Down thermal filling sheet and method of making the same

Abstract

This application provides a down-filled thermal insulation sheet and its preparation method. The method uses acrylic fibers as the inner and outer layers of fabric, and heat-presses the two acrylic fabric layers to form a pocket. A mixture of down and aerogel powder is filled into the pocket as a filling layer, resulting in a down-filled thermal insulation sheet. First, the aerogel powder is uniformly dispersed into the interior and between the down clusters through a rotating roller. Then, a corona polarization method is used to treat the down-filled thermal insulation sheet with high-voltage electrostatic electret treatment, charging the aerogel powder. When the aerogel powder approaches the down filaments, the filaments become induced to become charged, causing the internal aerogel powder to be adsorbed into the down interior, i.e., onto the surface of the down filaments, under the influence of the electrostatic field. Finally, the down-filled thermal insulation sheet is rubbed and charged using an electrostatic roller friction machine. The stable structure of down can support the effective space inside a down jacket, and the aerogel powder is adsorbed into the down clusters under electrostatic action, improving the thermal insulation performance of the garment.

Description

Technical Field

[0001] This invention relates to the field of thermal textile technology, specifically to a down-filled thermal insulation sheet and its preparation method. Background Technology

[0002] Down jackets, as a common winter garment, are generally divided into two types: lightweight down jackets and extreme cold down jackets. Down jackets often improve their warmth by increasing their thickness, thus failing to meet current demands for lightweight, simple, and convenient clothing.

[0003] Aerogels, as three-dimensional network nanoporous materials, have a porosity of over 90% and a density as low as 0.002 g / cm³. 3 It is the lowest density solid to date. Its thermal conductivity is as low as 0.013-0.018 W / (m·K), close to that of still air, making it a solid material with excellent heat retention properties. Its powder is lightweight and fine.

[0004] Patent application CN 202211172008.7 discloses an aerogel-modified down fabric. This method involves mixing pulverized silica aerogel, nano-silica, and an adhesive to obtain a coating. This coating is then applied to the surface of modified glass fibers using a textile coating finishing machine to obtain a filling layer for the down fabric. The filling layer is then covered with nylon and polyester. The modified glass fibers improve the mechanical properties of the aerogel. According to the international standard ASTM D1518—2014 "Method for Testing Thermal Resistance of Cotton Wool Systems (Hot Plate Method)," the thermal conductivity is measured to be 1.5 W / m. 2 The temperature was around K, and the test samples were evaluated for their warmth retention before and after washing. However, glass fiber is relatively stiff, resulting in poor comfort when used in clothing, and its manufacturing process is too complicated, making it unsuitable for large-scale production and practical use.

[0005] Patent application number CN 202211113065.8 discloses an aerogel thermal shell fleece fabric for down jackets and its preparation method. This method involves adding aerogel powder to a modified porous fiber spinning solution, then spinning the solution through a spinneret to obtain aerogel insulating fibers. The fabric woven from these fibers is then soaked in a phenolic resin solution and naturally air-dried to obtain an aerogel insulating fiber layer, thus achieving full utilization of the aerogel powder. Its drawbacks include poor mechanical properties of the fabric, poor moisture permeability and breathability of the garment, and difficulty in avoiding some degree of damage to the aerogel during the spinning process.

[0006] Patent application CN 201910217734.8 discloses an aerogel-modified down material and its products. This aerogel-modified down material includes down, aerogel powder, and an anti-powder-shedding structure. The anti-powder-shedding structure confines the aerogel powder to the down, preventing powder shedding during use. Its drawback is that the use of adhesives affects the loft of the down, and the use of adhesives can cause some polymer macromolecules to penetrate into the aerogel pores, thereby affecting the air content inside the aerogel and reducing its warmth retention effect.

[0007] In view of this, it is necessary to design a down-filled thermal insulation sheet and its preparation method to solve the above problems. Summary of the Invention

[0008] In view of the technical problems existing in the background art, this application provides a down-filled thermal insulation sheet and its preparation method. The preparation method uses acrylic fiber as the inner and outer fabric layers, and heat-presses the two acrylic fiber fabrics to form a pocket. A mixture of down and aerogel powder is filled into the pocket as a filling layer to obtain the down-filled thermal insulation sheet. First, the aerogel powder is uniformly dispersed into the interior and between the down clusters through a rotating roller. Then, a corona polarization method is used to treat the down-filled thermal insulation sheet with high-voltage electrostatic electret treatment, charging the aerogel powder. When the aerogel powder approaches the down filaments, the down filaments become induced to become charged, causing the internal aerogel powder to be adsorbed into the interior of the down, i.e., onto the surface of the down filaments, under the action of an electrostatic field. Finally, the down-filled thermal insulation sheet is rubbed and charged using an electrostatic roller friction machine. The aerogel powder is lightweight and has a small particle size, and under electrostatic action, it is adsorbed into the down clusters. The stable structure of the down can support the effective space inside the down garment. The electrostatic force can uniformly disperse and adsorb the aerogel powder, thereby providing the garment with superior thermal insulation performance.

[0009] In a first aspect, embodiments of this application provide a method for preparing a down-filled thermal insulation sheet, comprising the following steps: S1. Two layers of acrylic fabric are hot-pressed to form several pocket-shaped filling areas arranged in a grid pattern. The filling areas are reserved with gaps for filling down and aerogel powder. After the down and aerogel powder are filled, the gaps are hot-pressed to seal them, and down insulation wadding is obtained for later use. S2, Place the down insulation wadding obtained in step S1 into a drum, and rotate the drum to evenly disperse the aerogel powder into the interior and between the down clusters; wherein, the rotation speed is 45-50 r / min, and the rotation time is 15-30 min. S3, use a high-voltage electrostatic electret device to process the down insulation wadding obtained in step S2, with the charging voltage set to 2-6kV; so that the aerogel powder carries a charge, and when it approaches the down filaments, the down filaments are induced to become charged, so that the aerogel powder is adsorbed into the interior of the down, i.e. the surface of the down filaments, under the action of the electrostatic field. S4. Use an electrostatic roller friction machine to rub and charge the down insulation wadding obtained in step S3. Set the temperature to 45-60℃, the time to 15-30 min, and the rotation speed to 45-50 r / min. Through the action of external force, the down and acrylic fibers are rubbed efficiently, thereby quickly generating an electrostatic field and strengthening the adsorption and dispersion of aerogel powder inside the down insulation filling wadding.

[0010] Furthermore, the mass ratio of the down to the aerogel powder is 4:(1-5).

[0011] Furthermore, the aerogel powder is a hydrophobic silica aerogel with a particle size range of 0.1-10 μm, a porosity of 90%-95%, and a pore size range of 15 nm-30 nm.

[0012] Furthermore, in step S1, the hot-pressing temperature is 320°C.

[0013] Furthermore, the down is made of white duck down, with a loft of 16-17cm and a down content of 95%.

[0014] Secondly, this application embodiment also provides a down-filled thermal insulation pad, which is prepared by the preparation method described in the foregoing technical solution. The down-filled thermal insulation pad includes an inner layer, an outer layer, and a filling layer. The filling layer is located in the cavity between the outer layer and the inner layer. The filling layer is a mixture of down and aerogel powder. The charge of the down-filled thermal insulation pad is 0.13-0.17µC.

[0015] Furthermore, the mass ratio of the down to the aerogel powder is 4:(1-5).

[0016] Furthermore, both the inner and outer layers are made of acrylic fiber.

[0017] The beneficial effects of this invention are as follows: 1. In this invention, the outermost surface of the down fiber in the filling layer is a cell membrane composed of a bilayer membrane of sterols and triphosphates, both of which are poorly soluble in water. Therefore, down has excellent hydrophobic properties and is in the direction of easily losing electrons and becoming positively charged in the electrostatic sequence. The outer and inner acrylic fabrics are distributed on the right side of the down in the electrostatic sequence. The two have a large difference in their ability to gain and lose charges. Friction will inevitably occur during the wearing and use of the garment. The contact and friction between the down fiber and the outer and inner acrylic fabrics will generate static electricity to continuously provide a stable static power source.

[0018] 2. In this invention, the sample is treated with high voltage electret to actively generate charges and initially form an electrostatic field. Then, the sample is treated with triboelectric charging. Through the synergistic effect of the above two methods, the aerogel powder is adsorbed onto the surface of the down fibers under the action of the electrostatic field, thereby achieving uniform dispersion. In addition, the static electricity generated by the friction between the acrylic fibers and the down during subsequent use is used to maintain the stability of the electrostatic field, thereby maintaining the stable heat-insulating structure formed by the combination of aerogel powder and down.

[0019] 3. In this invention, the aerogel powder is lightweight and has a small particle size. Under the action of electrostatics, it will be adsorbed into the down clusters. The down has a stable structure and can support the effective space inside the down jacket. The electrostatics can be used to evenly disperse and adsorb the aerogel powder, thereby providing the garment with better thermal insulation performance. On this basis, the amount of down used can be reduced, the thickness of the down jacket can be reduced, and the thermal insulation effect reduced due to the reduction of down can be compensated by the distribution of the aerogel powder.

[0020] 4. In this invention, the filling area is sealed by hot pressing. The melting point of acrylic fiber is 317℃, and the hot pressing temperature of 320℃ can effectively ensure the adhesion of the two fibers, thereby effectively ensuring that the aerogel powder does not leak.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the down-filled thermal insulation sheet prepared according to the present invention.

[0024] Figure 2 This is a diagram showing the state of down adsorbed by electrostatic adsorption of aerogel powder.

[0025] Figure 3 This is a schematic diagram showing the distribution of the filling area and the hot-pressing area. Detailed Implementation

[0026] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0028] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0031] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0032] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0033] While using adhesives to confine aerogel powder to down prevents powder shedding during use, the use of adhesives can affect the loft of the down and cause some polymer macromolecules to penetrate into the aerogel pores, thus affecting the air content inside the aerogel and reducing its warmth retention.

[0034] Please see Figures 1 to 3 As shown in the figure, this application provides a method for preparing a down-filled thermal insulation sheet, including the following steps: S1. Two layers of acrylic fabric are hot-pressed to form several pocket-shaped filling areas arranged in a grid pattern. The filling areas are reserved with gaps for filling down and aerogel powder. After the down and aerogel powder are filled, the gaps are hot-pressed to seal them, and down insulation wadding is obtained for later use. The mass ratio of down to aerogel powder is 4:(1-5).

[0035] The hot-pressing temperature is 320℃. Hot-pressing is used to seal the filling area. Acrylic fiber has a melting point of 317℃, and the hot-pressing temperature of 320℃ effectively ensures the adhesion between the fibers, thus preventing leakage of the aerogel powder.

[0036] The down is made of white duck down, with a loft of 16-17cm and a down content of 95%.

[0037] The aerogel powder is made of hydrophobic silica aerogel with a particle size range of 0.1-10 μm, a porosity of 90%-95%, and a pore size range of 15 nm-30 nm.

[0038] S2, the down insulation wadding obtained in step S1 is placed into a drum. The drum rotates, and mechanical force is used to ensure that the aerogel powder is evenly dispersed into the interior and between the down clusters, and the two are evenly mixed; wherein, the rotation speed is 45-50 r / min, and the rotation time is 15-30 min. S3, use a high-voltage electrostatic electret device to process the down insulation wadding obtained in step S2, with the charging voltage set to 2-6kV; the high-voltage charging section charges the aerogel powder, and when it approaches the down filaments, the down filaments are induced to become charged, so that the aerogel powder is adsorbed into the down interior, i.e. the down filament surface, under the action of the electrostatic field. S4. Use an electrostatic roller friction machine to rub and charge the down insulation wadding obtained in step S3. Set the temperature to 45-60℃, the time to 15-30 min, and the rotation speed to 45-50 r / min. Through the action of external force, the down and acrylic fibers are rubbed efficiently, thereby quickly generating an electrostatic field and strengthening the adsorption and dispersion of aerogel powder inside the down insulation filling wadding.

[0039] In this application, the outermost surface of the down fiber is a cell membrane, which is composed of a bilayer membrane of sterols and triphosphates. Both of them are poorly soluble in water, so down has excellent hydrophobic properties and is in the direction of easily losing electrons and becoming positively charged in the electrostatic sequence. Acrylic fiber is selected as the outer and inner fabric. Acrylic fiber is distributed on the right side of down in the electrostatic sequence. The two have a large difference in the ability to gain and lose charges. Friction will inevitably be generated during the wearing and use of the clothing, and friction will inevitably generate static electricity, thus providing a stable static power source.

[0040] In this application, the mechanical force of a rotating roller is first used to ensure that the aerogel powder is evenly dispersed inside and between the down clusters, and the two are uniformly mixed. Then, a corona polarization method is used to treat the down insulation wadding with a high-voltage electrostatic electret device, causing the aerogel powder to carry a charge. When the aerogel powder approaches the down filaments, the down filaments become induced to become charged, causing the internal aerogel powder to be adsorbed into the down interior, i.e., onto the surface of the down filaments, under the influence of an electrostatic field. Finally, an electrostatic roller friction machine is used to rub and charge the down insulation wadding. The aerogel powder is lightweight and has a small particle size. Under the influence of electrostatics, it is adsorbed into the down clusters. The stable structure of the down can support the effective space inside the down jacket. By utilizing electrostatics, the aerogel powder can be evenly dispersed and adsorbed, thereby providing the garment with superior thermal insulation performance.

[0041] Secondly, this application provides a down-filled thermal insulation sheet prepared by the aforementioned method. The prepared down-filled thermal insulation sheet includes an inner layer 1, an outer layer 2, and a filling layer 5. The filling layer 5 is located in the cavity between the outer layer 2 and the inner layer 1, and the filling layer is a mixture of down 6 and aerogel powder 3. The inner layer 1 and the outer layer 2 are hot-pressed to form a plurality of pocket-shaped filling areas arranged in a grid pattern. Adjacent filling areas are connected by hot-pressing strips 4.

[0042] The mass ratio of down 6 to aerogel powder 3 is 4:(1-5).

[0043] The down is made of white duck down, with a loft of 16-17cm and a down content of 95%.

[0044] The aerogel powder is made of hydrophobic silica aerogel with a particle size range of 0.1-10μm and a porosity of 90%~95%.

[0045] The charge of this down insulation pad is 0.13-0.17µC; after 5 washes, the Clo value of this down insulation pad is 1.57clo, a decrease of only 0.01clo.

[0046] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0047] Example 1 This embodiment provides a method for preparing a down-filled thermal insulation sheet, including the following steps: S1. Two layers of acrylic fabric are hot-pressed to form several pocket-shaped filling areas arranged in a grid pattern. The filling areas are reserved with gaps for filling down and aerogel powder. After the down and aerogel powder are filled, the gaps are hot-pressed to seal them, and a down insulation wadding is obtained for later use. The mass ratio of down to aerogel powder is 4:2.

[0048] The down is made of white duck down with a loft of 17cm and a down content of 95%. The aerogel powder is made of hydrophobic silica aerogel with a particle size of 0.1-10μm, a porosity of 90%-95%, and a pore size of 15nm-30nm.

[0049] The filling area is sealed by hot pressing, with the hot pressing temperature set at 320℃.

[0050] S2, the down insulation wadding obtained in step S1 is placed into a drum, and the drum is rotated to evenly disperse the aerogel powder into the interior and between the down clusters; wherein, the rotation speed is 50 r / min and the rotation time is 30 min. S3, use a high-voltage electrostatic electret device to process the down insulation wadding obtained in step S2, with the charging voltage set to 4kV; the high-voltage charging section charges the aerogel powder, and when it approaches the down filaments, the down filaments are induced to become charged, so that the aerogel powder is adsorbed into the down interior, i.e. the down filament surface, under the action of the electrostatic field. S4. The down insulation wadding obtained in step S3 is rubbed and charged using an electrostatic roller friction machine. The temperature is set at 60℃, the time at 30min, and the rotation speed at 50 r / min. The external force causes the down and acrylic fibers to rub against each other efficiently, thereby quickly generating an electrostatic field and enhancing the adsorption and dispersion of aerogel powder inside the down insulation filling wadding.

[0051] Examples 2-5 and Comparative Example 1 Examples 2-5 and Comparative Example 1 provide a method for preparing a down-filled thermal insulation sheet. Compared with Example 1, the difference lies in the change of the mass ratio of down to aerogel powder in step S1, as shown in the table below. The rest is roughly the same as in Example 1 and will not be repeated here.

[0052] Example 6 Example 6 provides a method for preparing a down-filled thermal pad. Compared with Example 1, the difference is that the down used has a loft of 16cm. The rest is roughly the same as in Example 1, and will not be repeated here.

[0053] Comparative Example 2 Comparative Example 2 provides a method for preparing a down-filled thermal pad. The difference from Example 1 is that aerogel powder is not used. That is, the filling area is not filled with aerogel powder, but only with down. The rest is roughly the same as Example 1, and will not be described again here.

[0054] Comparative Example 3 Comparative Example 3 provides a method for preparing a down-filled thermal pad. Compared with Example 1, the difference is that the fabric is replaced with nylon instead of acrylic fiber. Otherwise, it is roughly the same as Example 1 and will not be described again here.

[0055] Comparative Example 4 Comparative Example 4 provides a method for preparing a down-filled thermal insulation sheet. The difference from Example 1 is that the down is replaced with cotton wadding. The rest is roughly the same as Example 1 and will not be described again here.

[0056] Comparative Example 5 Comparative Example 5 provides a method for preparing a down-filled thermal insulation sheet. Compared with Example 1, the difference is that step S2 is not performed. The rest is roughly the same as Example 1, and will not be described again here.

[0057] Comparative Example 6 Comparative Example 6 provides a method for preparing a down-filled thermal insulation sheet. Compared with Example 1, the difference is that step S3 is not performed. The rest is roughly the same as Example 1, and will not be described again here.

[0058] Comparative Example 7 Comparative Example 7 provides a method for preparing a down-filled thermal insulation sheet. Compared with Example 1, the difference is that step S4 is not performed. The rest is roughly the same as Example 1, and will not be described again here.

[0059] The following performance tests were conducted on the down insulation filling samples of each embodiment and comparative example. The test results are shown in Table 1. The specific test steps are as follows: Referring to the relevant standards in GB / T 3820-1997, "Determination of Thickness of Textiles and Textile Products", the thickness of the samples was tested using a nonwoven fabric thickness tester (Ningbo Textile Instrument Co., Ltd.). The relative humidity was 65±4.0%, and the temperature was 20±2.0 ℃. The readings were taken to a depth of 0.5 mm, and each sample was tested 10 times, with the average value taken.

[0060] According to the relevant standards in GB / T 11048-2018 "Determination of Thermal and Moisture Resistance of Textiles under Steady-State Conditions for Physiological Comfort (Evaporative Hot Plate Method)," the thermal insulation performance of the samples was tested using a YG-606D flat-plate fabric thermal insulation tester (Ningbo Textile Instrument Co., Ltd.). The samples were conditioned for 24 hours in a climate chamber with an air humidity of 65±3.0%, a temperature of 20±0.5 ℃, and an air velocity not exceeding 0.1 m / s. Each sample was tested three times using the flat plate method within this climate chamber, and the average value was taken to determine the Clo value of the sample.

[0061] Referring to the relevant standards in GB / T 8629-2017 "Home Washing and Drying Procedures for Textile Testing", all samples were tested by washing using a Y(B)089E fully automatic shrinkage tester (Wenzhou Darong Textile Instrument Co., Ltd.). The washing program was set to the 4N standard washing mode, with one washing cycle and a dehydration rate of 500 rpm. The accompanying fabric was 100% polyester fiber fabric, and the mass ratio of the sample to the accompanying fabric was 1:1. The detergent used was standard detergent 3 (ECE standard detergent 98).

[0062] Referencing the relevant standards in JJF (Textile) 071-2016 "Tester for Frictional Charge Density of Fabrics (Faraday Cylinder Method)", the samples were conditioned for 24 hours under environmental conditions of 35±5.0% relative humidity and 20±2.0 ℃, and then tested. The samples were immediately placed in the Faraday cylinder after the friction process was completed. Each sample was tested five times, and the average value was taken.

[0063] As shown in Table 1, the down insulation filling sheet of the present invention has superior warmth retention performance compared with the comparative example product. Examples 1-6 have a thinner thickness than Comparative Example 2, a more stable electrostatic field than Comparative Example 3, and better wash resistance. This indicates that the electrostatic field generated by the friction between acrylic fibers and down significantly disperses the aerogel powder, and the hydrophobic aerogel powder fully utilizes the internal space of the filling sheet, improving the warmth retention effect per unit space. Simultaneously, its hydrophobic properties improve the wash fastness of the down insulation filling sheet.

[0064] Specifically, when the mass ratio of down to aerogel powder exceeds the range of 4:(1-5), reaching 4:6 (Comparative Example 1), the clo value of the sample decreases, its warmth retention performance declines, and its thickness decreases. This is because continuously increasing the amount of aerogel powder filling leads to excessive aerogel powder filling a limited space, causing the down to be compressed as a whole, reducing the amount of still air it can hold, and consequently decreasing the clo value.

[0065] Without the addition of aerogel powder (Comparative Example 2), the sample had a lower Clos value, a larger thickness, and a significant decrease in warmth retention after five washes. This is because the fluffy down clusters, filling a large amount of the enclosed space, resulted in a higher overall sample thickness. However, the larger pores between the down clusters and down fibers allowed for normal air molecule movement, leading to increased thermal convection and a lower overall Clos value. After repeated washing, the hydrophobic lipids on the down surface were damaged, reducing hydrophobicity and consequently affecting its fluffiness, thus decreasing its warmth retention.

[0066] When the fabric was replaced with nylon (Comparative Example 3), the sample had a lower charge and the overall electrostatic field was unstable. This is because nylon and down are located close to each other in the electrostatic sequence, and they cannot effectively generate a charge when they rub against each other. As a result, the aerogel powder cannot be dispersed evenly and effectively, which is not conducive to its stable adsorption on the down fibers.

[0067] When down was replaced with cotton wadding (Comparative Example 4), the sample showed a lower Clo value and less charge, and the Clo value decreased significantly after 5 washes. This is because cotton fibers are long and thin, have a higher thermal conductivity, and are less warm than down. They also have a higher moisture regain, are prone to shrinkage after washing, and their loft decreases after multiple washes. Furthermore, cotton and acrylic fibers are close together in the electrostatic sequence, making them less likely to become charged by friction. The electrostatic field is unstable and cannot effectively adsorb and disperse with the aerogel powder, resulting in poor overall warmth retention.

[0068] When rolling mixing was not performed (Comparative Example 5), the down and aerogel powder inside the sample were not pre-dispersed, which caused the aerogel powder to aggregate inside the sample. The agglomeration between the powders resulted in poor overall uniformity of the sample, low Cro value, and poor heat retention.

[0069] When electrostatic electret treatment is not performed (Comparative Example 6), the acrylic fibers on the sample surface and the down and aerogel powder inside cannot be charged by high voltage. Consequently, the aerogel powder cannot be electrostatically adsorbed by a stable electrostatic field, resulting in uneven dispersion. Therefore, the sample has increased thermal convection, a lower Clos value, and poor heat retention.

[0070] When no triboelectric charging treatment was performed (Comparative Example 7), the charge carried by the sample during the high-voltage charging stage was not further sustained, resulting in the instability of the electrostatic field inside the sample. The overall charge of the sample decreased, the Cro value dropped, and the heat preservation effect was poor.

[0071] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a down-filled thermal insulation sheet, characterized in that, Includes the following steps: S1, hot-press two layers of acrylic fabric to form several grid-like pocket-shaped filling areas; gaps are reserved in the filling areas for filling down and aerogel powder. After the down and aerogel powder are filled, the gaps are hot-pressed to seal, and a down insulation wadding is obtained for later use; wherein, the mass ratio of the down to the aerogel powder is 4:(1-5). S2, Place the down insulation wadding obtained in step S1 into a drum, and rotate the drum to evenly disperse the aerogel powder into the interior and between the down clusters; wherein, the rotation speed is 45-50 r / min, and the rotation time is 15-30 min. S3. The down insulation wadding obtained in step S2 is processed using a high-voltage electrostatic electret device with a charging voltage of 2-6 kV. This causes the aerogel powder to carry a charge. When the aerogel powder approaches the down filaments, the down filaments become induced to become charged, causing the aerogel powder to be adsorbed onto the surface of the down filaments under the action of an electrostatic field. S4. Use an electrostatic roller friction machine to rub and charge the down insulation wadding obtained in step S3. Set the temperature to 45-60℃, the time to 15-30 min, and the rotation speed to 45-50 r / min. Through the action of external force, the down and acrylic fibers are rubbed efficiently, thereby quickly generating an electrostatic field and strengthening the adsorption and dispersion of aerogel powder inside the down insulation filling wadding.

2. The method for preparing the down-filled thermal insulation sheet according to claim 1, characterized in that, The aerogel powder is a hydrophobic silica aerogel with a particle size range of 0.1-10 μm, a porosity of 90%-95%, and a pore size range of 15 nm-30 nm.

3. The method for preparing the down-filled thermal insulation sheet according to claim 1, characterized in that, In step S1, the hot pressing temperature is 320°C.

4. The method for preparing the down-filled thermal insulation sheet according to claim 1, characterized in that, The down is made of white duck down, with a loft of 16-17cm and a down content of 95%.

5. A down-filled thermal insulation sheet, characterized in that, The down-filled thermal insulation sheet is prepared by the preparation method according to any one of claims 1-4, and the charge amount of the sheet is 0.13-0.17µC.

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