Polyamide filament, covering yarn, heat-storage warm-keeping fabric and preparation method of polyamide filament, covering yarn and heat-storage warm-keeping fabric

Abstract

The invention discloses a chinlon filament, a covering yarn, a heat storage and warm keeping fabric and a preparation method thereof.The chinlon filament comprises a shell and a cavity located in the shell, the cavity comprises a plurality of cavity units arranged at intervals, and the shell comprises a shell body, first columns and connecting parts located between every two adjacent cavity units; the connecting part is used for connecting the first cylinder and the shell body, the multiple cavity units are arranged in the circumferential direction of the first cylinder, and the center of the first cylinder coincides with the center of the chinlon filament; the area ratio of the cavities in the cross section of the chinlon filament is 20%-30%, and the cavities are used for storing air. The covering yarn comprises an inner core layer and an outer skin layer wrapping the inner core layer, the inner core layer comprises a plurality of chinlon filaments, and the outer skin layer comprises a plurality of heat storage fibers. The fabric comprises a surface layer and an inner layer which are attached to each other, and the surface layer and the inner layer are both prepared from covering yarn through warp and weft interweaving. According to the heat-storage warm-keeping fabric, the mass of the fabric can be reduced while the heat storage function of the yarn and the fabric is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of textiles, and in particular relates to nylon filaments, core-spun yarns, heat-storage and warm-keeping fabrics and a preparation method thereof. Background Art

[0002] With the development of modern technology, people's requirements for thermal insulation fabrics are not only to meet the requirements of heavy thermal insulation fabrics, but also to pursue new fabrics that are intelligently heat-storing, lightweight, and can meet the requirements of thermal insulation and heat storage. At present, most thermal storage yarns and fabrics on the market have only been improved in one aspect, either in terms of structure or composition, or multi-layer fabrics have been used to improve the thermal storage performance, which has improved the thermal storage performance of the fabric to a certain extent, but the fabric is thick and not light.

[0003] For example, the Chinese invention patent with publication number CN118407263B and patent name "A graphene heat storage fabric and its preparation method and application" discloses that a composite finishing agent of graphene wrapped with polyvinyl alcohol acetal is coated on the fabric layer to form a heat storage layer, which only improves the heat storage performance from the raw material, but the graphene coating will reduce the air permeability of the fabric, and the combination performance of the coating and the fabric is low, and the wear resistance is reduced. For another example, the Chinese utility model patent with publication number CN209537717U and patent name "A non-coated and non-liner anti-velvet heat storage yarn fabric" discloses that the performance of the heat storage fabric is improved through a specific organizational structure (including six warp yarns and two weft yarns interwoven), but the heat storage effect is not significant.

[0004] How to reduce the weight of fabric to make it lighter to wear while ensuring good heat storage and warmth retention of the fabric is an urgent problem to be solved. Summary of the invention

[0005] In view of this, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a nylon filament, core-spun yarn, heat-storage and warm-keeping fabric and a preparation method thereof, which can improve and enhance the heat storage function of the yarn and fabric while reducing the weight of the fabric.

[0006] One object of the present invention is to provide a nylon filament, comprising a shell and a cavity located inside the shell, the cavity comprising a plurality of cavity units arranged at intervals, the shell comprising a shell body, a first cylinder and a connecting portion located between two adjacent cavity units, the connecting portion being used to connect the first cylinder and the shell body, a plurality of the cavity units being arranged along the circumference of the first cylinder, the center of the first cylinder coinciding with the center of the nylon filament; the area of ​​the cavity in the cross section of the nylon filament accounts for 20% to 30%, the length of the cavity is equal to the length of the shell, and the cavity is used to store air.

[0007] By designing a cavity inside the shell of the nylon filament to store air, when the nylon filament is squeezed, the static air inside it will not be completely lost, and can be preserved longer, which is beneficial to improving the heat storage performance of the nylon filament.

[0008] According to some preferred implementation aspects of the present invention, each of the cavity units includes a plurality of cavity petals arranged at intervals, and the length of at least one cavity petal in each of the cavity units is greater than the length of the remaining cavity petals. The length of the cavity petal here refers to the distance between the two ends of the cavity petal in the cross section of the nylon filament.

[0009] According to some preferred embodiments of the present invention, the width of each cavity petal gradually increases from one end close to the center of the nylon filament to the other end. Such a configuration can make the structure of each cavity petal more stable, and when squeezed, the deformation produced is smaller, and more residual static air can be preserved.

[0010] According to some preferred embodiments of the present invention, the multiple cavity petals in each cavity unit are connected to each other at one end close to the center of the nylon filament, and the multiple cavity petals in each cavity unit are spaced apart from each other at one end away from the center of the nylon filament.

[0011] According to some preferred implementation aspects of the present invention, a partition is provided between two adjacent cavity petals in each cavity unit, one end of the partition is connected to the shell body, and the other end of the partition extends toward the first column.

[0012] According to some preferred implementation aspects of the present invention, each of the cavity units includes a cavity main lobe and cavity auxiliary lobes symmetrically arranged on both sides of the cavity main lobe, and the length of the cavity main lobe is greater than the length of the cavity auxiliary lobe. Such an arrangement is a preferred arrangement of the cavity unit, which can make the structure of the cavity more stable.

[0013] Another object of the present invention is to provide a method for preparing the nylon filament as described above, comprising the following steps:

[0014] The nylon filament is obtained by mixing the heat storage promoter with the solution containing the modified nylon and spinning the mixture; the thermal conductivity of the modified nylon is 0.128-0.151 W / (m·℃). The purpose of preparing the modified nylon is to reduce its original thermal conductivity by modifying the nylon to improve its warmth retention.

[0015] According to some preferred implementation aspects of the present invention, the solution containing modified nylon is a modified nylon melt solution obtained by adding a modified nylon melt to a solvent and then mixing uniformly; the modified nylon melt is prepared by melting nylon slices and then copolymerizing, surface crosslinking or enzyme modification. Specifically, copolymerization modification is to introduce other monomers, such as ethylene glycol or melamine cyanurate, into the nylon polymerization process to form a copolymer, thereby reducing the crystallinity of the fiber and improving its thermal insulation effect; or to graft a hydrophilic polymer, such as polyethylene glycol, onto the surface of the nylon fiber to increase the hydrophilicity of the nylon fiber surface, promote water vapor adsorption, and improve the thermal insulation effect. Surface crosslinking is to connect the polymer chains on the surface of the nylon fiber through a chemical crosslinking agent to form a network structure, thereby improving its thermal insulation. Enzyme modification is achieved by selectively degrading specific chemical bonds (amide bonds) on the surface of nylon fibers to change the structure and properties of the nylon fiber surface, thereby improving its warmth retention and ultimately obtaining modified nylon with a low thermal conductivity (0.128-0.151 W / (m·℃)).

[0016] Specifically, the specific method of copolymerization modification is: first, ethylene glycol is subjected to an esterification reaction under the condition of an excess of organic acid (containing two carboxyl groups), the reaction temperature is 200-240°C, and the reaction time is 3-5 hours to obtain a carboxyl-terminated polyester substance. Then, nylon chips are added and the temperature is continued to rise to make the nylon chips in a molten state. At this time, the hydroxyl groups in the nylon melt and the carboxyl groups on the above polyester substances undergo an esterification grafting reaction to obtain a modified nylon melt. The crystallinity of the modified nylon is lower than that of the original one, which can reduce its thermal conductivity.

[0017] According to some preferred implementation aspects of the present invention, the method of spinning after mixing the heat storage promoter with the solution containing modified nylon is: adding the heat storage promoter to the modified nylon melt solution and mixing evenly to obtain a mixed spinning solution, extruding the spinning solution and ejecting it from the spinneret to form a tow, and then subjecting it to monomer suction, side blowing cooling, bundling oiling, stretching and shaping, network entanglement, and winding to obtain the nylon filament; the mass ratio of the modified nylon melt in the spinning solution to the heat storage promoter is 95 to 99:1. Among them, the stretching is carried out at a temperature of 75 to 90°C, and the yarn fineness after stretching ranges from 70 to 90D; the spinning temperature is 270 to 320°C, the spinning speed is 800 to 1300 m / min, and the winding speed is 4500 to 5000 m / min. In addition, the shape of the spinneret is designed according to the cross-sectional shape of the target nylon filament.

[0018] According to some preferred implementation aspects of the present invention, the heat storage promoter includes a light absorbing material, and the light absorbing material is one or more of nano ceramic particles, graphene, carbon nanotubes, carbon black, carbon dots, MXene, zirconium carbide, and silicon carbide. In addition, the heat storage promoter also includes a dispersant and a coupling agent, wherein the mass proportion of the dispersant is 7% to 8%, and the mass proportion of the coupling agent is 3% to 4%; when the light absorbing material is nano ceramic particles, its average particle size is 50 to 100nm, and the composition is one or more of nano alumina and nano silicon dioxide.

[0019] The present invention further provides a core-spun yarn, comprising an inner core layer and an outer skin layer wrapped outside the inner core layer, wherein the inner core layer comprises a plurality of nylon filaments as described above, and the outer skin layer comprises a plurality of heat storage fibers. The nylon filaments are core-spun composited with other heat storage fibers to obtain a yarn with a stronger heat storage effect; wherein the density of the nylon filaments is 70-90D, and the grammage per square meter is 160-200g / m 2 ; The fineness of the core-spun yarn is 14~18tex.

[0020] According to some preferred implementation aspects of the present invention, the mass proportion of nylon filaments in the core-spun yarn is 60% to 70%.

[0021] According to some preferred embodiments of the present invention, phase change microcapsules are also attached to the outer surface of the outer skin layer, and the phase change microcapsules include a phase change core and a shell for wrapping the phase change core, and the material of the phase change core is one or more of paraffin, fatty acid, and fatty alcohol. Phase change microcapsules are added to enhance the absorption of light and heat by the yarn. The material of the shell is one or more of polyurethane, polymethyl methacrylate, and urea-formaldehyde resin. Phase change microcapsules can improve the thermal storage and warmth retention of yarns through photothermal conversion. Specifically, the phase change core is mainly used to absorb and release heat through phase change, thereby storing energy.

[0022] According to some preferred embodiments of the present invention, the heat storage fiber is a volcanic rock heat storage fiber or a spectrum thermal fiber. Volcanic rock fiber has a special microporous structure and a large specific surface area, which can absorb and store more heat. At the same time, it is rich in metal elements and can absorb thermal energy, which is beneficial to improve the heat storage capacity of the fabric. In addition, volcanic rock fiber can release far infrared rays, which can be transmitted to the deeper part of the human body under the skin, so that the temperature rises, and the generated warmth is radiated from the inside to the outside, promoting the improvement of human microcirculation. Spectral thermal fiber can absorb all-region rays in the solar spectrum, including visible light and invisible light. It is compounded with nylon filament to form a core-spun yarn, which can increase the absorption of light by the core-spun yarn and further improve the heat storage effect.

[0023] The present invention further provides a method for preparing the core-spun yarn as described above, comprising the following steps:

[0024] The nylon filaments were used as the inner core layer and the heat storage fiber was used as the outer skin layer for pretreatment respectively;

[0025] The inner core layer is subjected to multi-filament merging and twisting to form a first yarn, and the outer skin layer is subjected to a cotton cleaning process, a cotton carding process, a drawing process, a roving process and a spun yarn process in sequence to form a short fiber roving, which is then stretched and thinned to form a second yarn;

[0026] The first yarn and the second yarn are drafted and twisted together to form the core-spun yarn.

[0027] According to some preferred implementation aspects of the present invention, post-processing is also included. The post-processing method is: after cleaning the core-spun yarn, the phase change microcapsules are adsorbed on the surface of the outer skin layer of the core-spun yarn by a padding method.

[0028] Specifically, the core-spun yarn is subjected to standard soap washing to ensure that its surface is clean; then the phase change core (such as polyethylene glycol) is mixed with a cross-linking agent (such as N,N'-methylenebisacrylamide), and free radical polymerization is carried out in a raw material suspension of the shell (such as a methacrylic acid suspension), and the phase change core is encapsulated in polymethacrylic acid to obtain a phase change microcapsule; the phase change microcapsule is impregnated into the core-spun yarn so that the phase change microcapsule is physically adsorbed on the outer skin of the core-spun yarn; finally, curing is carried out to ensure a close bond between the phase change microcapsule and the core-spun yarn, thereby improving the durability of the phase change microcapsule function, and then the additives and impurities involved in the reaction are removed. The final weight gain rate of the core-spun yarn with the phase change microcapsule attached is 7% to 9%.

[0029] Another object of the present invention is to provide a heat-storage and warm-keeping fabric, wherein the fabric has the core-spun yarn as described above.

[0030] According to some preferred implementation aspects of the present invention, the fabric includes a surface layer and an inner layer that are bonded to each other, and the surface layer and the inner layer are both prepared by interweaving the core-spun yarn through warp and weft, the tissue structure of the surface layer is a honeycomb tissue, and the tissue structure of the inner layer is a twill tissue. The warp density of the surface layer and the inner layer is 240-280 strands / 10cm, and the weft density is 200-240 strands / 10cm.

[0031] The present invention also provides a method for preparing the heat storage and warmth retaining fabric as described above, comprising the following steps:

[0032] Using the core-spun yarn as the warp yarn and the weft yarn, interweaving the warp yarn and the weft yarn to obtain a surface transition layer and an inner layer respectively;

[0033] The light-absorbing material is attached to the surface transition layer by coating or dipping, and the surface layer is obtained after drying and curing; specifically, the coating method is: first pre-treating the surface transition layer to remove impurities and stains on its surface to ensure that the light-absorbing material can be firmly attached; then the light-absorbing material is mixed with a binder, a wetting agent, and a dispersant and then coated on the surface transition layer by rolling or spraying; finally, the final surface layer is obtained after curing, washing, and drying. The dipping method is: immersing the surface transition layer in a solution containing the light-absorbing material; squeezing out excess solution by a roller to make the light-absorbing material evenly attached to the surface transition layer; then drying and curing are performed to ensure the bonding strength between the light-absorbing material and the fabric to obtain the surface layer.

[0034] The surface layer and the inner layer are connected by sewing or bonding to obtain the fabric.

[0035] In some embodiments of the present invention, the surface layer adopts honeycomb tissue, and the concave and convex structure of the honeycomb tissue is used to fill the concave part of the honeycomb tissue with light-absorbing materials, thereby further improving its absorption of external heat. The inner layer adopts a twill tissue structure, which can improve the reflection of heat emitted by the human body, thereby achieving efficient heat storage and warmth preservation.

[0036] Due to the adoption of the above technical scheme, compared with the prior art, the benefits of the present invention are as follows: the nylon filament, core-spun yarn, heat-storage and warm-keeping fabric and preparation method thereof of the present invention, by designing a cavity inside the shell of the nylon filament for storing air, when the nylon filament is squeezed, the static air inside it will not be completely lost, and can be preserved for a longer time, which is beneficial to improving the heat storage performance of the nylon filament; the nylon filament is then core-wrapped and composited with other heat storage fibers to obtain a core with a stronger heat storage effect, and then phase change microcapsules are coated on the surface of its outer skin to enhance the absorption of light and heat; finally, the core-spun yarn with phase change microcapsules is used for weaving to obtain the surface layer and the inner layer of the fabric respectively, and the surface layer adopts a honeycomb structure, and the concave part thereof is filled with light-absorbing material to further improve the absorption of external heat, and finally the surface layer is connected with the inner layer to obtain a fabric with improved heat storage function, and the fabric has only two layers, and the warp yarn and weft yarn of the surface layer and the inner layer are both nylon filaments with a cavity structure, which can effectively reduce the quality of the fabric and improve the comfort of wearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1is a schematic diagram of the three-dimensional structure of nylon filaments in Example 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of the main structure of the cross section of the nylon filament in Example 1 of the present invention;

[0040] Figure 3 It is a schematic diagram of the three-dimensional structure of the core-spun yarn in Example 3 of the present invention;

[0041] Figure 4 This is an exploded view of the heat storage and warmth retaining fabric in Example 4 of the present invention;

[0042] Figure 5 This is a schematic diagram of the organizational structure of the surface layer of the heat storage and warmth retaining fabric in Example 4 of the present invention;

[0043] Figure 6 This is a schematic diagram of the organizational structure of the inner layer of the heat storage and warmth-keeping fabric in Example 4 of the present invention;

[0044] Wherein, the accompanying drawings are marked as follows:

[0045] Nylon filament-10, shell body-11, first column-12, connecting part-13, cavity-2, cavity petal-21, spacer-22, core-spun yarn-20, heat storage fiber-3, phase change microcapsule-4, fabric-30, surface layer-5, inner layer-6. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] The present invention provides a heat storage and warmth-keeping fabric, which comprises a surface layer 5 and an inner layer 6 which are bonded to each other, wherein both the surface layer 5 and the inner layer 6 comprise warp yarns and weft yarns, and the density of the warp yarns is 240 to 280 yarns / 10 cm, and the density of the weft yarns is 200 to 240 yarns / 10 cm; the tissue structure of the surface layer 5 is a honeycomb tissue, and the concave part of the honeycomb tissue is filled with a light-absorbing material to further improve its absorption of external heat. The tissue structure of the inner layer 6 is a twill tissue, which can improve the reflection of the heat emitted by the human body, thereby realizing efficient heat storage and warmth-keeping; the surface layer 5 and the inner layer 6 can be connected by sewing or bonding.

[0048] Furthermore, the warp and weft yarns of the surface layer 5 and the inner layer 6 are both core-spun yarns 20 with a fineness of 14 to 18 tex, and the core-spun yarn 20 includes an inner core layer and an outer skin layer wrapped outside the inner core layer, the inner core layer includes a plurality of nylon filaments 10, and the outer skin layer includes a plurality of heat storage fibers 3, and the heat storage fibers 3 are volcanic rock heat storage fibers or spectrum heat fibers. The mass proportion of the nylon filaments 10 in the core-spun yarn 20 is 60% to 70%. Specifically, the nylon filaments 10 include a shell and a cavity 2 located inside the shell, the cavity 2 is used to store air, and the length of the cavity 2 is equal to the length of the shell. The cavity 2 includes a plurality of cavity units arranged at intervals; the shell includes a shell body 11, a first column 12 and a connecting portion 13 located between two adjacent cavity units, the connecting portion 13 is used to connect the first column 12 and the shell body 11, and the plurality of cavity units are arranged along the circumference of the first column 12, and the center of the first column 12 coincides with the center of the nylon filament 10; the area of ​​the cavity 2 in the cross section of the nylon filament 10 accounts for 20% to 30%.

[0049] Each cavity unit includes a plurality of cavity petals 21 arranged at intervals, and the length of at least one cavity petal 21 in each cavity unit is greater than the length of the remaining cavity petals 21. In the present invention, the reason why at least one cavity petal 21 in each cavity unit is the longest is that when designing a spinneret that matches the cross-sectional shape of the nylon filament 10, if the partial structure of the spinneret used to form the cavity 2 is completely hollowed out, the middle part of the spinneret cannot be fixed. Therefore, at least one longest plate is set in the part of the spinneret that forms each cavity unit to be fixed to the annular outer edge of the spinneret.

[0050] In addition, the width of each cavity petal 21 gradually increases from one end close to the center of the nylon filament 10 to the other end. A spacer 22 is provided between two adjacent cavity petals 21 in each cavity unit, one end of the spacer 22 is connected to the shell body 11, and the other end of the spacer 22 extends toward the first column 12, so that the ends of the multiple cavity petals 21 in each cavity unit close to the center of the nylon filament 10 are connected to each other, and the ends of the multiple cavity petals 21 in each cavity unit away from the center of the nylon filament 10 are spaced from each other. Such a setting can make the structure of each cavity petal 21 more stable, and when squeezed, the deformation produced is smaller, and the residual static air can be preserved more, which is conducive to improving the heat storage performance of the nylon filament 10.

[0051] Furthermore, the outer surface of the outer skin layer is also attached with a phase change microcapsule 4, which includes a phase change core and a shell for wrapping the phase change core, wherein the material of the phase change core is one or more of paraffin, fatty acid, and fatty alcohol, and the material of the shell is one or more of polyurethane, polymethyl methacrylate, and urea-formaldehyde resin. The phase change core in the phase change microcapsule 4 absorbs and releases heat through phase change to achieve light-heat conversion for energy storage, which is beneficial to improving the heat storage and warmth retention of the core-spun yarn 20.

[0052] The present invention also provides a method for preparing a heat storage and warmth-keeping fabric, comprising the following steps:

[0053] Step 1: Preparation of modified nylon melt

[0054] After the nylon slices are melted, a modified nylon melt is prepared by copolymerization, surface crosslinking or enzyme modification, and the modified nylon melt is added to a solvent and mixed evenly to obtain a modified nylon melt solution. The thermal conductivity of the modified nylon is 0.128 to 0.151 W / (m·℃).

[0055] Step 2: Preparation of nylon filament 10

[0056] First, a spinneret is designed and processed according to the cross-sectional shape of the nylon filament 10, and then a light-absorbing material with a particle size of 50 to 100 nm is added to the modified nylon melt solution in step 1, and then ultrasonically dispersed for 15 to 45 minutes after stirring for 15 to 45 minutes. Finally, the upper dispersion is taken after centrifugal sedimentation, mixed with water and a molecular weight regulator and stirred evenly to obtain a spinning solution, and the mass ratio of the modified nylon melt to the heat storage accelerator in the spinning solution is 95 to 99:1. The spinning solution is extruded and ejected from the spinneret to form a filament bundle, the spinning temperature is 270 to 320°C, and the spinning speed is 800 to 1300 m / min; then, the nylon filament 10 is obtained through monomer suction, side blowing cooling, bundling oiling, stretching and shaping, network intertwining and winding. Among them, the stretching and shaping temperature is 75 to 90°C, the fineness of the yarn after stretching is 70 to 90D, and the winding speed is 4500 to 5000 m / min.

[0057] Step 3: Prepare the core-spun yarn 20

[0058] The nylon filament 10 and the heat storage fiber 3 are pretreated to clean the surface impurities and dirt. The nylon filament 10 is used as the inner core layer and the volcanic rock heat storage fiber is used as the outer skin layer. The inner core layer is subjected to multi-filament merging and twisting to form an elastic strand to obtain the first yarn; the outer skin layer is subjected to the cotton cleaning process, the cotton combing process, the drawing process, the roving process and the spinning process to form a short fiber roving, and the second yarn is obtained after drawing and thinning; then, the Cellophane spinning technology is used to feed the first yarn directly into the front roller without being drawn through the spinning frame, and the second yarn is fed into the front roller. After the two yarns pass through the tension device and the yarn guide, they are subjected to normal drawing and whisker compounding at the convergence point, and finally twisted to form the core-spun yarn 20; the core-spun yarn 20 is subjected to standard soap washing to ensure that its surface is clean and ready for use.

[0059] The phase change core (such as polyethylene glycol) and the cross-linking agent (such as N, N'-methylenebisacrylamide) are mixed, and free radical polymerization is performed in the raw material suspension of the shell to obtain the phase change microcapsule 4; the phase change microcapsule 4 is dipped into the cleaned core-spun yarn 20, so that the phase change microcapsule 4 is physically adsorbed on the outer skin of the core-spun yarn 20; finally, curing is performed to ensure that the phase change microcapsule 4 and the core-spun yarn 20 are tightly combined, and the durability of the function of the phase change microcapsule 4 is improved, and then the auxiliary agent and impurities involved in the reaction are removed to obtain the core-spun yarn 20 with the phase change microcapsule 4 attached to the outer skin. The final weight gain rate of the core-spun yarn 20 with the phase change microcapsule 4 attached is 7% to 9%. Among them, the mass proportion of the nylon filament 10 in the core-spun yarn 20 is 60% to 70%.

[0060] Step 4: Weaving

[0061] The core-spun yarn 20 with phase change microcapsules 4 attached to the outer skin layer obtained in step 3 is used as warp yarn and weft yarn respectively, and the warp yarn is closely interwoven with the weft yarn after winding, warping, sizing, and drawing to obtain a surface transition layer with a honeycomb structure and an inner layer 6 with a twill structure. The light-absorbing material is attached to the surface transition layer by coating or impregnation, and the surface layer 5 is obtained after drying and curing; finally, the surface layer 5 and the inner layer 6 are connected by bonding or sewing to obtain a heat storage and warmth-keeping fabric 30.

[0062] Among them, the light-absorbing material is one or more of nano-ceramic particles, graphene, carbon nanotubes, carbon black, carbon dots, MXene, zirconium carbide, and silicon carbide.

[0063] Example 1 Nylon filament

[0064] A nylon filament 10 of this embodiment includes a shell and a cavity 2 located inside the shell, the cavity 2 is used to store air, and the length of the cavity 2 is equal to the length of the shell. The cavity 2 includes a plurality of cavity units arranged at intervals, the shell includes a shell body 11, a first column 12, and a connecting portion 13 located between two adjacent cavity units, the connecting portion 13 is used to connect the first column 12 and the shell body 11, and the plurality of cavity units are arranged along the circumference of the first column 12, and the center of the first column 12 coincides with the center of the nylon filament 10; the area of ​​the cavity 2 in the cross section of the nylon filament 10 accounts for 25%.

[0065] Each cavity unit includes a plurality of cavity petals 21 arranged at intervals, and the width of at least one cavity petal 21 in each cavity unit is greater than the width of the remaining cavity petals 21. Specifically, in this embodiment, Figure 1 and Figure 2 As shown, the cavity 2 includes four cavity units, each of which includes three cavity petals 21 arranged at intervals, and a partition 22 is provided between two adjacent cavity petals 21 in each cavity unit, one end of the partition 22 is connected to the shell body 11, and the other end of the partition 22 extends toward the direction close to the first column 12. In addition, the width of each cavity petal 21 gradually increases from one end close to the center of the nylon filament 10 to the other end, which can make the structure of each cavity petal 21 more stable, and when squeezed, the deformation produced is smaller, and the residual static air can be preserved more, which is conducive to improving the heat storage performance of the nylon filament 10.

[0066] In this embodiment, each cavity unit includes a cavity main lobe and cavity auxiliary lobe symmetrically arranged on both sides of the cavity main lobe. The length of the cavity main lobe is greater than the length of the cavity auxiliary lobe. The cavity main lobe and the cavity auxiliary lobe are both cavity lobe 21.

[0067] Example 2 Preparation method of nylon filament

[0068] First, ethylene glycol is subjected to esterification reaction under the condition of excess oxalic acid, the reaction temperature is 240℃ and the reaction time is 3h, and a carboxyl-terminated polyester substance is obtained, and then nylon slices are added, and the temperature is continued to rise to 260℃, so that the nylon slices are in a molten state, so that the hydroxyl groups in the nylon melt and the carboxyl groups on the above polyester substances undergo esterification grafting reaction to obtain a modified nylon melt. Nano-alumina with a particle size of 55nm is added to the liquid state of the modified nylon melt, stirred for 15min, and then ultrasonically dispersed for 30min, and finally centrifuged for 5min to take the upper dispersion, mixed with water and maleic acid (molecular weight regulator) and stirred evenly to obtain a spinning solution, and the mass ratio of the modified nylon melt to the heat storage accelerator in the spinning solution is 99:1; the purpose of adding the molecular weight regulator here is to adjust and control the molecular weight of the nylon polymer to ensure that the spinning solution has a suitable viscosity for spinning. The spinning solution is extruded and ejected from the spinneret to form a filament bundle, at which the spinning temperature is 300°C and the spinning speed is 1300 m / min; then the filament bundle is subjected to monomer suction, side-blowing cooling, bundling oiling, stretching and shaping, network intertwining, and winding to obtain nylon filament 10. The stretching and shaping temperature is 85°C, and the fineness of the stretched yarn in this embodiment is 80D; the winding speed is 4800 m / min.

[0069] In this embodiment, the nylon slice is preferably nylon 6, and the original thermal conductivity of the nylon is reduced by modifying the nylon to improve its warmth retention. The thermal conductivity of the prepared modified nylon is 0.149 W / (m·°C).

[0070] Embodiment 3 heat storage warm fabric

[0071] A heat storage and warmth-keeping fabric of this embodiment, such as Figure 4 As shown, it includes a surface layer 5 and an inner layer 6 that are bonded to each other, and both the surface layer 5 and the inner layer 6 include warp yarns and weft yarns, and the density of the warp yarns is 260 yarns / 10cm, and the density of the weft yarns is 220 yarns / 10cm; Figure 5 As shown, the tissue structure of the surface layer 5 is a honeycomb tissue, and the concave part of the honeycomb tissue is filled with light-absorbing material to further improve its absorption of external heat. Figure 6 As shown, the tissue structure of the inner layer 6 is a twill tissue, which can improve the reflection of heat emitted by the human body, thereby achieving efficient heat storage and warmth preservation; the surface layer 5 and the inner layer 6 can be connected by sewing or bonding.

[0072] Furthermore, the warp yarns and weft yarns of the surface layer 5 and the inner layer 6 are both core-spun yarns 20 with a fineness of 16 tex, such as Figure 3As shown, the core-spun yarn 20 includes an inner core layer and an outer skin layer wrapped outside the inner core layer, the inner core layer includes a plurality of nylon filaments 10 in Example 1, and the outer skin layer includes a plurality of heat storage fibers 3, and the heat storage fibers 3 are volcanic rock heat storage fibers or spectrum heat fibers. The mass proportion of the nylon filaments 10 in the core-spun yarn 20 is 60%.

[0073] Furthermore, the outer surface of the outer skin layer is also attached with a phase change microcapsule 4, which includes a phase change core and a shell for wrapping the phase change core, wherein the material of the phase change core is one or more of paraffin, fatty acid, and fatty alcohol, and the material of the shell is one or more of polyurethane, polymethyl methacrylate, and urea-formaldehyde resin. The phase change core in the phase change microcapsule 4 absorbs and releases heat through phase change to achieve light-heat conversion for energy storage, which is beneficial to improving the heat storage and warmth retention of the core-spun yarn 20.

[0074] Embodiment 4 Preparation method of heat storage and warming fabric

[0075] Step 1: Preparation of modified nylon melt

[0076] Ethylene glycol is subjected to an esterification reaction under the condition of excess oxalic acid, the reaction temperature is 240°C, the reaction time is 3h, and a carboxyl-terminated polyester substance is obtained, and then nylon 6 slices are added, and the temperature is continued to rise to 260°C, so that the nylon 6 slices are in a molten state, and the hydroxyl groups in the nylon melt and the carboxyl groups on the above polyester substance undergo an esterification grafting reaction to prepare a modified nylon melt. In this embodiment, the nylon slice is preferably nylon 6, and the original thermal conductivity of the nylon is reduced by modifying the nylon to improve its warmth retention, and the thermal conductivity of the modified nylon obtained is 0.149W / (m·℃).

[0077] Step 2: Preparation of nylon filament 10

[0078] First, the spinneret is designed and processed according to the cross-sectional shape of the target nylon filament 10, and then the nano-alumina with a particle size of 55nm is added to the modified nylon melt solution in step 1, stirred for 15min and then ultrasonically dispersed for 30min, and finally centrifuged for 5min to take the upper dispersion, mixed with water and maleic acid and stirred evenly to obtain a spinning solution, and the mass ratio of the modified nylon melt to the heat storage accelerator in the spinning solution is 99:1. The spinning solution is extruded and ejected from the spinneret to form a filament bundle, the spinning temperature is 300℃, and the spinning speed is 1300m / min; then the nylon filament 10 is obtained through monomer suction, side blowing cooling, bundling oiling, stretching and shaping, network entanglement and winding. Among them, the stretching and shaping temperature is 85℃, the fineness of the yarn after stretching is 80D; the winding speed is 4800m / min.

[0079] Step 3: Prepare the core-spun yarn 20

[0080] The nylon filament 10 and the volcanic rock heat storage fiber are pretreated to clean the surface impurities and dirt. The nylon filament 10 is used as the inner core layer and the volcanic rock heat storage fiber is used as the outer skin layer. The inner core layer is subjected to multi-filament merging and twisting to form an elastic strand to obtain the first yarn; the outer skin layer is subjected to the cotton cleaning process, the cotton combing process, the drawing process, the roving process and the spinning process to form a short fiber roving, and the second yarn is obtained after drawing and thinning; the Cellophane spinning technology is then used to feed the first yarn directly into the front roller without being drawn through the spinning frame, and the second yarn is fed into the front roller. After the two yarns pass through the tension device and the yarn guide, they are subjected to normal drawing and whisker compounding at the convergence point, and finally twisted to form a core-spun yarn 20, and the fineness of the core-spun yarn 20 is 16tex; the core-spun yarn 20 is subjected to standard soap washing to ensure that its surface is clean and is ready for use.

[0081] Polyethylene glycol is mixed with N,N'-methylenebisacrylamide, and free radical polymerization is performed in a methacrylic acid suspension to encapsulate the phase change core in polymethacrylic acid to obtain a phase change microcapsule 4; the phase change microcapsule 4 is dipped into the cleaned core-spun yarn 20, so that the phase change microcapsule 4 is physically adsorbed on the outer skin of the core-spun yarn 20; finally, curing is performed to ensure that the phase change microcapsule 4 and the core-spun yarn 20 are tightly combined, and the durability of the function of the phase change microcapsule 4 is improved, and then the additives and impurities involved in the reaction are removed to obtain the core-spun yarn 20 with the phase change microcapsule 4 attached to the outer skin. The final weight gain rate of the core-spun yarn 20 with the phase change microcapsule 4 attached is 7.94%. Among them, the mass proportion of the nylon filament 10 in the core-spun yarn 20 is 60%.

[0082] Step 4: Weaving

[0083] The core-spun yarn 20 with phase change microcapsules 4 attached to the outer skin layer obtained in step 3 is used as warp yarn and weft yarn respectively, wherein the density of the warp yarn is 260 yarns / 10cm, and the density of the weft yarn is 220 yarns / 10cm; the warp yarn is closely interwoven with the weft yarn after bobbin yarn, warping, sizing, and threading to obtain a surface transition layer of a honeycomb structure and an inner layer 6 of a twill structure. Then, the surface transition layer is immersed in a solution containing graphene, and the excess solution is squeezed out by a roller, so that the graphene is evenly attached to the surface transition layer, and the surface layer 5 is obtained after drying and curing treatment; finally, the surface layer 5 and the inner layer 6 are connected by sutures to obtain a heat storage and warmth-keeping fabric 30.

[0084] The fabric 30 prepared in this embodiment was tested according to the methods in GB / T 18319-2019 "Test Method for Photothermal Performance of Textiles" and GB / T 30127-2013 "Test and Evaluation of Far Infrared Performance of Textiles". The maximum temperature rise value measured was 7.2°C, the average temperature rise value was 4.8°C, the far-infrared emissivity was 0.97, and the far-infrared radiation temperature rise value was 2.5°C. At the same time, the thermal resistance of the fabric 30 measured by the evaporation hot plate method was 1.235m 2 ·K / W, the heat preservation rate is 45%.

[0085] Comparative Example 1: Preparation method of fabric

[0086] The difference between Comparative Example 1 and Example 4 is that the nylon melt used to prepare nylon filaments in Comparative Example 1 has not undergone a modification step. During spinning, nano-alumina with a particle size of 55 nm is directly added to the nylon 6 solution, and the spinning solution is obtained after stirring, ultrasonic dispersion and centrifugation. The nylon filaments are obtained after spinning through a customized spinneret, and the remaining steps are the same.

[0087] The fabric prepared in this comparative example was tested according to the methods in GB / T 18319-2019 "Test Method for Photothermal Performance of Textiles" and GB / T 30127-2013 "Test and Evaluation of Far-Infrared Performance of Textiles". The maximum temperature rise value measured was 6.8°C, the average temperature rise value was 4.5°C, the far-infrared emissivity was 0.92, and the far-infrared radiation temperature rise value was 2.3°C. At the same time, the thermal resistance of the fabric measured by the evaporative hot plate method was 1.227m 2 ·K / W, the heat preservation rate is 42%.

[0088] Comparative Example 2 Preparation Method of Fabric

[0089] The difference between Comparative Example 2 and Example 4 is that in Comparative Example 2, when preparing nylon filaments, the spinneret is a conventional spinneret, so that the nylon filaments obtained by spinning do not include the cavity 2 and have a solid structure inside; the remaining steps are the same.

[0090] The fabric prepared in this comparative example was tested according to the methods in GB / T 18319-2019 "Test Method for Photothermal Performance of Textiles" and GB / T 30127-2013 "Test and Evaluation of Far-Infrared Performance of Textiles". The maximum temperature rise value measured was 6.0°C, the average temperature rise value was 4.3°C, the far-infrared emissivity was 0.89, and the far-infrared radiation temperature rise value was 1.5°C. At the same time, the thermal resistance of the fabric measured by the evaporative hot plate method was 1.024m 2 ·K / W, thermal insulation rate is 35%.

[0091] Comparative Example 3: Preparation method of fabric

[0092] The difference between Comparative Example 3 and Example 4 is that in Comparative Example 3, after the core-spun yarn is prepared, no post-treatment is performed on the core-spun yarn, that is, no phase change microcapsules 4 are attached to the surface of the outer skin layer of the core-spun yarn; the remaining steps are the same.

[0093] The fabric prepared in this comparative example was tested according to the methods in GB / T 18319-2019 "Test Method for Photothermal Performance of Textiles" and GB / T 30127-2013 "Test and Evaluation of Far-Infrared Performance of Textiles". The maximum temperature rise value measured was 6.4°C, the average temperature rise value was 4.5°C, the far-infrared emissivity was 0.92, and the far-infrared radiation temperature rise value was 2.2°C. At the same time, the thermal resistance of the fabric measured by the evaporative hot plate method was 1.186m 2 ·K / W, thermal insulation rate is 39%.

[0094] Comparative Example 4: Preparation method of fabric

[0095] The difference between Comparative Example 4 and Example 4 is that the surface transition layer woven in Comparative Example 4 is directly used as the surface layer and the inner layer for sewing, and the surface transition layer is not immersed in the solution of the light-absorbing material; the remaining steps are the same.

[0096] The fabric prepared in this comparative example was tested according to the methods in GB / T 18319-2019 "Test Method for Photothermal Performance of Textiles" and GB / T 30127-2013 "Test and Evaluation of Far-Infrared Performance of Textiles". The maximum temperature rise value measured was 6.7°C, the average temperature rise value was 4.6°C, the far-infrared emissivity was 0.95, and the far-infrared radiation temperature rise value was 2.3°C. At the same time, the thermal resistance of the fabric measured by the evaporative hot plate method was 1.189m 2 ·K / W, the heat preservation rate is 40%.

[0097] Results and Discussion:

[0098] It can be seen from the test data of Example 4 and Comparative Examples 1 to 4 that the thermal storage and heat preservation performance of the fabric 30 prepared in Example 4 is the best, and its maximum temperature rise value, average temperature rise value, far-infrared emissivity, far-infrared radiation temperature rise value, thermal resistance and heat preservation rate are all the highest. Among Comparative Examples 1 to 4, the measured data of Comparative Example 2 is the worst because there is no cavity 2 inside the nylon filament. It can be seen that the cavity 2 inside the shell of the nylon filament 10 of the present invention plays a key role in improving the thermal storage performance of the fabric. Due to the setting of the cavity 2, the static air inside it will not be completely lost, and it can be preserved for a longer time, which is conducive to improving the thermal storage and heat preservation performance. The test data of Comparative Examples 1, 3 and 4 show that the modification of nylon, the phase change microcapsules 4 on the outer skin layer of the core-spun yarn and the setting of the light-absorbing material on the surface layer 5 of the fabric 30 can all improve the thermal storage performance of the fabric 30 to varying degrees.

[0099] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A nylon filament, characterized in that: It includes a shell and a cavity located inside the shell, the cavity includes a plurality of cavity units arranged at intervals, the shell includes a shell body, a first column and a connecting portion located between two adjacent cavity units, the connecting portion is used to connect the first column and the shell body, a plurality of cavity units are arranged along the circumference of the first column, the center of the first column coincides with the center of the nylon filament; the area of ​​the cavity in the cross section of the nylon filament accounts for 20% to 30%, the length of the cavity is equal to the length of the shell, and the cavity is used to store air.

2. The nylon filament according to claim 1, characterized in that: Each of the cavity units includes a plurality of cavity petals that are spaced apart from each other, and the length of at least one cavity petal in each of the cavity units is greater than the length of the remaining cavity petals.

3. The nylon filament according to claim 2, characterized in that: The width of each cavity petal gradually increases from one end close to the center of the nylon filament to the other end.

4. The nylon filament according to claim 3, characterized in that: The ends of the multiple cavity petals in each cavity unit close to the center of the nylon filament are connected to each other, and the ends of the multiple cavity petals in each cavity unit away from the center of the nylon filament are spaced from each other.

5. The nylon filament according to claim 4, characterized in that: A partition is provided between two adjacent cavity petals in each cavity unit, one end of the partition is connected to the shell body, and the other end of the partition extends toward the direction close to the first column.

6. The nylon filament according to claim 2, characterized in that: Each of the cavity units includes a cavity main lobe and cavity auxiliary lobes symmetrically arranged on both sides of the cavity main lobe, and the length of the cavity main lobe is greater than the length of the cavity auxiliary lobe.

7. A method for preparing nylon filament according to any one of claims 1 to 6, characterized in that: The steps include: The nylon filament is obtained by mixing a heat storage accelerator with a solution containing modified nylon and spinning the mixture; the thermal conductivity of the modified nylon is 0.128-0.151 W / (m·°C).

8. The preparation method according to claim 7, characterized in that: The solution containing modified nylon is a modified nylon melt solution obtained by adding modified nylon melt to a solvent and mixing them uniformly; the modified nylon melt is prepared by melting nylon slices and then copolymerizing, surface crosslinking or enzyme modification.

9. The preparation method according to claim 8, characterized in that: The method for spinning after mixing the heat storage accelerator with a solution containing modified nylon is as follows: adding the heat storage accelerator to the modified nylon melt solution and mixing them evenly to obtain a mixed spinning solution, extruding the spinning solution and ejecting it from a spinneret to form a filament bundle, and then subjecting the filament bundle to monomer suction, side-blowing cooling, bundling and oiling, stretching and shaping, network intertwining, and winding to obtain the nylon filament; the mass ratio of the modified nylon melt to the heat storage accelerator in the spinning solution is 95 to 99:

1.

10. The preparation method according to claim 7, characterized in that: The heat storage accelerator includes a light absorbing material, and the light absorbing material is one or more of nano ceramic particles, graphene, carbon nanotubes, carbon black, carbon dots, MXene, zirconium carbide, and silicon carbide.

11. A core-spun yarn, characterized in that: It comprises an inner core layer and an outer skin layer wrapped outside the inner core layer, the inner core layer comprises a plurality of nylon filaments as claimed in any one of claims 1 to 6, and the outer skin layer comprises a plurality of heat storage fibers.

12. The core-spun yarn according to claim 11, characterized in that: The mass proportion of the nylon filaments in the core-spun yarn is 60% to 70%.

13. The core-spun yarn according to claim 11, characterized in that: Phase change microcapsules are also attached to the outer surface of the outer skin layer. The phase change microcapsules include a phase change core and a shell for wrapping the phase change core. The material of the phase change core is one or more of paraffin, fatty acid, and fatty alcohol.

14. The core-spun yarn according to claim 11, characterized in that: The heat storage fiber is a volcanic rock heat storage fiber or a spectrum heat storage fiber.

15. A method for preparing a core-spun yarn according to any one of claims 11 to 14, characterized in that: The steps include: The nylon filaments were used as the inner core layer and the heat storage fiber was used as the outer skin layer for pretreatment respectively; The inner core layer is subjected to multi-filament merging and twisting to form a first yarn, and the outer skin layer is processed to form a short fiber roving and then drawn and thinned to form a second yarn; The first yarn and the second yarn are drafted and twisted together to form the core-spun yarn.

16. The preparation method according to claim 15, characterized in that: The method also includes post-processing, wherein the post-processing method is: after the core-spun yarn is cleaned, the phase change microcapsules are adsorbed on the surface of the outer skin layer of the core-spun yarn by a padding method.

17. A heat storage and warmth-keeping fabric, characterized in that: The fabric has the core-spun yarn as described in any one of claims 11-14.

18. A heat storage and warming fabric as claimed in claim 17, characterized in that: It comprises a surface layer and an inner layer which are bonded to each other. Both the surface layer and the inner layer are prepared by interweaving the core-spun yarn through warp and weft. The tissue structure of the surface layer is a honeycomb tissue.

19. A method for preparing the heat storage and warming fabric according to claim 17 or 18, characterized in that: The steps include: Using the core-spun yarn as the warp yarn and the weft yarn, interweaving the warp yarn and the weft yarn to obtain a surface transition layer and an inner layer respectively; The light absorbing material is attached to the surface transition layer by coating or dipping, and the surface layer is obtained after drying and curing; The surface layer and the inner layer are connected to obtain the fabric.

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