450 results about "Melt spinning" patented technology

The invention belongs to the technical field of high polymer materials, and particularly relates to a high-strength papermaking forming net fiber. Comprising the following raw materials in parts by weight: 75-90 parts of polyethylene glycol terephthalate, 5-15 parts of polybutylene terephthalate, 3-10 parts of a modified fiber filler, 2-5 parts of modified graphene, 2-8 parts of silicon dioxide, 0.5-2 parts of a silane coupling agent KH-560, 1-3 parts of an anti-hydrolysis agent, 0.5-1.5 parts of an antioxidant and 0.3-1 part of a lubricant. Wherein the modified fiber filler is prepared by sequentially carrying out modification processes such as silane coupling agent, citric acid-glycerol esterification, iron bismuth oxide loading and the like on glass fibers; the modified graphene is prepared by introducing dopamine, cerium ions and glycidyl methacrylate for modification. The mechanical strength, the hydrolysis resistance and the wear resistance of the fiber are remarkably improved through the synergistic effect of all the components and the melt spinning-multi-stage stretching process, and the fiber is particularly suitable for a forming net of a high-speed paper machine.

The invention provides an anti-static knitted fabric based on charge gathering and directional guiding, a preparation method of the anti-static knitted fabric and a knitted fabric, and belongs to the technical field of knitted clothes. A first spinning component and a second spinning component are co-extruded through melt spinning to prepare composite fibers with a parallel composite structure, and the composite fibers are subjected to thermal mechanical treatment to obtain the composite yarn; the composite yarn is directionally introduced into a specific area of the fabric in a tuck-float stitch mode through an embedded weaving technology, and latent curl is activated through after-treatment. The moisture absorption expansion of the second spinning component is utilized to drive the composite yarn to macroscopically self-crimp, and the conductive filler inside is physically extruded to construct an efficient conductive skeleton, so that the humidity response adjustment and charge directional dispersion of the anti-static performance are realized, and the problems of fixed conductive state, local static accumulation and poor comfort of the existing fabric are effectively solved; and the safety and wearing experience of the clothes are improved.

The application discloses a light-weight moisture-conducting functional fabric and a preparation method thereof, and relates to the technical field of textiles.The light-weight moisture-conducting functional fabric comprises an inner layer and an outer layer, the inner layer is obtained by blending polyester fibers and nylon special-shaped cross-section fibers, and the outer layer is obtained by blending modified polypropylene fibers and hollow polyester fibers; the modified polypropylene fibers are obtained by melting and spinning the mixture of polypropylene chips and modified jade powder and then stretching; the prepared fabric not only has the characteristics of light weight and one-way moisture-conducting capability, can quickly discharge sweat outside the body, realizes dry and cool isolation between the skin and the outside world, and has multiple health protection functions such as persistent antibacterial property, efficient ultraviolet resistance and contact cool feeling.

The invention relates to the technical field of polymer dye synthesis, and discloses a monomer for a blue polyester fiber and a preparation method thereof.According to the monomer for the blue polyester fiber, 1, 4-arylamino substituted anthraquinone serves as a color development mother nucleus, a benzoate group is introduced to aryl of the 1, 4-arylamino substituted anthraquinone mother nucleus, and the monomer for the blue polyester fiber is obtained; the benzoate group is connected with the chromophoric parent nucleus through a carbon-carbon bond; the molecular terminal of the monomer for the blue polyester fiber is connected with an exposed ester group through an aryl group, and the exposed ester group is used for transesterification with dihydric alcohol under the melt polycondensation condition of polyester. The novel monomer for the blue polyester fiber, provided by the invention, has excellent color development performance and thermal stability, can be directly used for in-situ synthesis of blue polyester and can be directly used for melt spinning, and the color fastness and coloring uniformity of a product are improved; meanwhile, the monomer for the blue polyester fiber, provided by the invention, is simple in preparation method, low in cost and easy for large-scale production.

The invention relates to the field of textiles, and particularly discloses a preparation process of antibacterial fibers, which comprises the following steps: S1, respectively drying and preparing polymer slices and an antibacterial agent; s2, performing melt spinning on the polymer slices and an antibacterial agent, performing air cooling, and then performing traction and winding to obtain antibacterial fibers; wherein the antibacterial agent is prepared by mixing dodecyl trimethyl ammonium chloride, polyvinylpyrrolidone and core-shell type antibacterial particles according to the mass ratio of (0.4-0.5): (0.1-0.2): 1, the core-shell type antibacterial particles are prepared by loading nano-zinc oxide and nano-silver particles on intercalation modified montmorillonite and then forming a silicon dioxide coating layer through a sol-gel method, and the core-shell type antibacterial particles are prepared from the silicon dioxide coating layer through a sol-gel method. And carrying out spray drying to obtain the core-shell antibacterial particles. The preparation method has the characteristic of improving the antibacterial durability and uniformity of the antibacterial fiber.

The invention relates to the technical field of fibers, in particular to a controlled-release anti-aging polypropylene fiber and a preparation method thereof. The fiber is prepared from polypropylene homopolymer resin, a reaction type interface layer master batch and a controlled release anti-aging master batch, the reactive interface layer master batch is formed by reacting and extruding maleic anhydride modified polypropylene and 3-aminopropyl terminated polydimethylsiloxane, so that the interface compatibility is enhanced; the controlled-release anti-aging master batch contains hydroxyl and peracetylated cyclodextrin grafted siloxane carriers, and an ultraviolet absorbent, a light stabilizer and an antioxidant are included, so that the controlled release of an anti-aging agent is realized. The preparation method comprises the steps of master batch preparation, final mixing granulation, melt spinning and drafting setting. The fiber strength is remarkably improved, the boiling water shrinkage rate is reduced, the strength retention rate after ultraviolet aging reaches 93% or above, the yellow index change is small, and the outdoor service life is prolonged.

The invention relates to the technical field of fibers, and discloses a light-color warm-keeping fiber, a preparation method and application of the light-color warm-keeping fiber to fabrics. According to the invention, polyacrylonitrile modified silicon dioxide aerogel is used as a heat-insulating functional filler, cationic modified nano zinc oxide is used as an antistatic agent and an antibacterial agent, and the light-colored polyacrylonitrile fiber is prepared by adopting a melt spinning method and has good heat-insulating and warm-keeping properties; and the cationic inorganic-organic composite antibacterial antistatic agent is introduced, so that the antibacterial and antistatic properties of the fiber are optimized.

The invention discloses a modified polylactic acid fiber and a preparation method thereof. The preparation method comprises the following steps: providing polybasic hydroxyl-terminated D-polylactic acid; the method comprises the following steps: respectively providing betaine-grafted D-polylactic acid and a poly (butylene adipate terephthalate)-epoxy-polyether co-modified organic silicon-D-polylactic acid copolymer by taking the multi-hydroxyl-terminated D-polylactic acid as a main raw material, wherein the poly (butylene adipate terephthalate)-epoxy-polyether co-modified organic silicon-D-polylactic acid copolymer; and carrying out Haake blending and melt spinning on the betaine-grafted D-polylactic acid, a poly (butylene adipate-co-modified organosilicon-D-polylactic acid) copolymer, L-polylactic acid, an antioxidant and an anti-hydrolysis agent, so as to obtain the modified polylactic acid fiber. The preparation method comprises the following steps: carrying out Haake blending and melt spinning on the betaine-grafted D-polylactic acid, poly (butylene adipate-co-modified organosilicon-D-polylactic acid copolymer, L-polylactic acid, the antioxidant and the anti-hydrolysis agent. The modified polylactic acid fiber prepared by the method has the characteristics of easy decontamination, hydrophilicity, high temperature resistance and high toughness, and can effectively avoid water washing shedding, and the comprehensive performance is obviously improved.

The invention discloses a preparation method of a self-cleaning antibacterial anti-mite fabric, and relates to the technical field of fabric preparation, and the preparation method comprises the following steps: 1-5 g of Cu (NO3) 2.6 H2O, 0.1-1.5 g of isophthalic acid, 20-50 mL of water and a certain antibacterial enzyme mixture are sequentially poured into a glass beaker, stirring is performed for 30 min, uniform mixing is performed, and the antibacterial anti-mite fabric is obtained; pouring the mixture into a 25mL polytetrafluoroethylene inner container, putting the inner container into a high-pressure kettle, sealing, carrying out high-temperature reaction for 72 hours in a drying oven at 90 DEG C, separating out a light blue product by using a centrifugal machine after the reaction is completed, washing for multiple times by using water, drying, mixing the obtained light blue powder with PET slices, melting and granulating, and drying to obtain the PET composite material. The preparation method comprises the following steps: preparing a bio-enzyme coated with a metal frame, mixing the bio-enzyme coated with the metal frame with common polyester chips, carrying out melt spinning to prepare multifunctional polyester fibers containing the bio-enzyme coated with the metal frame, taking the polyester fibers as weft yarns and cotton fibers as warp yarns, and interweaving into gray fabric according to a certain rule, so that the problem that the existing antibacterial anti-mite fabric is poor in effect durability is solved.

The invention relates to the technical field of polyester yarns, in particular to a high-strength polyester yarn and a preparation method thereof.The method comprises the steps that PET slices with the intrinsic viscosity of 0.85-1.00 dL / g are subjected to melt spinning and cooled through circular blowing to obtain nascent fibers, the nascent fibers are subjected to surface activating treatment through low-temperature plasma or esterase bio-enzyme, and the high-strength polyester yarn is obtained; the preparation method comprises the following steps: firstly, activating fibers, then carrying out graft copolymerization reaction on the activated fibers and graft monomer solutions such as fluorinated acrylate and acrylic acid, and finally, cleaning, drying, carrying out thermal network and winding on the composite fibers, so that the prepared polyester yarn has the breaking strength of more than or equal to 7.7 g / D, the dry heat shrinkage rate of less than or equal to 3.5% and the shrinkage tension of less than or equal to 0.03 g / D, has the high functional characteristics of lasting super-hydrophobicity, antibacterial property and the like, is excellent in washing resistance, and is suitable for industrial production. The problem that functionalization is difficult due to surface inertia of the polyester fiber is solved, and the mechanical property and the surface characteristic of the polyester fiber are comprehensively improved.

The invention relates to the field of textile fabrics, and discloses a polylactic acid fabric and a preparation method thereof. The polylactic acid fabric is prepared by weaving polylactic acid fibers, the polylactic acid fibers are prepared by melt spinning of a polylactic acid material body, and the polylactic acid material body is prepared from the following raw materials in parts by weight: 100-120 parts of polylactic acid resin, 12-20 parts of a heat-resistant moisture absorbent, 6-10 parts of a toughening agent and 0.2-0.4 part of an antioxidant; the heat-resistant moisture absorbent is prepared from lignin fibers, poly (ethylene 2, 5-furandicarboxylate), poly (butylene adipate-co-terephthalate) and a dispersing agent. The preparation method comprises the following steps of melt spinning, rib knitting, heat setting, dyeing and aftertreatment. The polylactic acid fabric prepared by the invention has better heat resistance, moisture absorption and shrink deformation resistance, and is suitable for scenes with higher requirements on heat resistance and moisture absorption, such as underwear or infant clothes.

The application discloses a police clothing fabric convenient for heat dissipation and a processing technology, and the processing technology comprises the following steps: after carbon fibers are pretreated by a potassium permanganate solution and a KH550 aqueous solution, the carbon fibers are added into N,N-dimethylformamide, then ethylenediaminetetraacetic dianhydride is added into the mixture under stirring, and stirring reaction is carried out; the product is extracted, washed and dried to obtain ethylenediaminetetraacetic dianhydride modified carbon fibers; the modified carbon fibers are added into deionized water, then mannitol is added, concentrated sulfuric acid is used as a catalyst, and stirring reaction is carried out; the product is centrifuged, washed and dried to obtain modified carbon fibers; the modified carbon fibers and PET chips are mixed, then melt spinning is carried out, and the police clothing fabric convenient for heat dissipation is obtained through weaving; the fabric greatly improves the moisture absorption, sweat releasing, air permeability and heat dissipation performance of the fabric, improves the breaking strength of the fabric, and is suitable for being used as a police fabric.

The invention discloses an air-twisted three-dimensional carpet yarn and a preparation method thereof, and belongs to the technical field of carpet yarns. The technical problems that in a traditional carpet yarn preparation process, yarn abrasion is easily caused by mechanical twisting, and quality is unstable due to asynchronous paying-off of multiple strands of yarn are solved. According to the technical scheme, traditional mechanical twisting is replaced with air twisting; the preparation process comprises the steps of melt spinning, drafting forming, clear color separation puffing deformation, air twisting, rolling and the like. Wherein the multiple strands of single yarns are bulked and deformed through independent channels before being twisted, so that respective separated clear color separation structures are formed. The adopted air twisting machine is provided with a conical pipe with a spiral air guide plate so as to form twisting rotational flow, a synchronous paying-off mechanism is arranged, and a stepping motor drives a plurality of paying-off shafts to synchronously rotate to release yarn through a gear transmission set. Non-contact twisting is achieved through airflow dynamics, mechanical abrasion is avoided, and meanwhile position precision and tension consistency of yarn are guaranteed through synchronous paying-off.

The invention discloses an anti-ultraviolet polylactic acid fiber as well as a preparation method and application thereof, and belongs to the technical field of polylactic acid fibers. The polylactic acid fiber is prepared by mixing, melting and spinning modified polylactic acid slices and a plasticizer. Wherein the modified polylactic acid slice is prepared from the following raw materials in parts by mass: 60 to 80 parts of polylactic acid, 15 to 25 parts of graft modified polylactic acid and 5 to 10 parts of modified zinc oxide. The graft modified polylactic acid is a product obtained by introducing a carbazole group on a polylactic acid molecular chain by polylactic acid and vinylcarbazole through a free radical graft polymerization method, and the modified zinc oxide is obtained by loading polydopamine on zinc oxide and grafting lipoic acid. According to the modified polylactic acid slice provided by the invention, graft modified polylactic acid and modified zinc oxide are added on the basis of a polylactic acid matrix, so that the anti-ultraviolet performance of polylactic acid fibers is enhanced, ultraviolet aging is delayed, the ultraviolet transmittance is reduced and the application of the polylactic acid fibers in outdoor textiles is expanded under the action of multiple mechanisms.

The invention discloses a preparation method of traceable polyester staple fibers, which comprises the following steps: mixing a tracing raw material and a renewable synthetic fiber raw material, and carrying out melt spinning to obtain the traceable regenerated polyester staple fibers, the tracing raw material comprising at least two of cobalt Prussian blue analogues, germanate fluorescent materials and metal oxides. The invention also provides a traceable polyester staple fiber product prepared by the preparation method. According to the method, two color changes under thermal stimulation and solvent stimulation of primary-color polyester fibers can be achieved, meanwhile, the tracing germanate fluorescent particles and the metal oxide tracing particles are added to make up for the defect that color changes are difficult to recognize after the fibers are dyed, and meanwhile the tracing means is complicated, so that the fibers are difficult to counterfeit.

The application discloses a phase change composite microcapsule, a rapid heat management fabric and a preparation method and application thereof. The phase change composite microcapsule with a thorn ball structure is prepared, and the attapulgite with a polarity significantly different from that of the phase change core material is introduced into the shell layer, so that the attapulgite is preferentially dispersed on the surface of the shell layer to form a super-high specific surface area heat conduction structure, and the heat conduction efficiency and the cycle stability are improved. Therefore, the microcapsule prepared by the application has good dispersibility and thermal stability, can be used for preparing a composite phase change fiber by melt spinning and woven into a fabric, realizes the unification of flexibility and high-temperature rapid heat management performance, and breaks through the limitation of low heat conduction efficiency and poor processing adaptability of traditional phase change materials.

The invention relates to the field of spinning, and particularly discloses a polyester filament yarn preparation process which comprises the following steps: drying polyester chips, mixing the dried polyester chips with a hydrophilic agent, carrying out melt spinning to form nascent fibers, adopting a linear spinneret plate during spinning at the spinning speed of 4000-6000 m / min, carrying out traction treatment, carrying out heat setting treatment, carrying out alkali treatment, and winding to obtain the polyester filament yarn. Preparing polyester filament yarns; wherein the hydrophilic agent is a mixture of PEG (Polyethylene Glycol) 2000 and PEG 400 in a mass ratio of 1: (2-3). The preparation method has the characteristic that the prepared polyester filament yarn has better hygroscopicity and more excellent mechanical properties.

The present application belongs to the technical field of high-performance polypropylene fiber, and particularly relates to a preparation method of water mark-free high-performance polypropylene fiber. The preparation method of the water mark-free high-performance polypropylene fiber comprises the following steps: S1, adding polypropylene chips, fillers, compatilizers, antioxidants and nucleating agents into a high-speed mixer to obtain premix by high-speed mixing; S2, melt spinning the premix obtained in step S1 to obtain the water mark-free high-performance polypropylene fiber. The polypropylene chips are used as the main material, and the interaction of the specific inorganic fillers and the compatilizers can significantly improve the tensile property of the fiber, effectively reduce the water drop diffusion time and accelerate the drying rate.

The invention provides a degradable fiber temporary plugging agent and a preparation method thereof, and belongs to the technical field of oil-gas field development. The temporary plugging agent is composed of polylactic acid-polyurethane block copolymer fibers, and the preparation method of the temporary plugging agent comprises the steps that S1, lactide and an initiator containing dihydroxyl are subjected to ring opening polymerization under the action of a first catalyst, and a hydroxyl-terminated prepolymer is formed; s2, reacting the prepolymer with diisocyanate under the action of a second catalyst to synthesize a polylactic acid-polyurethane block copolymer; s3, preparing fibers through a melt spinning or electrostatic spinning process; the degradation rate and the mechanical property of the fiber can be regulated and controlled by regulating and controlling the initiator type, the diisocyanate type, the isocyanato index R value and the catalyst dosage, so that the fiber is suitable for the wide-temperature-range reservoir conditions of 45-120 DEG C, and the technical problems of contradiction between the strength and the degradability, narrow temperature adaptability, secondary damage to the reservoir and the like of a traditional temporary plugging agent are effectively solved.

The invention discloses a dyeing-free black soft polyester fiber and a preparation method thereof, and belongs to the technical field of waste polyester recycling. The preparation method comprises the following steps: melting and extruding waste PET (Polyethylene Terephthalate) with the intrinsic viscosity of 0.50-0.80 dL / g through a twin-screw extruder, and depolymerizing in an EG / BHET homogeneous system to obtain an oligomer with the polymerization degree of 5-7; mixing with carbon black slurry and a polycondensation catalyst, and carrying out pre-polycondensation and final polycondensation to obtain regenerated functional polyester; and finally, carrying out melt spinning under the conditions that the temperature is 275-285 DEG C and the speed is 2500-3500 m / min, so as to obtain the fiber with the monofilament of 0.5-2.0 dtex, the tensile modulus of 30-60 cN / dtex and the color fastness of more than or equal to grade 4. By accurately controlling the depolymerization degree and the dispersion system, the problems of pigment agglomeration, complex process and high fiber modulus in the prior art are solved, high-added-value recycling of the waste PET is realized, and the product can be used for close-fitting textiles.

This invention relates to the field of polymer materials technology, specifically disclosing the application of low melt flow index (MFI) polyoxymethylene (POM) in improving the spinning performance of POM. Using heteropolyacids as catalysts, and controlling the polymerization temperature and the amount of heteropolyacid catalyst added, low MFI POM with a melt flow index of 0.1 g / 10 min to 2.5 g / 10 min was prepared. After compounding this low MFI POM with a heat-stabilizing agent in a certain proportion, it was blended with general-purpose POM and extruded into granules. Unexpectedly, the thermal stability of the POM was significantly improved, and it also exhibited moderate rheological properties. When applied to the melt spinning process, the spinnability of the POM was significantly improved. Compared with the POM without the addition of this low MFI, the draw ratio increased by approximately 1.4 times, and the tensile strength of the POM fiber reached 6–8 g / d, a maximum increase of approximately 1.4 times. The yield and strength of the finished fiber product were significantly improved.

The application provides a method for improving the thermal stability of industrialized polyethylene fiber fabric, comprising the following steps: A) blending polyethylene raw material, a photoinitiator and an auxiliary crosslinking agent to obtain a mixture; B) melt spinning the mixture to obtain polyethylene fibers; C) after drawing and weaving the polyethylene fibers, polyethylene fiber fabric is obtained; D) the polyethylene fiber fabric is subjected to ultraviolet light irradiation to obtain modified polyethylene fiber fabric. The core advantage of the application lies in the simplicity of the operation process and the obviousness and high efficiency of the treatment effect. By finely adjusting the blending system and the ultraviolet light irradiation conditions, the thermal stability of the polyethylene fiber fabric is significantly improved from multiple aspects, thereby solving the limitation of the polyethylene fiber fabric in the application of fabric textiles, and providing a reliable scheme for the industrialized development of ordinary polyethylene fiber fabric.

Method for manufacturing yarn, wherein said yarn comprises a plurality of continuous filaments, wherein said method comprises at least the following steps:the step of spinning, preferably melt spinning, a plurality of continuous filaments; andthe step of treating said plurality of continuous filaments by means of a pressurized fluid supplied by two or more nozzles,and wherein one or more of said nozzles deliver said fluid at a varying pressure and / or rate and / or temperature.

The invention relates to the technical field of fibers, and discloses a heating temperature-regulating fiber and a preparation method thereof. A photo-thermal material graphene-loaded zirconium dioxide composite material is prepared and is introduced into a phase-change material as a light-absorbing and heating material, a photo-thermal heat storage additive with good heat resistance is prepared, the photo-thermal heat storage additive and a compatilizer maleic anhydride grafted polypropylene are jointly added into polypropylene slices for melt spinning, and the prepared fiber has light-absorbing and heating and energy-storage and temperature-regulating properties; maleic anhydride grafted polypropylene is introduced, carboxyl of the maleic anhydride grafted polypropylene can react with epoxy groups of the photo-thermal heat storage additive under the melting condition, the maleic anhydride grafted polypropylene is used as a compatilizer to improve the compatibility among the components, and meanwhile, the moisture absorption performance of the fiber is also improved due to the introduction of the carboxyl.

The application relates to the technical field of polyester staple fiber manufacturing, and discloses super-fine polyester staple fiber for special paper and a manufacturing process thereof, which comprises the following steps: Step 1, drying PET chips and PET-PEG master batches; Step 2, melt blending the PET-PEG master batches with antioxidants and heat stabilizers; Step 3, melt blending, homogenizing and devolatilizing the PET chips and active carriers to form a composite melt, and then cooling, solidifying, cutting and granulating; Step 4, drying the composite granular master batches; Step 5, melt spinning; and Step 6, processing and forming the nascent fibers. In the application, the antioxidants and the heat stabilizers are uniformly dispersed in the PET-PEG melt in advance, the thermal oxygen degradation and hydrolysis of PEG segments and a PET matrix are inhibited, the melt rheological property is stabilized, the melt is blended and melted with the PET chips, the hydrophilic segments of the PET-PEG are uniformly dispersed in the PET matrix, selective adhesion of bubbles is reduced, and the fibers are uniformly dispersed in water.

The invention relates to a melt-spinning apparatus for producing synthetic threads, having a plurality of melt-spinning devices, a plurality of godet devices and a plurality of spooling machines. The melt-spinning devices each have a plurality of spinning nozzles arranged in a row, with each of which a plurality of driven godets of the godet devices and a plurality of winding points of the spooling machines are associated. At least one control platform is arranged above the spooling machines. In order to achieve as compact a design and the best operability possible, the melt-spinning devices having the spinning nozzles and the spooling machines having the winding points are arranged one above the other, oriented in the same direction, wherein a plurality of control platforms are provided which are individually arranged between adjacent melt-spinning devices.

This invention provides a hollow fiber membrane with an asymmetric structure, its preparation method, and its applications, relating to the technical field of polymer separation membrane materials. The method includes the following steps: melt spinning a masterbatch followed by sequential air cooling, spray cooling, and a second air cooling to obtain virgin hollow fibers; then, isothermal heat treatment of the virgin hollow fibers to obtain heat-treated hollow fibers; subsequently, cold stretching to expand pores and hot stretching to create pores are performed on the heat-treated hollow fibers, followed by isothermal stress relief to obtain a hollow fiber membrane with an asymmetric structure. This invention solves the technical problem of existing methods for preparing asymmetric hollow fiber membranes relying on toxic organic solvents, which are harmful to the health of workers and the environment. It achieves the technical advantages of a solvent-free preparation process, simple technology, green sustainability, and a membrane with high flux, high rejection rate, and high antifouling performance.

The application belongs to the field of polyester fibers, and particularly relates to a flame-retardant polyester fabric, and a preparation method thereof, which comprises the following steps: uniformly mixing 80-100 parts of PET polyester chips, 5-15 parts of ionic liquid modified magnesium hydroxide and 1-5 parts of an antioxidant, and then performing blending extrusion through a double-screw extruder, drawing and cutting to obtain flame-retardant modified polyester masterbatch; then uniformly mixing 70-90 parts of PET polyester chips and 10-30 parts of the flame-retardant modified polyester masterbatch, and performing melt spinning on a double-screw high-speed composite spinning machine to obtain flame-retardant polyester fibers. The prepared polyester fibers have excellent flame-retardant performance and mechanical properties.

The invention belongs to the technical field of polyamide thermoplastic elastomer preparation and elastic fibers, and discloses a fiber-grade polyamide thermoplastic elastomer preparation method, which comprises a ring-opening reaction, a pre-polycondensation reaction and a polycondensation reaction, and specifically comprises the following steps: firstly, preparing a double-carboxyl-terminated prepolymer of which the end group is carboxyl through a ring-opening reaction of caprolactam; then the binary acid mixture and the diamine mixture are sequentially subjected to pre-polycondensation reaction and polycondensation reaction to prepare the polyamide thermoplastic elastomer, and the obtained polyamide thermoplastic elastomer can be used for preparing the polyamide elastic fiber through melt spinning. The polyamide thermoplastic elastomer disclosed by the invention does not have a bonding phenomenon in a melt spinning process, and has excellent mechanical properties and elastic properties. The preparation method is simple, large-scale preparation can be carried out in an existing polymerization device, the obtained elastomer can be subjected to spinning processing in existing spinning equipment, the production efficiency is high, and the preparation method has great application prospects.

This invention discloses a method for preparing silicon carbide fibers with an in-situ boron nitride coating. The method involves melt spinning a metal-doped polycarbosilane precursor to obtain doped polycarbosilane precursor fibers. These precursor fibers are then subjected to a non-melting treatment in an oxidizing atmosphere to obtain non-melting fibers. The non-melting fibers are then subjected to inorganic pyrolysis to obtain inorganic fibers. These inorganic fibers are then densified and sintered to obtain boron-containing SiC fibers. Finally, the boron-containing SiC fibers are subjected to high-temperature treatment in a nitrogen atmosphere to obtain silicon carbide fibers with an in-situ boron nitride coating. This invention provides a simple preparation method, resulting in an in-situ self-grown BN coating with high crystallinity, good stability, and excellent uniformity. The coating is tightly bonded to the SiC fibers, is low-cost, and can be mass-produced. Furthermore, it significantly improves the fiber's temperature resistance and high-temperature creep resistance, allowing the fiber to serve for extended periods at higher temperatures.