Artificial eyelash product and method of manufacturing the same

Abstract

An artificial lash product and a method for manufacturing the artificial lash product are provided. The artificial lash product includes a stem portion for supporting and connecting a plurality of lash hairs at their root portions. At least one of the plurality of lash hairs is made of a polyimide material.

Description

Technical Field

[0001] This disclosure relates to the field of beauty products technology, specifically to an artificial eyelash product and its manufacturing method. Background Technology

[0002] Artificial eyelash products are cosmetic products that are applied to the edge of the eyelid or above the natural eyelashes to increase the length, density, curl, or color of the eyelashes. They include, but are not limited to, strip eyelashes, cluster eyelashes, single eyelashes, and irregularly shaped eyelashes, and are widely used in daily makeup, beauty styling, film and television production, stage performances, and other fields.

[0003] Existing artificial eyelash products are typically manufactured using polymer materials such as polybutylene terephthalate (PBT), polyester (PET), or nylon. The process involves first extruding and drawing continuous monofilaments, then implanting each monofilament individually into a separately prepared lash band. This "extrusion-implantation" method limits the shape achievable by the cross-section of the lash filament to what the extrusion die can produce. Whenever a new lash shape or arrangement is needed, a new die and matching implantation equipment are required. Furthermore, the reliance on manual or semi-automatic implantation steps limits production capacity and can lead to inter-filament variations in length, spacing, and fixation strength. In addition, traditional PBT, PET, and nylon monofilaments are prone to softening and losing their shape, and generally lack inherent flame retardancy. Simultaneously, extruded monofilaments typically require a relatively large and near-circular cross-section to achieve sufficient bending stiffness. Therefore, traditional lashes formed from these materials may be heavier than intended and easily lose their curl shape under heat or moisture conditions. Summary of the Invention

[0004] This disclosure provides an artificial eyelash product and a corresponding method for manufacturing the artificial eyelash product.

[0005] In a first aspect, this disclosure provides an artificial eyelash product comprising: a strip portion for supporting and connecting the roots of a plurality of eyelash filaments; and the plurality of eyelash filaments. At least one of the plurality of eyelash filaments is made of a polyimide material.

[0006] In a second aspect, this disclosure provides a method for manufacturing an artificial eyelash product, comprising: preparing a stem for supporting and connecting the roots of multiple eyelash filaments; and cutting a polyimide material to form the multiple eyelash filaments. Attached Figure Description

[0007] Figure 1 A schematic diagram of the structure of an artificial eyelash product provided in one or more embodiments of the present disclosure is shown.

[0008] Figure 2A method for preparing an artificial eyelash product provided by one or more embodiments of the present disclosure is shown.

[0009] Figure 3 A schematic diagram of the structure of the eyelash strands in one or more embodiments of the artificial eyelash product provided in this disclosure is shown.

[0010] Figure 4 A-4C illustrates a structural schematic diagram of an exemplary artificial eyelash product having a corresponding arrangement of eyelash filaments on a substantially straight stem, according to one or more embodiments of the present disclosure.

[0011] Figure 5 A-5C illustrates a structural schematic diagram of an exemplary artificial eyelash product having a corresponding arrangement of eyelash filaments on an arcuate band, according to one or more embodiments of the present disclosure. Detailed Implementation

[0012] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0013] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this disclosure are only used to explain the relative positional relationship or movement between the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indication will also change accordingly.

[0014] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly set on the other component, or there may be intermediate components. When a component is described as "connected to" another component, it can be directly connected to the other component, or there may be intermediate components.

[0015] Furthermore, the terms "first" and "second" in this disclosure are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this disclosure.

[0016] Figure 1A structural schematic diagram of an artificial eyelash product provided in one or more embodiments of this disclosure is shown. For example... Figure 1 As shown, the artificial eyelash product includes: a band 11 for supporting and connecting the roots of a plurality of eyelash filaments 12; and a plurality of eyelash filaments 12, wherein at least one of the plurality of eyelash filaments 12 comprises a polyimide material. In some embodiments, each of the plurality of eyelash filaments 12 has a root fixed to the band. In one or more embodiments, each of the plurality of eyelash filaments 12 is made of a polyimide material. The plurality of eyelash filaments 12 may have the same color or have a gradient color along the length direction of each eyelash filament.

[0017] Here, the multiple eyelash strands 12 can have any suitable color or color combination. In some embodiments, the eyelash strands 12 can have substantially the same color. In other embodiments, different eyelash strands 12 can have different colors, lightness, hue, or transparency levels. The color of each eyelash strand 12 can be substantially uniform along its length, or it can vary along the length of the eyelash strand 12. For example, the eyelash strands 12 can exhibit a color transition, gradient, or ombre effect from a first color located at or near the root of the eyelash strand 12 to a second color located at or near its tip. This transition can be continuous or can occur through one or more intermediate colors, lightness, or hues. In other embodiments, the eyelash strands 12 can include two or more discrete color regions arranged along their length, such as alternating, segmented, striped, speckled, or other patterned regions.

[0018] The color variations can also differ between the multiple eyelash strands 12. For example, adjacent eyelash strands 12 can have the same color, different colors, gradient colors, or different color gradients. In some embodiments, the multiple eyelash strands 12 can collectively form a color gradient in the width direction of the artificial eyelash, such that the color gradually changes from one side of the artificial eyelash to the other. In other embodiments, selected groups of eyelash strands 12 can have their own colors or color patterns to provide highlights, embellishments, or other decorative effects.

[0019] The colors described above may include natural eyelash or hair colors, such as black, brown, gray, or combinations thereof; or may include decorative colors, including red, orange, yellow, green, blue, purple, pink, metallic, fluorescent, iridescent, or other colors. The eyelash strands 12 may also be transparent, translucent, partially transparent, or may incorporate pigments, dyes, reflective materials, glitter, or other visually distinctive materials. Any of the above color arrangements may be used alone or in combination.

[0020] The band 11 is a basic structural component in artificial eyelash products used to support and fix multiple eyelash strands 12. It is formed along the eyelid extension direction to support each eyelash strand and maintain its overall shape, as well as to connect and fix it to the skin of the human eyelid or natural eyelashes. The band 11 can be strip-shaped, arc-shaped, band-shaped, mesh-shaped, or other shapes suitable for conforming to the eyelid. Its width, thickness, and curvature can be adjusted according to different product specifications and wearing requirements. The material of the band 11 can be polyimide, or it can be a thermoplastic polymer, thermosetting polymer, metal, or other materials suitable for artificial eyelash products. The band 11 can be manufactured separately and then connected to the eyelash strands 12 by a fixing means, or it can be integrally formed with the eyelash strands 12. In one or more embodiments, the band 11 has an elongated cylindrical shape with a circular cross-section.

[0021] In one or more embodiments, the stem 11 has an elongated cylindrical shape, such as a monofilament with a circular cross-section. The cylindrical stem 11 can be formed of a polyimide material or another flexible polymer material, and can be transparent, black, or colored.

[0022] The term "lash filament" as used in this article refers to long, thin filaments configured to mimic natural eyelashes. Each lash filament has a proximal end fixed to the band 11 and a distal free end extending outward from the band 11. The length, width, thickness, cross-sectional profile, surface texture, and curvature of the lash filaments can all affect the appearance and wearing comfort of the artificial eyelash product.

[0023] In one or more embodiments of this disclosure, each eyelash filament 12 has a length of about 4 mm to 16 mm, for example, about 6 mm to 14 mm; a root width of about 50 μm to 300 μm, for example, about 80 μm to 150 μm; a free end width of about 5 μm to 50 μm; and a thickness corresponding to the thickness of the polyimide material from which the eyelash filament 12 is cut, for example, about 10 μm to 100 μm, such as about 12.5 μm, about 25 μm, about 50 μm, or about 75 μm. In one or more embodiments, the ratio of the root width to the free end width is about 2:1 to 20:1, for example, about 4:1 to 10:1, such that the eyelash filament 12 tapers in a manner similar to that of a natural eyelash. In one or more embodiments, adjacent eyelash filaments 12 are arranged along the band 11 at a spacing of about 0.2 mm to 2 mm, and this spacing may vary along the band 11, for example, with a smaller spacing in the middle region and a larger spacing in the end region, and vice versa. In one or more embodiments, the radius of curvature of the curled structure described herein is approximately 4 mm to 15 mm. Any of the dimensions and proportions described above may be combined with any other embodiment described herein, and each listed range includes every intermediate value and subrange within that range.

[0024] As used herein, "polyimide material" includes any polymeric material containing repeating imide groups (–CO–N–CO–) in its molecular structure. Instead of extruding monofilaments and implanting them into the girdle as is the conventional practice, one or more embodiments of this disclosure form multiple eyelash filaments 12 by precisely cutting a polyimide film, such that the shape of each eyelash filament is determined by the cutting process rather than an extrusion die. In one or more embodiments of this disclosure, the girdle 11 is made of a flexible material to conform to the curvature of the eyelid, the eyelash filaments 12 are cut from a polyimide film, multiple eyelash filaments 12 are arranged along the girdle 11, the roots of the eyelash filaments 12 are fixed to the girdle 11, and the free ends extend outwards. In another embodiment, the girdle 11 and the eyelash filaments 12 are cut from the same polyimide material into a single, integral piece, thereby maintaining a continuous connection between the girdle 11 and the eyelash filaments 12 without requiring any separate eyelash implantation steps.

[0025] In one or more embodiments of this disclosure, the long-term service temperature of the polyimide material is approximately 200°C to 380°C, with some grades remaining stable at 300°C, short-term peak temperatures reaching 400°C to 470°C, and thermal decomposition temperatures typically above 500°C. In contrast, PBT has a heat deflection temperature of only about 60°C under a load of 1.82 MPa and a melting point of about 224°C to 225°C; glass fiber reinforced PBT (GF-PBT) has a heat deflection temperature of about 205°C to 220°C under the same load, still far below the service temperature of the polyimide material. This difference in heat resistance allows the polyimide eyelash filaments 12 described herein to be cut, heat-set, and worn under conditions that would deform PBT- or GF-PBT-based eyelash filaments without softening or losing their curled shape.

[0026] Other conventional eyelash filament materials exhibit similar limitations. PET typically has a glass transition temperature of only about 70°C to 80°C and a melting point of about 250°C to 260°C; nylon monofilaments may absorb a few percent by weight of moisture, causing the monofilaments to plasticize and loosen their previously shaped curl in humid environments. Furthermore, the limiting oxygen index (LOI) of PBT, PET, and nylon is typically only about 20% to 23%, so the monofilaments of these materials can ignite and continue to burn with molten droplets; in contrast, the LOI of the polyimide material of one or more embodiments of this disclosure is typically about 36% or higher, and it is self-extinguishing without molten droplets, with some grades meeting the UL 94 V-0 standard. Polyimide materials also typically have an elastic modulus of about 2.5 GPa or higher in film form and absorb relatively less moisture, so eyelash filaments 12 cut from polyimide material can maintain their stiffness and shaped curl under hot or humid wearing conditions, while conventional monofilaments would soften or loosen under these conditions.

[0027] The curl retention of the eyelash strands 12 can be assessed by measuring the initial curl angle of the heat-set eyelash strands after exposing them to a high-temperature, high-humidity environment (e.g., at a temperature of about 60°C to about 80°C and a relative humidity of about 90% for about 24 hours), followed by measuring the retained curl angle. In some embodiments, eyelash strands 12 formed of polyimide material and heat-set as described herein retain at least about 85% (e.g., about 85% to about 95%) of their initial curl angle after exposure. Under substantially the same test conditions, comparable heat-set eyelash strands formed of polybutylene terephthalate (PBT) or nylon retain a lower percentage of their initial curl angle. Flame retardancy can also be assessed by briefly exposing the eyelash strands to an open flame and observing their behavior after the flame source is removed. In some embodiments, the polyimide eyelash strands 12 exhibit localized charring and self-extinguishing behavior without sustained burning or melting dripping.

[0028] Compared to conventional PBT, PET, or nylon eyelash filaments, the polyimide eyelash filaments 12 of one or more embodiments of this disclosure better maintain their curl angle and shape when heated, thus ensuring the appearance of the artificial eyelash product remains consistent throughout the day or under stage lighting. The self-extinguishing flame retardancy of the polyimide material also makes the product safer to use around open flames or heated styling tools; and the relatively high modulus of elasticity of the polyimide material allows each eyelash filament 12 to be cut into a thinner cross-section while retaining sufficient flexural stiffness, keeping the eyelash filament 12 lightweight and comfortable to wear. Because the eyelash filament 12 is cut rather than extruded, its width, taper, and bifurcation can be changed simply by editing the cutting program, without the need to design and create new extrusion molds for each new eyelash filament.

[0029] In one or more embodiments of this disclosure, the polyimide material includes one or more selected from polyimide films, modified polyimide materials, and composite polyimide materials. Polyimide films refer to film products made from polyimide as a matrix through processes such as casting and stretching. Their thickness is generally from a few micrometers to several hundred micrometers, exhibiting good flatness and mechanical strength. They can be directly used as cutting raw materials and are suitable for continuous roll feeding. Modified polyimide materials refer to polyimide-derived materials whose properties are adjusted based on the basic structure of polyimide through copolymerization, blending, filling, or surface modification. Modification methods may include introducing flexible segments to improve flexibility, adding inorganic fillers to improve wear resistance, and introducing specific functional groups to improve interfacial adhesion with coating materials. Composite polyimide materials refer to composite structural materials comprising two or more layers of different materials bonded together through lamination, coating, co-extrusion, etc. These layers include polyimide layers, each with different mechanical, optical, or surface properties, resulting in a richer structural character for the final eyelash strand 12. Examples include two-layer composite eyelash strands with different bending stiffness in the inner and outer layers, or colored composite eyelash strands with a color layer and a matrix layer. In practical applications, thinner polyimide films are preferred for lightweight, natural-looking artificial eyelash products; thicker or composite polyimide materials can be used for voluminous, three-dimensional artificial eyelash products to improve the support performance of the eyelash strand 12; products with special gloss effects or specific colors can use corresponding modified polyimide materials. These different material forms can be used in combination or switched on the same production line according to orders without requiring a complete change of production equipment, allowing a single manufacturing platform to cover various specifications of artificial eyelash products.

[0030] As a further example of modified polyimide materials, carbon black can be used to fill the polyimide material with, for example, about 0.5% to 10% (by weight) of carbon black or another dark pigment dispersed in the polyimide matrix to provide eyelash filaments 12 with a deep, uniform black color throughout their thickness direction, so that the cut edges of the eyelash filaments 12 exhibit the same color as their surface without the need for a separate color coating; siloxane-modified polyimide materials can be used, wherein flexible siloxane segments are copolymerized into the polyimide backbone to reduce the flexural stiffness of the eyelash filaments 12 or the band 11, thereby improving wearing comfort; and matte fillers such as silica particles can be dispersed in the polyimide matrix to reduce surface gloss and provide a matte appearance without surface texture. Different modified polyimide materials can be used in different areas of the same artificial eyelash product, for example, the band 11 uses a siloxane-modified polyimide material, while the eyelash filaments 12 use a stiffer unmodified polyimide film, bonded as a pre-laminated composite material before cutting.

[0031] In one or more embodiments of this disclosure, the cross-section of the multiple eyelash strands 12 perpendicular to the extension direction adopts one or more of the following structures: a flat structure, a tapering structure, and a bifurcated structure. The cross-section perpendicular to the extension direction refers to the cross-sectional shape obtained by cutting the eyelash strand along the normal plane of its length direction, which directly affects the visual width, bending stiffness, and similarity to natural eyelashes. A flat structure refers to a cross-section where the width of the eyelash strand is significantly larger than its thickness, forming a flat, strip-like cross-section, which is beneficial for creating a thick and full appearance. A tapering structure refers to a cross-section where the cross-section of the eyelash strand gradually decreases from the root to the free end along the extension direction, making the free end of the eyelash strand thinner, which is beneficial for simulating the natural tapering shape of natural eyelashes from root to tip, improving the simulation effect of the product. A bifurcated structure refers to a structure where the eyelash strand branches into two or more strands 12 at a certain position in the extension direction, which can form multiple tips based on a single eyelash strand, which is beneficial for increasing the fullness of the tip. In one or more embodiments of this disclosure, all eyelash strands 12 in a set of artificial eyelash products adopt a flat structure; in another embodiment, some eyelash strands 12 adopt a tapering structure, while others adopt a flat structure, forming a layered and rich appearance through combination; in one or more embodiments of this disclosure, the free end of the eyelash strand 12 adopts a forked structure to enrich the visual effect at the tip, while the root adopts a wider flat structure to increase the overall coverage. The above-mentioned different cross-sectional structures can all be achieved by adjusting the cutting process parameters without changing the processing equipment, thereby enabling rapid switching between different products and reducing manufacturing costs.

[0032] In one or more embodiments of this disclosure, the multiple eyelash strands 12 employ a single-layer structure or a multi-layer composite structure. A single-layer structure refers to an eyelash strand composed of a single material layer, which is a homogeneous single material viewed in cross-section, without obvious interlayer interfaces. This design simplifies processing, and the material thickness can be adjusted by selecting polyimide films of different specifications. It is suitable for cost-sensitive products or products with relatively standard appearance requirements. A multi-layer composite structure refers to an eyelash strand formed by laminating two or more layers of different materials. The layers are bonded together through adhesion, hot pressing, or co-extrusion to form a stable connection. The different layers can vary in material type, thickness, color, elastic modulus, or surface treatment. For example, an eyelash strand may include an inner polyimide matrix layer and an outer color coating layer; or it may include a two-layer structure formed by laminating a rigid polyimide layer and a flexible modified layer to adjust the overall bending performance of the eyelash strand; or it may employ a three-layer composite form consisting of a color layer, a polyimide matrix layer, and a protective layer, enabling the eyelash strand to simultaneously possess color, strength, and durability. The multi-layer composite eyelash filament 12 can be formed by uniformly cutting multi-layer composite polyimide material, wherein each layer of the material has been pre-laminated before cutting, and the multi-layer is completed simultaneously during the cutting process, without the need to cut each layer separately, thus balancing functionality and processing efficiency.

[0033] In one or more embodiments of this disclosure, the surface of the plurality of eyelash strands 12 has as follows Figure 3 The uneven texture shown may also have a smooth surface. An uneven texture refers to a microscopic or macroscopic undulating structure on the surface of the eyelashes, including but not limited to regularly arranged raised structures, grooved structures, fish-scale structures, diagonal stripes, grid structures, random rough textures, or other surface morphologies with a certain pattern. An uneven texture helps to change the way light reflects off the surface of the eyelashes, giving them a matte finish that more closely resembles the visual effect of natural eyelashes, while also improving adhesion to products such as mascara. A smooth surface refers to a clean and smooth surface with relatively low surface roughness, which is conducive to creating a stronger gloss effect and is suitable for product designs that require a glossy effect. In one embodiment, all eyelashes 12 in the same artificial eyelash product use an uneven texture to present a uniform matte and natural effect; in another embodiment, the eyelashes 12 near the root use an uneven texture to increase coverage, while the free end uses a smooth surface to increase gloss, forming a novel composite visual effect with a sense of layering; different batches of products can use either an uneven texture or a smooth surface according to market demand, and switching can be achieved by adjusting processing parameters without changing equipment, meeting the aesthetic preferences and usage needs of different consumers.

[0034] In one or more embodiments of this disclosure, a color coating is provided on the surface of the polyimide material. The color coating is a functional layer formed on the outer surface of the polyimide material to impart a predetermined color or appearance effect to the eyelash 12. It includes not only conventional coloring layers but also various surface functional layers with decorative or optical effects. The color coating can be formed directly on at least one surface of the polyimide material, for example, formed only on one side surface, formed simultaneously on both sides surface, or formed as a continuous coating covering the material. The color coating can cover the entire surface of the polyimide sheet, or it can cover only a local area, for example, forming a color coating only in the eyelash filament area and not in the stem 11 area, or forming color coatings of different colors in different areas. The color coating can be formed by spraying, roller coating, dip coating, scraping coating, screen printing, flexographic printing, pad printing, inkjet printing, vacuum deposition, or other surface coloring processes commonly used in the art. It can include one or more colors, such as black, brown, dark brown, gray, blue, purple, green, gold, silver, etc., and can also form gradients, two-tone, multi-tone, or partial patterns. For example, a darker color can be formed at the root of the eyelash filament 12 and a lighter color at the free end to simulate the color variation of natural eyelashes. The color coating can also have different gloss effects (high gloss, semi-high gloss, matte, pearlescent, metallic, or holographic gloss) and can simultaneously provide protective effects that improve abrasion resistance, weather resistance, or chemical corrosion resistance. Because the color coating is applied to the polyimide material before cutting, the entire batch of eyelash filaments 12 is colored in one step rather than individually, maintaining color consistency across the entire batch. This eliminates the need for manual coloring steps on the production line, and different colors or visual effects can be produced simply by changing the coating formulation.

[0035] In one or more embodiments of this disclosure, the eyelash filaments 12 form a curled structure in the extension direction. A curled structure refers to the continuous or intermittent bending of the eyelash filaments, either entirely or partially, along their length, causing them to deviate from their original straight state, thereby mimicking the upward curl of natural eyelashes. In one embodiment, each eyelash filament forms the same curl angle, for example, the curl angle formed by all eyelash filaments 12 is between 20° and 80°; in another embodiment, different eyelash filaments 12 form different curl angles, for example, the eyelash filaments 12 in the middle region form a relatively large curl angle, while the eyelash filaments 12 in the side regions form a relatively small curl angle, to create a more natural overall appearance. The curled structure can form a continuous arc shape, or it can form a multi-segment bending structure, a spiral structure, a wavy structure, or other curved structures; the eyelash filaments can be curled only at the free end or curled entirely; the same eyelash filament can also form different curvatures along its length, for example, a smaller curvature at the root and a gradually increasing curvature towards the free end. Different specifications of products can have different curl levels, such as natural curl, medium curl, thick curl, or super curl, forming different product series. These curl structures can be formed through a heat-setting process or other processing methods that maintain the predetermined shape. Because the curl structure is set before the product reaches the user, artificial eyelashes maintain their curved shape throughout the day without needing frequent re-curling like straighter lashes. Furthermore, by providing several curl levels through the same cutting and setting process, a single production line can supply the entire product range without requiring tool readjustment.

[0036] In one or more embodiments of this disclosure, multiple eyelash filaments 12 and the band 11 are formed by integral cutting. Integral cutting means that the band 11 and multiple eyelash filaments 12 are formed by processing the same piece of polyimide material in a single step, eliminating the need to subsequently fix each eyelash filament 12 individually to the band 11. In one embodiment, the polyimide material is fixed on a processing platform, and the contours of the band 11 and all eyelash filaments 12 are cut in one step using a preset cutting path. After cutting, the band 11 and eyelash filaments 12 remain continuously connected, directly forming an integral artificial eyelash structure. Integral cutting can employ laser cutting, precision die-cutting, CNC cutting, vibratory knife cutting, waterjet cutting, or other processing methods capable of forming fine contours. In one or more embodiments of this disclosure, a CNC cutting device is used to complete the cutting according to a preset graphic program to ensure the dimensional consistency and cutting accuracy of the eyelash filaments 12. In one or more embodiments of this disclosure, multiple artificial eyelash products can be arranged simultaneously on the same polyimide material, forming multiple products through a single cutting operation, and then uniformly separated. Connecting bridges or positioning frames can be provided between adjacent artificial eyelash products to facilitate continuous production and subsequent packaging. Artificial eyelash products formed by integral cutting can also undergo color treatment, heat setting treatment, surface treatment, or other subsequent processing without affecting the overall structure. Since the band 11 and the eyelash strands 12 are cut from the same piece of polyimide material, the step of individual hair implantation or bonding used in conventional manufacturing is completely eliminated. Furthermore, since there is no separate interface between the band 11 and the eyelash strands 12, the resulting structure has sufficient dimensional consistency and mechanical stability for continuous automated production.

[0037] In one or more embodiments, the band 11 includes multiple strip layers, and the multiple lash strands 12 include multiple lash strand layers. Each strip layer and its corresponding lash strand layer are integrally formed by cutting a single layer of polyimide film, and the multiple strip layers are stacked on top of each other. Specifically, two or more lash layers can be formed by integrally cutting polyimide material, and each lash layer in the multi-layer lash layer includes a strip layer and a lash strand layer integrally formed with the strip layer, wherein the strip layer and the lash strand layer are integrally cut from a single sheet of polyimide film. The multi-layer lash layers are then stacked to form an artificial eyelash product. The multi-layer lash layers can be aligned with each other, wherein the strip layers overlap and align, and the lash strand layers extend in the same or offset directions, thereby forming a multi-layer artificial eyelash product. In this stacking configuration, each individual lash layer constitutes one layer in a multi-layer structure, and the multiple strip layers are stacked on top of each other and fixed together at least at their respective strip layers by lamination, thermal bonding, adhesive bonding, ultrasonic welding, or mechanical clamping, such that the lash strand layers of each lash layer are stacked to produce increased density, enhanced volume, or a more pronounced three-dimensional effect. There is no particular limitation on the number of lash layers; for example, it can be two, three, four, or more layers, depending on the desired lash style and density. In some embodiments, the different lash layers in the stacked structure can have different lash lengths, different curl angles, different colors, or different cross-sectional shapes, thereby giving the resulting multi-layered artificial lash product a natural, gradient appearance with different textures and visual depths. In other embodiments, each lash layer is cut from a polyimide film of different thicknesses or material formulations, so that each layer of lashes 12 has different flexibility, stiffness, or surface properties, thereby further expanding the range of achievable aesthetic and tactile effects. Depending on specific processing requirements, the stacked multi-layered structure can be formed before or after subsequent processing steps (such as color coating or heat setting). By integrally cutting individual lash layers from a polyimide film and then stacking multiple lash layers, this manufacturing process combines the precision and efficiency of laser or die-cutting with the design flexibility of layer-by-layer construction, enabling the rapid production of highly customized, dense, and three-dimensional artificial lash products without complex individual lash assembly.

[0038] exist Figure 4 A-4C and Figure 5In A-5C, multiple eyelashes 12 can be arranged in two or more overlapping layers on the band 11 to provide a three-dimensional, layered appearance. For example, the root regions of the eyelashes 12 in the first layer can be aligned on the band 11, while the root regions of the eyelashes 12 in the second or subsequent layers can be superimposed on and / or staggered relative to the root regions of the first layer in the width direction and / or extension direction of the band 11. The eyelashes 12 in each layer can have different lengths, densities, tilt angles, curls, and / or spacing, and can be grouped into discrete clusters of eyelashes. Figure 4 A-4C schematically illustrates an example with a generally straight band 11, in which groups of eyelashes of different sizes or densities are arranged in layers along the band 11. Figure 5 A-5C schematically illustrates an example with an arcuate band 11, wherein layered lash filament assemblies can extend at different angles and can overlap or space out to provide individual styling effects. The layered arrangement can be secured using any of the securing techniques described herein and can be combined with a one-piece cut structure or separately manufactured band 11 and lash filaments 12. In one or more embodiments, a single segment of band 11, measured along its extension direction, can have a width from 0.1 mm to 40 mm. At the smaller end of this range, the segment can support a single, discrete clump of lash filaments 12; while at the larger end of the range, the segment can extend substantially across the wearer's entire eye. For example, the width of a single segment can be about 5 mm or about 30 mm, thereby allowing the single segment to support multiple lash filaments 12.

[0039] Figure 2 A method for manufacturing an artificial eyelash product according to one or more embodiments of this disclosure is illustrated. For example... Figure 2 As shown, the method includes: Step 21: Prepare the rootstock 11 for supporting and connecting the roots of multiple eyelashes 12.

[0040] The structure and shape of the stem 11 can be combined as described above. Figure 1 In some embodiments, the hairline 11 is prepared separately and then fixed to the eyelash filament 12; in other embodiments, the hairline 11 and the eyelash filament 12 are integrally cut and formed together, as described below.

[0041] Step 22: Cut the polyimide material to form multiple eyelash strands 12.

[0042] The method of this embodiment does not limit the execution of each process step to the listed order. Those skilled in the art can adjust, combine, or appropriately change the order of some steps according to equipment conditions, production methods, or product specifications, without affecting the formation of the final product. For example, for an embodiment using integral cutting and molding, the overall cutting can be completed first, followed by local trimming; for an embodiment where the band 11 and eyelash filaments 12 are manufactured separately, the eyelash filaments 12 can be formed first, then the band 11 can be formed, and finally, the fixed connection can be completed. The band 11 can be a flexible band 11 used in existing artificial eyelash products, or it can be made of polyimide, thermoplastic polymer, thermosetting polymer, or other materials suitable for artificial eyelash products; the band 11 can be pre-manufactured or formed simultaneously during subsequent cutting; the band 11 can adopt a strip, arc, band, mesh, continuous structure, or segmented structure, and its width, thickness, and length can be adjusted according to different product specifications. Cutting is not limited to conventional mechanical cutting, but refers to various processing methods that can process polyimide materials according to a predetermined contour to form the eyelash filament 12 contour, including but not limited to laser cutting, ultraviolet laser cutting, femtosecond laser cutting, precision die cutting, CNC tool cutting, vibratory knife cutting, waterjet cutting, die stamping, micro-blanking, photolithography combined with etching, or other processing methods that can form fine contours. In one or more embodiments of this disclosure, continuous processing is performed using CNC laser cutting equipment. The polyimide material can be in roll form, sheet form, block form, or other material feeding forms that can meet the cutting requirements; the roll form is particularly suitable for continuous production, and can be placed on an unwinding mechanism, kept flat by a tension control mechanism, and then continuously fed into the cutting equipment. Cutting process parameters include but are not limited to laser power, laser wavelength, pulse frequency, pulse width, focal position, scanning speed, cutting speed, feed rate, tool pressure, tool angle, tool amplitude, cooling method, and auxiliary gas pressure, etc. Those skilled in the art can combine or adjust the above parameters according to the thickness of the polyimide material, the product size, and the type of processing equipment. After forming multiple eyelash strands 12, surface cleaning, removal of cutting residue, surface coating, heat setting, trimming, inspection, packaging, sterilization, or other post-processing steps can be performed according to product requirements. For embodiments using a separate manufacturing approach, the multiple eyelash strands 12 can be fixed to the root portion 11 by hot melt bonding, adhesive bonding, ultrasonic welding, laser welding, insertion, mechanical clamping, or other fixing methods. For embodiments using an integrated cutting approach, the above fixing steps are no longer required. Since the eyelash strands 12 are formed by cutting polyimide film rather than extruding and drawing, changing the size, arrangement, or shape of the eyelash strands 12 only requires modifying the cutting program, without the need to process new extrusion molds. This eliminates the mold changeover steps that would otherwise make small-batch or customized production slow and expensive, while still supporting continuous roll feeding and automated processing.

[0043] In one specific example, a polyimide film with a thickness of approximately 25 μm is unwound from a roll and fed into an ultraviolet laser cutting device. This device operates at a wavelength of 355 nm, a pulse frequency of approximately 80 kHz, an average power of approximately 8 W, and a cutting speed of approximately 300 mm / s. The focal position is adjusted so that the cut eyelash strands 12 have a length of approximately 8 mm to 12 mm, gradually narrowing from a root width of approximately 120 μm to a free end width of approximately 20 μm. Under these parameters, a single polyimide film sheet can produce multiple complete artificial eyelash products. The band 11 and eyelash strands 12 of each product are cut in a single process, and the edge roughness is low enough that no additional edge finishing steps are required before heat setting.

[0044] In another specific example, a CO2 laser with a wavelength of approximately 10.6 μm and an average power of approximately 20 W to 60 W is used to cut polyimide films with a thickness of approximately 50 μm to 75 μm suitable for denser products. Nitrogen or compressed air is introduced into the cutting area as an auxiliary gas to suppress carbonization and carbon residue at the cut edges. After cutting, any residual carbonized debris is removed by ultrasonic cleaning or brushing. In yet another example, cold etching is performed using a femtosecond laser with a pulse width of less than approximately 1 ps, resulting in virtually no heat-affected zone at the cut edges. This creates extremely fine features, such as forked free ends with a filament width of less than approximately 20 μm, without edge melting or discoloration. Therefore, the cutting method can be selected based on the film thickness and the desired fineness of the features to be cut: for example, UV or femtosecond laser cutting for thin films and fine features, CO2 laser cutting for thicker films at higher throughput, and precision die-cutting for high-volume production of fixed designs.

[0045] As described above, the polyimide material used to form the eyelashes 12 can be a polyimide film, a modified polyimide material, or a composite polyimide material. Different product lines can utilize these material options—for example, a thinner polyimide film for natural-looking products and a composite polyimide material for voluminous products—and the material used on a given production line can be changed according to the product model without altering the overall cutting process or replacing the cutting equipment.

[0046] In one or more embodiments of this disclosure, cutting polyimide material to form multiple eyelash filaments 12 includes adjusting cutting process parameters such that the multiple eyelash filaments 12 form one or more of a flat structure, a tapered structure, and a forked structure. Cutting process parameters may include cutting speed, cutting path, focal point position, laser power, tool angle, feed rate, etc. For example, a flat eyelash filament 12 can be formed by changing the cutting path width, a tapered eyelash filament 12 can be formed by gradually changing the cutting path, and a forked eyelash filament 12 can be formed by adding branch cutting paths to the free ends of the eyelash filament 12. The same cutting procedure can use different parameters in different areas, thereby forming multiple eyelash filaments 12 with different structures in a single processing operation. Different structures of eyelash filaments 12 can be formed without changing processing equipment, improving production flexibility and reducing manufacturing costs when switching between different products.

[0047] In one or more embodiments of this disclosure, cutting polyimide material to form multiple eyelash filaments 12 includes: cutting a single layer of polyimide material to form multiple eyelash filaments 12, or cutting polyimide material with a composite structure to form multiple eyelash filaments 12. When using a single layer of polyimide material, a single layer of eyelash filaments 12 can be directly formed, simplifying the manufacturing process. When using a polyimide material with a composite structure, each layer can be cut simultaneously to form eyelash filaments 12 with a composite structure. Different layers can be integrally formed through hot pressing, adhesive bonding, or co-extrusion, followed by uniform cutting. The same cutting process is applicable to both single-layer materials and composite materials, improving equipment compatibility and reducing the number of production line adjustments.

[0048] In a specific example, a bilayer polyimide film is prepared by co-extruding a base polyimide layer of about 18 μm and a colored polyimide surface layer of about 5 μm, and the resulting composite film is fed into the aforementioned cutting device so that the root 11 and the eyelash 12 are cut from the two layers simultaneously, thereby giving the free end of the eyelash 12 a significantly darker or lighter hue than the base layer, without any separate coloring step.

[0049] In one or more embodiments of this disclosure, cutting polyimide material to form multiple eyelash strands 12 includes: adjusting cutting process parameters to create an uneven texture on the surface of the multiple eyelash strands 12 (e.g., Figure 3 (As shown) or a smooth surface. For example, surfaces with different roughness can be formed by adjusting the laser energy density, or regular textures can be formed by controlling the tool processing path; after cutting, the surface morphology can be further optimized by combining stamping, micro-etching, or polishing processes. The surface state of the eyelash 12 can be controlled by the cutting process, reducing subsequent processing steps, improving manufacturing efficiency, and enriching the product's appearance.

[0050] In one or more embodiments of this disclosure, the polyimide material is in roll form. The roll form of the polyimide material can be mounted on an unwinding mechanism and continuously fed to a cutting device via a tension control mechanism; it can also be further configured with an automatic deviation correction device, a tension detection device, and a rewinding mechanism to achieve continuous automated production; for rolls of different widths, online slitting can be performed according to product specifications. This roll feeding method is suitable for continuous production, reduces manual loading and unloading, improves material utilization, and facilitates automated production.

[0051] In one or more embodiments of this disclosure, the method for preparing artificial eyelash products further includes: before cutting the polyimide material to form multiple eyelash filaments 12, slitting the polyimide material in roll form into multiple polyimide segments, wherein the polyimide segments are in roll form or block form; and then cutting the multiple polyimide segments to form multiple eyelash filaments 12. The size of the segments can be determined according to the processing range of the cutting equipment. For example, large-size rolls can be first cut into multiple smaller rolls and then fed into different processing equipment; or they can be directly cut into sheet materials for single-station processing; different segments can also correspond to different product models, thereby enabling the simultaneous production of products of multiple specifications, improving material management efficiency, and enabling different equipment to use the same raw materials, thus improving production flexibility.

[0052] In one or more embodiments of this disclosure, the method for preparing an artificial eyelash product further includes: forming a color coating on the surface of the polyimide material before cutting the polyimide material to form multiple eyelash filaments 12. The color coating can be formed in a continuous roll state or in a sheet state; after forming the color coating, uniform cutting is performed so that each eyelash filament 12 formed has a predetermined color; the color coating can be formed in a single color, multiple colors, gradient colors, or partial coloring manner. Completing the overall coloring in advance can avoid coloring each filament individually after cutting, improving color consistency and processing efficiency.

[0053] Because polyimide surfaces are relatively inert and may have low surface energy, in one or more embodiments of this disclosure, the surface of the polyimide material is pretreated, for example by corona treatment, atmospheric plasma treatment, flame treatment, or by applying a primer layer, to increase the surface energy and improve the adhesion of the color coating to the polyimide material. In one specific example, a roll of polyimide film is passed through a corona treatment station at a linear speed matching the coating station until the surface energy reaches about 50 dyn / cm or higher. A pigment layer is applied by gravure coating or slot coating, dried in an online oven, and then wound or fed directly into a cutting device. A coating applied in this way to a corona-treated surface is able to resist peeling at the cut edges during subsequent cutting and heat setting of the eyelashes 12. In another example, a metallic or pearlescent effect is produced by vacuum depositing a thin metal layer (e.g., an aluminum layer tens of nanometers thick) onto the polyimide material prior to cutting, optionally followed by a transparent protective topcoat.

[0054] In one or more embodiments of this disclosure, the method for preparing artificial eyelashes further includes: heat-setting multiple eyelash strands 12 to form a curled structure in the extension direction. Heat setting can be performed using hot air, infrared heating, a hot press mold, a high-temperature roller, or other heat treatment methods; the heat setting temperature can be set according to the properties of the polyimide material, for example, from 150°C to 350°C; the heat setting time can be adjusted according to product specifications; the curling angle can be controlled by changing the shape of the setting mold. Heat setting can stably maintain the curled shape of the eyelash strands 12, improve product consistency, and reduce the need for users to re-curl them during use.

[0055] In one specific example, the cut eyelash strands 12 are pressed tightly onto a heated forming mold at approximately 280°C and held for about 15 seconds to form a curl with a radius of curvature of approximately 8 mm; in another example, the eyelash strands 12 are placed on a bending jig and passed through a hot air tunnel held at approximately 220°C for about 30 seconds, producing a considerable curl with fewer localized surface marks. Therefore, the heat setting method can be selected based on the desired balance between cycle time and surface finish.

[0056] In one or more embodiments of this disclosure, the stem 11 is also cut from polyimide material, and the outline of the stem 11 is formed according to a predetermined shape in the same or separate cutting steps using the cutting equipment described above.

[0057] In one or more embodiments of this disclosure, the stalk 11 and the multiple eyelashes 12 are referenced Figure 1The method described involves cutting a single piece from the same polyimide material, so that after cutting, only waste material around the edges needs to be removed to obtain a complete artificial eyelash product; multiple artificial eyelash product patterns can be arranged on a single piece of polyimide material to allow for batch cutting.

[0058] In one or more embodiments of this disclosure, the method for preparing an artificial eyelash product further includes fixing multiple eyelash strands 12 to a band 11. When the eyelash strands 12 and the band 11 are manufactured separately, the multiple eyelash strands 12 can be installed onto the band 11 by adhesive bonding, hot melt bonding, ultrasonic welding, laser welding, mechanical clamping, or other fixing means; an automatic hair grafting device can be used to fix the eyelash strands 12 at predetermined intervals to ensure consistent arrangement; after fixing, further post-processing operations such as trimming, heat setting, quality inspection, and packaging can be performed. These fixing means can be selected according to different materials and product structures, while still ensuring that the eyelash strands 12 are firmly and uniformly fixed to the band 11. In one or more embodiments where the multiple eyelash strands 12 and the band 11 are manufactured separately, the root region of the eyelash strands 12 can be pre-fixed to the band 11 by ultrasonic welding or laser welding before final fixing.

[0059] In one or more embodiments where multiple eyelash filaments 12 and the band 11 are manufactured separately, the root region of the eyelash filament 12 can be fixed to the band 11 by ultrasonic welding or laser welding. Ultrasonic or laser energy can locally melt the root region of the eyelash filament 12 and / or the surface of the band 11 to form a preliminary connection before final fixation. After the fixation step, the root region can be trimmed, and the connection can optionally be strengthened by adhesive bonding, thermal bonding, or another fixation technique described herein.

[0060] The above are merely some embodiments of this disclosure, and neither the text nor the accompanying drawings are intended to limit the scope of protection of this disclosure. Any equivalent structural transformations made based on the overall concept of this disclosure and the content of this specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of this disclosure.

Claims

1. An artificial eyelash product, comprising: stem; as well as Multiple eyelash strands, each with a root fixed to the band. At least one of the multiple eyelash strands contains a polyimide material.

2. The artificial eyelash product according to claim 1, wherein, The polyimide material includes one or more selected from polyimide films, modified polyimide materials, or composite polyimide materials.

3. The artificial eyelash product according to claim 1, wherein, The cross-section of the multiple eyelashes perpendicular to the extension direction of the multiple eyelashes has one or more of the following structures: flat structure, gradually narrowing structure, or bifurcated structure.

4. The artificial eyelash product according to claim 1, wherein, The multiple eyelashes have a single-layer structure or a multi-layer composite structure.

5. The artificial eyelash product according to claim 1, wherein, The surface of the multiple eyelashes has an uneven texture or a smooth surface.

6. The artificial eyelash product according to claim 1, wherein, The stem has a slender cylindrical shape with a circular cross-section.

7. The artificial eyelash product according to claim 1, wherein, The multiple eyelashes form a curled structure in the direction of extension.

8. The artificial eyelash product according to claim 1, wherein, The multiple eyelash strands and the hair shaft are formed by integral cutting.

9. The artificial eyelash product according to claim 1, wherein, The root portion includes multiple root layers, and the multiple eyelash strands include multiple eyelash strand layers. Each stroma layer and its corresponding eyelash layer are integrally formed by cutting a single layer of polyimide film, and the multiple stroma layers are stacked on top of each other.

10. A method for preparing an artificial eyelash product, comprising: Prepare a stem for supporting and connecting the roots of multiple eyelashes; as well as The polyimide material is cut to form the multiple eyelash strands.

11. The method according to claim 10, wherein, The polyimide material includes one or more selected from polyimide films, modified polyimide materials, or composite polyimide materials.

12. The method according to claim 10, wherein, Cutting the polyimide material to form the multiple eyelash strands includes: Adjust the cutting process parameters so that the cross-section of the multiple eyelashes perpendicular to the extension direction of the multiple eyelashes has one or more of the following structures: flat structure, gradually narrowing structure, or bifurcated structure.

13. The method according to claim 10, wherein, The polyimide material is a single-layer polyimide material or a polyimide material with a multi-layer composite structure.

14. The method of claim 10, wherein, Cutting the polyimide material to form the multiple eyelash strands includes: Adjust the cutting process parameters to give the surface of the multiple eyelashes an uneven texture or a smooth surface.

15. The method according to claim 10, wherein, The polyimide material is in roll form.

16. The method of claim 15, further comprising: Before cutting the polyimide material to form the multiple eyelash strands, the polyimide material in roll form is slit into multiple polyimide segments, wherein the polyimide segments are in roll or block form. The cutting of the polyimide material to form the multiple eyelash strands includes: The plurality of polyimide segments are cut to form the plurality of eyelash strands.

17. The method of claim 10, further comprising: The root region of the multiple eyelashes is fixed to the band by ultrasonic welding or laser welding.

18. The method of claim 10, further comprising: The multiple eyelash strands are heat-set to form a curled structure in the extension direction of the multiple eyelash strands.

19. The method according to claim 10, wherein, The band and the multiple eyelashes are formed by integrally cutting the polyimide material.

20. The method of claim 10, further comprising: A polyimide material is integrally cut to form multiple eyelash layers, wherein one of the multiple eyelash layers includes a band layer and an eyelash filament layer connected to the band layer; as well as The multiple eyelash layers are stacked to form the artificial eyelash product.

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