50 results about "Hemp fiber" patented technology

The application relates to the technical field of layered fabrics, and discloses a moisture-conducting layered composite fabric based on multi-element blended yarn and a preparation method thereof. By constructing a gradient moisture-conducting layered structure with a moisture-conducting inner layer and a moisture-absorbing outer layer, the moisture-absorbing and moisture-conducting performance of the layered fabric is optimized; the multi-element blended yarn of moisture-absorbing and sweat-releasing polyester staple fiber, cotton fiber and hemp fiber and modified pure cotton yarn are used in the inner layer to realize moisture absorption and moisture conduction through wicking effect; the outer layer is made of pure cotton fabric which can quickly absorb the moisture conducted by the inner layer and evaporate to the environment, forming a moisture-conducting path. The prepared layered composite fabric not only has excellent moisture-absorbing and moisture-conducting performance, but also has improved washing resistance and antibacterial durability.

This invention relates to a blending process for hemp fiber and sorona fiber, belonging to the technical field of blending and processing of natural fibers and bio-based elastic fibers. The blending process for hemp fiber and sorona fiber of this invention includes the following steps: raw material selection → pre-spinning process → post-spinning process → packaging. This invention solves the problems of poor spinnability, high breakage rate, and stiffness and wrinkling in pure wet-spun hemp through specific proportions and wet spinning processes, achieving high-count, stable, and high-quality production. This significantly improves spinnability, enhances yarn quality, and greatly improves hand feel and comfort, achieving high elasticity and comfort to meet user needs.

This patent discloses a preparation process for a biomass-based cross-corrugated lattice sandwich structure, relating to the field of building materials. The preparation process of the biomass-based cross-corrugated lattice sandwich structure is as follows: raw materials—bamboo / jute fibers—are cut neatly, washed, and dried; the raw materials are layered sequentially and set aside; epoxy resin and curing agent are mixed in a specific ratio, thoroughly stirred, and then used to impregnate the raw materials; the mixture is placed in a corrugated mold and hot-pressed to form a corrugated structure; a slotted interlocking design is applied to the corrugated structure to prepare a cross-corrugated structure; plywood is used as the face panel, and the cross-corrugated structure is used as the core layer, connected by adhesives to prepare the biomass-based cross-corrugated lattice sandwich structure. This patent applies agricultural and forestry biomass materials to the preparation of lattice structures, meeting both structural load-bearing requirements and national requirements for developing environmentally friendly materials. It is of great significance for developing lightweight, high-strength biomass-based engineering materials and providing added value to agricultural and forestry biomass.

The application provides a preparation method of high-elasticity anti-ultraviolet short fiber filament composite yarn, and solves the problems of single function, insufficient elasticity and poor anti-ultraviolet durability of traditional yarns through differential pretreatment, segmented cotton mixing, variable twist roving, double-elasticity system sirofil composite spinning and far-infrared synergistic heat setting innovative process. The method uses seaweed fiber and hemp fiber as raw materials, softens hemp through mechanical rubbing and twisting, alkali boiling and swelling, improves seaweed fiber through low-temperature plasma etching and gradient drying, combines double-elasticity filament bundle and a dynamic tension compensation device, and finally prepares yarn with an elasticity recovery rate of greater than or equal to 90%, an UPF of greater than or equal to 55, and the functions of moisture absorption, antibiosis and far-infrared radiation. The production efficiency is improved by 50%, the energy consumption is reduced by 30%, and the method is suitable for summer clothes and sports clothing fields and has remarkable economic and social benefits.

The application discloses a ramie fiber diaphragm based on fiber crystalline domain entropy regulation and a preparation method and application thereof, and belongs to the technical field of preparation of cellulose diaphragms for capacitors. The preparation method comprises the following steps: pretreating ramie raw materials by soaking, cooking and cutting to obtain ramie sections, then performing low-temperature beating to maintain high crystallinity of the fibers and realize refinement, forming a suspension slurry, then performing ultrasonic dispersion, screening and dissociation dispersion to obtain uniform fine slurry, and finally performing wet laying molding and freeze drying to obtain the ramie fiber diaphragm which has a three-dimensional interconnected porous structure and high tough mechanical properties. The application fully utilizes the alkaloid characteristics of the ramie fiber to realize alkali-free cooking, and the process is environmentally friendly. Through the synergistic effect of low-temperature beating and freeze drying, the fiber intrinsic toughness is maintained while the multi-stage ion transmission channel is constructed. The obtained diaphragm has excellent air permeability, porosity and mechanical strength.

This utility model discloses a linen-like fabric, relating to the field of fabric technology. The key technical points are: it includes a base layer, with several staggered protrusions (first and second) fixedly connected to both sides of the base layer; several square-shaped ventilation grooves are formed on the base layer, with the ventilation grooves and protrusions (second) positioned relative to each other and their diagonals running along the length of the protrusions (second); ventilation holes are provided around each ventilation groove; a contact strip covering the protrusions (first) is fixedly connected to the side of the base layer away from the protrusions (second); the contact strip is lifted by the protrusions (first) to form a ventilation channel with the base layer; the weave density of the contact strip is less than that of the base layer; and linen fibers are incorporated into this utility model, which have excellent moisture absorption and dissipation properties, increasing the fabric's absorption rate of sweat and accelerating the evaporation of moisture from the fabric.

The utility model discloses a kind of hemp fiber blended anti-crease yarn softening treatment devices, including shell, the inside of shell is equipped with workbench, the middle part of workbench is installed with soaking groove, symmetrically distributed pressure roller is rotatably connected between the front and rear inner wall of soaking groove, the right side wall of shell is equipped with outlet, further including pretreatment mechanism;Pretreatment mechanism: it includes main shaft, collar, arc plate, installation groove, copper column, sliding block and silica gel strip, the inside left end of shell is rotatably connected with main shaft, the outer arc surface of main shaft is equipped with evenly distributed collar, the opposite inner side outer arc surface of two front and rear adjacent collars is equipped with arc plate, this hemp fiber blended anti-crease yarn softening treatment device, local heating pretreatment realizes hemp fiber softening and gap puffing to promote softening agent penetration efficiency while adjustable structure adaptation different diameter yarn with the linkage of sliding block and collar, L-shaped rod guidance, solve the uneven heating and the deficiency of weak equipment adaptability.

The application relates to the field of interior plate processing, and discloses a composite hemp fiber door interior plate film pressing forming device and process, which comprises a machine table for supporting the overall device, the upper surface of the machine table is provided with a supporting rod, the top end of the supporting rod is provided with a top plate, the outer wall of the supporting rod is slidably connected with a moving table, the inner wall of the machine table is provided with a hydraulic cylinder, the top end of the output shaft of the hydraulic cylinder is fixedly connected to the lower surface of the moving table, the upper surface of the moving table is provided with a lower die, the lower surface of the top plate is provided with an upper die mechanism, the outer wall of the machine table is provided with a supporting frame, and the upper surface of the supporting frame is provided with a control assembly. Through the setting of the near-infrared moisture meter, the moisture of the product can be detected by the near-infrared moisture meter after the hot pressing step is completed; when the moisture exceeds the threshold value, the control element sends a signal to control the air blowing pump and the air suction pump to work, so that air can be guided to enter from the air conveying pipe.

This utility model discloses a humidity control device for cold storage, including a base plate, a top plate above the base plate, support frames at the corners of the bottom of the top plate, two linkage seats above the top plate, a bearing plate fixed to the top of the two linkage seats, a dehumidifier body at the top of the bearing plate, a sealing door with hinges installed on one side of the outer wall of the dehumidifier body, two door handles on the outer wall of the sealing door, an air inlet at the lower end of the surface of the dehumidifier body, a humidity sensor installed on the surface of the dehumidifier body above the air inlet, a lower mesh plate at the center of the interior of the dehumidifier body, a hemp fiber moisture-absorbing layer installed on the top of the lower mesh plate, and a mesh plate inside the dehumidifier body above the hemp fiber moisture-absorbing layer. This utility model not only ensures the dehumidification control effect of the control device on the cold storage, but also improves the convenience of use and expands the humidity control range of the cold storage.

This utility model discloses an antibacterial bamboo fiber spunlace fabric, including a spunlace fabric body and a structural layer. The absorbent layer of this utility model is made of sponge material, which increases the thickness of the spunlace fabric and has better water absorption, allowing it to retain more moisture. The mesh fabric can make the spunlace fabric body and the absorbent layer more firmly connected and make the spunlace fabric body less prone to tearing, thus improving the strength of the spunlace fabric body. The surface layer is made of interwoven bamboo fiber and hemp fiber, giving the surface a rough surface. The first fiber pad is made of polyester fiber yarn, which has high durability. The second fiber pad is made of cotton fiber, which has good water absorption and can also have a better cleaning effect on stubborn stains. The second cleaning layer is tightly arranged, and the finished product feels close to textiles, making the surface of the second cleaning layer softer, giving the spunlace fabric body a soft cleaning surface.

This utility model relates to a hemp feeding mechanism for a hemp combing machine, belonging to the field of hemp yarn processing. It includes a carrying body; a conveying mechanism located inside the carrying body; a guiding component located on the upper surface of the carrying body; and a cleaning mechanism located on the right side of the carrying body, comprising a mounting box located on the right side of the carrying body; a negative pressure module connected to the lower surface of the mounting box; and two pipes connected to the front and rear surfaces of the mounting box, with the other ends of both pipes penetrating the carrying body. Through the cleaning mechanism, this utility model utilizes the cooperation between the negative pressure module and the conical sleeve to automatically extract hemp fibers accumulated in the roller groove, preventing short fibers from converging and reducing the roller's gripping force, ensuring the roller is always in a highly efficient working state, reducing conveying failures caused by fiber accumulation, and improving the stability and reliability of the hemp feeding mechanism.

This utility model relates to the field of fiber grading technology, specifically a hemp fiber gradient separation device, including a cylinder, a feeding pipe, a screen cylinder, and a long fiber discharge assembly. The screen cylinder is rotatably installed on the inner bottom of the cylinder and extends through the cylinder to the bottom. A motor is located at the bottom of the screen cylinder, below the cylinder, for rotating the screen cylinder within the cylinder during operation. The feeding pipe is located on the side of the cylinder, and multiple feed pipes communicating with the cylinder and facing the screen cylinder are located on the side of the feeding pipe. The long fiber discharge assembly is installed at the top of the cylinder. This utility model delivers the pulp mixture under pressure to the surface of the screen cylinder through the feed pipes, causing the pulp mixture to form an upward vortex within the cylinder. Simultaneously, the screen cylinder rotates within the cylinder, allowing short fibers to enter the screen cylinder while long fibers are blocked outside. Multiple feed pipes are vertically arranged to supplement the kinetic energy of the vortex formed by the pulp mixture, thereby effectively separating short and long fibers and improving the separation effect.

This invention discloses an inorganic powdered aromatherapy coating and its preparation and application methods. The coating comprises the following raw materials in weight percentages: slaked lime powder: 50%–65%; glutinous rice extract: 10%–18%; short-cut hemp fibers (80-120 mesh): 5%–10%; short cotton fibers (100-150 mesh): 3%–8%; natural mineral fillers: 5%–12%; composite fragrance powder: 8%–15%; nano-silica: 0.5%–2%; and natural plant adhesives: 0.5%–2%. This invention utilizes modern microencapsulation technology, fiber orientation process, and optimized inorganic matrix formulation to prepare the inorganic powdered aromatherapy coating. This coating not only provides a long-lasting, health-beneficial aroma release but also allows for the creation of various modern artistic textures through application techniques, achieving a deep integration of material and aesthetics. It is suitable for the restoration of ancient buildings, Chinese garden architecture, and interior wall decoration of health-oriented living spaces.

This invention relates to the field of material injection molding technology, specifically to a high-strength hemp fiber composite material and its injection molding process. This invention overcomes the problems of low interfacial weld strength and poor formability in existing fiber composite materials. The injection molding process of this invention first involves extruding and granulating a fiber mixture, treated carbon fibers, resin, and crosslinking agent under low-temperature control to obtain the composite material. Then, pre-impregnated carbon cloth is positioned within the mold cavity. During the injection molding stage, variable pressure wavefront control is implemented. The first stage uses low-speed injection to smoothly compact the high-viscosity melt into continuous carbon cloth. The second stage involves high-speed mold filling, utilizing high shear heat to precisely trigger the unsealing and ring-opening of the latent crosslinking agent, forming a three-dimensional covalent bond network. Finally, a stepped high-pressure holding process eliminates reactive micropores. This process solves the molding defects of natural fiber carbonization due to heat and the easy erosion of carbon cloth inserts, improving the interlayer bonding strength and mechanical strength of the injection-molded parts, and is suitable for the manufacture of large lightweight automotive structural components.

This utility model discloses a high-efficiency degumming device for flax fibers, including a base. A degumming frame is fixedly installed on the top left side of the base, and a housing is fixedly installed on the top right side of the base. A motor is fixedly installed on the front side of the housing, and a rotating rod is fixedly installed at the output end of the motor. The other end of the rotating rod passes through the interior of the housing and is fixedly connected to a half gear. A toothed plate is movably engaged on the left side of the half gear, and a beating plate is fixedly installed at the bottom of the toothed plate. Through the combination of the above structures, this utility model achieves beating of the degummed flax fibers, thereby thoroughly separating the fiber bundles from the xylem, improving the fiber extraction rate, and removing residual glue and impurities, thus ensuring the strength and quality of the final yarn.

The invention discloses a high-breathability, cool-feeling and smooth bamboo and linen yarn fabric and application thereof in clothes, belongs to the technical field of textiles, and aims to solve the problems that the breathability is reduced, the hand feeling is hardened and the adhesive force of a coating is weak due to the fact that most of traditional coating modes adopt overall uniform coating, and pores of the fabric are prone to being blocked. The fabric is of a composite structure mainly comprising bamboo fibers and hemp fibers, the ratio of the hemp fibers is smaller than or equal to 10%, the surfaces of the inner side and the outer side of the fabric are each coated with a functional coating, the functional coatings are arranged in a hexagonal or rhombic grid or honeycomb shape, and the inner side portions of the functional coatings are connected with the surfaces of the fabric in a bonding mode. The bamboo fiber and hemp fiber blended structure is adopted, the hexagonal, rhombic or honeycomb discontinuous grid coating is matched, hole blocking of the coating is avoided, the air permeability of the fabric is greatly improved, meanwhile, the cool feeling component rapidly conducts heat, and continuous contact cool feeling is achieved.

This utility model relates to an integrated machine for unpacking / loosening / removing impurities from hemp stalks. It includes a rectangular, horizontally arranged chassis with inlet and outlet ports at the front and rear ends, respectively. A conveyor is located inside the chassis. A main roller is positioned above the conveyor, perpendicular to the longitudinal direction of the chassis, with both ends of its shaft rotatably connected to the side wall of the chassis. Inner front auxiliary rollers and inner rear auxiliary rollers are located above the main roller on both sides. Radial steel nails are evenly distributed on the rolling surfaces of the main roller, inner front auxiliary rollers, and inner rear auxiliary rollers, and these radial steel nails are arranged in an alternating pattern. The key feature is that the conveyor is a vibrating conveyor, and the conveyor belt is a wire mesh conveyor belt. Using this utility model to extract hemp fibers can improve the impurity removal effect and product quality. It is suitable for extracting hemp fibers from bundled hemp stalks.

The present application relates to the technical field of fiber composite materials, in particular to a hemp fiber reinforced composite luggage case plate and a preparation method thereof, the hemp fiber reinforced composite luggage case plate comprises a decorative surface layer, a structural reinforcement core layer and a water-resistant inner layer which are sequentially stacked; the decorative surface layer is made of modified hemp fiber and PP resin fiber; the structural reinforcement core layer is made of low-melting-point PET fiber and high-melting-point PET fiber; the water-resistant inner layer is made of modified hemp fiber and PP resin fiber; the surface of the modified hemp fiber is coated with a composite interface layer containing phytic acid, lanthanide rare earth elements and polydimethylsiloxane. By constructing the composite interface layer containing phytic acid, lanthanide rare earth elements and polydimethylsiloxane on the surface of the hemp fiber, the moisture and heat aging resistance of the hemp fiber composite material is greatly improved, and the reliability requirements of the long-term service of the automobile luggage case plate are met.

The application relates to a preparation method of a brick mud structure hemp fiber-based fabric flexible radiation refrigeration coating, and belongs to the technical field of flexible fabric radiation refrigeration functional coating. In order to solve the problems of the existing biomass-based radiation refrigeration material, such as complicated process, weak interlayer bonding force, easy delamination and peeling, easy cracking when being bent, poor water washing resistance and poor environmental protection, a method for directly forming a brick mud structure hemp fiber-based flexible radiation refrigeration coating on a fabric surface in situ is provided. The radiation refrigeration material is combined with the fabric substrate closely without independent film forming and complicated process. The radiation refrigeration material has the advantages of bionic structure, high efficiency, high flexibility, water washing resistance, bending resistance and green degradable characteristics, and fills the application blank of the biomass-based radiation refrigeration coating in the flexible fabric field.

This application relates to the technical field of stenter equipment and discloses a cotton and linen fabric stenter, including a frame. A first support is fixedly connected to the upper side of the frame. Two first guide grooves are opened on the outer side of the first support. A mounting frame is slidably connected to the inner side of the two first guide grooves. A flattening roller is rotatably mounted inside the mounting frame. This cotton and linen fabric stenter, by setting the flattening roller in conjunction with air jet holes and oblique grooves, can supply air to the interior of the flattening roller under the action of an air pump through air pipes and air outlets. The air is ejected through the air jet holes, avoiding direct contact between the cotton and linen fabric and the flattening roller, and enabling the fabric to be flattened non-contactly with the metal roller surface. This prevents the linen fibers from being snagged by the protrusions of the flattening roller, significantly reducing the risk of snagging and breakage. The adaptive tensioning component can tension the fabric to ensure the stenter effect. The air pump, air pipes, and air outlets constitute an air supply system, providing an air source to reduce friction between the fabric and the flattening roller.

The application discloses a PBAT-based full-biodegradable mulching film and a preparation method and application thereof, and belongs to the technical field of mulching film processing. The PBAT-based full-biodegradable mulching film is made of the following raw materials in parts by mass: PBAT 70-85 parts, super-micro hemp fiber powder 5-10 parts, PLA 5-10 parts, plasticizer 2-5 parts and anti-aging agent 0.5-2 parts. In addition, the application further provides a preparation method of the PBAT-based full-biodegradable mulching film, which comprises the following steps: mixing the raw materials, and then melt blending, granulating, and blow molding to obtain the PBAT-based full-biodegradable mulching film. In addition, the application further provides application of the PBAT-based full-biodegradable mulching film in tobacco planting. The application realizes the guarantee of the strength of the mulching film and the reduction of the cost of the mulching film.

The application provides a biomass antibacterial sweat-absorbing fabric and a preparation method thereof, and belongs to the technical field of fabrics. First, raw materials are mixed, and then spinning and weaving are performed to obtain a textile fabric; wherein the raw materials include 20-50 parts of hemp fibers, 15-40 parts of bamboo fibers, 10-30 parts of polyester fibers, 5-15 parts of modified particles, and 3-10 parts of sodium diatomite; then the textile fabric is immersed in a finishing liquid, and after being taken out, drying and washing are performed to obtain the biomass antibacterial sweat-absorbing fabric. The hemp fibers, the bamboo fibers and the polyester fibers are used as raw materials, and the synthetic fibers and the natural fibers are mixed, the hemp fibers and the bamboo fibers make the fabric have good moisture absorption and air permeability, and the polyester fibers ensure that the fabric has good strength and wear resistance. The moisture absorption and the antibacterial performance of the fabric are further improved by introducing the modified particles, and the modified particles can be combined with the fibers to form an antibacterial functional film on the surface of the fibers.

The present application relates to the technical field of vamp, and provides a manufacturing method of a high-degradability string yarn vamp and the vamp manufactured by the method, the method comprising the following steps: preparing lightweight degradable string yarn formed by twisting hemp fiber yarn, polylactic acid yarn and modal yarn together, and reinforcing degradable string yarn formed by twisting bio-based nylon and hemp fiber yarn; shuttle weaving a vamp main body by using the lightweight degradable string yarn and cutting a wearing opening; placing the reinforcing degradable string yarn in an X-shaped arrangement at a forefoot position of the vamp main body and placing the reinforcing degradable string yarn in an S-shaped arrangement at both side positions and extending to a heel; and sewing and fixing the reinforcing degradable string yarn to form a reinforcing layer; after polishing and dust removing the vamp main body, spraying water-based PHA paint, and baking to form a film after standing, the vamp manufactured by the method has a biodegradation rate of greater than 90% within 180 days under composting conditions, has high strength, high comfort and high environmental protection, and solves the problems of difficult degradation and VOCs pollution of the existing vamp materials.

This invention discloses an antibacterial and antistatic cellulose blended yarn. The raw materials for preparing the blended yarn include natural fibers, deodorizing hemp pulp fibers, antistatic carbon fibers, mineral-modified fibers, and an antistatic agent. The raw materials, by weight, include the following components: 20-30 parts natural fibers, 10-12 parts deodorizing hemp pulp fibers, 10-20 parts antistatic carbon fibers, and 6-8 parts mineral-modified fibers. The natural fibers include bamboo fibers, cotton fibers, and hemp fibers, and possess inherent antibacterial components. The mineral-modified fiber raw materials are nano-zinc oxide and nano-titanium dioxide particles. The advantages of this invention compared to existing technologies are: the antibacterial and antistatic cellulose blended yarn of this invention has a soft and smooth hand feel and improved weaving performance; it retains the unique antibacterial and moisture-wicking functions of hemp fibers, while inheriting the comfortable and skin-friendly characteristics of cotton and viscose regenerated cellulose fibers; and it improves the antistatic performance of the blended yarn.

A biomimetic mother-of-pearl interlocking structure hydrophobic hemp fiber-based radiation cooling membrane and its preparation method are disclosed, belonging to the field of radiation cooling technology. To address the problems of environmentally unfriendly raw materials, high cost, complex preparation processes, and low cooling efficiency in existing radiation cooling materials, this invention provides a preparation technology for a hemp fiber-based biomimetic radiation cooling membrane and a flexible fabric coating. Using industrial hemp recycled fibers as the core green matrix, through synergistic design of material innovation, structural innovation, and process innovation, it comprehensively solves the technical defects of existing radiation cooling materials, providing a new green solution for the large-scale application of radiation cooling technology in multiple scenarios. This radiation cooling membrane, using recycled industrial hemp fibers as the matrix, combines the characteristics of being environmentally friendly, having a biomimetic interlocking structure, and providing high-efficiency radiation cooling. The preparation process is simple and can be mass-produced, meeting the application needs of multiple fields such as building energy conservation, outdoor equipment manufacturing, electronic equipment thermal management, and agricultural greenhouse film control.

(Main claim): The lightweight panel for dry construction is characterized in that it consists of a core of hemp shives and / or hemp fibers, wherein the binding of the fibers is carried out exclusively or predominantly by thermally activated lignin powder and the core is bonded on both sides with a paper or non-woven lamination.

This invention discloses an intelligent dyeing and finishing equipment and process for Tencel-linen blended woven fabrics, relating to the field of dyeing and finishing equipment technology. It includes a dye liquor shell with an installation mechanism for dyeing and finishing the Tencel-linen blended woven fabric. The installation mechanism utilizes the meshing transmission of a first bevel gear and a second bevel gear to drive a stirring bracket and a spiral fan blade to form a vortex, causing the dye liquor to flow upwards in a spiral shape. This ensures thorough mixing of the dye liquor while preventing direct impact on the Tencel-linen blended woven fabric, thus preventing fabric damage or uneven dyeing. A disturbance plate swings up and down within a slide rail bracket, working in conjunction with the spiral dye liquor flow, essentially providing micro-vibration "assisted turning" from below the fabric. This ensures that the front and back sides and the middle layer of the Tencel-linen blended fabric are evenly contacted with the dye liquor, while simultaneously dislodging air bubbles from the gaps in the linen fibers, preventing air bubbles from hindering dye liquor penetration and solving the problem of difficult linen fiber penetration.

The application provides a bio-based composite carpet and a production method thereof. The bio-based composite carpet is made by hot-pressing and compounding at least three layers of fiber webs, the three layers of fiber webs comprising: a first layer of fiber web with an area density of 750 g / m2-850 g / m2, comprising polylactic acid sheath-core fibers and surface-modified hemp fibers; a second layer of fiber web with an area density of 600 g / m2-750 g / m2, comprising hollow fibers, polylactic acid sheath-core fibers and surface-modified hemp fibers; and a third layer of fiber web with an area density of 900 g / m2-1100 g / m2, comprising hollow fibers, polylactic acid sheath-core fibers and surface-modified hemp fibers; the polylactic acid sheath-core fibers comprise a sheath layer and a core layer, the sheath layer comprises a first polylactic acid, and the core layer comprises a second polylactic acid, the melting point of the first polylactic acid is lower than that of the second polylactic acid, and the three layers of fiber webs are bonded together by the melted first polylactic acid. The application reduces the complexity of the process and the processing cost.