Textile fiber coated with essential oil and method for preparing the same

Abstract

The present application provides a kind of textile fiber coated with essential oil and a preparation method thereof, relating to the technical field of textile fiber.The textile fiber coated with essential oil of the present application, the body of textile fiber is distributed with at least one closed hollow structure in the position close to surface, the closed hollow structure is coated with essential oil, and the depth of closed hollow structure along the cross section of textile fiber is not less than 1 / 20 of the diameter of textile fiber.The present application can achieve good coating performance of textile fiber on essential oil without using microcapsules coated with essential oil, and realize long-acting release of essential oil.

Description

Technical Field

[0001] This invention belongs to the field of polyester fiber technology and relates to a textile fiber coated with essential oil and its preparation method. Background Technology

[0002] Functional textile fibers are becoming increasingly widely used, among which essential oil-loaded textile fibers have effects such as fragrance, mosquito repellency, and sleep aid, depending on the type of essential oil. Currently, there are two main methods for preparing essential oil-loaded textile fibers. The first is the bulk fusion method, where essential oils are made into microcapsules and then mixed with a polymer solution (or molten polymer) and spun into fibers. The second is the finishing method, which uses finishing techniques to attach essential oils or essential oil microcapsules to the surface of the fiber. The first method (bulk fusion method) produces microcapsules with high stability and resistance to detachment, but it is costly. The essential oils need to be prepared into microcapsules first, and the high temperature during melt processing can damage the microcapsules or cause thermal degradation of the essential oils. Alternatively, the polymer solution can cause the microcapsules to swell, potentially leading to leakage. In addition, since the microcapsules are distributed throughout the fiber's overall structure, excessive addition can significantly reduce the fiber's mechanical properties. For example, according to existing technology 1, adding 2.5 wt% peppermint oil microcapsules to PP results in a tensile strength retention rate of nearly 99% and good spinnability. However, adding 3.5% peppermint oil microcapsules reduces the tensile strength retention rate to around 80% and worsens spinnability. The second method (post-treatment method) can maintain the fiber's main structure essentially unchanged, but even if the microcapsules are attached to the fiber surface through chemical grafting, problems such as low adhesion and poor washability still exist, and they are prone to detachment during use.

[0003] Therefore, the existing technology for preparing textile fibers loaded with essential oils urgently needs to be improved.

[0004] Existing technology 1: Preparation of peppermint oil microcapsules and their blending melt spinning, Synthetic Fibers, 2017, 46 (02): 8-12. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a textile fiber coated with essential oil and a method for preparing the same.

[0006] The technical solution of the present invention is as follows:

[0007] A textile fiber coated with essential oil, wherein the body of the textile fiber has at least one closed hollow structure distributed near the surface, and the closed hollow structure is coated with essential oil; The depth of the closed hollow structure along the cross-section of the textile fiber is not less than 1 / 20 of the diameter of the textile fiber.

[0008] Preferably, the textile fiber is selected from one or more of polyester, spandex, polypropylene, acrylic, nylon and vinylon.

[0009] Preferably, the essential oil is selected from one or more of the following: artemisia essential oil, lavender essential oil, rose essential oil, peppermint essential oil, lemon essential oil, sweet orange essential oil, bergamot essential oil, grape essential oil, tea tree essential oil, grapefruit essential oil, rosemary essential oil, eucalyptus essential oil, basil essential oil, and jasmine essential oil.

[0010] Preferably, the depth of the closed hollow structure along the cross-section of the textile fiber is no greater than 1 / 3 of the diameter of the textile fiber.

[0011] Preferably, the diameter of the textile fiber is 10μm-1mm.

[0012] A method for preparing a textile fiber coated with essential oil as described in any of the above claims, wherein after the fiber filament is drawn and formed but before winding, the essential oil is sprayed onto the surface of the fiber filament and then subjected to hot stretching to obtain the textile fiber. The surface of the fiber filament has an open hollow structure, and the essential oil penetrates into the open hollow structure. The width of the opening in the open hollow structure at the surface position does not exceed 1 / 4 of the diameter of the fiber filament. The open hollow structure closes after the thermal stretching to form the closed hollow structure.

[0013] Preferably, the open hollow structure is spun into shape according to the structural design of the spinneret; The nozzle for spraying the essential oil is located directly above the fiber filament, which is then stretched taut.

[0014] Preferably, the width of the opening does not exceed the width of the hollow structure in the cross-section.

[0015] More preferably, the width of the hollow structure in the cross-section is not less than 1.2 times the width of the opening.

[0016] Preferably, the temperature of the hot stretching is not less than 20°C higher than the glass transition temperature of the initial fiber, and the stretching ratio of the hot stretching is 1.5-5 times.

[0017] The beneficial effects of this invention are: (1) This invention proposes a novel textile fiber structure loaded with essential oils. The textile fiber forms a closed hollow structure on the surface of the essential oil. The textile fiber loaded with essential oils still has good mechanical strength, and the loading stability of essential oils is good, which can achieve long-term release.

[0018] (2) The present invention forms an open hollow structure on the surface of the fiber to absorb the sprayed essential oil, and after thermal stretching, the open hollow structure closes to form a closed hollow structure, thereby stably coating the essential oil. The textile fiber body near the middle does not carry essential oil, and can still maintain the performance of the textile fiber well, especially the high retention rate of tensile strength.

[0019] (3) The spinning fiber of the present invention is first spun into a fiber filament with an open hollow structure, and then formed into a closed hollow structure encapsulating essential oil by hot stretching, so that the essential oil is encapsulated in the inside of the textile fiber. However, the essential oil does not need to be encapsulated with microcapsules first, and it will not affect the spinning process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the cross-sectional structure of the polyester coated with essential oil in Example 1; Among them, 1-polyester body, 2-closed hollow structure, 3-artemisia oil.

[0021] Figure 2 This is a schematic diagram of the cross-sectional structure of the initial fiber filament in Example 1.

[0022] Figure 3 This is a schematic diagram of the spinneret hole structure used in Example 2; Among them, 4 is the solid non-spinning zone, and 5 is the hollow spinneret zone.

[0023] Figure 4 This is a schematic diagram of the cross-sectional structure of the fiber filament in Example 2. Detailed Implementation

[0024] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0025] On the one hand, the present invention proposes a textile fiber coated with essential oil, wherein the body of the textile fiber has at least one closed hollow structure distributed near the surface, and the closed hollow structure is coated with essential oil. The depth of the closed hollow structure along the cross-section of the textile fiber is not less than 1 / 20 of the diameter of the textile fiber.

[0026] The textile fiber of this invention contains at least one closed hollow structure near its surface that can encapsulate essential oils. This eliminates the need for microcapsule structures, allowing the essential oils to be encapsulated within the fiber body, achieving encapsulated loading and resulting in a good sustained-release effect. If the depth of the closed hollow structure is insufficient, its volume is inadequate, and the amount of essential oil it can hold is small, leading to less pronounced efficacy. Furthermore, insufficient depth also hinders the effective encapsulation of the essential oils.

[0027] In this invention, the closed hollow structure can be individual, such as spherical or elliptical, or it can be continuous along the length of the textile fiber, i.e., long line.

[0028] In this invention, the depth of the closed hollow structure along the cross-section of the textile fiber refers to the depth parallel to the diameter direction.

[0029] In some embodiments, the textile fiber is selected from one or more of polyester, spandex, polypropylene, acrylic, nylon, and vinylon. In this invention, the essential oil does not need to be microencapsulated, and there is no need to consider the compatibility between the microcapsules and the textile fiber. There are no particular restrictions on the material of the textile fiber; commonly used textile fiber materials, such as polyester, spandex, polypropylene, and acrylic, can all be used.

[0030] In some embodiments, the essential oil is selected from one or more of the following: artemisia essential oil, lavender essential oil, rose essential oil, peppermint essential oil, lemon essential oil, sweet orange essential oil, bergamot essential oil, grape essential oil, tea tree essential oil, grapefruit essential oil, rosemary essential oil, eucalyptus essential oil, basil essential oil, and jasmine essential oil. In this invention, there are no particular limitations on the essential oil; different essential oils can be selected based on different efficacy requirements, such as mosquito-repellent essential oils, sleep-aiding essential oils, stress-relieving essential oils, energizing essential oils, and antibacterial essential oils.

[0031] In some embodiments, the depth of the closed hollow structure along the cross-section of the textile fiber is no greater than 1 / 3 of the diameter of the textile fiber.

[0032] If the depth of the closed hollow structure along the cross-section of the textile fiber exceeds one-third of the fiber diameter, it will result in lower mechanical strength of the textile fiber, potentially leading to breakage during use. For example, the depth of the closed hollow structure along the cross-section of the textile fiber can be 1 / 20, 1 / 15, 1 / 12, 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, or 1 / 3 of the fiber diameter. For instance, if the textile fiber diameter is 100 μm, the depth of the closed hollow structure along the cross-section could be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, or 60 μm. Furthermore, the depth of the closed hollow structure along the cross-section of the textile fiber should not exceed one-quarter of the fiber diameter.

[0033] In some embodiments, the diameter of the textile fiber is 10 μm-1 mm. The diameter of the textile fiber can be selected according to needs or application scenarios. For example, the diameter of the textile fiber can be 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1 mm, etc.

[0034] On the other hand, the present invention also proposes a method for preparing textile fibers coated with essential oil as described in any of the above claims, wherein after the fiber filament is drawn and formed but before winding, the essential oil is sprayed onto the surface of the fiber filament and then subjected to hot stretching to obtain textile fibers. The surface of the fiber filament has an open hollow structure, into which essential oils penetrate. The width of the opening in the open hollow structure on the surface does not exceed 1 / 4 of the diameter of the fiber filament. The open hollow structure closes after thermal stretching, forming a closed hollow structure.

[0035] In this invention, the surface of the spun fiber has an open hollow structure. The sprayed essential oil, under positive pressure, penetrates through the opening into the hollow structure, thus accommodating the essential oil within the fiber. Through thermal stretching, the fiber deforms and elongates, closing the opening and forming a closed-pore structure that encapsulates the essential oil. The width of the opening in the hollow structure does not exceed one-quarter of the diameter of the textile fiber. If the opening is too wide, it may not close completely under thermal stretching, and the contained essential oil may overflow during subsequent stretching processes. Besides some of the sprayed essential oil entering the hollow structure, some is adsorbed on the surface of the fiber but not into the hollow structure. This portion of essential oil is removed during thermal stretching and texturing processes. Since most of the sprayed essential oil does not contact the fiber, a recovery device can be installed below the fiber to allow for re-spraying.

[0036] Furthermore, the width of the opening at the surface of the hollow structure is not less than 1 / 10 of the diameter of the textile fiber. For example, the width of the opening can be 1 / 10, 1 / 9, 1 / 8, 1 / 7, 1 / 6, 1 / 5, 1 / 4, etc., of the textile fiber diameter. For instance, if the diameter of the textile fiber is 20μm, the width of the opening can be 2μm, 3μm, 4μm, 5μm, etc.; if the diameter of the textile fiber is 100μm, the width of the opening can be 10μm, 12μm, 15μm, 18μm, 20μm, 25μm, etc.

[0037] In some embodiments, the open hollow structure is spun into wires according to the structural design of the spinneret; When the essential oil is sprayed, the nozzle is positioned directly above the fiber filament, causing the fiber filament to be taut.

[0038] In this application, the open hollow fiber filament can be obtained directly during the spinning process by designing the spinneret's spinneret holes. The obtained open hollow structure is in the form of a long line. The fiber filament is taut under force, and the nozzle for essential oil spraying is located directly above the fiber filament, allowing excess essential oil to drip vertically and be collected.

[0039] In some embodiments, the width of the opening does not exceed the width of the hollow structure in cross-section. That is, the width of the opening can be equal to or less than the width of the hollow structure in cross-section, which can prevent the contained essential oil from overflowing before heat stretching. When the width of the opening is less than the width of the hollow structure in cross-section, the hollow structure has the characteristic of "small opening and large cavity," making it less likely for the essential oil contained inside to overflow before heat stretching, and allowing for a larger amount of essential oil to be contained.

[0040] In this invention, the opening width of the hollow structure refers to the shortest distance at the opening position, and the width of the hollow structure in the cross-section refers to the maximum width in the cross-section.

[0041] In some embodiments, the width of the hollow structure in the cross-section is not less than 1.2 times the width of the opening. For example, the width of the hollow structure in the cross-section can be 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 2 times, etc., the width of the opening.

[0042] In some embodiments, the heat-stretching temperature is not less than 20°C higher than the glass transition temperature of the initial fiber, and the heat-stretching ratio is 1.5-5 times. During heat stretching, the polymer chains are stretched and moved under the influence of temperature and external force, completing the transformation from an open hollow structure to a closed hollow structure. The heat-stretching temperature should not be too high, otherwise it will affect the stability of the essential oil or cause thermal degradation. For example, when the Tg of polyester is 78°C, the heat-stretching temperature can be 98°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, etc.; for example, when the Tg of nylon is 55°C, the heat-stretching temperature can be 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, etc.

[0043] The technical solution of the present invention will be further described and illustrated below with reference to various embodiments. Unless otherwise specified, the parts mentioned in the following embodiments are parts by weight.

[0044] Example 1 A schematic diagram of the cross-sectional structure of the polyester coated with essential oil in this embodiment is attached. Figure 1 As shown, the cross-section of the polyester is spherical with a diameter of 20μm. The polyester body 1 has a closed hollow structure 2 distributed near the surface. The closed hollow structure 2 is in the shape of a continuous long line and encloses and contains artemisia essential oil 3. The depth h1 of the closed hollow structure along the cross-section of the polyester is 1 / 6 of the diameter h2 of the polyester.

[0045] The method for preparing the essential oil-coated polyester in this embodiment is as follows: PET polyester is melt-spun using a spinning orifice with a specific structure to obtain a pre-filament with a hollow structure having one opening on its surface. A schematic diagram of the cross-sectional structure of the pre-filament is attached. Figure 2 As shown, the open hollow structure appears as a continuous long line on the surface, with an opening width h3 that is 1 / 5 of the fiber diameter h5. The cross-sectional width h4 of the open hollow structure is 1.2 times the opening width h3. The nozzle for the mugwort essential oil is located directly above the fiber. The mugwort essential oil is sprayed onto the taut fiber and penetrates into the open hollow structure. The fiber is then hot-stretched at 120°C (2x stretch). After hot stretching, the open hollow structure transforms into a closed hollow structure, encapsulating and containing the mugwort essential oil, resulting in polyester, which is then wound.

[0046] The polyester coated with mugwort essential oil obtained in this embodiment was washed 30 times according to the method of AATCC 61-2020, and then the mugwort essential oil content was tested by HPLC. The test was performed in parallel 5 times, and the essential oil content was not less than 82%.

[0047] The mosquito-repellent performance of the polyester coated with mugwort essential oil in this embodiment was tested according to GB / T 30126-2013 "Test and Evaluation of Mosquito Repellent Performance of Textiles". The initial repellency rate was 71%, and the repellency rate after 180 days was 63%, indicating that the essential oil in the polyester coated with mugwort essential oil in this embodiment has good slow-release performance.

[0048] Example 2 The method for preparing the nylon coated with essential oil in this embodiment is as follows: PA6 is spun using a melt spinning method, employing a spinneret with a specific structure. A schematic diagram of the spinneret structure is attached. Figure 3 As shown, a fiber filament with a hollow structure having eight openings on its surface was obtained. A schematic diagram of the cross-sectional structure of the fiber filament is attached. Figure 4 As shown, the cross-section of the initial fiber filament is generally square. The eight open hollow structures are continuous long lines on the surface, with an opening width h6 equal to 1 / 12 of the fiber filament diameter (side length of the square) h7. The width of the open hollow structure in the cross-section is equal to the opening width h6. The eucalyptus oil nozzle is located directly above the initial fiber filament. The eucalyptus oil is sprayed onto the taut fiber filament and penetrates into the open hollow structures. It is then hot-stretched at 110°C with a stretch ratio of 2.5 times. After hot stretching, the open hollow structures transform into closed hollow structures that encapsulate and contain the eucalyptus oil, resulting in a nylon filament encapsulated with eucalyptus oil, which is then wound.

[0049] The closed hollow structure of the nylon containing eucalyptus oil has a depth of 1 / 8 of the nylon diameter along the cross-section of the polyester.

[0050] The nylon coated with eucalyptus oil obtained in this embodiment was washed 30 times according to the method of AATCC 61-2020, and then the eucalyptus oil content was tested by HPLC. The test was performed in parallel 5 times, and the oil content was not less than 80%.

[0051] The mosquito-repellent performance of the nylon coated with eucalyptus oil in this embodiment was tested according to GB / T 30126-2013 "Test and Evaluation of Mosquito Repellent Performance of Textiles". The initial repellency rate was 75%, and the repellency rate after 180 days was 69%, indicating that the essential oil in the nylon coated with eucalyptus oil in this embodiment has good slow-release performance.

[0052] As described above, the basic principles, main features, and advantages of the present invention have been shown and described. Those skilled in the art should understand that the present invention is not limited to the above embodiments, which are merely preferred embodiments and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made in accordance with the scope of the patent and the description should still fall within the scope of the present invention. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A textile fiber coated with essential oil, characterized in that, The body of the textile fiber has at least one closed hollow structure distributed near the surface, and the closed hollow structure is covered with essential oil; The depth of the closed hollow structure along the cross-section of the textile fiber is not less than 1 / 20 of the diameter of the textile fiber.

2. The textile fiber coated with essential oil according to claim 1, characterized in that, The textile fibers are selected from one or more of polyester, spandex, polypropylene, acrylic, nylon and vinylon.

3. The textile fiber coated with essential oil according to claim 1, characterized in that, The essential oil is selected from one or more of the following: artemisia essential oil, lavender essential oil, rose essential oil, peppermint essential oil, lemon essential oil, sweet orange essential oil, bergamot essential oil, grape essential oil, tea tree essential oil, grapefruit essential oil, rosemary essential oil, eucalyptus essential oil, basil essential oil, and jasmine essential oil.

4. The textile fiber coated with essential oil according to claim 1, characterized in that, The depth of the closed hollow structure along the cross-section of the textile fiber is no greater than 1 / 3 of the diameter of the textile fiber.

5. The textile fiber coated with essential oil according to claim 1, characterized in that, The diameter of the textile fiber is 10μm-1mm.

6. A method for preparing a textile fiber coated with essential oil according to any one of claims 1-5, characterized in that, After the fiber filament is drawn and formed but before winding, the essential oil is sprayed onto the surface of the fiber filament and then subjected to hot stretching to obtain the textile fiber. The surface of the fiber filament has an open hollow structure, and the essential oil penetrates into the open hollow structure. The width of the opening in the open hollow structure at the surface position does not exceed 1 / 4 of the diameter of the fiber filament. The open hollow structure closes after the thermal stretching to form the closed hollow structure.

7. The method for preparing textile fibers coated with essential oils according to claim 6, characterized in that, The open hollow structure is spun into shape according to the structural design of the spinneret; The nozzle for spraying the essential oil is located directly above the fiber filament, which is then stretched taut.

8. The method for preparing textile fibers coated with essential oils according to claim 6, characterized in that, The width of the opening does not exceed the width of the hollow structure in the cross-section.

9. The method for preparing textile fibers coated with essential oils according to claim 8, characterized in that, The width of the hollow structure with the opening is not less than 1.2 times the width of the opening.

10. The method for preparing textile fibers coated with essential oils according to claim 6, characterized in that, The temperature of the hot stretching is not less than 20°C higher than the glass transition temperature of the initial fiber, and the stretching ratio of the hot stretching is 1.5-5 times.

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