layer from the paper fishing curtain and place it on a dry surface to continue dewatering, thereby removing most of the water to form a wet pulp layer.

[0051] As an example, dry the wet pulp layer. The wet pulp layer can be dried in the sun or in a drying room by air drying or natural air drying.

[0052] In the third aspect of the present invention, the present invention provides a vacuum insulation panel. The vacuum insulation panel includes the above-mentioned core material or the core material prepared by the above method. Thus, the vacuum insulation panel has excellent heat insulation performance and a long service life.

[0053] In the fourth aspect of the present invention, the present invention provides a heat insulation device. The heat insulation device includes the above-mentioned vacuum insulation panel. Thus, the heat insulation device has excellent heat insulation performance, low production cost and a long service life.

[0054] According to the embodiments of the present invention, the heat insulation device includes but is not limited to refrigerators, freezers, insulated cabinets, etc.

[0055] For those not specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product specifications shall be followed. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through regular channels.

[0056] Example 1

[0057] Example 1 provides a core material. The preparation process of the core material provided in Example 1 is as follows: (1) Cut the PET fibers into particles with a fiber length of 3 mm to 5 mm, then soak them in water for 2 h and cook for 30 min until the fibers become soft, obtaining soft PET fibers.

[0058] (2) Take 70 parts by weight of the above-mentioned soft PET fibers (PET fiber porosity is 80%), 25 parts by weight of viscose fibers (viscose fiber porosity is 65%), 2 parts by weight of defoaming agent and 1 part by weight of dispersant and put them into a beater, add an appropriate amount of water, and beat to form a uniform mixed slurry. The solid content of the mixed slurry is 4%.

[0059] (3) Pour the prepared mixed slurry into a trough, and use a bamboo curtain to scoop it up in the mixed slurry. Gently shake the scooping paper curtain in water to evenly distribute the fibers on the curtain surface, forming a thin layer of fiber pulp layer; Place the scooped fiber pulp layer together with the scooping paper curtain on the absorbent cloth, gently press out the excess water, then remove the fiber pulp layer from the scooping paper curtain and place it on a dry surface to continue dewatering, thereby removing most of the water to form a wet pulp layer; Dry the wet pulp layer in a drying room to obtain the core material.

[0060] Example 2

[0061] Example 2 provides a core material. The difference in the preparation process of the core material in Example 2 from that in Example 1 is as follows: (2) Take 65 parts by weight of the above-mentioned soft PET fibers (the porosity of PET fibers is 80%) and 30 parts by weight of viscose fibers (the porosity of viscose fibers is 65%), as well as 2 parts by weight of defoamer and 1 part by weight of dispersant and put them into a beater, add an appropriate amount of water, and carry out beating to form a uniform mixed slurry. The solid content of this mixed slurry is 4%.

[0062] Comparative Example 1

[0063] Comparative Example 1 provides a core material. The preparation process of the core material in Comparative Example 1 is as follows: (1) Cut the PET fibers into particles with a fiber length of 3 mm to 5 mm, then soak them in water for 2 h and cook for 30 min until the fibers become soft to obtain soft PET fibers.

[0064] (2) Take 97 parts by weight of the above-mentioned soft PET fibers (the porosity of PET fibers is 80%) and 2 parts by weight of defoamer and 1 part by weight of dispersant and put them into a beater, add an appropriate amount of water, and carry out beating to form a uniform mixed slurry. The solid content of this mixed slurry is 4%.

[0065] (3) Pour the prepared mixed slurry into a trough, and use a bamboo curtain to scoop it up in the mixed slurry. Gently shake the scooping paper curtain in water to evenly distribute the fibers on the curtain surface, forming a thin layer of fiber pulp layer; Place the scooped fiber pulp layer together with the scooping paper curtain on the absorbent cloth, gently press out the excess water, then remove the fiber pulp layer from the scooping paper curtain and place it on a dry surface to continue dewatering, thereby removing most of the water to form a wet pulp layer; Dry the wet pulp layer in a drying room to obtain the core material.

[0066] Comparative Example 2

[0067] Comparative Example 2 provides a core material. The preparation process of the core material in Comparative Example 2 is as follows: (1) Cut the PET fibers into particles with a fiber length of 3 mm to 5 mm, then soak them in water for 2 h and cook for 30 min until the fibers become soft to obtain soft PET fibers.

[0068] (2) Take 97 parts by weight of the above-mentioned soft PET fibers (the porosity of the PET fibers is 80%), 2 parts by weight of an antifoaming agent, and 1 part by weight of a dispersant and put them into a beater, add an appropriate amount of water, and beat to form a uniform mixed slurry.

[0069] (3) Add 0.5% of polyvinyl alcohol (conventional glue - PVA) by the mass of the PET fibers to the trough in advance, then pour the beaten mixed slurry into the trough, use a bamboo curtain to fish in the mixed slurry, gently shake the paper fishing curtain in the water to make the fibers evenly distributed on the curtain surface, forming a thin layer of fiber pulp layer; place the lifted fiber pulp layer together with the paper fishing curtain on the absorbent cloth, gently press out the excess water, then remove the fiber pulp layer from the paper fishing curtain, and place it on a dry surface to continue dewatering, so as to remove most of the water to form a wet pulp layer; dry the wet pulp layer in a drying room to obtain the core material.

[0070] Test Example

[0071] In order to verify the performance of the core material provided by the present invention, further tests are carried out on the thermal conductivity, tensile strength, and whether flying dust is generated during cutting of the core materials prepared in Examples 1 - 2 and Comparative Examples 1 - 2.

[0072] The performance test results of the core materials prepared in Examples 1 - 2 and Comparative Examples 1 - 2 are shown in Table 1.

[0073] Table 1

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A core material, comprising a main substrate, characterized in that, The main substrate contains no less than 90 wt% of PET fibers, and no less than 15 wt% of viscose fibers is incorporated into the core material.

2. The core material according to claim 1, characterized in that Based on the total mass of the core material, the mass proportion of the viscose fibers is 20% - 30%.

3. The core material according to claim 1 or 2, characterized in that, The porosity of the viscose fibers is not less than 60%, preferably 65% - 70%.

4. The core material according to claim 1 or 2, characterized in that, The porosity of the PET fibers is not less than 60%, preferably 80% - 85%.

5. The core material according to claim 1 or 2, characterized in that, The mass of the main substrate accounts for 65% - 80% of the mass of the core material; and / or, the main substrate is PET fibers.

6. The core material according to claim 1 or 2, characterized in that, It includes 65 wt% - 80 wt% of the PET fibers and 20 wt% - 30 wt% of the viscose fibers.

7. A method for preparing the core material according to any one of claims 1-6, characterized in that, It includes: Crush and soften the PET fibers; Perform beating treatment on the softened PET fibers and viscose fibers in water to obtain a mixed slurry; Deposit the mixed slurry on a partition board to form a wet pulp layer and then dry it.

8. The method according to claim 7, wherein Before the beating treatment of the softened PET fibers and the viscose fibers in water, add at least one of an antifoaming agent and a dispersant to the water, and then perform the beating treatment; Preferably, the addition amount of the antifoaming agent is 2% - 4% of the total mass of the core material; and / or, The addition amount of the dispersant is 1% - 2% of the total mass of the core material.

9. A vacuum insulating panel, characterized in that, It includes the core material described in any one of claims 1 - 6 or the core material prepared by the method described in claim 7 or 8.

10. A heat insulation device, characterized in that, It includes the vacuum insulation panel described in claim 9.

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