具体实施方式：
[0032]The following description of the embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention.
1. Introduction
[0033]The system and method for automating production of electrospun textile products of preferred embodiments function to produce complex three-dimensional shapes through the process of electrospinning. Electrospinning uses strong electric fields to pull fibers from liquids. The system and methods of the preferred embodiments involve the design and use of a device employing electrospinning to facilitate on-demand production of textile products and fabrics in complex 3D shapes. The systems and methods detailed herein include approaches for electrospinning for clothing on demand, larger scale electrospinning chambers to contain large textiles and articles of clothing, and controlled deposition of fibers in and onto complex molds. The system and method preferably involve the use of a standalone device wherein an electrospinning dispensing system deposits fibers onto a mold structure. The mold structure is changeable so as to enable customization of shape, size, and features of an electrospun product.
[0034]The system and method enable the creation of electrospun fabrics and textiles in 2-dimensional configurations as well as complex, non-uniform 3-dimensional configurations. The process is enabled by a variety of mechanisms that offer novel and highly controlled approaches to fiber deposition. Using the process of electrospinning to create articles of clothing and other textiles on demand is itself a novel use for this technology. As opposed to traditional textile manufacturing of 2D rolls of fabric that require additional processing, the system and method can create seamless 3D textile products in unique user-defined shapes. Another unique element of the system and method described herein is large-scale production capacity in three axes. Chambers large enough to fit entire articles of clothing have not been utilized in state-of-the-art electrospinning setups described in the literature. Seamless one-piece textiles can be produced on complex 2D projection molds or 3D mold scaffolds of the necessary size. Another aspect of the system and method is the controlled deposition of fibers into complex shapes.
[0035]The system and method can also be used as a post-processing technique for existing 3D structures and shapes. The system and method can add layers of fibers to existing structures that would otherwise be difficult to cover in a precise manner. The design and approach of the system and method can be used to create patterns and detail work in a controlled manner through management of the electrospinning process and through mold design.
[0036]As one potential benefit, the system and method produce a seamless textile product through a single manufacturing process—textile production, patterning, and assembly can be reduced to the electrospinning manufacturing process of a system of a preferred embodiment. This can greatly simplify prototyping stage of textile production as well as production.
[0037]The system and method can additionally function to provide a substantially convenient approach to producing products in a variety of forms through the use of dynamic mold systems. A user can use 3D printing, laser cutting, and other suitable prototyping techniques to easily create new molds that can be used to produce a variety of clothing products.
[0038]The system and method function to address the unmet needs of creating complex shapes through electrospinning. Traditional electrospinning technology is limited to simple sheets and cylinders. Such systems do not address complex geometry production, adaptability of forms, or product scale that can result from producing textile products. Collectors with complex shapes present unique challenges for current electrospinning setups, resulting from a number of factors, including non-uniform charge distributions that prevent full deposition of fibers, and an inability to produce patterned or textured fabrics. The use of dynamic 3D geometries in electrospinning setups presents its own unique set of challenges arising from a number of factors, including regulating a gap distance between the structures and dispensing array.
[0039]The system and method described herein is primarily described as being applied to production of textile products such as shirts, skirts, pants, hats, gloves, undergarments, or any suitable textile product. However, the system and method may alternatively be applied to the production of any suitable product such as custom formed air filters, custom textile solutions, on-demand textile solutions, or other suitable applications.
[0040]The systems and methods described herein include new elements of electrospinning technologies including electrospinning dispensing and collector design, and/or interaction of involved subsystems.
[0041]As an exemplary list of features, the system and methods for automating production of electrospun textile products may include the following features and/or variations addressing the electrospinning dispensing system: pneumatic syringes to provide electrical insulation between the pump and dispensing array; syringe cartridges for quick reloading of solutions; specific tubing formulations and modifications that can promote consistent pumping and charge distribution (including the minimization of charge leakage/buildup); applications of near-field electrospinning, which can be used to control the confinement of the electrospun beam to produce highly controlled colors, patterns, and details; combinations of electrospinning and melt spinning for particular applications; methods to aid in fluid charge residence and speed of fiber deposition; automated cleaning systems; using reloadable cartridges; formation of fiber with multiple colors (including different colors dispensed simultaneously through various nozzles); formation of fibers of varying fiber types; motion systems that control the gap distance (the distance between the end of the nozzles and the surface of the structure) and position of the dispensing system required to achieve uniform coverage across sufficiently complex shapes; free-surface electrospinning dispensing system, which may increase throughput and reduce garment completion time; and/or other suitable variations in the electrospinning delivery system and process.
[0042]As another exemplary list of features, the system and methods for automating production of electrospun textile products may include the following features and/or variations addressing the electrospinning collector: use of “2D projection electrospinning” to create seamless 3D shapes out of 2D projection plates while avoiding many of the problems and challenges faced by electrospinning to form complex 3D geometries; special coatings for the 2D/3D scaffolding to ease in fabric confluence and removal; charged or grounded cores to allow use of non-conductive scaffolds; use of complex 3D structures as a fiber deposition target; mold structures made from or coated in conductive paint/material; folded mold structures to reduce system volume and promote textures; patterns, and features in finished garments; and/or other suitable variations in the electrospinning collector system and process.
2. System for Automating Production of Electrospsun Textile Products
[0043]As shown in FIG. 1, a system for automating production of electrospun textile products can include an insulated enclosure 110, an electrospinning dispensing system 120, a solution supply system 130, a mold structure 140, a cyclical mold actuator 150, and a charge unit 160.
[0044]In a preferred embodiment, the system is used in 2D projection electrospinning, wherein the electrospun fibers are deposited onto a flattened 2D projection mold as shown in FIG. 2. The flattened 2D projection mold is preferably moved in a cyclical pattern. Over time, the fibers coat the mold, and wrap around the edges, creating a seamless object. The object, in this case a garment, can then be removed from the mold and opened to fit over a 3D shape (e.g., a wearer's body). There are a number of advantages to 2D projection electrospinning, including control of the dispensing system, and possible elimination of the motion in multiple dimensions. The machine depicted in FIG. 1 allows for translation of the 2D projection mold along one defined axis. Another potential benefit can include the reduction in the size and footprint of the machine, which can enable the device to more easily fit inside homes, closets, workshops, etc.
[0045]The preferred embodiment preferably includes a first and second dispensing area that are directed in opposing directions so as to dispense fiber on both sides of the 2D projection mold simultaneously as shown in FIGS. 1 and 2. Alternative embodiments could include a two-stage production process with a mold rotation. The mold rotation can be manually performed or may be mechanically automated.
[0046]In alternative embodiments, the system may alternatively be applied to electrospinning onto 3D molds as shown in FIG. 3. The 3D mold embodiment can include a mechanically actuated dispensing system and/or or mold structure. In yet another embodiment, the system can include a multi-faced (i.e., “faceted”), wherein at least two electrospinning dispensing areas are aligned in non-parallel orientations. The multi-faced embodiment can function to apply the 2D projection electrospinning approach to 3D molds with a limited set of substantially flat faces, wherein some of the faces are aligned on intersecting planes as shown in FIG. 4. A multi-faced approach may include variations of the 2D projection electrospinning embodiment and/or 3D mold electrospinning embodiment.
2.1 Insulated Enclosure
[0047]The insulated enclosure 110 of a preferred embodiment functions to limit interference from the outside environment. The insulated enclosure 110 is a structural chamber in which active electrospinning occurs during the production process. The active electrospinning area is the space between the charged parts of the electrospinning dispensing system 120 and the mold structure 140.
[0048]Various components of the system use and control high voltages of electricity that can be damaging to other components of the system. The insulated enclosure along with other protective elements isolates the source of electrical discharge in order to prevent interference through (but not limited to) electrical arcing. This can be done by way of a Faraday cage around sensitive components and/or insulating the actuation seam to the area of active electrospinning as shown in FIG. 5.
[0049]The insulated enclosure, in addition to providing electrical insulation, can additionally function as a structural chassis on which some or all of the components of the system may be directly or indirectly coupled. The insulated enclosure 110 can include an electrospinning sub-chamber and a controller sub-chamber. The electrospinning sub-chamber can include insulating design elements to shield electrical components in the control chamber from the electromagnetic fields generated in the electrospinning sub-chamber. The electrospinning sub-chamber of the insulated enclosure can include framing supports and a set of walls. The walls can be made from electrically insulating material such as acrylic, glass, polycarbonate, or any suitable insulating material. The insulated enclosure 110 can additionally include insulating systems such as a Faraday cage. Additionally the walls can be used as a mounting structure of the electrospinning dispensing system. In one variation, a wall used to mount the electrospinning dispensing system can include an array of possible nozzle mounting elements. The nozzle mounting elements can be an array of electrospinning nozzle holes. The number of electrospinning nozzle holes can be greater than the number of supported electrospinning nozzles which can function to give positioning options for the electrospinning nozzles as shown in FIG. 1. A nozzle mounting system can additionally include positioning options. In one variation, a nozzle mounting element can enable a nozzle to be repositioned along at least one axis and/or rotate about at least one axis. In one variation, the nozzle mounting elements are static positioning elements, but in an alternative variation, the positioning of a nozzle mounting elements could be actuated and controlled.
[0050]The controller sub-chamber is preferably a substantially enclosed container, which can contain processors, solution supply components of the solution supply system 130. The controller sub-chamber can be a walled structure that acts as a base of the system wherein the electrospinning sub-chamber sits above or on top of the controller sub-chamber. Other arrangements or configurations may alternatively be used. The controller sub-chamber can additionally isolate components from the electrospun fiber.
[0051]The controller sub-chamber can include an access port wherein the cyclical mold actuator 150 couples to the mold structure 140. The cyclical mold actuator 150 is preferably substantially contained within the controller sub-chamber to isolate the motor and actuating components from the electromagnetic fields of the electrospinning sub-chamber. The access port can be a seam, gap, or defined hole. Insulating padding or other insulation mechanisms can be used.
2.2 Electrospinning Dispensing System
[0052]The electrospinning dispensing system 120 of a preferred embodiment functions to deliver, eject, or otherwise dispense electrospun fiber onto the mold structure 140. The electrospinning dispensing system employs the process of electrospinning but can alternatively use alternative process variations such as melt electrospinning, coaxial electrospinning, emulsion electrospinning, and other suitable variations. The electrospinning dispensing system 120 preferably delivers fiber to the outside of a mold structure 140. However, alternatively or additionally, the electrospinning dispensing system 120 can be centrally located with a surrounding mold structure, and the electrospinning dispensing system 120 can direct fiber application to the inside walls of a mold structure as shown in FIG. 6.
[0053]The electrospinning dispensing system 120 preferably acts as a source of fiber formed during extraction of the electrospinning solution through an electrical charge. The electrospinning dispensing system 120 preferably receives a supply of electrospinning solution from the solution supply system 130. The charge unit 160 can charge the electrospinning solution relative to the mold structure to a charge point resulting in an eruption of the electrospinning solution from a point on the electrospinning dispensing system 120. During travel towards the mold structure, the liquid transforms into a fiber. The fiber is preferably substantially uniform and can have various properties depending on the electrospinning solution and electrospinning process. As a result of electrostatic repulsion, the fiber can experience a whipping process wherein different parts of the fiber are pulled in different directions towards the collector so as to contact the collector over a collection zone.
[0054]The electrospinning dispensing system 120 preferably includes an array of electrospinning dispensing nozzles 122 as shown in FIG. 7. The array of electrospinning dispensing nozzles 122 includes a set of nozzles 124, alternatively referred to as spinnerets. A nozzle 124 can be a hypodermic needle or any suitable type of localized solution deliver mechanism. The nozzle 124 is connected to the charge unit that delivers a high-voltage current (preferably a direct current 5 to 50 kV) to the solution delivered through the solution supply system 130.
[0055]In one variation, a longer nozzle can be used. An alternative approach is to use a flange, wire, or other metallic leads that extend from the body of the nozzle back into the tubing, as shown in FIG. 8, thereby increasing charge residence time without extending the length of the nozzle.
[0056]A nozzle is preferably mechanically coupled to a point on the insulated enclosure 110, but may alternatively be structurally supported by any suitable chassis. The nozzle 124 is preferably fixtured so that a delivery port of the nozzle 124 is directed at the mold structure 140. The nozzles can be repositionable through a dynamic nozzle positioning system. In one variation, the nozzles can be repositionable across a set of nozzle mounting elements (i.e., a set of fixture points for a nozzle) in the insulated enclosure 112. The repositionable property of the nozzles functions to ensure the adaptability of an electrospinning setup with various sized molds. The dynamic nozzle positioning system can be a grid of nozzle support structures that allows nozzles to be placed in custom arrangements depending on the requirements of the mold, and adjusted throughout the electrospinning process, or through the use of nozzles that can be slid along paths in the support structure. A nozzle mounting element can be support structure such as a defined cavity that presents a single positioning option (e.g., a nozzle hole), a positioning axis (e.g., a defined groove in which a nozzle may be fixed), or any suitable mechanism in which a nozzle can be positioned.
[0057]The array of electrospinning nozzles 122 is preferably positioned along one face of the insulated enclosure. The dispensing area is preferably a surface of the insulated enclosure 110 and is preferably a flat, planar surface. The array of electrospinning nozzles 122 are preferably mounted across a two-dimensional area. The dispensing area can alternatively be along a curved or non-uniform surface. The dispensing area surface is preferably substantially parallel to a surface of the mold structure to which the fiber will be deposited, which functions to promote uniform gap distance between the nozzles and the collection zone of a nozzle. There is preferably at least one subset of the array of electrospinning nozzles 122 distributed on a first surface. There can alternatively be multiple surfaces along which a subset of the array of electrospinning nozzles 122 can be mounted. The various subsets are preferably positioned around a substantially centrally located mold structure 140. Preferably, there is a first array of electrospinning nozzles 122 mounted along a first surface and a second array of electrospinning nozzles 122 on a second surface as shown in FIGS. 1 and 2. The first array of electrospinning nozzles is preferably mounted so as to direct electrospinning in a direction opposing the direction of electrospinning of the second array. The second array of electrospinning nozzles are preferably positioned along a face such that electrospinning on an opposing side of a mold structure.
[0058]As described below, the mold structure 140 is preferably actuated relative to the electrospinning dispensing system 120, but a subset or all of the nozzles in the array of electrospinning nozzles 122 can be actuated as a group or individually as shown in FIGS. 9A and 9B.
[0059]Alternative, electrospinning dispensing systems may alternatively be used such as free surface or wire electrospinning. To increase the rate of fiber deposition, and eliminate problems caused by nozzle dispensing systems, a free surface electrospinning setup can be used in conjunction with 2D projections or 3D molds. Free surface electrospinning can be uniquely used in conjunction with 2D projection molds, as movement of a free surface electrospinning apparatus is prohibitively difficult due to its size and complexity. A static, flat free surface electrospinning setup may produce complex 3D garments from a 2D projection mold without any motion of the dispensing system.
[0060]Free surface electrospinning uses a large surface area electrode coated with conductive solution to produce a field of fiber jets, as opposed to the one-jet-per-nozzle setup traditionally used. In one variation, a free surface electrospinning system includes a solution faucet that dispenses the solution down a charged plate, and allow electrospinning to take place from the surface of the plate as shown in FIG. 10A. This could also be adapted to remove the plate, and allow charged fluid to fall through the air while electrospinning before being collected and recirculated. In another variation, a gravity-driven system can use a solution reservoir positioned above a nozzle array. Gravity drives the solution through nozzles composing a nozzle array as shown in FIG. 10B. Another approach could use a “bowl” system that dispenses electrospun fibers from the edge of the bowl as shown in FIG. 10C. This could also make use of an off-axis cleaning plate that spins and effectively cuts off polymer build up from the edges of the plate. Lastly, a drum system could allow for polymer to be electrospun from the edges of a rotating drum, either through pump action or by the centrifugal force of the fluid on the edge of the drum as shown in FIG. 10D.
[0061]In one variation, the electrospinning dispensing system 120 can be used to deliver varying colors, fiber types, and/or fiber/textile qualities. The electrospinning dispensing system 120 can include individually configurable dispensing nozzles.
[0062]In a color control variation, at least a first and second nozzle can be configured for a first and second fiber color. In one implementation, fiber color configuration is controlled by connection to different solution sources as shown in FIG. 11A. In another implementation, an individual dispensing nozzle system can include a colorant system that can dynamically color the solution during delivery to the nozzle or during the electrospinning process as shown in FIG. 11B. The colorant system may alternatively be any suitable solution augmentation system that can act inline to one or more nozzles. The first and second nozzles can be positioned in substantially the same region (i.e., adjacent nozzle placement) so as to have similar collection zones. The adjacent nozzles can be individually controlled so as to control the mixing and/or layering of fiber application during actuation of the mold structure 140. Alternatively, the nozzles of different colors can be placed in distinct regions in the array of electrospinning dispensing nozzles 122.
[0063]Similarly, at least a first and second nozzle can be configured for different fiber types. For example, a first nozzle can include a connection to a silk solution while a second nozzle includes a connection to cotton solution.
[0064]In yet another alternative, the electrospinning process can be altered through varying a property of the dispensing charge, collector charge, nozzle properties, solution properties, nozzle positioning (e.g., gap distance, angle, etc.), mold structure actuation, or any suitable properties. These changes can be substantially fixed changes or modulated over time.
[0065]In one variation, the electrospinning dispensing system 120 can include a multi-electrospinning process system, wherein there are at least two different electrospinning processes used simultaneously or in combination. In one implementation melt spinning (which is a type of electrospinning that uses a heating element to melt a polymer before fiber production through an electric field) and electrospinning can be used simultaneously. A melt electrospinning processes can be configured for a first nozzle, and a second electrospinning process as described herein can be used in a second nozzle, which can be used for a combination of rapid fiber production and detail work.
[0066]The electrospinning dispensing system 120 can additionally include a cleaning system, which functions to address the situation of polymer buildup on the ends of the nozzles that may inhibit the electrospinning process. In one variation, the cleaning system includes a friction pad that is retractable over a nozzle as shown in FIG. 12A. The friction pad can be a rubber diaphragm that a nozzle is placed into and then retracted when polymer buildup occurs. The contact with the friction pad is preferably sufficient to remove polymer buildup. Other individual nozzle cleaning systems may be used such as pressurized air systems, buildup-wiping arm, or any suitable mechanism. Alternatively, the cleaning system may be a nozzle array cleaning system wherein the cleaning mechanism type cleans a collection of nozzles. In one variation a roller could be used which extends a rubber surface or brushes over various nozzles in succession as shown in FIG. 12B. Alternative cleaning approaches also include the use of a moving plate that can remove built up polymer from each nozzle/nozzle, and spinning brushes or arms that can remove built up polymer from multiple nozzles on each pass.
2.3 Solution Supply System
[0067]The solution supply system 130 of a preferred embodiment functions to deliver the electrospinning fluid to the electrospinning dispensing system no.
[0068]The solution is preferably a solvent with melted or dissolved solids, wherein a resulting fiber is formed from the solution during the electrospinning process. The solution contains various mixtures of fabric materials and solutions to dissolve and carry them through the other components of the system. An electrospinning solution can be used to form synthetic fiber, cotton fiber, silk fibers, mixed fibers, and/or any suitable type of fiber. One such solution consists of polyester and cellulose (the main constituent found in cotton) dissolved in acetone. Varying the ratio of polyester to cellulose changes the look and feel of the resultant fibers. Another consists of silk that has undergone a solubilization process and been dissolved in water. The solution can also be comprised of non-fiber materials that add an additional level of functionality to the fabric that is not present in traditional textiles. For example, materials including (but not limited to) medicinal chemicals or fire-retardants can be added to the initial solution and carried with the resultant electrospun fiber to be embedded in the resultant electrospun fabric. These embedded materials can enable the use of the electrospun fabric in medicinal or protective applications.
[0069]In a preferred embodiment, the solution supply system 130 includes a solution reservoir (e.g., a tank) 132, solution transport 134 connected to the solution reservoir and the electrospinning dispensing system 120, and a pump system 136 as shown in FIG. 13. In the preferred dispensing system, the solution transport 134 (e.g., tubing) runs between the solution reservoir and/or a pump to at least one nozzle. The solution reservoir can be a tank or any suitable container that stores the solution for multiple nozzles. In another variation, there is a set of solution reservoirs. The set of solution reservoirs can include different solution types or the same solution type. Additionally, one of the sets of solution reservoirs can be used by a single nozzle or a set of nozzles. The solution transport 134 is preferably a set of tubing connections. The solution transport 134 may alternatively be any suitable piping system, channels, or other suitable system to transport solution to the electrospinning dispensing system 120. Herein, tubing will be used as the exemplary form of the solution transport system.
[0070]To prevent charge flowing back down the tubing lines, specific tubing formulations can be used. Less conductive plastic tubing such as FEP lined Tygon can aid in preventing charge leakage when compared to some varieties of soft rubber tubing. Additionally, chokes or ferrite beads placed on or around the tubing lines can be used to capture stray charge and prevent it from flowing down the tubing lines.
[0071]The solution supply system can include a solution cartridge system wherein the solution reservoir includes an attachable reservoir. A solution cartridge can be swapped in and out so as to enable easy and fast restocking of solution. Cartridges containing the material solution can contain a quick releasing mechanism to allow for easy insertion/removal in the device. Pods are also used for cleaning the system with various solutions and/or air. Special pods or subsections of existing pods are inserted for this purpose. As shown in FIG. 14, one variation can include a pump system actuator element such as a plunger or air connect; a bladder with a cleaning liquid or air that can be pumped when the bladder is punctured or otherwise engaged; a chamber of solution; and a release valve. The release valve can be a quick release valve, a puncturable seal, or any suitable type of valve.
[0072]A solution cartridge contains or can be filled with an electrospinning solution as described above. A solution cartridge can contain separation mechanisms within them to allow for separating of chemical constituents. Different solution types can be contained within one cartridge by leveraging specific gravities to promote separation of the solution types as shown in FIG. 14. Solution supplies of differing material may be mixed and blended to allow for precise material makeup of an end fibrous garment. Solution material control may be used to dynamically control color, material properties (e.g., strength, fiber thickness, and the like), fiber composition (e.g., breakdown of cotton, silk, polyester, etc.), or other suitable properties. In one variation solution mixing can be achieved through use of cartridges with different solutions. In another variation, multiple solution supply packages of differing solutions can be added to a cartridge. This might manifest in precise control over how much of a material constituent is present in the end product (e.g. 10% polyester). Moreover, unique material makeups could be achieved with this system when multiple solutions are available for selective supply through the solution supply system 130. For instance, layers or sections of a garment could be made of entirely different materials (e.g. silk on the inside, nylon on the outside) without adding seams, significant thickness, or other bonding steps or artifacts to the end product.
[0073]As described above, a colorant system can be used to alter the coloring of the solution. Dying the solution can be done to allow for colored products. The dye may be applied before any other processes, or dye can be placed within the nozzle, allowing for a base solution to be combined before the fiber-pulling process. The color-adding process can be remotely controlled; so various colors can be added at various points of a single job or garment.
[0074]As an alternative to pumping the conductive solutions through tubing to the dispensing nozzle, a pneumatic or hydraulic powered syringe can be used directly as the dispensing system. In this concept, a pneumatic or hydraulic line 1501 compresses a special plunger 1502 in the syringe body, as shown in FIG. 15, which dispenses the fluid at a controlled rate. This results in all the electrically conductive material remaining in the syringe, which is easier to control and mitigates charge leakage/interference with other components of the machine.
[0075]A syringe pumping system can similarly use replaceable cartridges. A syringe cartridge can include one or more loaded syringes as shown in FIG. 16. Alternatively, the solution reservoir of the cartridge can couple to form a syringe mechanism. A syringe system can include the ability to maintain uniform pressure across multiple lines of fluid simultaneously, and prevent clogging or other dispensing abnormalities from impairing system function. The replaceable cartridge system can use existing tubing, or contain its own clean set of one-time-use tubing.
2.4 Mold Structure
[0076]The mold structure 140 of a preferred embodiment functions to provide a collector element that acts as the mold for a resulting textile product. The mold structure preferably includes a mold collector 142 that can be mechanically coupled to the cyclical mold actuator 150. The mold collector 142 functions as the core element to which fiber is deposited during the electrospinning process and, as such, includes a structural form that can define the 3D properties of a resulting textile product. In one variation, the mold collector 142 is a fixed element so as to produce substantially similar textile products repeatedly. In another variation, the mold collector 142 can be a transformable mold collector wherein t