Method for producing fibers with phase change energy storage function

Abstract

A method for producing fibers with phase change energy storage capabilities is provided. [Solution] The method includes step 1 of filling a microporous carrier with a phase change material, step 2 of covering the microporous carrier with a polymer capable of forming polymeric fibers, step 3 of preparing a functional masterbatch using the covered microporous carrier, and step 4 of melt-spinning the functional masterbatch and the main material of the fiber. [Effects] After the polymer with high molecular fiber forming ability is coated with a microporous carrier, compatibility with the fiber polymer is improved, and the phase change material is less likely to leak during the granulation and spinning process, making it easier to preserve in the fiber. Compared to functional composite fibers with a skin-core structure, this process is simpler, fiber yield is higher, and there are no special requirements for the type of fiber polymer, making it applicable in a wider range of applications.

Description

[Technical Field]

[0001] This application relates to the production of functional fibers, and more particularly to a method for producing fibers with phase change energy storage functionality. [Background technology]

[0002] Chemical fibers are an important raw material for textiles such as clothing. Compared to natural fibers, they offer advantages such as better stability, a wider range of sources, and a longer service life. Because the raw materials used in chemical fibers are highly pure, their functionality is limited to a single function. Fabrics are typically given multiple properties by blending multiple fibers or adding functional components to fibers. For example, adding nanoparticle titanium dioxide to polyamide fibers can produce polyamide fibers capable of absorbing ultraviolet light. While adding functional components can enhance fiber performance, differences between the functional components and the base fiber material mean that the two are not compatible. Furthermore, some particulate additives can create stress concentration points, reducing the mechanical properties of the fiber. Furthermore, some additives should be avoided for skin contact and cannot be exposed to air, limiting their use in functional fibers. Skin-core fibers are composite fibers composed of two parts: an outer skin and an inner core. The core can be completely covered or partially exposed. The skin is typically the fiber's main component, while the core can contain various functional components. The surface of a skin-core fiber retains the functionality of the fiber itself, while the various functional components added to the core provide additional performance. However, skin-core fibers also suffer from interfacial compatibility issues and strain mismatch due to differences in the materials used between the skin and core, which affect the fiber's mechanical properties. Furthermore, conventional equipment for producing skin-core fibers uses melt spinning, in which the skin and core melts are simultaneously passed through a hollow annular spinneret, and the core and skin melts are then cooled and formed into yarn. This method places high demands on equipment and technology, limits the melting range of raw materials, and is unable to produce composite fibers with significant differences between the skin and core materials.

[0003] Fibers with phase change energy storage function are produced by spinning together a phase change material that can transition between a solid state and a liquid state. The currently most commonly used fiber is the skin-core structure described above, in which the phase change material is distributed in the core of the fiber and the skin can surround the core containing the phase change material. Composite fibers with a skin-core structure can avoid the exposure of the phase change functional component. However, the manufacturing technology for fibers with a skin-core structure is highly difficult, there are many restrictions on the fiber raw materials, and the material of the core is easily exposed to the skin, which affects the dyeing effect. Therefore, it is a focus of research by those skilled in the art to find a simple method to produce fibers with phase change energy storage function that will not expose the phase change material to human skin during use. Summary of the Invention [Means for solving the problem]

[0004] The composite spinning technology of the skin-core structure used in the fiber with phase change energy storage function is difficult to manufacture, and there are many restrictions on the raw materials of the fiber. In addition, the material of the core part is easily exposed to the skin part, which affects the dyeing effect. In order to solve these problems, the present application proposes a method for manufacturing the fiber with phase change energy storage function, which method includes: Step 1: filling a microporous carrier with a phase change material; Step 2: coating a microporous support with a polymer capable of forming polymeric fibers; Step 3: preparing a functional masterbatch using the coated microporous carrier; and step 4, melt-spinning the functional masterbatch and the main material of the fiber.

[0005] Regarding step 1, in the fiber with phase change energy storage function of the present application, the functional phase change material is one or a combination of two or more of lauryl alcohol, n-hexadecane, n-heptadecane, octadecane, methyl palmitate, and fatty acid methyl esters. The phase change temperatures of these materials are approximately 18°C, 24°C, 28°C, 30°C, and 32°C. When the temperature of a person's skin is higher than the phase change temperature, the phase change material changes from solid to liquid, absorbing heat in the process of changing from solid to liquid, thereby lowering the surface temperature of the skin and making the person feel cooler. When the external temperature changes from higher than the phase change temperature of the phase change material to lower than the temperature of the phase change material, the phase change material changes from liquid to solid, releasing heat in the process of changing from liquid to solid, so that the person's skin does not feel uncomfortable due to the sudden drop in temperature.

[0006] The microporous carrier is made of oxide particles or microspheres with many pores inside, with a particle size of 0.2 to 50 μm and a pore size of 10 to 20 nm. Specifically, the microporous carrier is selected from the group consisting of microporous aluminum oxide, microporous silicon dioxide, and microporous titanium dioxide. The molecular particle size of the phase change material of the present application is from several nanometers to over 10 nanometers, and can enter the microporous carrier in a liquid state. The microporous carrier corresponds to a carrier for the phase change material.

[0007] To fill the microporous carrier with as much phase-change material as possible, the phase-change material must first be liquefied. In its liquid state, the phase-change material can easily penetrate into the microporous carrier. The microporous carrier and the phase-change material are mixed uniformly, heated to 50-70°C, thoroughly stirred, vacuumed, and filtered. The filtered microporous carrier is then temporarily stored in an environment below the phase change temperature of the phase-change material.

[0008] In step 2, the microporous carrier from step 1 is pulverized to a particle size of 500 mesh or more, and an appropriate amount of white oil is added and thoroughly mixed with the microporous carrier. Then, the microporous carrier is mixed with a polymer powder having polymer fiber-forming ability in a certain ratio to obtain a microporous carrier covered with a filled phase change material. The polymer having polymer fiber-forming ability is selected from polyethylene, polyamide, polyethylene terephthalate, and polypropylene. Preferably, the polymer having polymer fiber-forming ability and the masterbatch substrate in step 2 are selected to be the same polymer as the main material of the fiber in order to improve the spinnability of the fiber.

[0009] In step 3, the microporous carrier powder obtained in step 2 is processed into a functional masterbatch capable of phase change energy storage. Specifically, the fiber polymer substrate and the microporous carrier powder coated with a phase change material are mixed in a certain ratio, and then melted, extruded, cooled, and pelletized to form a functional masterbatch capable of phase change energy storage. By controlling the particle size of the masterbatch to be close to that of the fiber polymer, uneven distribution of certain components due to excessive particle size difference during mixing is avoided. Specifically, the fiber polymer in this application is selected from polyethylene, polyamide, polyethylene terephthalate, and polypropylene.

[0010] In step 4, a fiber with phase-change energy storage function is manufactured using a melt spinning method. Specifically, a functional masterbatch capable of phase-change energy storage and the main fiber material are uniformly mixed at a certain ratio and then melt-extruded through a screw extruder. During processing, the phase-change material is coated in the microporous carrier, minimizing loss of the phase-change material. As a result, a fiber with phase-change storage function is manufactured in which the phase-change material is coated with the fiber polymer, resulting in low loss, leakage resistance, and uniform dispersion. Specifically, the fiber polymer in this application is selected from the group consisting of polyethylene, polyamide, polyethylene terephthalate, and polypropylene. [Effects of the Invention]

[0011] The beneficial effects of the present application are: First, the inventive step of this application is that the phase change material is first filled into a microporous material with high thermal conductivity, and then the microporous material is sealed, granulated, and spun into fibers. This spinning method effectively reduces the loss of the phase change material during the processing process and avoids the exposure of the phase change material during use. Second, in a preferred embodiment, the polymer capable of forming polymeric fibers, the masterbatch substrate, and the main material of the fibers are the same polymer. This allows the microporous material to be better dispersed during the processing, and the phase change material to be more uniformly dispersed in the fibers. Third, by using a microporous material with high thermal conductivity as the carrier for the phase change material, the thermal conductivity will be increased and the phase change material will be able to react faster and transform into different forms during use, which will help the human body adapt to changes in the external environment and provide better comfort. Fourth, compared with functional composite fibers with a skin-core structure, the process of the present invention is simpler, the fiber yield is higher, and there are no special requirements for the type of fiber polymer, so the range of application is wider. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a graph showing phase change energy storage of fibers of Examples 1-2 and Comparative Examples 1-3. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present application will be described below based on examples, but the examples given are only for the purpose of explaining the present application and are not intended to limit the scope of the present application.

[0014] Example 1 A method for producing polyethylene long fibers with phase change energy storage function, comprising the steps of: Step 1: Aluminum oxide microspheres with a D90 particle size of 10 μm and a micropore diameter of 15 nm are mixed with lauryl alcohol with a phase change temperature of 24°C and octadecane with a phase change temperature of 28°C. The mixture is heated to 50-70°C and thoroughly stirred. The mixture is then vacuumed and filtered to obtain microporous aluminum oxide microspheres. Octadecane The filtered microporous aluminum oxide microspheres filled with lauryl alcohol and the phase change material were temporarily stored in an environment below the phase change temperature of the phase change material, i.e., below 18.2°C.

[0015] Step 2: The microporous aluminum oxide microspheres obtained in Step 1 are pulverized to a particle size of 500 mesh or more, and then an appropriate amount of white oil is added to fully coat the surface of the aluminum oxide microspheres with the white oil. The white oil is then thoroughly mixed with a certain amount of polyamide powder so that the polyamide powder is fully coated on the surface of the aluminum oxide microspheres, and the phase change material is then sealed in the micropores of the aluminum oxide.

[0016] In step 3, the aluminum oxide microspheres from step 2 were mixed with polyethylene powder with fiber-forming ability in a certain ratio. After mixing, the mixture was melted, extruded, cooled, and pelletized to obtain a functional masterbatch capable of phase change energy storage.

[0017] Step 4: The mass ratio of the polyethylene chips and the polyethylene phase change energy storage functional masterbatch from step 3 is 95:5, and after uniform mixing, they are introduced into the spinning machine, and the temperatures of zones 1 to 5 of the spinning machine are controlled at 210°C, 215°C, 220°C, 215°C, and 215°C, respectively, to melt the polyethylene chips and the polyethylene phase change energy storage functional masterbatch. The melt is then discharged through a circular spinneret, horizontally blown, dried, oiled, drafted, and packaged, thereby obtaining polyethylene fibers with phase change energy storage function.

[0018] Example 2 A method for producing polyamide filaments with phase change energy storage capabilities, comprising the steps of: Step 1: Microporous silicon dioxide with a D90 particle size of 8 μm and a micropore diameter of 10 nm and fatty acid methyl ester with a phase change temperature of 28°C to 32°C (excluding methyl palmitate) The mixture is homogeneously mixed with methyl palmitate, which has a phase change temperature of 28°C, heated to 50-70°C, thoroughly stirred, vacuumed, and filtered. After filtration, the porous silicon dioxide is coated with the fatty acid methyl ester. (excluding methyl palmitate) The microporous silicon dioxide filled with the phase change material and filtered was temporarily stored in an environment below the phase change temperature of the phase change material, ie, below 32°C.

[0019] Step 2: The microporous silicon dioxide obtained in Step 1 is pulverized to a particle size of 500 mesh or more, and then an appropriate amount of white oil is added to fully coat the surface of the microporous silicon dioxide with the white oil. Then, the polyethylene terephthalate powder is thoroughly mixed with the microporous silicon dioxide to fully coat the surface of the microporous silicon dioxide, and the phase change material is sealed in the microporous silicon dioxide.

[0020] Step 3: The microporous silicon dioxide from step 2 was mixed with polyethylene terephthalate (PET) with fiber-forming ability in a certain ratio. After mixing, the mixture was melted, extruded, cooled, and pelletized to obtain a functional masterbatch capable of phase-change energy storage.

[0021] Step 4: The mass ratio of the polyethylene terephthalate chips and the polyethylene terephthalate phase change energy storage functional masterbatch from step 3 is 95:5, and after uniform mixing, they are introduced into the spinning machine. The temperatures of sections 1 to 5 of the spinning machine are controlled at 245°C, 255°C, 255°C, 260°C, and 255°C, respectively, to melt the polyethylene terephthalate chips and the polyethylene terephthalate phase change energy storage functional masterbatch. The melt is then discharged through a circular spinneret, blown sideways, dried, oiled, and drafted, and then packaged, thus forming a phase change energy storage functional masterbatch. Polyamide Length Fiber was obtained.

[0022] Example 3 A method for producing polyethylene terephthalate long fibers with phase change energy storage function, comprising the steps of: Step 1: Aluminum oxide microspheres with a D90 particle size of 50 μm and a micropore size of 10 nm and fatty acid methyl esters with a phase change temperature of 28°C to 32°C (excluding methyl palmitate) The mixture is homogeneously mixed with methyl palmitate having a phase change temperature of 28°C, heated to 50-70°C, thoroughly stirred, vacuumed, and filtered. After filtration, the methyl palmitate and fatty acid methyl esters are deposited on the porous aluminum oxide. (excluding methyl palmitate) The filtered microporous aluminum oxide microspheres filled with the phase change material were temporarily stored in an environment below the phase change temperature of the phase change material, i.e., below 28°C.

[0023] Step 2: The microporous aluminum oxide microspheres obtained in Step 1 are pulverized to a particle size of 500 mesh or more, and then an appropriate amount of white oil is added to fully coat the surface of the aluminum oxide microspheres with the white oil. The white oil is then thoroughly mixed with a certain amount of polyethylene terephthalate powder to fully coat the surface of the aluminum oxide microspheres, and the phase change material is then sealed in the micropores of the aluminum oxide.

[0024] Step 3: The aluminum oxide microspheres from step 2 were mixed with polyethylene terephthalate chips with fiber-forming ability in a certain ratio. After mixing, the mixture was melted, extruded, cooled, and pelletized to obtain a functional masterbatch capable of phase-change energy storage.

[0025] Step 4: The mass ratio of the polyethylene terephthalate chips and the polyethylene terephthalate phase change energy storage functional masterbatch from step 3 is 95:5, and after uniform mixing, they are introduced into the spinning machine. The temperatures of zones 1 to 5 of the spinning machine are controlled at 260°C, 270°C, 280°C, 290°C, and 295°C, respectively, to melt the polyethylene terephthalate chips and the polyethylene terephthalate phase change energy storage functional masterbatch. The melt is then discharged through a circular spinneret, blown sideways, dried, oiled, and drafted, and then packaged, thus forming a phase change energy storage functional masterbatch. Polyethylene terephthalate length Fiber was obtained.

[0026] In the above Examples 1 to 3, staple fibers of appropriate specifications can also be produced using a staple fiber spinning method.

[0027] (Comparative Example 1) 1 is a polyethylene continuous fiber produced by a spinning process using the polyethylene powder having fiber-forming ability of Example 1.

[0028] (Comparative Example 2) This is a polyamide continuous fiber produced by a spinning process using the polyamide chips having fiber-forming ability of Example 2.

[0029] (Comparative Example 3) This is polyethylene terephthalate filament produced by a spinning process using the polyethylene terephthalate chips of Example 3.

[0030] 1. Cool to the touch test The phase change storage fibers of Examples 1 to 3 and Comparative Examples 1 to 3 were knitted into 160g single jerseys and subjected to a cool-to-touch test. Measurements were performed using a precision rapid thermal property measuring device in accordance with the Japanese standard JISL1927, and the enthalpy test results for the fibers of Examples 1 to 3 and Comparative Examples 1 to 3 were also performed using differential scanning calorimetry (DSC). The results are shown in Table 1 (cool-to-touch test results).

[0031] [Table 1]

[0032] As can be seen from Table 1 above, compared with the comparative example, all of the examples have higher Qmax values, which explains why the fabrics knitted using continuous fibers with phase change energy storage provide a better cooling sensation when they come into contact with the skin. This is because the heat from the skin can be instantly transferred to the main fiber material, and then from the main fiber material to the microporous material, and the microporous material has a good heat transfer coefficient, so it can also conduct heat to the phase change material, which can absorb more heat after the phase change, making the human body feel cooler.

[0033] 2. Continuous cooling test The phase change storage fibers of Examples 1 to 3 and Comparative Examples 1 to 3 were tested for temperature change within 60 minutes using 160g single jerseys according to the method specified by the Japanese testing organization BOKEN, and the test results are shown in Table 2 (results of sustained cool sensation test).

[0034] [Table 2]

[0035] As can be seen from Table 2, within 60 minutes of testing, all of the Examples had lower temperatures than the Comparative Examples. This is because the phase change material absorbs heat through phase change, allowing the sample surface to maintain a lower temperature, providing a sustained cooling sensation.

[0036] 3. Phase change energy storage function test The phase-change energy storage fibers of Examples 1-3 and Comparative Examples 1-3 were knitted into 160g single jersey knits and tested for temperature change within 45 minutes using the method specified by the Japan Inspection Organization (BOKEN). Specifically, the samples were dried, folded twice, a sensor was placed between the samples, and a thermo-hygrostat was set to 20°C and 60% RH. The samples were left in the thermo-hygrostat for 2 hours, then held at 40°C with the same humidity for 15 minutes, and then held at 20°C and 60% humidity for 30 minutes. The temperature change for each sample within the 45 minutes was recorded, and the graph is shown in Figure 1. As can be seen from Figure 1, during the temperature rising stage, the temperature of the embodiment is always lower than that of the comparative example. When the external temperature rises, the phase change material can reduce the heat on the sample surface through phase change heat absorption and maintain coolness. Therefore, during the cooling stage, the temperature of the embodiment is always higher than that of the comparative example. When the external temperature drops, the phase change material releases heat through phase change and replenishes the heat on the sample surface, so that it can maintain warmth. Therefore, the fiber with phase change energy storage function of the present application has the functions of phase change heat absorption and heat generation.

[0037] The above is only a preferred embodiment of the present application, and does not limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. Step 1: filling a microporous carrier with a phase change material; Step 2: coating a microporous carrier with a polymer capable of forming polymeric fibers; Step 3: preparing a functional masterbatch using the coated microporous carrier; Step 4: melt-spinning the functional masterbatch and the main material of the fiber; Step 1 is to uniformly mix the microporous carrier with an excess amount of phase change material, heat the mixture to 50-70°C, thoroughly stir, and then evacuate and filter the mixture. The processed microporous carrier is temporarily stored in an environment lower than the phase change temperature of the phase change material. Step 2 is a method for producing a fiber with phase change energy storage function, characterized in that the microporous carrier of step 1 is pulverized to a particle size of 500 mesh or more, and then an appropriate amount of white oil is added and thoroughly mixed with the microporous carrier, and then mixed with a polymer powder having polymer fiber forming ability in a certain ratio to obtain a microporous carrier covered with a filled phase change material.

2. 2. The method for producing a fiber with phase change energy storage function according to claim 1, wherein the microporous carrier has a particle size of 0.2 to 50 μm, a pore diameter of the micropores of 10 to 20 nm, and is selected from the group consisting of microporous aluminum oxide, microporous silicon dioxide, and microporous titanium dioxide.

3. 2. The method for producing a fiber with phase-change energy storage function according to claim 1, wherein step 3 comprises uniformly mixing the polymer having the ability to form polymeric fiber as a base material with the microporous carrier prepared in step 2, followed by melting, extruding, cooling, and pellet cutting to obtain the functional masterbatch capable of storing phase-change energy.

4. 2. The method for producing a fiber with phase-change energy storage function according to claim 1, wherein step 4 is to obtain short or long fibers with phase-change energy storage function by melt spinning using the functional masterbatch of step 3 and the main material of the fiber.

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