Volcanic rock-based heat storage and thermal insulation fiber and preparation method thereof

Abstract

The invention provides a volcanic rock-based heat storage and warm keeping fiber and a preparation method thereof, and the method comprises the following steps: S1, dispersing volcanic rock in a sodium carbonate aqueous solution to obtain porous volcanic rock; s2, mixing the porous volcanic rock with paraffin to obtain the porous volcanic rock loaded with the paraffin; s3, dispersing the porous volcanic rock loaded with the paraffin into nano oxide hydrosol to obtain hole-sealed volcanic rock; wherein the nano oxide comprises silicon dioxide; s4, the hole-sealed volcanic rock is subjected to surface modification through an amino silane coupling agent, and heat storage and heat preservation particles are obtained; and S5, mixing the heat-storage and warm-keeping particles with polyester chips, and performing melt spinning to obtain the heat-storage and warm-keeping fiber. A stable phase change heat storage structure is constructed and is introduced into a fiber system in a form suitable for polyester melt spinning, so that the fiber has stable heat storage capacity and relatively good warm keeping durability while maintaining good processing performance.

Description

Technical Field

[0001] This application relates to the field of textile technology, specifically to a heat-storing and heat-insulating fiber based on volcanic rock and its preparation method. Background Technology

[0002] With the development of functional textiles, thermal insulation fiber materials have been widely used in outdoor clothing, workwear, and protective clothing. Existing thermal insulation fibers mainly achieve heat retention or enhanced thermal sensation by improving the bulkiness of the fiber or fabric, introducing far-infrared functional materials, or introducing functional components with moisture-absorbing and heat-generating properties.

[0003] In existing technologies, some attempts have been made to introduce mineral materials such as volcanic rock into fiber systems to endow the fibers with far-infrared related functions. For example, patent application CN118087078A discloses a method for preparing volcanic rock regenerated cellulose fiber based on coaxial spinning technology. By combining volcanic rock powder with regenerated cellulose material, the resulting fiber possesses functional properties such as far-infrared radiation. This type of technology mainly relies on the porous structure and far-infrared characteristics of volcanic rock materials, which can improve the feeling of heat during wear or reduce heat loss to a certain extent.

[0004] However, the heat-retaining mechanism of the aforementioned volcanic rock fibers mainly manifests as heat absorption or enhanced heat radiation; they do not possess significant heat storage capacity and are difficult to continuously release heat when the ambient temperature decreases or human activity decreases. Therefore, the heat-retaining effect of this type of fiber is quite sensitive to changes in external conditions, and its heat storage stability and durability remain insufficient.

[0005] On the other hand, existing technologies also include solutions that improve the warmth retention of fibers through moisture absorption and heat generation mechanisms. For example, patent CN118563470A discloses a moisture-absorbing and heat-generating wool blend knitted yarn and its preparation method. By utilizing the characteristic of fiber materials to release heat during moisture absorption, a certain degree of heat generation and warmth retention effect is achieved. This type of technology can enhance the feeling of warmth when wearing the garment under specific humidity conditions.

[0006] However, the heat generation process of moisture-absorbing and heat-generating fibers usually depends on the ambient humidity or the sweating of the human body. Their heat generation behavior is instantaneous and conditionally dependent. When the ambient humidity is low or the moisture absorption process is over, the heat generation effect is difficult to sustain. Therefore, the heat retention stability in low temperature and dry environments is still limited.

[0007] In summary, while existing heat-storing and heat-insulating fiber technologies have made some progress in far-infrared heat preservation or moisture-absorbing heat generation, they still generally suffer from the following shortcomings: First, some technical solutions can only achieve heat absorption or heat reflection, lacking effective heat storage and heat release regulation capabilities; second, some heating mechanisms are highly dependent on environmental conditions, resulting in insufficient stability and durability of the heat preservation effect; and third, in practical applications, it is difficult to achieve stable and continuous heat storage and heat preservation effects while taking into account fiber processing performance.

[0008] Therefore, how to further improve the heat storage and insulation properties of fibers remains a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] This application provides a heat-storing and heat-insulating fiber based on volcanic rock and its preparation method, which solves the problems that existing heat-insulating fibers mainly rely on heat absorption, far-infrared or moisture absorption heat generation mechanisms and lack stable heat storage capacity, and whose heat-insulating effect is sensitive to changes in environmental conditions and is difficult to achieve long-lasting heat storage and heat insulation while taking into account fiber processing performance.

[0010] In a first aspect, this application provides a method for preparing heat-storing and heat-insulating fibers based on volcanic rock, comprising the following steps: S1: Disperse volcanic rocks in an aqueous sodium carbonate solution to selectively dissolve the volcanic rocks and form channels, thus obtaining porous volcanic rocks; S2: The porous volcanic rock is mixed with paraffin wax, so that the paraffin wax melts and enters and is loaded into the pores of the porous volcanic rock to obtain porous volcanic rock loaded with paraffin wax. S3: The porous volcanic rock loaded with paraffin is dispersed in a nano-oxide hydrosol, so that the nano-oxide particles form an inorganic network on the surface of the porous volcanic rock to seal the pores, thereby obtaining sealed volcanic rock; wherein, the nano-oxide includes silicon dioxide; S4: The sealed volcanic rock is surface modified using an aminosilane coupling agent to obtain heat-storing and heat-insulating particles; S5: The heat-storing and heat-insulating particles are mixed with polyester chips and then melt-spun to obtain heat-storing and heat-insulating fibers.

[0011] According to this application, by constructing a stable phase change heat storage structure and introducing it into the fiber system in a form suitable for polyester melt spinning, the fiber can maintain good processing performance while possessing stable heat storage capacity and good heat retention durability.

[0012] Specifically, in step S1, the volcanic rock is selectively dissolved to form a porous structure, which provides an internal bearing space for the subsequent introduction of phase change materials, thereby avoiding the problem of insufficient stability caused by the phase change materials existing only in the form of surface adhesion. In step S2, paraffin is introduced and loaded into the pores of porous volcanic rock, so that the phase change material is in a confined space, which enables the absorption and release of heat during temperature changes, thereby giving the system the ability to store heat and regulate temperature. In step S3, by constructing an inorganic network structure on the porous volcanic rock surface loaded with phase change material, the pores are sealed to effectively inhibit the migration and leakage of phase change material during high-temperature processing or use, thereby improving the stability and durability of the heat storage structure. In step S4, the volcanic rock after sealing is surface modified to improve its interfacial compatibility with the polyester matrix, which is conducive to the uniform dispersion of heat storage and heat preservation particles in the polyester melt spinning system and avoids adverse effects on the spinning process and fiber mechanical properties. In step S5, the heat-storing and heat-insulating particles obtained by the above treatment are introduced into polyester chips and melt-spun, so that the heat-storing structure is stably embedded in the fiber, thereby achieving the synergy of heat storage and heat-insulating performance at the fiber scale.

[0013] Through the synergistic effect of the above steps, the method provided in this application can achieve the stable existence of phase change heat storage structure in the fiber without significantly affecting the fiber processing stability, thereby obtaining heat storage and heat insulation fiber with both heat storage and heat preservation properties.

[0014] In some embodiments, step S1 includes: 100 parts by weight of volcanic rock with an average particle size of 1-5 μm were dispersed in 400-600 parts by weight of 0.5-2 mol / L sodium carbonate aqueous solution and soaked at 70-90℃ for 2-5 h to obtain porous volcanic rock.

[0015] In some of the above embodiments, volcanic rocks with a particle size of 1-5 μm are selected, which exhibit good dispersibility and structural stability during subsequent processing and spinning, facilitating the uniform distribution of functional particles at the fiber scale. Simultaneously, volcanic rocks within this particle size range are more prone to selective dissolution of the surface and interior in sodium carbonate aqueous solution, thereby forming a richer and more interconnected pore structure, providing ample space for the subsequent introduction of phase change materials. Furthermore, by controlling the amount and concentration of sodium carbonate aqueous solution and performing immersion treatment at 70-90°C, the easily soluble components can be gently dissolved without damaging the overall framework structure of the volcanic rock, promoting the gradual formation of a stable porous structure within the volcanic rock.

[0016] By adopting the above-described embodiments, the obtained porous volcanic rock can maintain good mechanical stability while possessing suitable pore structure characteristics, thereby laying the foundation for the loading of phase change materials, pore sealing treatment, and stable introduction into the polyester spinning system in subsequent steps.

[0017] In some implementations, step S2 includes: 100 parts by mass of porous volcanic rock were mixed with 10-30 parts by mass of paraffin and loaded at 60-80°C under vacuum for 20-60 minutes to obtain porous volcanic rock loaded with paraffin.

[0018] In some of the above embodiments, paraffin wax is heated at 60-80°C to a molten state, allowing it to enter the pores of the porous volcanic rock under capillary action and pressure difference, thus achieving effective loading of the phase change material in the carrier. Simultaneously, loading under vacuum conditions effectively removes air from the pores of the porous volcanic rock, further enhancing the driving force for paraffin wax penetration into the pores, ensuring that the paraffin wax preferentially enters and fills the internal pores of the volcanic rock, rather than merely adhering to its surface.

[0019] By adopting the above-described embodiments, the phase change material paraffin can be stably loaded into the internal pores of porous volcanic rock, providing a foundation for constructing a heat storage structure with heat storage capacity and good stability, and creating favorable conditions for subsequent pore sealing treatment and application in fiber systems.

[0020] In some implementations, step S2 includes: 100 parts by weight of porous volcanic rock, 10-30 parts by weight of paraffin wax and 0.1-0.3 parts by weight of stearamide were mixed and loaded at 70-90℃ under vacuum for 20-60 minutes to obtain porous volcanic rock loaded with paraffin wax.

[0021] In some of the above embodiments, stearamide acts as a crystallization regulator in the loading process of paraffin within the pores of porous volcanic rock. Its molecular structure contains both long-chain alkyl and amide groups, enabling it to form relatively stable intermolecular interactions with paraffin molecules after the paraffin melts and enters the pores, thereby regulating the crystallization process of paraffin. Within the confined space of porous volcanic rock, the introduction of stearamide helps induce paraffin to form a more uniform and refined crystalline structure, reducing the inhomogeneity of crystal morphology during phase transitions and allowing paraffin to maintain relatively stable phase transition behavior during multiple phase transition cycles.

[0022] Meanwhile, the presence of stearamide helps to enhance the interaction between paraffin and the pore walls of porous volcanic rock, making the phase change material present a more stable confined state within the pores, thereby helping to improve the stability and repeatability of the phase change thermal storage structure in subsequent processing and use.

[0023] In some implementations, step S3 includes: 100 parts by weight of porous volcanic rock loaded with paraffin were dispersed in 50-150 parts by weight of nano-oxide hydrosol with a solid content of 20wt%-40wt%. After soaking at 20-40℃ for 20-60 min, the volcanic rock was dried at 90-120℃ for 1-3 h to obtain sealed volcanic rock.

[0024] In some of the above embodiments, porous volcanic rock loaded with paraffin is dispersed in a nano-oxide hydrosol, allowing the nano-oxide particles to gradually deposit and adsorb onto the surface and pore areas of the porous volcanic rock during the soaking process, thereby forming a continuous inorganic capping layer on the particle surface. This process facilitates the effective sealing of the pore areas without significantly altering the internal pore structure of the volcanic rock, providing physical confinement and structural locking for the phase change material.

[0025] Subsequently, drying at 90–120°C promotes further contact and connection between the nano-oxide particles, forming a relatively stable inorganic network structure on the porous volcanic rock surface, thereby sealing the pores. This inorganic network structure can effectively inhibit the migration of paraffin within the pores while maintaining a certain degree of permeability, which is beneficial to improving the stability of the phase change material during subsequent processing and use.

[0026] Through the above implementation methods, a stable inorganic sealing structure can be constructed on the surface of porous volcanic rock, confining the phase change material within the pores of the volcanic rock. This provides key support for constructing a heat storage structure with good heat storage stability and lays the foundation for subsequent surface modification and application in polyester fiber systems.

[0027] In some embodiments, in step S3, the nano-oxide further includes nano-titanium dioxide, and the mass ratio of nano-silica to nano-titanium dioxide is 10:0.1~1.

[0028] In some of the above embodiments, introducing a small amount of nano-titanium dioxide onto the basis of nano-silica can further regulate the structure and function of the sealing layer. Nano-silica particles have small particle sizes and high surface activity, making it easy to form a continuous inorganic network structure on the surface of porous volcanic rock. Nano-titanium dioxide, with its high refractive index, helps improve the sealing layer's ability to reflect thermal radiation, thereby reducing heat loss to the outside at the fiber scale. Simultaneously, nano-titanium dioxide particles exhibit good structural stability. Their synergistic distribution with nano-silica in the sealing layer helps improve the density and overall stability of the inorganic network, enabling the sealing layer to form a more stable covering structure in the pore opening region, thereby further enhancing the confinement and locking effect on the phase change material within the pores.

[0029] By controlling the mass ratio of nano-silica to nano-titanium dioxide within the range of 10:0.1~1, the high refractive index nano-titanium dioxide can play an effective role in the sealing layer while ensuring the continuity of the inorganic network, without significantly increasing the rigidity of the sealing layer or adversely affecting the subsequent processing. This approach helps to achieve a balance between thermal management effectiveness and structural compatibility.

[0030] By adopting the above-described implementation method, an inorganic sealing layer with both sealing stability and heat reflection regulation capability can be constructed on the surface of porous volcanic rock, thereby further improving the stability and overall heat preservation effect of the phase change thermal storage structure in the fiber.

[0031] In some embodiments, the average particle size of nano-silica is 5-20 nm, and the average particle size of nano-titanium dioxide is 5-20 nm.

[0032] In some implementations, step S4 includes: 100 parts by weight of sealing volcanic rock were dispersed in 1000-2000 parts by weight of 1wt%-2wt% aminosilane coupling agent in an ethanol aqueous solution, and reacted at 40-60℃ for 2-4 hours to obtain heat storage and heat preservation particles.

[0033] In some of the above embodiments, by using an aminosilane coupling agent to modify the surface of the pore-sealing volcanic rock, an organic functional structure can be introduced into the surface of the pore-sealing volcanic rock, creating a more favorable interface between the inorganic sealing layer and the organic polyester matrix. One end of the aminosilane coupling agent can interact with the inorganic oxides on the surface of the pore-sealing volcanic rock, while the organic functional structure introduced at the other end helps to enhance its interaction with the polyester matrix, thereby improving the compatibility of the heat-storing and heat-insulating particles in the polyester melt system.

[0034] Through the above surface modification treatment, the heat-storing and heat-insulating particles are more easily and uniformly dispersed in the polyester matrix during subsequent melt spinning, which helps to reduce particle agglomeration in the melt and improve the stability of the spinning process. At the same time, the improved interfacial compatibility also helps to alleviate the interfacial stress concentration between the particles and the polyester matrix, so that the resulting fiber maintains its heat storage function while also taking into account good processing and performance properties.

[0035] In some embodiments, in step S5, the mass of the heat-storing and heat-insulating particles is 1% to 7% of the mass of the polyester chips.

[0036] In some of the above embodiments, by controlling the addition amount of heat-storing and heat-insulating particles within the range of 1% to 7%, a continuous and effective heat-storing functional distribution can be constructed in the polyester fiber, allowing the phase change heat storage structure to fully function within the fiber, thereby improving the overall heat-storing and heat-insulating effect of the fiber. Simultaneously, the above-mentioned addition range helps maintain the fluidity and spinning stability of the polyester melt system while ensuring the heat-storing function, allowing the heat-storing and heat-insulating particles to be uniformly dispersed within the fiber, thus balancing the fiber's processing and performance characteristics.

[0037] In some embodiments, the paraffin wax has a melting point of 35-50°C.

[0038] In some of the above embodiments, by selecting paraffin wax with a melting point of 35-50℃ as the phase change material, its phase change temperature range is well matched with the human body's comfortable temperature range and the clothing wearing environment, which is beneficial for the effective absorption and release of heat during actual wear. Paraffin wax within this melting point range can undergo a stable solid-liquid phase change process when the ambient temperature or human body surface temperature changes, thereby absorbing excess heat when the temperature rises and releasing the stored heat when the temperature falls, which helps to improve the heat storage and temperature regulation effect of the fiber and the wearing comfort. Furthermore, paraffin wax within the above melting point range has good thermal stability during subsequent polyester melt spinning and use, and can remain stable under the confinement of the porous volcanic rock's channels and sealing structure, thus facilitating the long-term stable performance of the heat storage function.

[0039] In some embodiments, the polyester chips comprise PET chips with an intrinsic viscosity of 0.62 to 0.68 dL / g.

[0040] In some of the above embodiments, by selecting PET chips with an intrinsic viscosity of 0.62~0.68 dL / g, the polyester melt possesses suitable flowability and fiber-forming properties during melt spinning, which is beneficial for the uniform dispersion of heat-retaining particles in the melt. PET chips within this intrinsic viscosity range can ensure the fiber's mechanical properties while also taking into account the coating and load-bearing capacity of inorganic heat-retaining particles, thereby facilitating the acquisition of structurally stable and functionally uniform heat-retaining fibers.

[0041] Secondly, this application provides a heat-storing and heat-insulating fiber based on volcanic rock, prepared according to the method described in any embodiment of the first aspect.

[0042] According to this application, the heat-storing and heat-insulating fiber based on volcanic rock is prepared according to the method described in any embodiment of the first aspect, and therefore has the beneficial effects of the first aspect.

[0043] Compared with the prior art, the beneficial effects of this application are at least as follows: 1) By constructing a confined phase change heat storage structure inside volcanic rock, the phase change material is stably loaded in the porous carrier channels, so that the fiber not only has heat absorption or heat radiation related functions, but also can effectively store and release heat, significantly improving the heat storage capacity and the stability of the heat preservation effect. 2) By forming an inorganic sealing structure on the surface of porous volcanic rock, the phase change material inside the pores is effectively confined and locked, which helps to suppress the migration or leakage of the phase change material during processing and use, thereby improving the stability and reliability of the heat storage function during long-term use. 3) By introducing crystallization regulators and regulating the crystallization behavior of phase change materials, the phase change heat storage process becomes more uniform and repeatable, which helps to improve the consistency of heat storage and temperature regulation effect in multiple thermal cycles. 4) By modifying the surface of the sealed volcanic rock, the interfacial compatibility between it and the polyester matrix is ​​improved, so that the heat storage functional particles can be stably introduced into the polyester melt spinning system, achieving the heat storage function while taking into account the fiber's processing performance and structural stability. 5) The preparation method provided in this application has a clear process flow and controllable steps. The material system used has good compatibility with polyester melt spinning process, is suitable for industrial continuous production, and can meet the stability and consistency requirements of functional fibers in practical applications. Detailed Implementation

[0044] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this specification, unless otherwise specified, "parts" refers to "parts by weight".

[0048] The following describes embodiments of this application. 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 are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0049] Polyester chips, PET chips with an intrinsic viscosity of 0.65 dL / g; Volcanic rock powder with an average particle size of approximately 3 μm; Paraffin wax has a melting point of 36℃~40℃; Nano-sized silica, with an average particle size of approximately 10 nm; Nano-sized titanium dioxide with an average particle size of approximately 10 nm; Example

[0050] Preparation of heat-storing and heat-insulating fibers based on volcanic rock: S1: Volcanic rock powder is added to a sodium carbonate aqueous solution, wherein the mass ratio of volcanic rock to sodium carbonate aqueous solution is 100:500, and the concentration of the sodium carbonate aqueous solution is 1.0 mol / L. The mixture is soaked at 80℃ for 3 hours to selectively dissolve some of the soluble silica-alumina components in the volcanic rock, thereby forming a porous structure within the volcanic rock. After soaking, the solid is filtered and separated, and repeatedly washed with deionized water until the washing solution is neutral. It is then dried at 105℃ for 2 hours to obtain porous volcanic rock.

[0051] S2: The obtained porous volcanic rock, paraffin wax, and stearamide were mixed, with a mass ratio of 100:20:0.2. The mixture was heated to 70°C to completely melt the paraffin wax, and maintained under vacuum for 40 minutes, allowing the molten paraffin wax to enter the pores of the porous volcanic rock under pressure difference and capillary action. After loading, the solid was eluted with n-hexane as the elution solvent to remove free paraffin wax adhering to the surface of the porous volcanic rock. The solid was then filtered and dried under vacuum at 60°C for 1 hour to obtain porous volcanic rock loaded with paraffin wax.

[0052] S3: The above-mentioned porous volcanic rock loaded with paraffin is added to the nano-oxide hydrosol, wherein the mass ratio of the porous volcanic rock loaded with paraffin to the nano-oxide hydrosol is 1:1, the solid content of the nano-oxide hydrosol is 30wt%, and the nano-oxide is composed of nano-silica and nano-titanium dioxide in a mass ratio of 10:0.5. The mixture is soaked at 30°C for 30 minutes to allow the nano-oxide particles to deposit on the surface and pore areas of the porous volcanic rock. Subsequently, the obtained material is dried at 105°C for 2 hours to allow the nano-oxide particles to form a continuous and stable inorganic network structure on the surface of the porous volcanic rock, sealing the pores and obtaining sealed volcanic rock.

[0053] S4: The above-mentioned pore-sealing volcanic rock was added to an ethanol-water solution of γ-aminopropyltriethoxysilane, wherein the mass ratio of the pore-sealing volcanic rock to the ethanol-water solution (ethanol to water volume ratio of 95:5) was 100:1500, and the mass fraction of γ-aminopropyltriethoxysilane in the ethanol-water solution was 1.5 wt%. The reaction was carried out at 50°C for 3 h. After the reaction was completed, the solid was filtered and separated, and dried at 110°C for 2 h to obtain heat-storing and heat-insulating particles.

[0054] S5: The above-mentioned heat-storing and heat-insulating particles are mixed with polyester chips and then melt-spun, wherein the amount of heat-storing and heat-insulating particles added is 4% of the mass of polyester chips. The mixture is vacuum-dried at 120°C for 6 hours to reduce the moisture content of the raw materials.

[0055] The dried mixture is fed into a melt spinning machine for melt extrusion. The temperatures of each zone of the extruder are set sequentially to 265℃, 270℃, 275℃, and 280℃. The melt is filtered through a 40μm metal screen and then enters a metering pump, where it is extruded through the spinning assembly. During the spinning process, the spinneret adopts a conventional circular spinneret structure. After being extruded, the melt is cooled and solidified by cooling air to form nascent filaments.

[0056] The nascent filaments are drawn at a temperature controlled at 80℃ with a total draw ratio of 3.2 times to ensure full orientation of the fiber molecular chains, thereby obtaining continuous filaments with stable mechanical properties. The drawn filaments are then oiled and wound to obtain heat-retaining fibers. Example

[0057] Preparation of heat-storing and heat-insulating fibers based on volcanic rock: It is largely the same as Example 1, except that step S2 is different, which is as follows: S2: The obtained porous volcanic rock and paraffin wax are mixed, wherein the mass ratio of porous volcanic rock, paraffin wax, and stearamide is 100:20. The mixture is heated to 70°C to completely melt the paraffin wax, and maintained under vacuum for 40 minutes, allowing the molten paraffin wax to enter the pores of the porous volcanic rock under the drive of pressure difference and capillary action. After loading, the obtained solid is eluted with n-hexane as the elution solvent to remove free paraffin wax adhering to the surface of the porous volcanic rock. The solid is then filtered and separated, and vacuum dried at 60°C for 1 hour to obtain porous volcanic rock loaded with paraffin wax. Example

[0058] Preparation of heat-storing and heat-insulating fibers based on volcanic rock: It is largely the same as Example 1, except that step S3 is different, which is as follows: S3: The above-mentioned porous volcanic rock loaded with paraffin is added to a nano-oxide hydrosol, wherein the mass ratio of the porous volcanic rock loaded with paraffin to the nano-oxide hydrosol is 1:1, the solid content of the nano-oxide hydrosol is 30wt%, and the nano-oxide is nano-silica. The mixture is soaked at 30°C for 30 minutes to allow the nano-oxide particles to deposit on the surface and pore areas of the porous volcanic rock. Subsequently, the obtained material is dried at 105°C for 2 hours to allow the nano-oxide particles to form a continuous and stable inorganic network structure on the surface of the porous volcanic rock, sealing the pores and obtaining sealed volcanic rock.

[0059] Comparative Example 1 Preparation of heat-storing and heat-insulating fibers based on volcanic rock: Volcanic rock powder was added to a sodium carbonate aqueous solution at a mass ratio of 100:500, with the sodium carbonate aqueous solution having a concentration of 1.0 mol / L. The mixture was soaked at 80°C for 3 hours to selectively dissolve some of the soluble silica and aluminum components in the volcanic rock, thereby forming a porous structure within the rock. After soaking, the solid was filtered and separated, and repeatedly washed with deionized water until the washing solution was neutral. It was then dried at 105°C for 2 hours to obtain porous volcanic rock.

[0060] The aforementioned porous volcanic rock was added to a nano-oxide hydrosol, wherein the mass ratio of the paraffin-loaded porous volcanic rock to the nano-oxide hydrosol was 1:1, the solid content of the nano-oxide hydrosol was 30 wt%, and the nano-oxide consisted of nano-silica and nano-titanium dioxide in a mass ratio of 10:0.5. The mixture was soaked at 30°C for 30 min to allow nano-oxide particles to deposit on the surface and pore areas of the porous volcanic rock. Subsequently, the resulting material was dried at 105°C for 2 h to allow the nano-oxide particles to form a continuous and stable inorganic network structure on the surface of the porous volcanic rock, sealing the pores and obtaining sealed volcanic rock.

[0061] The aforementioned pore-sealing volcanic rock was added to an ethanol-water solution of γ-aminopropyltriethoxysilane, wherein the mass ratio of the pore-sealing volcanic rock to the ethanol-water solution (ethanol to water volume ratio of 95:5) was 100:1500, and the mass fraction of γ-aminopropyltriethoxysilane in the ethanol-water solution was 1.5 wt%. The reaction was carried out at 50 °C for 3 h. After the reaction was completed, the solid was filtered and separated, and then dried at 110 °C for 2 h to obtain heat-storing and heat-insulating particles.

[0062] The above-mentioned heat-storing and heat-insulating particles were mixed with polyester chips and then melt-spun, wherein the amount of heat-storing and heat-insulating particles added was 4% of the mass of polyester chips. The mixture was vacuum-dried at 120°C for 6 hours to reduce the moisture content of the raw materials.

[0063] The dried mixture is fed into a melt spinning machine for melt extrusion. The temperatures of each zone of the extruder are set sequentially to 265℃, 270℃, 275℃, and 280℃. The melt is filtered through a 40μm metal screen and then enters a metering pump, where it is extruded through the spinning assembly. During the spinning process, the spinneret adopts a conventional circular spinneret structure. After being extruded, the melt is cooled and solidified by cooling air to form nascent filaments.

[0064] The nascent filaments are drawn at a temperature controlled at 80℃ with a total draw ratio of 3.2 times to ensure full orientation of the fiber molecular chains, thereby obtaining continuous filaments with stable mechanical properties. The drawn filaments are then oiled and wound to obtain heat-retaining fibers.

[0065] Comparative Example 2 Preparation of heat-storing and heat-insulating fibers based on volcanic rock: Volcanic rock powder was added to a sodium carbonate aqueous solution at a mass ratio of 100:500, with the sodium carbonate aqueous solution having a concentration of 1.0 mol / L. The mixture was soaked at 80°C for 3 hours to selectively dissolve some of the soluble silica and aluminum components in the volcanic rock, thereby forming a porous structure within the rock. After soaking, the solid was filtered and separated, and repeatedly washed with deionized water until the washing solution was neutral. It was then dried at 105°C for 2 hours to obtain porous volcanic rock.

[0066] The obtained porous volcanic rock, paraffin wax, and stearamide were mixed in a mass ratio of 100:20:0.2. The mixture was heated to 70°C to completely melt the paraffin wax, and maintained under vacuum for 40 minutes, allowing the molten paraffin wax to penetrate the pores of the porous volcanic rock under pressure difference and capillary action. After loading, the resulting solid was eluted with n-hexane as the elution solvent to remove free paraffin wax adhering to the surface of the porous volcanic rock. The solid was then filtered and dried under vacuum at 60°C for 1 hour to obtain porous volcanic rock loaded with paraffin wax.

[0067] The aforementioned porous volcanic rock loaded with paraffin was added to an ethanol-water solution of γ-aminopropyltriethoxysilane (ethanol to water volume ratio of 95:5), wherein the mass ratio of the porous volcanic rock loaded with paraffin to the ethanol-water solution was 100:1500, and the mass fraction of γ-aminopropyltriethoxysilane in the ethanol-water solution was 1.5 wt%. The reaction was carried out at 50 °C for 3 h. After the reaction was completed, the solid was filtered and separated, and then dried at 110 °C for 2 h to obtain heat-storing and heat-insulating particles.

[0068] The above-mentioned heat-storing and heat-insulating particles were mixed with polyester chips and then melt-spun, wherein the amount of heat-storing and heat-insulating particles added was 4% of the mass of polyester chips. The mixture was vacuum-dried at 120°C for 6 hours to reduce the moisture content of the raw materials.

[0069] The dried mixture is fed into a melt spinning machine for melt extrusion. The temperatures of each zone of the extruder are set sequentially to 265℃, 270℃, 275℃, and 280℃. The melt is filtered through a 40μm metal screen and then enters a metering pump, where it is extruded through the spinning assembly. During the spinning process, the spinneret adopts a conventional circular spinneret structure. After being extruded, the melt is cooled and solidified by cooling air to form nascent filaments.

[0070] The nascent filaments are drawn at a temperature controlled at 80℃ with a total draw ratio of 3.2 times to ensure full orientation of the fiber molecular chains, thereby obtaining continuous filaments with stable mechanical properties. The drawn filaments are then oiled and wound to obtain heat-retaining fibers.

[0071] Test section Fabric preparation: The heat-retaining and warm-insulating fibers obtained in the above embodiments and comparative examples were subjected to doubling and twisting treatment. The twisting method was bidirectional twisting, and the twist degree was controlled at 300T / m, ultimately obtaining a heat-retaining and warm-insulating yarn. Using the above heat-retaining and warm-insulating yarn, a knitted fabric was prepared using a circular knitting machine with a gauge of 28 stitches and a single-sided plain weave structure. During the weaving process, the yarn linear density, weaving tension, and loop formation conditions were kept consistent, and the resulting fabric had a weight of 220g / m². 2 The thickness is 1.2mm. All fabrics were placed in an environment of 20±2℃ and 65±5% relative humidity for 24 hours before testing.

[0072] Thermal insulation performance test: Each fabric was cut into 10cm×10cm samples for cooling performance testing. During the test, a constant temperature heating plate was used as the heat source. The temperature of the heating plate was set to 37℃ and kept stable. The sample was laid flat on the surface of the heating plate and fixed with pressure. It was heated for 10 minutes under this condition. Then, the sample was quickly transferred to a constant temperature environment at 10℃ to cool under natural convection. The time T0 (min) required for the sample surface temperature to drop from 35℃ to 25℃ was recorded. The results are shown in Table 1.

[0073] Heat retention and thermal insulation performance durability test: The above fabric samples were washed with water at 40℃, detergent dosage of 2g / L, and washing time of 15min. After washing, the samples were rinsed with clean water and dried. The heat retention and thermal insulation performance test was repeated on the fabric samples under the same test conditions after 20 washes. The time T1 (min) required for the surface temperature of the sample to drop from 35℃ to 25℃ after washing was recorded. The results are shown in Table 1.

[0074] Table 1 As shown in Table 1, the T0 and T1 values ​​of each embodiment are significantly higher than those of Comparative Example 1 and Comparative Example 2, indicating that the heat-storing and heat-insulating fiber provided in this application can maintain good heat-storing and heat-insulating performance in the initial state and after multiple washes, and has a high heat-storing and heat-insulating effect. The possible reason is that in Comparative Example 1, only volcanic rock material was introduced without loading phase change heat-storing components, mainly relying on the material's own heat absorption or far-infrared related characteristics, resulting in limited heat storage and release capacity, thus its heat-storing and heat-insulating effect is weak. In Comparative Example 2, although paraffin phase change material was loaded, the pores were not effectively sealed, making it easy for the phase change material to migrate or be lost during subsequent processing and use, thus affecting both its heat-storing and heat-insulating performance and its durability.

[0075] As can be seen from Examples 1 and 2, under the premise of adopting a sealed pore structure, the introduction of crystallization regulating components has a certain impact on the heat storage stability of the phase change system in the pores. When a crystallization regulator is introduced during the process of loading paraffin onto porous volcanic rock, it helps to improve the crystallization state and distribution uniformity of the phase change material in the pores, thereby making the resulting fiber perform better in terms of initial heat storage and heat preservation performance and heat preservation durability after washing.

[0076] As can be seen from Examples 1 and 3, under the condition of using the same sealing structure, the composition of inorganic components in the sealing layer also has a certain influence on the heat storage and insulation effect. When titanium dioxide with a high refractive index is introduced into the sealing layer at the same time, it helps to further enhance the heat retention capacity, so that the resulting fiber performs better in terms of heat storage and insulation performance and durability.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method of preparing a volcanic rock-based heat-retaining thermal fiber, characterized by, The method comprises the following steps: S1: dispersing the volcanic rock in a sodium carbonate aqueous solution to cause selective corrosion of the volcanic rock and form pores, and obtaining porous volcanic rock; S2: mixing the porous volcanic rock with paraffin, melting the paraffin into the pores of the porous volcanic rock, and obtaining porous volcanic rock loaded with paraffin; S3: dispersing the porous volcanic rock loaded with paraffin in a nano-oxide hydrosol, causing nano-oxide particles to form an inorganic network on the surface of the porous volcanic rock to seal the pores, and obtaining sealed volcanic rock; wherein the nano-oxide comprises silicon dioxide; S4: modifying the surface of the sealed volcanic rock using an amino silane coupling agent, and obtaining heat-storing and warm-keeping particles; S5: mixing the heat-storing and warm-keeping particles with polyester chips, melting and spinning, and obtaining heat-storing and warm-keeping fibers.

2. The method of claim 1, wherein, The step S1 comprises: 100 parts by mass of volcanic rock with an average particle size of 1-5 μm are dispersed in 400-600 parts by mass of a 0.5-2 mol / L sodium carbonate aqueous solution, and soaked at 70-90°C for 2-5 h to obtain porous volcanic rock.

3. The method of claim 1, wherein, The step S2 comprises: 100 parts by mass of porous volcanic rock are mixed with 10-30 parts by mass of paraffin, and loaded at 60-80°C under vacuum for 20-60 min to obtain porous volcanic rock loaded with paraffin.

4. The method of claim 3, wherein, The step S2 comprises: 100 parts by mass of porous volcanic rock, 10-30 parts by mass of paraffin, and 0.1-0.3 parts by mass of stearamide are mixed, and loaded at 70-90°C under vacuum for 20-60 min to obtain porous volcanic rock loaded with paraffin.

5. The method of claim 1, wherein, The step S3 comprises: 100 parts by mass of porous volcanic rock loaded with paraffin are dispersed in 50-150 parts by mass of a nano-oxide hydrosol with a solid content of 20wt%-40wt%, soaked at 20-40°C for 20-60 min, and dried at 90-120°C for 1-3 h to obtain sealed volcanic rock.

6. The method of claim 5, wherein, In the step S3, the nano-oxide further comprises nano-titanium dioxide, and the mass ratio of the nano-silicon dioxide and the nano-titanium dioxide is 10:0.1-1.

7. The method of claim 1, wherein, The step S4 comprises: 100 parts by mass of sealed volcanic rock are dispersed in 1000-2000 parts by mass of an ethanol aqueous solution of 1wt%-2wt% amino silane coupling agent, and reacted at 40-60°C for 2-4 h to obtain heat-storing and warm-keeping particles.

8. The method of claim 1, wherein, In the step S5, the mass of the heat-storing and warm-keeping particles is 1%-7% of the mass of the polyester chips.

9. The method according to any one of claims 1 to 8, characterized in that, The method satisfies at least one of the following conditions: 1) the melting point of the paraffin is 35-50°C; 2) the polyester chips comprise PET chips with an intrinsic viscosity of 0.62-0.68 dL / g.

10. A heat-accumulating thermal fiber, characterized by, Prepared according to the method of any one of claims 1-9.

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