A double-layer nonwoven material and a preparation method and application thereof

Abstract

The application relates to the technical field of non-woven product processing, and particularly discloses a double-layer non-woven material and a preparation method and application thereof. The double-layer non-woven material comprises a surface layer and an inner layer. The raw material of the surface layer is ES fiber, and the raw material of the inner layer comprises heat-sensitive modified three-dimensional polyester fiber and ES fiber. The heat-sensitive modified three-dimensional polyester fiber has higher surface activity and thermal conductivity, can be closely interpenetrated with the ES fiber, improves the air permeability and thermal conductivity of the material, makes the expandability of the three-dimensional polyester fiber reach the extreme, and combines the optimization of the processing technology of the blended fiber hot air non-woven material, so that the material has higher bulkiness, is more three-dimensional and light, and is more in line with the ergonomic structure of the eye area.

Description

Technical Field

[0001] This invention belongs to the field of nonwoven product processing technology, specifically relating to a double-layer nonwoven material, its preparation method, and its application. Background Technology

[0002] Modern people commonly suffer from excessive eye strain, which can lead to increasingly sensitive eyes, excessive tearing, dryness, soreness, and decreased vision. Steam eye masks are often used to quickly relieve eye discomfort during short breaks. These masks utilize the principle of steaming, which stimulates the surface of the eye with heat, opening pores, relaxing muscles, dilating capillaries, and promoting blood and lymphatic circulation, thus alleviating discomfort.

[0003] Currently, a series of steam eye mask products have appeared on the market. For example, patent CN 108743027 B discloses a steam eye mask and its manufacturing method. In addition to relieving eye fatigue, this steam eye mask also has beauty and skin care effects. However, due to the ergonomic structure of the human eyeball and the area around the eyes, specifically because our eyes are not a flat plane, conventional flat non-woven fabrics generally cannot adapt to the three-dimensional structure of the eyes, thus preventing the effective conduction of steam heat.

[0004] After deconstructing the steam eye mask into layers, this invention discovered that the material on the skin-contacting side of the steam eye mask plays a decisive role in the fit. Therefore, there is an urgent need in the market for a material that can perfectly conform to the three-dimensional structure of the eyes when the steam eye mask is heated at around 40°C. Summary of the Invention

[0005] To address the problem of poor fit between the skin-contact material and the eyeball in existing steam eye masks, this invention optimizes the processing technology of hot air nonwoven materials and combines them with heat-sensitive modified three-dimensional polyester fibers to improve the breathability and thermal conductivity of the material. This results in the development of a hot air nonwoven material that conforms to the three-dimensional structure of the eye, is skin-friendly, soft, delicate, and highly fluffy.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of the present invention provides a double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of ES fiber with a diameter of 0.6 to 3.0D; and the inner layer comprises heat-modified three-dimensional polyester fiber and ES fiber.

[0008] This invention, through specific selection of fiber type, fiber ratio, fiber thickness ratio, and hot air process parameters during the hot air nonwoven manufacturing process, yields a double-layer hot air nonwoven material that satisfies both the requirements of being soft and delicate against the skin and having high fluffiness and a strong fit. The outer layer of this double-layer composite hot air nonwoven material is made of ES fiber, while the inner layer is a mixture of three-dimensional polyester fiber and ES fiber. When applied to steam eye masks, the self-heating steam causes the inner fiber to expand further, making the steam eye mask more three-dimensional and lightweight, with more uniform temperature diffusion, thus improving the user experience.

[0009] In some embodiments, the mass ratio of heat-modified three-dimensional polyester fiber to ES in the inner layer material is (1-4):1.

[0010] This invention specifically selects ES fiber as the surface and inner layer materials. ES fiber is a bicomponent composite fiber with a core-sheath structure. The sheath has a low melting point and high flexibility, while the core has a high melting point and high strength. This allows the surface and inner layer materials to undergo heat treatment, resulting in a portion of the sheath melting at the fiber intersections to form a fusion, while the remaining portion retains its fibrous state, thus achieving bonding. This bonding method has a small thermal shrinkage rate, preventing the material from easily deforming.

[0011] In some embodiments, the inner layer material contains heat-modified three-dimensional polyester fibers with a diameter of 2-8D and ES fibers with a diameter of 1-6D.

[0012] This invention achieves a balance between the bonding effect, three-dimensionality, lightness, breathability, and fluffiness of the inner and outer layers by specifically selecting the type and thickness of the inner layer raw material fibers.

[0013] In some embodiments, the preparation steps of the heat-sensitive modified three-dimensional polyester fiber are as follows:

[0014] S1. Immerse the three-dimensional polyester fiber in a mixed acid solution, stir at room temperature for 4-8 hours, filter, wash, and dry at 50-80℃ to constant weight to obtain surface-treated three-dimensional polyester fiber.

[0015] S2. The surface-treated three-dimensional polyester fiber obtained in step S1 is immersed in dopamine hydrochloride solution, washed, and dried to constant weight to obtain the heat-sensitive modified three-dimensional polyester fiber.

[0016] In some embodiments, in step S1, the mixed acid solution is prepared by mixing 30-70 wt% sulfuric acid and 20-50 wt% nitric acid in a volume ratio of (1-4):1.

[0017] Compared with other types of polyester fibers, three-dimensional polyester fibers have a 3D hollow spiral microstructure instead of a 2D planar structure and good bulkiness. However, the mixture of three-dimensional polyester fibers and ES fibers presents an irregular stacking state of individual fibers, which makes it impossible for the material obtained after surface heat treatment to expand evenly, affecting the fit with the eye.

[0018] This invention first uses acid treatment to distribute -OH and -COOH hydrophilic functional groups on the surface of three-dimensional polyester fibers. The -COOH group is formed by the oxidation of some hydroxyl groups. This improves the surface activity of the three-dimensional polyester fibers, so that the subsequent mixing with ES fibers is not a random stacking state, but a tight interweaving between fibers. This results in a uniform distribution of the cross points of the fused fibers after heat treatment with the surface raw materials, improving the breathability of the material. Furthermore, the presence of oxygen-containing polar functional groups such as -OH and -COOH is beneficial for the subsequent grafting of dopamine. The hydroxyl groups, oxidized carbonyl groups, and carbon-nitrogen bonds contained in dopamine are beneficial for improving the thermal conductivity and thermal diffusion of the material, maximizing the expandability of the three-dimensional polyester fibers, and making the steam eye mask more three-dimensional, lightweight, and fits the eyes better.

[0019] A second aspect of the present invention provides a method for preparing a double-layer nonwoven material, comprising the following steps:

[0020] The surface and inner layers of raw materials are loosened, mixed, cleaned, and combed to obtain a surface fiber web and an inner fiber web. The two layers of fiber web are then combined together, hot-rolled after 5-20 seconds of hot air, and then wound into shape to obtain the double-layer nonwoven material.

[0021] In some embodiments, the surface density of the surface fiber web is 10–40 g / m². 2 The inner fiber web has a surface density of 20–70 g / m². 2 .

[0022] In some embodiments, the specific parameters of the hot air are: the hot air chamber temperature is 120-150°C, and the ironing machine temperature is 125-160°C.

[0023] In some embodiments, the specific parameters of the hot rolling are: production speed of 10-30 m / min, temperature of 110-160°C, and pressure of 0.2-0.8 MPa.

[0024] A third aspect of the present invention provides an application of a double-layer nonwoven material in a steam eye mask.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This invention uses ES fiber as the surface material and a mixture of heat-modified three-dimensional polyester fiber and ES fiber as the inner layer material. By optimizing the processing technology of the blended fiber hot air nonwoven material, a hot air nonwoven material is developed that satisfies both the skin-friendly softness and delicateness on the skin side and the high fluffiness and strong fit. When applied to steam eye masks, the steam generated by the self-heating of the eye mask causes the inner fiber to expand further, making the steam eye mask fluffier, more three-dimensional and lighter, and with more uniform temperature diffusion when heated to 40°C, thus improving the user experience of the steam eye mask.

[0027] 2. This invention first improves the surface activity of three-dimensional polyester fibers through acid treatment, making them interlock tightly with ES fibers and improving the breathability of the material. Then, by grafting dopamine, the thermal conductivity and thermal diffusion of the material are improved by utilizing the hydroxyl groups, carbonyl groups and carbon-nitrogen bonds contained in dopamine, allowing the expandability of three-dimensional polyester fibers to be maximized, making the steam eye mask more three-dimensional, lightweight and conforming to the three-dimensional structure of the eyes. Detailed Implementation

[0028] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0029] Preparation Example 1

[0030] The preparation steps of heat-sensitive modified three-dimensional polyester fiber A are as follows:

[0031] S1. Immerse the three-dimensional polyester fiber in a mixed acid solution, which is a mixture of 50wt% sulfuric acid and 30wt% nitric acid in a volume ratio of 2:1. Stir at room temperature for 6 hours, filter, wash with deionized water, and dry at 60°C to constant weight to obtain surface-treated three-dimensional polyester fiber.

[0032] S2. The surface-treated three-dimensional polyester fiber obtained in step S1 is immersed in a 0.06 mol / L dopamine hydrochloride solution for 12 hours, washed, and dried at 60°C to constant weight to obtain heat-sensitive modified three-dimensional polyester fiber A.

[0033] Preparation Example 2

[0034] The preparation steps of heat-sensitive modified three-dimensional polyester fiber B are as follows:

[0035] The three-dimensional polyester fiber was immersed in a mixed acid solution, which was composed of 50 wt% sulfuric acid and 30 wt% nitric acid in a volume ratio of 2:1. The mixture was stirred at room temperature for 6 hours, filtered, washed with deionized water, and dried at 60°C to constant weight to obtain the heat-sensitive modified three-dimensional polyester fiber B.

[0036] Preparation Example 3

[0037] The preparation steps of heat-sensitive modified three-dimensional polyester fiber C are as follows:

[0038] The three-dimensional polyester fiber was immersed in a 0.06 mol / L dopamine hydrochloride solution for 12 hours, washed, and dried at 60°C to constant weight to obtain the heat-sensitive modified three-dimensional polyester fiber C.

[0039] Preparation Example 4

[0040] The preparation steps for modified polyester fibers are as follows:

[0041] The difference between this preparation example and preparation example 1 is that the three-dimensional polyester fiber is replaced by polyester fiber.

[0042] Example 1

[0043] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 2D ES fiber; and the inner layer comprises 6D heat-modified three-dimensional polyester fiber A and 5D ES fiber in a mass ratio of 3:1.

[0044] The preparation method of the double-layer nonwoven material in this embodiment includes the following steps: opening, mixing, removing impurities, and combing the surface material and the inner material respectively to obtain a density of 30 g / m³. 2 The surface fiber web has a density of 50g / m². 2 The inner layer of fiber web is formed by combining the two layers of fiber web together. After 15 seconds of hot air, it is hot rolled. The specific parameters of the hot air are: hot air chamber temperature of 135℃ and ironing machine temperature of 140℃. The specific parameters of the hot rolling are: production speed of 20m / min, temperature of 140℃ and pressure of 0.6Mpa. Then it is wound into shape to obtain a double-layer nonwoven material.

[0045] Example 2

[0046] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 0.6D ES fiber; and the inner layer comprises 2D heat-modified three-dimensional polyester fiber A and 1D ES fiber in a mass ratio of 1:1.

[0047] The preparation method of the double-layer nonwoven material in this embodiment includes the following steps: opening, mixing, removing impurities, and combing the surface material and the inner material respectively to obtain a density of 10 g / m³. 2 The surface fiber web has a density of 20g / m². 2The inner layer of fiber web is formed by combining the two layers of fiber web together. After 10 seconds of hot air, it is hot rolled. The specific parameters of the hot air are: hot air chamber temperature of 120℃ and ironing machine temperature of 125℃. The specific parameters of the hot rolling are: production speed of 10m / min, temperature of 110℃ and pressure of 0.2Mpa. Then it is wound into shape to obtain a double-layer nonwoven material.

[0048] Example 3

[0049] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 3D ES fiber; and the inner layer comprises 8D heat-modified three-dimensional polyester fiber A and 6D ES fiber in a mass ratio of 4:1.

[0050] The preparation method of the double-layer nonwoven material in this embodiment includes the following steps: opening, mixing, removing impurities, and combing the surface material and the inner material respectively to obtain a density of 40 g / m³. 2 The surface fiber web has a density of 70g / m². 2 The inner layer of fiber web is formed by combining the two layers of fiber web together. After 20 seconds of hot air, it is hot rolled. The specific parameters of the hot air are: hot air chamber temperature of 150℃ and ironing machine temperature of 160℃. The specific parameters of the hot rolling are: production speed of 30m / min, temperature of 160℃ and pressure of 0.8Mpa. Then it is wound into shape to obtain a double-layer nonwoven material.

[0051] Example 4

[0052] This embodiment provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that the heat-sensitive modified three-dimensional polyester fiber A in the inner layer raw material is replaced by an equal amount of heat-sensitive modified three-dimensional polyester fiber B.

[0053] Example 5

[0054] This embodiment provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as that in Embodiment 1, except that the heat-sensitive modified three-dimensional polyester fiber A in the inner layer raw material is replaced by an equal amount of heat-sensitive modified three-dimensional polyester fiber C.

[0055] Example 6

[0056] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 2D ES fiber; and the inner layer comprises 6D heat-modified three-dimensional polyester fiber A and 5D ES fiber in a mass ratio of 0.8:1.

[0057] The preparation method of the double-layer nonwoven material in this embodiment is the same as that in Embodiment 1.

[0058] Example 7

[0059] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 2D ES fiber; and the inner layer comprises 6D heat-modified three-dimensional polyester fiber A and 5D ES fiber in a mass ratio of 4.3:1.

[0060] The preparation method of the double-layer nonwoven material in this embodiment is the same as that in Embodiment 1.

[0061] Example 8

[0062] This embodiment provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as in Embodiment 1, except that the surface density of the inner layer fiber web is 15 g / m². 2 .

[0063] Example 9

[0064] This embodiment provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as in Embodiment 1, except that the surface density of the inner layer fiber web is 75 g / m². 2 .

[0065] Comparative Example 1

[0066] This comparative example provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as that in Example 1, except that the heat-sensitive modified three-dimensional polyester fiber A in the inner layer raw material is replaced by an equal amount of three-dimensional polyester fiber.

[0067] Comparative Example 2

[0068] A double-layer nonwoven material comprising a surface layer and an inner layer, wherein the surface layer is made of 0.5D ES fiber; and the inner layer comprises 6D heat-modified three-dimensional polyester fiber A and 5D ES fiber in a mass ratio of 3:1.

[0069] The preparation method of the double-layer nonwoven material in this comparative example is the same as that in Example 1.

[0070] Comparative Example 3

[0071] A double-layer nonwoven material comprising an outer layer and an inner layer, wherein the outer layer is made of 3.5D ES fiber; and the inner layer comprises 6D heat-modified three-dimensional polyester fiber A and 5D ES fiber in a mass ratio of 3:1.

[0072] The preparation method of the double-layer nonwoven material in this comparative example is the same as that in Example 1.

[0073] Comparative Example 4

[0074] This comparative example provides a double-layer nonwoven material and its preparation method. The specific implementation method is the same as that in Example 1, except that the heat-sensitive modified three-dimensional polyester fiber A in the inner layer raw material is replaced by an equal amount of modified polyester fiber.

[0075] Performance testing:

[0076] 1. Breathability test:

[0077] This invention demonstrates the bulkiness of a material through its air permeability. According to standard GB / T5453-1997, an automatic air permeability meter (YG461G type) was used for air permeability testing. The double-layer nonwoven materials obtained in each embodiment and comparative example were placed between two clamps of the automatic air permeability meter, with a sample test area of ​​20 cm². 2 A constant test pressure difference of 100 Pa was used, and three tests were conducted at different locations for each double-layer nonwoven material, and the average value was taken.

[0078] 2. Thermal conductivity test

[0079] Referring to GB / T11048-2018 "Determination of thermal and moisture resistance of textiles under steady-state conditions for physiological comfort", the thermal resistance R of the fabric was tested using a thermal and moisture resistance tester (Ningbo Textile Instrument Factory, China). The thermal conductivity k of the material was calculated according to the formula k=d / R, where d is the thickness of the material. The higher the thermal conductivity, the better the thermal conductivity of the material under steady-state conditions.

[0080] The results are shown in Table 1.

[0081] Table 1 Performance Test Results

[0082]

[0083]

[0084] As shown in Table 1, the air permeability of the double-layer nonwoven materials in Examples 1-3 is all higher than 94%. Combined with the thermal conductivity, this indicates that the material has high fluffiness when exposed to the steam generated by the self-heating of the eye mask, meeting the requirements for a close fit to the eyes. Compared to Example 1, the heat-sensitive modified three-dimensional polyester fiber used in Example 4 was not grafted with dopamine, which led to a decrease in the thermal conductivity of the material; while the heat-sensitive modified three-dimensional polyester fiber used in Example 5 was not treated with mixed acid, which is not conducive to the subsequent grafting of dopamine, also leading to a decrease in thermal conductivity.

[0085] Compared to Example 1, Examples 6-7 altered the mass ratio of heat-modified three-dimensional polyester fiber A to ES fiber in the inner layer raw material; Comparative Examples 2-3 altered the thickness of ES fiber in the outer layer raw material. These changes are all detrimental to the bonding between the inner and outer layer fiber webs, leading to a decrease in the material's air permeability and thermal conductivity. Compared to Example 1, Examples 8-9 altered the density of the inner layer fiber web surface, which can improve air permeability to some extent, but this is due to high porosity and cannot improve bonding.

[0086] Compared to Example 1, the three-dimensional polyester fibers used in Comparative Example 1 were not acid-treated, resulting in a lack of tight interlocking when mixed with ES fibers. This led to uneven distribution of the fused fiber intersections, affecting the material's air permeability and thermal conductivity. Compared to Example 1, Comparative Example 4 used ordinary polyester fibers instead of three-dimensional polyester fibers during acid treatment, reducing the material's bulkiness and consequently decreasing its air permeability.

[0087] The embodiments and comparative examples described above do not limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A double-layer nonwoven material comprising a surface layer and an inner layer, characterized in that, The outer layer material is ES fiber with a thickness of 0.6 to 3.0D, and the inner layer material includes heat-modified three-dimensional polyester fiber and ES fiber.

2. The double-layer nonwoven material according to claim 1, characterized in that, The mass ratio of heat-sensitive modified three-dimensional polyester fiber to ES in the inner layer raw material is (1-4):

1.

3. The double-layer nonwoven material according to claim 1, characterized in that, The inner layer raw material contains heat-modified three-dimensional polyester fibers with a thickness of 2-8D and ES fibers with a thickness of 1-6D.

4. The double-layer nonwoven material according to claim 1, characterized in that, The preparation steps of the heat-sensitive modified three-dimensional polyester fiber are as follows: S1. Immerse the three-dimensional polyester fiber in a mixed acid solution, stir at room temperature for 4-8 hours, filter, wash, and dry at 50-80℃ to constant weight to obtain surface-treated three-dimensional polyester fiber. S2. The surface-treated three-dimensional polyester fiber obtained in step S1 is immersed in dopamine hydrochloride solution, washed, and dried to constant weight to obtain the heat-sensitive modified three-dimensional polyester fiber.

5. The double-layer nonwoven material according to claim 4, characterized in that, In step S1, the mixed acid solution is prepared by mixing 30-70 wt% sulfuric acid and 20-50 wt% nitric acid in a volume ratio of (1-4):

1.

6. A method for preparing a double-layer nonwoven material according to any one of claims 1-5, characterized in that, The process includes the following steps: loosening, mixing, removing impurities, and combing the surface and inner layers of raw materials to obtain a surface fiber web and an inner fiber web. The two layers of fiber web are then bonded together, hot-rolled after 5-20 seconds of hot air, and then wound into shape to obtain the double-layer nonwoven material.

7. The method for preparing the double-layer nonwoven material according to claim 6, characterized in that, The surface fiber web has a surface density of 10–40 g / m². 2 The inner fiber web has a surface density of 20–70 g / m². 2 .

8. The method for preparing the double-layer nonwoven material according to claim 6, characterized in that, The specific parameters of the hot air are: the temperature of the hot air chamber is 120-150℃, and the temperature of the ironing machine is 125-160℃.

9. The method for preparing a double-layer nonwoven material according to claim 6, characterized in that, The specific parameters for hot rolling are: production speed of 10-30 m / min, temperature of 110-160℃, and pressure of 0.2-0.8 MPa.

10. The application of a double-layer nonwoven material according to any one of claims 1 to 5 or a double-layer nonwoven material obtained by the preparation method according to any one of claims 6 to 9 in a steam eye mask.

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