Fiber processing system and methods

Abstract

The technology disclosed relates to a system and methods of processing of natural fibers, such as banana fibers. The processed natural fibers can be used in textile and nonwoven applications, such as a natural fiber-containing nonwoven fabric. The natural fiber processing, involving cleaning and degumming the natural fiber, is associated with sustainability and low environmental impact as measured by material accessibility, scalability, waste reduction, and production of reusable byproducts. In many implementations, the disclosed processing system and methods leverage ultrasound irradiation. In some implementations, the disclosed processing system and methods leverage ionic liquid-assisted ultrasound irradiation.

Description

FIBER PROCESSING SYSTEM AND METHODSCROSS-REFERENCE AND INCORPORATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 535,137, filed August 29, 2023, and U.S. Provisional Application No. 63 / 564,399, filed March 12, 2024, which are incorporated herein by reference in their entirety.FIELD OF THE TECHNOLOGY DISCLOSED

[0002] The technology disclosed generally relates to systems and method of processing natural fibers for textile applications and the use of natural fibers in nonwoven fabrics, particularly the use of banana fibers in such textiles.BACKGROUND

[0003] The subject matter discussed in this section should not be assumed to be prior art merely as a result of its mention in this section. Similarly, a problem mentioned in this section or associated with the subject matter provided as background should not be assumed to have been previously recognized in the prior art. The subject matter in this section merely represents different approaches, which in and of themselves can also correspond to implementations of the claimed technology.

[0004] The majority of textiles today are based on synthetic fibers, which have a number of well recognized negative environmental impacts in both production and usage of such textiles. Natural fibers are an alternative to the synthetic kinds, but there are also drawbacks associated therewith. Many natural fibers also have negative environmental impacts associated with production, including cultivation of the fiber source and processing of the fibers. Typical processing of natural fiber is cost- and time-prohibitive and often includes the use of potentially hazardous chemicals. The use of such chemicals can negate or undo the environmental benefits of using a natural fiber, such as sustainably sourced natural fibers, in textile production. These factors limit the feasibility of large-scale, environmentally conscious production of sustainably- sourced natural fibers.

[0005] Nonwoven fabrics typically comprise a blend of short and long fibers that are bonded by chemical processes, mechanical processes, heat, and other various manufacturing processes. Nonwoven fabric materials differ from other fabrics in that traditional techniques, such as weaving or knitting, are not used in the formation of a nonwoven fabric. In contrast, nonwoven fabrics are typically formed as sheets with entangled fibers therein. Nonwoven fabrics can be engineered to possess specific functionality or properties that are ideal for certain applications,including durability, absorbency, insulation (thermal insulation, acoustic insulation, etc.), repellency (e.g., chemical or water repellency), flame retardance, cushioning, and so on.

[0006] It is advantageous from a sustainability perspective to produce nonwoven fabrics comprising natural fibers, as the source for natural fiber is often a renewable resource.

[0007] An opportunity arises for natural fiber processing systems and methods that demonstrate improved scalability while also limiting the potential environmental impact of production. An opportunity also arises for a nonwoven fabric that contains natural fibers (exclusively or in a composite of natural and synthetic fibers) and possesses desirable properties for versatile industry application.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In the drawings, like reference characters generally refer to like parts throughout the different views. Also, the drawings are not necessarily to scale, with an emphasis instead generally being placed upon illustrating the principles of the technology disclosed. In the following description, one or more implementations of the technology disclosed are described with reference to the following drawings.

[0009] FIG. 1 is a schematic diagram of a fiber treatment system according to many implementations of the technology disclosed.

[0010] FIG. 2 illustrates an example of a reverse wet process for the processing of banana fibers.

[0011] FIG. 3 illustrates an example of an ultrasound-assisted process for processing banana fibers.

[0012] FIG. 4 illustrates an example ionic liquid-assisted ultrasound process for processing banana fibers.DETAILED DESCRIPTION

[0013] The following detailed description is made with reference to the figures. Sample implementations are described to illustrate the technology disclosed, not to limit its scope, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows.

[0014] The technology disclosed herein relates to the processing and refinement of natural fibers and a nonwoven fabric containing natural fibers, such as a composite that includes both natural and synthetic fibers or a fabric composed entirely of natural fibers. The disclosed processing and refinement of natural fibers generates fibers that are suitable in a number of textile and non-textile applications. The resulting natural fibers can be carded, spun and / orotherwise processed into slivers, yams, etc. that can be used to create various fabrics. These natural fiber-containing fabrics have a number of improved properties in comparison to other fabrics due to the properties and / or characteristics of the natural fibers refined using processes discussed herein. Further, the environmental impact of such fabrics can be reduced due to the inclusion of natural fibers.

[0015] The disclosed natural fiber-containing nonwoven fabric exhibits flame resistance, acoustic dampening, insulation, and other properties influenced by the presence of natural fibers in the nonwoven fabric. Nonwoven fabrics, in contrast to fabrics constructed using a woven technique, rely on chemical, mechanical, heat or solvent, and / or electrical based methods to bond fibers together into a fabric. Nonwoven fabrics have a wide variety of applications, including apparel (e.g., clothing and accessories), upholstery (e.g., furnishing, carpeting, etc.), disposable medical garments (e.g., facial masks, surgical gowns, etc.), filters (e.g., HEPA filters, coffee filters, or tea bags), geotextiles (e.g., nonwoven geotextile sandbags), absorbent products (e.g., diapers and feminine hygiene products), paper products, shipping and transportation materials, and many others.

[0016] Fabric and textile production is associated with sizable environmental consequences, including water pollution, deforestation, excessive energy consumption, greenhouse gas emissions, and human health toxicity associated with chemical use and microplastics. Notably, “fast fashion” and the use of disposable fabric products in the medical industry are some of the top culprits of fabric-related environmental harm. The fashion industry, for example, is responsible for 10% of all human-caused greenhouse gas emissions and uses more energy than the aviation and shipping sectors combined. Single-use personal protective equipment (PPE), such as facial masks and medical garments, are a long-known contributor to plastic pollution, chemical pollution, greenhouse gas emissions, and generation of non-recyclable waste. The impact of single-use PPE skyrocketed in response to the COVID-19 pandemic, as evidenced by the ~89 million disposable medical masks used per month during peak pandemic time periods according to one World Health Organization estimate. Many staple crops for the manufacturing of widely used fabrics are notably damaging. Cotton, for example, can consume approximately 7,500 to 10,000 liters of water per kilogram. To provide wood pulp necessary to make fabrics like Rayon and Viscose, 70 million tons of trees are cut down annually. All of these factors, from the production of a textile or fabric to the sourcing and processing of the materials that go into such, all contribute to the environmental footprint associated with the end product.

[0017] Consequently, innovations to the fabric manufacturing industry are highly desirable. In addition to the importance of sustainability efforts for the sake of the environment, the above-described issues are just a few of many sources of financial, health, and ethical concerns ripe for improvement. However, a number of barriers exist delaying the development of alternative fabric sources and processing approaches. A variety of natural, renewable fiber sources have been identified (e.g., banana, flax, cotton, hemp, and so on) but traditional natural fiber processing can be prohibitively labor-intensive, costly, low-yield, and / or dependent on the use of hazardous chemicals.

[0018] The technology disclosed provides a solution to the problem of feasible, yet sustainable, fabric processing by leveraging banana fibers. Banana fibers are a renewable resource, as they are derived from the banana plant. Banana plants are a perennial and include a stem that grows from a rhizome. Banana fibers are typically a waste product of the banana cultivation process, and the banana stems are cut down and destroyed regularly due to the large volume of banana production as a food crop. The cutting of the banana stem maintains the high output of the plant by allowing new stems to grow that will bear another bunch. Bananas are grown in over 150 countries, producing an average of 150 million tons of banana fruit each year. Hence, the use of banana fibers as a natural fiber source in materials manufacturing is ecologically and economically beneficial because banana fibers are easily accessible, cost- effective, and offer a form of waste reduction in pre-existing production activity. Moreover, the processing of banana fibers can create beneficial byproducts, such as water and other source materials from which molecular compounds, including bioactives with antimicrobial and / or antioxidant properties, can be extracted and refined. Notably, fibrous portions of the banana plant often possess a high water content, and this water can be extracted during the processing of the banana fibers. The processing of other categories of fibers is often associated with notoriously high water consumption levels; hence, the production of usable water as a byproduct of banana fiber processing is advantageous compared to its alternatives.

[0019] Banana fiber growth, extraction, and processing are low-energy and low-maintenance operations compared to many other fiber sources, and accordingly, these operations may all be performed in locations close to downstream locations of use, further reducing the environmental impact of the material due to reduction in transportation costs. Yam for use in textile and fabric production can be made of exclusively natural fibers, such as banana fibers, or from a blend of different natural fibers and / or synthetic fibers. Fabrics may be made exclusively from banana fibers when suitable for intended use, and in other applications, the integration of banana fiber to the overall composition of a fabric can substantially reduce the volume of other natural and / or synthetic fibers, thereby reducing detrimental impacts caused by the use of such fibers.

[0020] In one example implementation, the natural fiber can be derived from banana plants as treated or untreated banana fibers for use in textiles, fabrics and / or other applications. In other implementations, the natural fiber can be derived from other sources, such as flax, cotton, or hemp. A use of banana fibers can be in nonwoven fabrics, such as described herein. Banana fiber containing non-woven fabrics can comprise some non-zero percentage of natural fibers, derived from a single source or a blend of natural fibers from multiple sources. The remaining percentage of the nonwoven fabric composition may include a synthetic fiber or blend of synthetic fibers, such as polyesters (PET, PTT, or PBT), olefines (PE, PP, or HDPE), nylon, aramides, acrylates, biosynthetics (Modal or Viscose), etc. In one implementation, the nonwoven fabric can include a percentage of natural fiber composition within the range of 50-90% of the nonwoven fabric. In another implementation, the percentage of natural fiber composition can be within the range of 60-80% of the nonwoven fabric.

[0021] In one implementation, the nonwoven fabric includes a 65-75% composition of banana fibers. The remaining 23-35% composition of the nonwoven fabric can include one or more synthetic fibers, such as polyethylene terephthalate (PET) and polyethylene (PE) fibers (e.g., an overall composition for the nonwoven fabric including 70% banana fiber, 20% PET fiber, and 10% PE fiber). In other implementations, alternative natural fibers may be used in addition to, or in place of, the banana fiber such as cotton fiber, hemp fiber, or flax fiber. For clarity and conciseness, the disclosed systems and methods described herein will predominately reference banana fibers, but it is to be appreciated that additional implementations exist within the spirit and scope of the technology disclosed comprising natural fibers cultivated from nonbanana sources.

[0022] Banana fibers contain the versatile lignin molecule, which offers a variety of benefits to natural fiber-containing materials including reduced flammability / flame retardancy and UV protection. Lignin can act as a natural flame retardant due to a number of factors, such as its high char formation rate, richness in phenolic structures, and synergistic effects with other flame retardants. The high char residue formation rate of lignin during combustion results in a char layer that can act as a barrier, thereby slowing down heat release and reducing the availability of volatile compounds that can act as fuel for fire. The char layer also acts as an insulating barrier, protecting the underlying material from the flames. Phenolic structures are known for their thermal stability and resistance to decomposition under high temperatures, enhancing the material’s overall flame retardancy. The phenolic richness of lignin, in addition to its richness in ketones and intramolecular hydrogen bonding, also contribute to the natural UV protection property of lignin.

[0023] Many implementations of the technology disclosed comprise banana fibers, derived from the banana plant, as a natural fiber component of the nonwoven fabric. Banana plants in general, such as Musa acuminata, Musa balbisiana, and Musa paradisiaca, have a typical lignin content of 5-10% and a cellulose content of 60-65%. Table 1 details the lignin, hemicellulose, and cellulose content of various natural fibers, each of which may be included in a nonzero percentage of the disclosed fabric composition.TABLE 1

[0024] Table 2 details the cellulose, hemicellulose, lignin, and pectin content of various banana cultivars, organized by specific portions of the banana plant.TABLE 2Cellulose, Hemicellulose, Lignin, Pectin Content of the Banana Pseudostem and Peduncle

[0025] Now, the discussion turns to an exemplary fiber treatment system that can be used to treat various natural fibrous materials, according to many implementations of the technology disclosed.Fiber Treatment System

[0026] Implementations including systems and methods for the processing of natural fibers, such as banana fibers, and nonwoven fabrics that include banana fibers. FIG. l is a schematic diagram of a fiber treatment system 100 according to many implementations of the technology disclosed. First, the components of system 100 will be introduced, followed by a discussion of the interconnections and respective features of the components. In addition to the banana fiber, the fiber treatment system 100 results in other products, such as water and biomass, which is discussed further herein.

[0027] More specifically, FIG. 1 illustrates an example fiber treatment system 100 that includes a fiber separation unit 110, an optional sizing unit 120, a processing unit 130, an optional post-treatment unit 140, and an optional carding unit 150. Fibrous material is processedthrough treatment system 100 and results in finished or usable fibers, such as those that can be used to create yarns for use in textiles or fabrics, or for other applications. Based on the specific treatment leveraged within the fiber treatment system 100, the quality of the finished or usable fiber can be varied (e.g., depending on the intended use of the resulting fibers). The fiber treatment system 100 can be used to treat a range of fibrous materials, including natural fibrous materials. Natural fibrous materials are often derived from plant sources and can include hemp, banana, flax, jute, rattan, sisal, and other fiber sources readily recognizable to a user skilled in the art. Various processing characteristics associated with the fiber treatment system 100 can be modified based on the fiber source and / or desired finished fiber materials. In one example, modification of the sizing unit 120 can allow the fiber length to be modified from 2 mm to 100 cm for various applications requiring different dimensions of fibers (e.g., feminine pads versus hair extensions). In another example, the post treatment and carding units 140, 150 can be modified to produce fibers with characteristics fine-tuned for textile applications.

[0028] The fiber treatment system 100 can also operate as a closed system or substantially closed system; i.e., designed to be regenerative or restorative in nature, such as by the reuse or recycling of materials, thereby generating minimal waste. Water can be reused within the system 100, conserving and reducing the input needed for processing fibrous material through the fiber treatment system 100. Additionally, chemicals and / or other materials used during the fiber treatment can be reused and replenished as needed. Other by-products of the fiber treatment system 100, including biomass that can be exploited to obtain various active bio-ingredients, can be used for other downstream applications, such as cosmetics or pharmaceuticals. In this manner, the environmental impact of the fiber treatment system 100 can be reduced, in comparison to typical fiber separation processes that are not regenerative by design and either require a greater influx source of input material and / or generate a larger volume of waste.

[0029] The fiber treatment process within the fiber treatment system often begins with fiber separation. Natural fibers from many plant sources, such as banana, flax, etc., are bundled together in their natural state to form a stem. To treat the fibers from such sources, the fibers need to be exposed and at least partially separated. The fiber separation can be done manually, with laborers stripping the fibers individually, in groups, or sheets from the plant material. Alternatively, a fiber separation unit 110, such as a decorticator, can be used to process the plant materials and remove the untreated fibers therefrom. The decorticator separates the bast fiber from the rest of the plant material, which can then be further processed and refined as needed. As part of the decortication process, the plant material may release stored water. In the case of banana fiber processing, a large amount of water is released during the decortication process.The water extracted from the plant material can be captured and used, i.e., within the fiber treatment system 100. The extracted water can also be captured and used for other purposes, such as bottled or packaged for consumption. A water treatment process or system can be included in or coupled to the fiber treatment system 100 to assist with preparing the water for consumption.

[0030] Sizing unit 120 of system 100 is referred to herein as “optional,” meaning that some implementations include sizing unit 120 while other implementations do not. The optional sizing unit 120 can cut the fibers to a desired length before the fibers are processed in the processing unit 130. The sizing unit 120 can include one or more knives and / or cutting edges that can be controlled to size the fibers. In many instances, it may be desirable for the fibers to be processed by the fiber treatment system 100 to generate an end result with a predetermined length. As fibers move through the treatment system 100, the length of the fibers will shrink by a certain amount or range (e.g., due to dehydration and other physical and chemical modifications resulting from the fiber processing). By sizing the fibers (using the sizing unit 120) prior to processing via the processing unit 130, it is possible to output fibers of a pre-determined length. In this manner, fiber treatment system 100 can output fibers substantially characterized by a selected pre-determined length.Fiber Processing Unit

[0031] The processing unit 130 is responsible for the processing and cleaning of the fibers. In the case of natural fibers, for example, the processing unit can be used to further refine the fiber material by removing gums and other non-fiber compounds of the fiber. In some implementations, the processing unit 130 leverages chemical operations to process and / or treat the fibers. In other implementations, the processing unit 130 leverages electrical operations to process and / or treat the fibers. In yet other implementations, the processing unit 130 leverages mechanical operations to process and / or treat the fibers. In many implementations, the processing unit 130 leverages a combination of chemical, electrical, and / or mechanical operations to process and / or treat the fibers. It is to be appreciated that while chemical, electrical, and mechanical processing operations are provided as illustrative examples, this list is not limiting to the spirit or scope of the technology disclosed. A user skilled in the art will recognize that a large volume of various processing operations may be employed for fiber processing, and for the sake of clarity and conciseness, only an exemplary subset containing common categories of processing operations is listed herein.

[0032] In one implementation, the processing unit 130 is a batch unit, such as a batch reactor, in which fibers are processed / treated in batches. In another implementation, the processing unit 130 is a continuous unit, such as a flow-through reactor, in which a stream of fiber material can be treated / processed. The class of processing unit and action(s) used to process / treat the fibers in the processing unit 130 can be based on the type of fibers, the desired quality of the resulting fiber, the intended target application of the resulting fiber, and so on.

[0033] In one example implementation, the processing unit 130 can be a batch reactor in which the fibers to be treated / processed are placed in a solution bath. The fibers can be incubated in the solution for a predetermined amount of time and / or until treated (i.e., processed) to a predetermined amount, as determined by a defined metric. In a further example, the solution within the reactor can be moved so that the solution flows over and / or through the fibers, thereby speeding the treatment / processing of the fibers. In another implementation, the processing unit 130 can include a mechanical agitator to further assist with circulating the solution amongst the fibers and separating the fibers during the processing / treatment. In such an implementation, the mechanical agitator can comprise one or more ultrasonic transducers that emit ultrasonic radiation of a predetermined frequency (or range of frequencies) and at a predetermined intensity (or range of intensities). Next, further details regarding the fiber processing performed in association with processing unit 130 are provided.

[0034] In many implementations, the solution selected for use in the processing unit 130 to treat (i.e., process) the fibers may be obtained from a manufacturer or developed using internal procedures, depending on the intended fiber processing operations. Factors influencing the selection of a processing solution include the fiber source and / or characteristics of the fiber source, as well as the intended processed fiber generated as output and / or target characteristics of the processed fiber. In an implementation involving batch reactor processing, the solution is added to the reactor and used for a predetermined number of batches until replacement of the solution is required. Alternatively, sensors can monitor the solution in the reactor and additional components of the solutions can be added thereto as needed in order to maintain the solution within a desired criterion, such as a certain concentration range or pH range of the solution. The concentrations and components of the solution(s) used to treat / process the fibers can be commercial or proprietary.

[0035] After treatment and processing in the processing unit 130, the fibers can be placed in a post-treatment unit 140. In the post-treatment unit 140, the fibers can be washed and treated. The wash removes any residual chemical and separated components from the fibers and the treatment can include the addition of one or more of a surfactant, an emulsion and / or other fibertreatment. The characteristics and parameters of a post-treatment operation on the processed fibers can be varied or configured based on the desired fiber end product and / or based on the fiber source. In one example, a fiber softener or enzyme can be added to increase the hand (i.e., soft touch) of the fiber. In another example, a lubrican or other additives can be added to modify the fiber processability.

[0036] After the post-treatment unit 140 (or directly after the processing unit 130) the fibers may enter a carding unit 150. In some implementations, the fibers are carded by the carding unit 150, whereas in other implementations, the carding unit 150 is omitted. A fiber carding process is characterized by the aligning, disentangling, and / or intermixing of the fibers, often via a mechanical action. In an implementation comprising the carding unit 150, the fibers are carded by carding unit 150 to produce a more “finished” fiber product (i.e., wherein improved finishing is defined by the improved alignment, disentanglement, or intermixing of the fibers) that can be used in spinning, for example. In other implementations, the fibers can be dried after the posttreatment unit 140 without undergoing a carding process.

[0037] As previously discussed, the fiber treatment system 100 allows for many various customizations to optimize the fiber processing based on the type of fiber to be processed and intended target properties of the resultant fiber product (e.g., length, quality, size, and so on). In many implementations of the technology disclosed, the fiber treatment system 100 is applied to banana fiber.Banana Fiber

[0038] The banana is an herbaceous, flowering plant including a pseudostem that supports the leaves and fruit. After fruiting, the pseudostem no longer produces fruit. Farmers cut the pseudostem once it no longer produces fruit to allow for offshoots to grow and produce fruit. A large amount of waste biomass is generated from the production of banana fruits, including the pseudostems post-fruiting.

[0039] Banana pseudostems contain bundles of fibers that can be separated, processed, and used in a variety of fiber applications. The fibers of the banana pseudostem run the length of the pseudostem, providing a source of long fibers. The coarseness of the fibers varies from coarse to fine across the cross-section of the pseudostem, allowing for fibers to be processed separately for different target applications (or different grades of fibers) based on variable properties like coarseness. In addition to fiber, the pseudostem contains a large volume of water. This water can be extracted during processing of the pseudostems and used for a variety of purposes. In oneexample, the extracted water can be used in fiber processing system 100. In another example, the extracted water can be treated to generate potable water.

[0040] With the fiber removed, there is still remaining biomass from the banana pseudostems that can be applied to other use cases, including energy generations, compost, etc. Consequently, a substantial portion (and often, the entirety) of the banana pseudostem can be used, reducing the waste that would be generated by banana cultivation without harvesting the banana fiber.

[0041] Numerous approaches exist for the processing of natural fibers (e.g., banana fibers), as described above with reference to FIG. 1. The discussion now turns to detailed examples of banana fiber treatment processes.Banana Fiber Processing: Reverse Wet Process

[0042] FIG. 2 illustrates an example of a reverse wet process 200 for the processing of banana fibers, according to many implementations of the technology disclosed. Briefly, reverse wet process 200 removes the hemicellulose and lignin from the banana fibers, resulting in clean, degummed fibers that are suitable for downstream applications, including industrial or textile manufacturing.

[0043] At an operation 202, decorticated banana fibers (i.e., after removal of an outer covering) are placed or fed into a treatment vessel, such as the processing unit 130 of the system 100 of FIG. 1. Within the treatment vessel, the decorticated banana fibers are exposed to a first solution in operation 204. Various particular implementations of the technology disclosed include differing compositions of the first solution. The first solution can include, for example, a base or alkaline, an oxidizer or oxidizing agent, and / or a bleaching agent.

[0044] A listing of non-limiting examples regarding the first solution of operation 204 will now be provided for teaching purposes. In one example implementation, the solution includes sodium hydroxide, hydrogen peroxide and a hypochlorite. The concentration of sodium hydroxide in the solution can be between a range of 2% - 10%, preferably a range of 3% - 5%, and more preferably a concentration of 4%. The concentration of the hydrogen peroxide in the solution can be between a range of 0.2% - 1.5%, preferably a range of 0.4% - 0.7%, and more preferably a concentration of 0.5%. The concentration of hypochlorite in the solution can be between a range of 0.1% - 1%, preferably a range of 0.15% - 0.35%, and more preferably a concentration of 0.25%. The liquor ratio of the first solution can be between 1 : 10 to 1 :60, and preferably is 1 : 15. A temperature range of the first solution at operation 204 can be between 50°C - 100°C, preferably between 70°C - 90°C, and more preferably a temperature of 80°C. The duration of the exposure of the first solution to the banana fibers at operation 204 can be betweena range of 15 - 75 min, preferably between 15 - 30 min, and more preferably a duration of 20 min. In other implementations, the concentration of the components of the solution, the temperature of the solution, and / or the duration of the exposure to the solution differ from these example ranges, depending on factors such as the type of fiber being processed and / or the desired end product fiber.

[0045] In many implementations, one or more various factors influencing process 200 (e.g., the concentrations of one or more components of the first solution, the temperature(s) applied during at least one operation of process 200, and / or the time duration of one or more incubation periods during process 200) may be determined in dependence upon at least one other factor based on a relationship between the two or more factors. For example, the duration of an operation may be determined in dependence on a temperature of the operation. In other implementations, one or more factors influencing process 200 are to be individually determined as independent factors.

[0046] At an operation 206, the fiber product is rinsed with water. The duration of the wash (e.g., 15 min, 30 min, or 60 min), the number of wash cycles (e.g., 1, 2, or 3 cycles), and / or other parameters of the rinse (e.g., temperature) at operation 206 differ in various implementations. In one exemplary implementation, the fiber product from operation 204 is rinsed twice with water at operation 206. The rinse at operation 206 can leverage water sourced from the plant material, such as any water expelled during the decortication process. In some implementations, the water used for rinsing during operation 206 can be reused until a pre-determined threshold of contamination is reached. Metrics used to determine extent of contamination can include, for example, a concentration of solids present in the water and / or a pH of the water. The recycling of water byproduct as well as reusing water during the rinse of operation 206 decrease the overall water consumption of process 200.

[0047] At an operation 208, the banana fibers are exposed to a second solution. In many implementations, the second solution includes a caustic agent, such as sodium hydroxide. The second solution assists with further cleaning the fibers and / or preparing the fibers for future processing operations, such as the post-treatment at operation 212.

[0048] A listing of non-limiting examples regarding the second solution of operation 208 will now be provided for teaching purposes. The sodium hydroxide concentration of the second solution can be within a range of 2% - 15%, preferably between 5% - 10%, and more preferably a concentration of 10%. A temperature range of the second solution at operation 208 can be within a range of 50°C - 100°C, preferably between 70°C - 90°C, and more preferably a temperature of 80°C. The duration of the exposure of the second solution to the banana fibers atoperation 208 can be within a range of 15 - 75 min, preferably between 20 - 45 min, and more preferably a duration of 30 min. As with the first solution in operation 204, the second solution components, temperature and / or duration of incubation can similarly be varied to achieve and / or maintain a desired fiber product.

[0049] At an operation 210, the fiber product is rinsed again with water, preferably twice. The rinse at operation 210 can be performed substantially in the same way as in the rinse at operation 206. In an alternative implementation, the rinse at operation 210 deviates from the rinse at operation 206 by at least one parameter, such as temperature, duration, or re-use of water. Similarly, the rinse at operation 210 can be sourced from the plant material and / or reused, when feasible (limitations to feasibility may include, at least, volume of available water from a particular source and contamination of available water from the particular source).

[0050] At operation 212, the fibers can undergo a post-treatment process, such as the application of a softener, surfactant, conditioner and / or emulsion. In an example implementation, the post-treatment of the fibers at operation 212 can include a vegetable oil emulsion, a softening cationic agent, and a surfactant. The vegetable oil emulsion can include castor oil, soybean oil, aloe vera and / or other oils. The concentration of the oil emulsions can be within a range of 0.5% - 2%, preferably a concentration of approximately 2%. The softening agent can be diethyl-ester- dimethyl-ammonium-chloride of a concentration within a range of 0.2% - 1%, preferably a concentration of 0.5%. The surfactant can be sodium dodecyl sulfate of a concentration within a range of 0.2% - 0.5%, preferably a concentration of 0.5%. The post-treatment process at operation 212 can be applied at a temperature range between 20°C - 80°C, preferably around 60°C. The duration of the exposure of the fibers to the post-treatment process of operation 212 can be between 15 min - 75 min, preferably for 60 min. The liquor ratio can be between 1:10 — 1 :60, and preferably around 1 :40. As with other previously described operations of process 200, the example compositions, variables, and exact values provided here in association with operation 212 are provided purely as illustrative examples and should not be considered limiting to the spirit or scope of the technology disclosed.

[0051] At an operation 214, the post-treatment fibers can be dried and, optionally, substantially as previously described with reference to system 100, the fibers may also be carded in preparation for use in one or more fiber applications. The fibers can be spread out and air dried, dried using an oven, dried in the outdoor environment and / or other drying method. The resultant banana fibers of the process 200 can be used in a variety of applications, including industrial and textile applications.Banana Fiber Processing: Ultrasound- Assisted Process

[0052] FIG. 3 illustrates an example of an ultrasound-assisted process 300 for processing banana fibers, according to many implementations of the technology disclosed. The process 300 removes hemicellulose and lignin from the banana fibers, to create clean, degummed fibers that can be used in a variety of fiber applications, such as industrial or textile uses. The addition of ultrasound irradiation during the solution-based treatment of the banana fibers reduces the amount of time that the fibers are exposed to the solution(s) of the process 300.

[0053] At an operation 302, decorticated banana fibers are placed or fed into a treatment vessel, such as the processing unit 130 of the system 100 of FIG. 1. Within the treatment vessel, the decorticated banana fibers are exposed to a first solution and ultrasound irradiation at an operation 304. The ultrasound irradiation can be provided by an ultrasound bath, an ultrasound reactor with an immersed sonotrode, one or more ultrasound transducers positioned about a vessel, and / or other means of ultrasound irradiation of the bath that will be readily recognized by a user skilled in the art.

[0054] A listing of non-limiting examples regarding the first solution of operation 304 will now be provided for teaching purposes. The first solution can be a caustic solution that includes sodium hydroxide having a concentration within a range of 2% - 15%, preferably between 5% - 12%, and more preferably a concentration of 10%. The liquor ratio of the first solution can be within a range of 1 : 10 - 1 :70, preferably one of 1 : 10, 1 :20, or 1 :40 and more preferably a ratio of 1 :40. The temperature of the first solution can be within a range of 50°C - 100°C, preferably between 70°C - 90°C, and more preferably a temperature of 80°C. The duration of the exposure of the first solution to the banana fibers at operation 304 can be within a range of 15 - 150 min, preferably between 15 - 120 min, and more preferably a duration of 15 min, with the application of ultrasound irradiation.

[0055] Further, the ultrasound irradiation that is applied at operation 304 can have a variety of characteristics. Preferably the irradiation is applied at a power range of 500W - 3000W and a frequency of 20 - 50 kHz, preferably a power range of 1800W - 2200W and a frequency of 20 - 30 kHz, and more preferably a power of 2000W and a frequency of 25 kHz. The ultrasound irradiation can be applied using one or more ultrasound transducers, one or more sonotrodes and / or other sources of ultrasonic irradiation.

[0056] At an operation 306, the fibers are rinsed after the applied treatment during operation 304. The rinse removes remnants of the solution used at operation 304 and more generally assists in cleaning the fibers. In one implementation, the fibers can be rinsed twice in water at operation 306. In other implementations, the fibers may be subjected to a different number of rinse cycles,as described previously. At an operation 308, the fibers are bleached in a second solution (“bleaching solution”), including the addition of the application of ultrasound irradiation.

[0057] A listing of non-limiting examples regarding the second solution of operation 308 will now be provided for teaching purposes. The bleaching solution can include hydrogen peroxide, sodium hydroxide, and a hypochlorite. The concentration of hypochlorite in the solution can be within a range of 0.1% - 3%, preferably a range of 0.1% - 1%, and more preferably a concentration of 0.25%. The concentration of the hydrogen peroxide in the solution can be within a range of 0.2% - 3%, preferably a range of 0.5% - 2%, and more preferably a concentration of 0.5%. The concentration of sodium hydroxide in the solution can be within a range of 2% - 10%, preferably a range of 2% - 5%, and more preferably a concentration of 4%. The liquor ratio of the first solution can be within a range of 1 : 10 to 1 :60, and preferably is 1 :40. A temperature range of the second solution at operation 308 can include 15°C - 100°C, preferably between 20°C - 90°C, and more preferably a temperature of 80°C. The duration of the exposure of the second solution to the banana fibers at operation 308 can be within a range of 10 - 145 min, preferably between 10 - 120 min, and more preferably a duration of 15 min. The application of the ultrasound irradiation at operation 308 can be substantially the same as that applied at operation 304, as described above.

[0058] At an operation 310, the fiber product is rinsed again with water, preferably twice. The fibers are further treated at an operation 312 after the rinsing of operation 310. In operation 312, the fibers can undergo a post-treatment process, such as the application of a softener, surfactant, conditioner and / or emulsion. In an example implementation, the post-treatment of the fibers at operation 312 can include a vegetable oil emulsion, a softening cationic agent and a surfactant. The vegetable oil emulsion can include castor oil, soybean oil, aloe vera and / or other oils. The concentration of the oil emulsions can be within a range of 0.5% - 2%, preferably a concentration of about 2%. The softening agent can be diethyl-ester-dimethyl-ammonium- chloride, with a concentration within a range of 0.25% - 1%, preferably a concentration of 1%. The surfactant can be sodium dodecyl sulfate with a concentration within a range of 0.2% - 0.5%, preferably a concentration of 0.5%. The post-treatment process at operation 312 can be applied at a temperature range between 20°C - 80°C, preferably around 60°C. The duration of the exposure of the fibers to the post-treatment process of operation 312 can be between 15 min - 75 min, preferably for 30 min. The liquor ratio can be between 1 : 10 - 1 :60, and preferably around 1 :40.

[0059] The fibers are exposed to ultrasound irradiation during the post-treatment process of operation 312, with the ultrasound irradiation having substantially similar characteristics as thatadministered during operation 304 and operation 308. As with other previously described operations of process 300, the example compositions, variables, and exact values provided here in association with operation 312 are provided purely as illustrative examples and should not be considered limiting to the spirit or scope of the technology disclosed.

[0060] At an operation 314, the post-treatment fibers can be dried (and optionally carded) in preparation for use in one or more fiber applications. The fibers can be spread out and air dried, dried using an oven, dried in the outdoor environment and / or other drying method. The resultant banana fibers of the process 300 can be used in a variety of applications, including industrial and textile applications.Banana Fiber Processing: Ionic Liquid-Assisted Ultrasound Process

[0061] FIG. 4 illustrates an example of a liquid-assisted ultrasound process 400 for processing banana fibers, according to many implementations of the technology disclosed. The process 400 removes hemicellulose and lignin from the banana fibers, to create clean, degummed fibers that can be used in a variety of fiber applications, such as industrial or textile uses. The addition of ultrasound irradiation during the solution-based treatment of the banana fibers reduces the amount of time that the fibers are exposed to the solution(s) of the process 400. The use of an ionic liquid in the banana fiber separation process reduces the need for other chemicalbased solutions, which can reduce the environmental impact of the processing.

[0062] At an operation 402, decorticated banana fibers are placed or fed into a treatment vessel, such as the processing unit 130 of the system 100 of FIG. 1. Within the treatment vessel, the decorticated banana fibers are exposed to a first solution and ultrasound irradiation at an operation 404.

[0063] A listing of non-limiting examples regarding the first solution of operation 404 will now be provided for teaching purposes. The first solution can be a solution of a base or alkaline, an oxidizer or oxidizing agent, and a bleaching agent. In one example, the solution includes sodium hydroxide, hydrogen peroxide and a hypochlorite. The concentration of sodium hydroxide in the solution can be within a range of 2% - 10%, preferably a range of 3% - 5%, and more preferably a concentration of 4%. The concentration of the hydrogen peroxide in the solution can be within a range of 0.2% - 1.5%, preferably a range of 0.4% - 0.7%, and more preferably a concentration of 0.5%. The concentration of hypochlorite in the solution can be within a range of 0.1% - 1%, preferably a range of 0.2% - 0.5%, and more preferably a concentration of 0.25%. The liquor ratio of the first solution can be within a range of 1 : 10 to 1 :60, and preferably is 1 :40. A temperature range of the first solution at operation 304 can bebetween 50°C - 100°C, preferably between 80°C - 90°C, and more preferably a temperature of 90°C. The duration of the exposure of the first solution to the banana fibers at operation 304 can be between a range of 15 - 75 min, preferably between 15 - 30 min, and more preferably a duration of 20 min.

[0064] The ultrasound irradiation that is applied at operation 404 can have a variety of characteristics. Preferably the irradiation is applied at a power range of 500W - 3000W and a frequency of 20KHz - 50KHz, preferably a power range of 1800W - 2200W and a frequency of 20KHz - 30KHZ, and more preferably a power of 2000W and a frequency of 25KHz. The ultrasound irradiation can be applied using one or more ultrasound transducers, one or more sonotrodes and / or other sources of ultrasonic irradiation.

[0065] At an operation 406, the fibers are rinsed after the applied treatment of operation 404. The rinse removes remnants of the solution used at 404, and more generally, assists in cleaning the fibers. The fibers are rinsed twice in water at operation 406. In other implementations, the fibers may be subjected to a different number of rise cycles, as described previously. At an operation 408, the banana fibers are exposed to an ionic liquid solution.

[0066] A listing of non-limiting examples regarding the ionic liquid solution of operation 408 will now be provided for teaching purposes. The ratio of water to the ionic liquid can be within 25% - 60%. During the treatment using the ionic liquid solution at operation 408, ultrasound irradiation can be applied to fibers and ionic liquid solution. This irradiation can have substantially similar characteristics as the earlier applied ultrasound irradiation at operation 402. A temperature range of the first solution at operation 408 can be within 50°C - 100°C, preferably between 80°C - 90°C, and more preferably a temperature of 80°C. The duration of the exposure of the first solution to the banana fibers at operation 408 can be within a range of 15 - 75 min, preferably between 20 - 60 min, and more preferably a duration of 30 min. The liquor ratio of the ionic solution is preferably approximately 1 :40. The use of the ionic solution should, ideally, remove much of the non-cellulose materials that are included in the fibers.

[0067] In various particular implementations, the ionic liquid solution of operation 408 can include an ionic liquid selected from one of l-ethyl-3-methylimidazolium acetate, l-butyl-3- methylimidazolium acetate, 1 -decyl-3 -methylimidazolium chloride, 1 -ethyl -3- methylimidazolium bis(triflouromethylsulfonyl)imide, and / or l-butyl-3 -methylimidazolium bis(triflouromethylsulfonyl)imide. A user skilled in the art will readily recognize a number of alternative ionic liquids that may suitably be used. In some implementations, the ionic liquid solution can be reused, the reuse of solution monitored by similar contamination metrics as described previously. After the fibers have been treated in the ionic liquid solution, they can berinsed in a slightly acidic solution (e.g., 1% acetic acid) to assist with neutralizing remaining alkalinity.

[0068] At an operation 410, the fiber product is rinsed again with water, preferably twice. In other implementations, the fibers may be subjected to a different number of rise cycles, as described previously. The fibers are further treated at an operation 412. At operation 412, the fibers can undergo a post-treatment process, such as the application of a softener, surfactant, conditioner and / or emulsion. In an example implementation, the post-treatment of the fibers at operation 412 can include a vegetable oil emulsion, a softening cationic agent and a surfactant. The vegetable oil emulsion can include castor oil, soybean oil, aloe vera and / or other oils. The concentration of the oil emulsions can be within a range of 0.5% - 2%, preferably a concentration of about 2%. The softening agent can be diethyl-ester-dimethyl-ammonium- chloride, with a concentration within a range of 0.2% - 1%, preferably a concentration of 1%. The surfactant can be sodium dodecyl sulfate with a concentration within a range of 0.2% - 0.5%, preferably a concentration of 0.5%. The post-treatment process at operation 412 can be applied at a temperature range between 20°C - 60°C, preferably around 40°C. The duration of the exposure of the fibers to the post-treatment process of operation 412 can be within a range of 15 min - 75 min, preferably 60 min. The liquor ratio can be within a range of 1 : 10 - 1 :60, and preferably approximately 1 :40. The fibers are exposed to ultrasound irradiation during the posttreatment process of operation 412, with the ultrasound irradiation having substantially similar characteristics as that administered during operation 404 and operation 408.

[0069] As with other previously described operations of process 400, the example compositions, variables, and exact values provided here in association with operation 412 are provided purely as illustrative examples and should not be considered limiting to the spirit or scope of the technology disclosed.

[0070] At an operation 414, the post-treatment fibers can be dried (and optionally carded) in preparation for use in one or more fiber applications. The fibers can be spread out and air dried, dried using an oven, dried in the outdoor environment and / or other drying method. The resultant banana fibers of the process 400 can be used in a variety of applications, including industrial and textile applications.Objective Indicia of Novelty and Non-Obviousness

[0071] Experimental data describing the properties of a natural fiber-containing nonwoven fabric, according to many implementations of the technology disclosed, are now provided as objective indicia of novelty and non-obviousness. The described natural fiber-containingnonwoven fabric can contain banana fibers or a blend of banana and other fibers or materials. In an example, the banana fibers used in the nonwoven fabric can be refined or treated, such as by using one or more of the example processes described above. Alternatively, minimally processed or raw banana fibers can be used in the nonwoven fabric, such as washed or raw banana fibers. Minimally processed banana fibers can include increased amounts of hemicellulose, lignin, waxes and / or other materials than banana fibers that have been more refined or more treated. In an example, the use of minimally processed banana fiber in a nonwoven fabric may be desirable, as the additional, non-removed materials associated with the minimally processed banana fiber can contribute to the overall characteristic(s) or properties of the nonwoven fabric and / or with the formation of the nonwoven fabric.

[0072] A nonwoven fabric composed of approximately 70% banana fiber, 20% PET, and 10% PE was subjected to standardized testing (described in further detail below), the results of which are shown in Table 3.TABLE 3

[0073] Weight and density measurements were obtained according to the ASTM D3776 standard measurement of fabric mass per unit area. Thickness measurements were obtained according to the FORD FLTM BN 023-02 standard thickness test for padding material. Tensilestrength and elongation measurements were obtained according to the ASTM D461-87 standard test methods for felt, including measurements for both the machine direction (MD) and transverse direction (CD). Flammability measurements were obtained according to the FMVSS 302 standard for flammability of interior materials, including measurements for both the machine direction (MD) and transverse direction (CD). Thermal transmission measurements were obtained according to the ASTM C518 standard test method for steady-state thermal transmission properties, including both a thermal resistance R-value and a thermal conductivity (heat transfer) coefficient. Acoustic performance measurements were obtained according to the ASTM El 050 standard test method for impedance and absorption of acoustical materials.

[0074] The nonwoven fabric containing banana fibers subjected to testing, with results shown above in Table 3, was formed using an airlay process. In other implementations, the nonwoven fabric may be formed using alternative processes including staple, melt-blown, spunbond, spunlace, flashspun, bonding, and others readily recognizable to a user skilled in the art.

[0075] In addition to the aforementioned acoustic insulation properties, the disclosed banana fiber-containing nonwoven fabric may possess additional properties (e.g., improved durability, flame resistance, flame retardance, etc.) allowing the nonwoven fabric to be used in a variety of applications with unique requirements. Example applications for such nonwoven fabrics can include manufactured materials for buildings, vehicles, or home furnishings; transport or shipping materials; insulation material; pulping in the paper industry; sorbent use cases (e.g., oil absorption); fashion and apparel; bioremediation use cases; food-grade packaging; and so on. In many implementations, the banana fiber-containing nonwoven fabric can have increased flame retardancy or decreased flammability.Particular Implementations

[0076] Some particular implementations and features for the technology disclosed are described in the following discussion.

[0077] Many implementations of the technology disclosed relate to systems and methods for processing banana fibers. Other implementations relate to systems and methods for processing other classes of natural fibers, such as cotton fiber, hemp fiber, flax fiber, agave fiber, and so on. Many implementations also relate to nonwoven fabrics containing natural fibers.

[0078] In many disclosed implementations, the nonwoven fabric can include a non-zero percentage composition of banana-derived fibers (such as unprocessed, processed, and / or refined banana fibers) and the remaining composition can be the synthetic fiber(s). The fibers can bearranged or formed into a product using one or more methods, such as those previously described, including airlay processing.

[0079] In one implementation, the nonwoven fabric comprises some non-zero percentage of natural fibers derived from a single source. In another implementation, the nonwoven fabric comprises a blend of natural fibers from multiple sources. The remaining percentage of the nonwoven fabric composition may include a synthetic fiber or blend of synthetic fibers, such as polyesters (PET, PTT, or PBT), olefines (PE, PP, or HDPE), nylon, aramides, acrylates, biosynthetics (Modal or Viscose), etc. In one implementation, the nonwoven fabric can include a percentage of natural fiber composition within the range of 50-90% of the nonwoven fabric. In another implementation, the percentage of natural fiber composition can be within the range of 60-80% of the nonwoven fabric.

[0080] One disclosed method relates to the processing of banana fibers leveraging a reverse wet process. The method can comprise soaking decorticated banana fibers in a solution containing sodium hydroxide (NaOH) and one or more of peroxide and hypochlorite, washing the fibers with clean water, treating the fibers with a caustic solution of NaOH, washing the fibers with clean water a second time, treating the fibers with a post-treatment solution, and washing and drying the fibers for processing through a carding technique. The process of soaking decorticated banana fibers in a solution containing NaOH and one or more strong oxidizers can result in cleaning and / or bleaching of the fiber. The post-treatment solution can comprise a vegetable oil emulsion, a softening cationic agent, and a surfactant. In some implementations, no carding technique is used.

[0081] The decorticated banana fibers can, for example, have a length in the range of 2 inch to 30 inches long. The banana fibers may be less than 1 inch, and banana fibers at 1.5 inches long can be used for various nonwoven textiles. Decorticated fibers may be, for example, approximately 48 inches long with a variability of 12 - 24 inches. Chopped fibers may have a smaller range of lengths, such as lengths less than 1 inch to 6 inches or more. For example, fully wet processed (i.e., a reverse wet, ionic, or ultrasound process) fibers can be applied to fabric applications at lengths of 5 mm. Fibers in the length range of 2 - 1800 mm can be used, for example, for applications such as medical fabrics and make-up wipes. Fibers in the length range of 38 - 154mm can be used, for example, for yam spinning or nonwoven fabrics. Fibers with a length up to 1800 mm can be used for hair extensions. The first NaOH solution for soaking may have a concentration in the range of 2 - 10%. The peroxide of the soaking solution may have a concentration in the range of 0.2 - 1.5%. The hypochlorite solution may have a concentration in the range of 0.1 - 1%. The soaking process can be performed at a liquor ratio of 1 : 10, 1 :20, or1 :40. The soaking process may also be performed at a temperature between 60 - 100 °C for a duration in the range of 20 - 60 minutes. The soaking process can be performed with a solution comprising NaOH at a concentration of 4%, an oxygen peroxide concentration of 0.5%, and a hypochlorite concentration of 0.25%, for example (but may be performed with differing ratios of concentrations). The soaking process can be performed at a liquor ratio of 1 :40, a temperature of 80 °C, and an incubation duration of 20 minutes, for example.

[0082] The second NaOH solution (caustic solution) of the treatment step can have a concentration in the range of 5 - 10%. The treatment with the caustic solution of NaOH can be performed at a temperature between 60 - 100 °C for a duration in the range of 20 - 60 minutes. The treatment with the caustic solution of NaOH can be performed at an NaOH concentration of 10%, a temperature of 80 °C, and an incubation duration of 30 minutes, for example.

[0083] The vegetable oil emulsion is selected from a group consisting of castor oil, soybean oil, and aloe vera. The vegetable oil emulsion may have a concentration in the range of 0.5 - 2%. The softening cationic agent can be diethyl ester dimethyl ammonium chloride, and the concentration of the softening cationic agent may have a concentration in the range of 0.2 - 1%. The surfactant can be sodium dodecyl sulfate, and the concentration of the surfactant can be 0.5%. Treatment with the vegetable oil emulsion, softening agent, and surfactant can be performed with a concentration of 2% for the vegetable oil emulsion, a concentration of 0.5% for the softening cationic agent, and a concentration of 0.5% for the surfactant example (but may be performed with differing ratios of concentrations).

[0084] The resultant fiber product can undergo washing and drying operations using techniques such as air-drying, oven-drying, and / or sun-drying. The resultant banana fiber product may comprise a reduced hemicellulose content and / or a reduced lignin content that is suitable for textile and industrial applications. In contrast to other methods of processing natural fibers, such as banana fibers, the disclosed methods have a reduced environmental impact, wherein environmental impact is measured by one or more of a water consumption, a usage of a toxic or hazardous chemical, a production of microplastics, release of greenhouse gas emissions, and / or the byproducts and waste generated as a result of one or more operations associated with the processing of the fibers.

[0085] Another disclosed method relates to the processing of banana fibers leveraging an ultrasound-assisted process. The method can comprise soaking decorticated banana fibers in a solution containing sodium hydroxide (NaOH), applying ultrasound irradiation to the solution using an ultrasonic reactor or an ultrasonic bath, washing the fiber and extracting the liquid, bleaching the fiber with a strong oxidizer, washing the fiber with a castor oil emulsion solutionand textile softeners, and drying the fiber for processing through carding. The decorticated banana fibers can have a length ranging from two to thirty inches. The NaOH solution has a concentration ranging between 2% to 10% and a liquor ratio of 1 :5, 1 : 10, or 1 : 10. The ultrasound irradiation can be applied at a power ranging between 500 to 3000 watts and a frequency between 25 kHz to 40 kHz. The ultrasound irradiation can be applied for a duration ranging from 15 minutes to 2 hours, and can be applied at a temperature in the range of 60 to 100 degrees Celsius. The ultrasonic reactor can be equipped with a high efficiency sonotrode (e.g., a Cascatrode®). The strong oxidizer can be at least one of a hypochlorite or oxygen peroxide. The hypochlorite solution for bleaching can have a concentration in the range of 0.5 - 2%. The textile softener can be a cationic textile softener, such as diethyl ether dimethyl ammonium chloride. The diethyl dimethyl ammonium chloride is used in a 0.5% solution. The castor oil emulsion solution and the textile softener can be emulsified using a surfactant, and the surfactant used can be sodium dodecyl sulfate (SDS) at a concentration of 0.2%. The drying step can be carried out using a suitable drying method, such as air-drying, oven-drying, or sun-drying.

[0086] It is to be understood that the preceding description is presented to enable the use of the disclosed system and methods, but a user skilled in the art will recognize that many variations and similar components can be used for the same purpose without deviating from the scope of the technology disclosed.

[0087] Some implementations relate to a system, comprising one or more components, configured to perform one or more operations of the methods disclosed herein arranged in various permutations. A disclosed fiber treatment system may include a fiber separation unit and a fiber processing unit. In some implementations, the fiber treatment system includes a sizing unit, a post-treatment unit, a carding unit, or a combination of two or more of the sizing unit, post-treatment unit, and / or carding unit.

[0088] One disclosed method relates to an ultrasound-assisted wet process for cleaning, degumming, and separating cellulose fiber from banana stems, leveraging an ionic liquid. The method comprises treating decorticated banana fibers in a solution, applying ultrasound irradiation to that solution for a duration of 30 minutes to 2 hours at a temperature between 60 and 100 degrees Celsius, washing the fiber with clean water at 60 degrees Celsius, treating the clean fiber with a blend of water and an ionic liquid solution, applying ultrasound irradiation to the solution for a duration of 20 minutes to 1 hour at a temperature between 50 and 90 degrees Celsius, rinsing the fiber with a slightly acidic solution of acetic acid at 1% concentration, and rinsing the fiber with clean water and drying the fiber. The solution used to treat the decorticated banana fiber contains at least one or more of sodium hydroxide, hydrogen peroxide, andhypochlorite. The sodium hydroxide solution can have a concentration ranging between 2 - 10%. The hydrogen peroxide solution can have a concentration ranging between 0.2 - 1.5%. The hypochlorite solution can have a concentration ranging between 0.1 - 1%. The solution can have a liquor ratio of 1 :40. Ultrasound irradiation can be applied to the banana fibers in the solution using at least one of an ultrasound reactor, a plurality of ultrasound transducers, and an ultrasound bath. The power of the ultrasound irradiation can range from 500 to 2000 watts and the frequency of the ultrasound irradiation can range from 25 - 40 kHz. The fiber can be washed with clean water at a temperature ranging between 40 and 80 degrees Celsius. The ionic liquid solution used to treat the fiber can be blended with water to have an overall ratio of 25 - 60% water to ionic liquid. The ionic liquid used for degumming can be selected from a plurality of water-soluble ionic liquids. The ionic liquid can be selected from a group consisting of: 1-ethyl- 3-methylimidazolium acetate, l-butyl-3-methylimidazolium acetate, l-decyl-3- methylimidazolium chloride, l-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and l-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. The ultrasound irradiation applied to the cleaned fiber, along with the ionic liquid solution / water blend, can be applied at a power ranging from 500 to 3000 watts and a frequency between 25 kHz and 40 kHz. The fiber can be rinsed with an acidic solution followed by clean water. The fiber can further be treated with a vegetable oil emulsion, a softening cationic agent, and a surfactant. The vegetable oil emulsion can be selected from the group consisting of castor oil, soybean oil, and aloe vera. The clean, degummed cellulose fiber can undergo a carding operation post-processing.

[0089] The technology disclosed has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Obviously, many modifications and variations of the technology disclosed are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the technology disclosed may be practiced otherwise than as specifically described. For example, the relative quantities of the components within the disclosed composition may be varied to optimize the desired effects, additional reactants or ingredients may be added, and / or similar compounds may be substituted for one or more of the compounds described. Additional advantageous features and functionalities associated with the systems, methods, and processes of the present disclosure will be apparent from the appended claims. Moreover, those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the implementations described herein.

[0090] The method described in this section and other sections of the technology disclosed can include one or more of the following features and / or features described in connection with additional methods disclosed. In the interest of conciseness, the combinations of features disclosed in this application are not individually enumerated and are not repeated with each base set of features. The reader will understand how features identified in this method can readily be combined with sets of base features identified as implementations.

[0091] However, these implementations are explicitly listed for convenience of description and should not be considered limitations of the implementations of the technology disclosed.

[0092] The preceding description is presented to enable the making and use of the technology disclosed. One or more modifications to the disclosed implementations will be apparent, and the general principles defined herein may be applied to other implementations and applications without departing from the spirit and scope of the technology disclosed. Thus, the technology disclosed is not intended to be limited to the implementations shown but is to be accorded the widest scope consistent with the principles and features disclosed herein. The scope of the technology disclosed is defined by the appended claims.

[0093] What is claimed is:

Claims

CLAIMS1. A method for ultrasound-assisted processing of banana fibers, the method comprising: soaking banana fibers in a sodium hydroxide solution, wherein the banana fibers are de-bundled; applying ultrasound irradiation to the sodium hydroxide solution, while the banana fibers are soaking in the sodium hydroxide solution, wherein the ultrasound irradiation is applied using an ultrasonic reactor or an ultrasound bath; washing the banana fibers and extracting any remaining liquid from the banana fibers; bleaching the banana fibers with a strong oxidizing agent; washing the banana fibers with (i) a castor oil emulsion solution and (ii) a textile softener; and drying the banana fibers for post-processing comprising a carding procedure.

2. The method of claim 1, wherein a length of the banana fibers is 2 - 1800 millimeters.

3. The method of claim 1, wherein the sodium hydroxide solution has: (i) a concentration between 2 - 10% and (ii) a liquor ratio of 1 :5, 1 : 10, or 1 :20.

4. The method of claim 1, wherein applying the ultrasound irradiation further comprises: applying the ultrasound irradiation at a power level of 500 to 3000 watts and a frequency value of 25 - 40 kHz, wherein the ultrasound irradiation is performed (i) for a duration period of 15 - 120 minutes and (ii) at a temperature of 60 - 100 °C.

5. The method of claim 1, wherein the ultrasonic reactor is equipped with a high efficiency sonotrode.

6. The method of claim 1, wherein the bleaching further comprises: bleaching the banana fibers with the strong oxidizing agent (i) for a duration period of 15 - 120 minutes and (ii) at a temperature of 15 - 80 °C, wherein: the strong oxidizing agent is at least one of a hypochlorite solution and a peroxide solution, and the hypochlorite solution has a concentration of 0.5 - 2%.

7. The method of claim 1, wherein the castor oil emulsion solution has a concentration of 0.5 - 2%.

8. The method of claim 1, wherein the textile softener is a cationic textile softener comprising a solution of 0.5% diethyl ether dimethyl ammonium chloride.

9. The method of claim 1, further including emulsifying the caster oil emulsion solution and the textile softener with a surfactant, wherein the surfactant comprises a solution of 0.2% sodium dodecyl sulfate.

10. The method of claim 1, wherein the drying further comprises one or more of an airdrying procedure, an oven-drying procedure, or a sun-drying procedure.

11. A method for ultrasound-assisted processing of banana fibers to clean, degum, and separate cellulose fiber from banana stems, the method comprising: soaking banana fibers in a first solution comprising one or more of a sodium hydroxide, a peroxide, and a hypochlorite, wherein the banana fibers are de-bundled; applying ultrasound irradiation to the first solution, while the banana fibers are soaking in the first solution, wherein the ultrasound irradiation is applied using an ultrasonic reactor, a plurality of ultrasound transducers, or an ultrasound bath; washing the banana fibers with a water solution; treating the banana fibers with a second solution comprising an ionic liquid, further including applying ultrasound irradiation to the second solution, wherein the ultrasound irradiation is applied using an ultrasonic reactor, a plurality of ultrasound transducers, or an ultrasound bath; rinsing the banana fibers with a first rinse solution of 1% acetic acid and subsequently rinsing the banana fibers with a second rinse solution of water; and drying the banana fibers.

12. The method of claim 11, wherein treating the banana fibers further comprises: applying the ultrasound irradiation to the first solution (i) for a duration period of 30 - 120 minutes and (ii) at a temperature of 60 - 100 °C, wherein: the first solution comprises one or more of a sodium hydroxide solution having a concentration of 2 - 10%, a hydrogen peroxide solution having a concentration of 0.2 - 1.5%, and a hypochlorite solution having a concentration between 0.1 - 1%, the first solution has a liquor ratio of 1 :40, and the ultrasound irradiation is applied at a power level of 500 to 3000 watts and a frequency value of 25 - 40 kHz.

13. The method of claim 11, wherein the washing of the banana fibers with the water solution is performed at a temperature of 40 - 80 °C.

14. The method of claim 11, wherein treating the banana fibers with the second solution further comprises: applying the ultrasound irradiation to the first solution (i) for a duration period of 20 - 60 minutes and (ii) at a temperature of 50 - 90 °C, wherein: the second solution comprises a mixture of water and a water-soluble ionic liquid solution at a ratio of 25 - 60% water to water-soluble ionic liquid solution, and the ultrasound irradiation is applied at a power level of 500 to 3000 watts and a frequency value of 25 - 40 kHz.

15. The method of claim 1, wherein the ionic liquid is selected from a group consisting of: l-ethyl-3-methylimidazolium acetate, l-butyl-3-methylimidazolium acetate, 1 -decyl-3 -methylimidazolium chloride, l-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and l-butyl-3 -methylimidazolium bis(trifluoromethylsulfonyl)imide.

16. The method of claim 11, further comprising treating the banana fibers with a vegetable oil emulsion, a softening cationic agent, and a surfactant.

17. The method of claim 16, wherein the vegetable oil emulsion is selected from a group consisting of a castor oil, a soybean oil, and an aloe vera.

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