Method for manufacturing a nonwoven fabric material made of bacterial nanocellulose

Abstract

The present invention relates to a method for preparing a dimensionally stable hydrogel composed of bacterial nanocellulose, comprising the steps of providing a sugar-containing solution, inoculating a bacterial strain into the sugar-containing solution, culturing the solution, and washing a nonwoven material produced from the culture.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a hydrogel composed of bacterial nanocellulose, comprising the steps of providing a sugar-containing solution, inoculating a bacterial strain into the sugar-containing solution, culturing the solution, and washing the hydrogel produced in the culture, and to a nonwoven material manufactured using the above process steps.

[0002] Dimensionally stable hydrogels made of bacterial nanocellulose are known. These bacterial nanocelluloses are prepared by culturing suitable strains of bacteria in an aqueous acidic buffered nutrient medium, during which a dimensionally stable hydrogel is formed at the interface between the nutrient medium and air, which can sometimes last for several weeks. Depending on the manufacturing process, hydrogels prepared in this way meet the requirements of vegan products. These dimensionally stable hydrogels are also referred to hereinafter as "nanocellulose gels." Background Technology

[0003] Due to their structural similarity to human skin, good compatibility with the human body, and high water retention capacity, nanocellulose gels can be used, in particular, as massage sponges, towels, wet wipes, or protective films. Nanocellulose gels can be loaded during growth and configured to possess specific properties (e.g., color, taste, scent, surface structure, permeability, active substance loading). Furthermore, in-situ modification, that is, adding other additives to the nutrient medium to influence synthesis during the ongoing culture process, is known. Additionally, it is known to modify biomaterials based on bacterial nanocellulose following their synthesis (post-modification).

[0004] For this purpose, an instant powder has been developed within the scope of the present invention, which greatly simplifies the domestic production of nanocellulose gels. This powder, dissolved in water, is also suitable for subsequent filling and modification of nanocellulose. In the presence of the instant solution, the corresponding bacterial strain cultured therein initiates the growth of the 'active' nanocellulose gel of the new probiotic, which is subsequently useful for its hygienic storage and modification.

[0005] 'Microbial polymers' are bacteria, fungi, or algae.

[0006] It includes polymers produced by microorganisms such as algae. Nanocellulose is preferably synthesized by culturing microbial strains such as Gluconacetobacter, Enterobacter, Agrobacterium, Pseudomonas, and Rhizobium. In addition to Gluconacetobacter hansenii and Gluconacetobacter kombuchae, Gluconacetobacter xylinus, the bacterial strain most extensively studied and documented herein, is particularly suitable for the preparation of nanocellulose gels. Nanocellulose gels are prepared by microorganisms at the interface between a nutrient medium containing D-glucose and air. In other manufacturing processes mentioned below, sucrose in an aqueous solution is the carbon source. Bacteria extrude cellulose in the form of fibrils, and these fibrils aggregate to form fibers at the interface between the culture medium and air. This creates a three-dimensional interwoven fiber network composed of about 99% water and 1% nanocellulose.

[0007] Due to the special material properties of this biopolymer, its extremely high level of biocompatibility, structural similarity to the body's own protein-based tissues, and its diverse forms and numerous modification options, it is already being used in pharmaceuticals, medicine, cosmetics, and food chemistry. Bacterial nanocellulose is sterilizable under normal conditions and is characterized by high moisture content and mechanical stability, while its surface and consistency are described as pleasantly soft and particularly smooth. For example, in cosmetics, it is utilized in the form of face masks rich in active ingredients and vitamins. In medicine, blood vessels, implants, and wound dressings made from bacterial nanocellulose are being researched and used.

[0008] References:

[0009] K.-Y. Lee, JJ Baker, A. Bismarck: Surface functionalization of bacterial cellulose as the route to produce green polylactide nanocomposites with improved properties, Composites Science and Technology (2009);

[0010] D. Klemm, D. Schumann, F. Kramer, N. HeßM. Hornung, H.-P. Schmauder, S. Marsch: Nanocelluloses as Innovative Polymers in Research and Application. Advances in Polymer Science (2006), 205(Polysaccharides II);

[0011] H. Wang, F. Guan, X. Ma, S. Ren: Production and performance determination of modified bacterial cellulose, ShipinKeji (2009), (5), 28-31;

[0012] N. Hessler, D. Klemm: Alteration of bacterial nanocellulose structure by in situ modification using polyethylene glycol and carbohydrate additives, Cellulose (Dordrecht, Netherlands) (2009), 16(5), 899-910;

[0013] D. Klemm, D. Schumann, F. Kramer, N. HeßM. Hornung, H.-P. Schmauder, S. Marsch: Nanocelluloses as Innovative Polymers in Research and Application. Advances in Polymer Science (2006), 205(Polysaccharides II), ±49-96;

[0014] M. Seifert: Modification of the structure of bacterial cellulose by the composition of the nutrient medium in the culturing of Acetobacter xylinum (Modifizierung der Struktur von Bacteriencellulosedurch die Zusammenstellung des Nahrmediumsbei der Kultivierung von Acetobacterxylinum [EN: Modification of the structure of bacterial cellulose by the composition of the nutrient medium in the culturing of Acetobacter xylinum].

[0015] The nanocellulose gel according to the present invention, in the form of a purified nonwoven material, can be used for massage purposes and is actively used in physical therapy, complementary medicine, osteopathy, somatic therapy (also used as cooling or heating pads, massage aids, and haptic stimulants), and personal hygiene (wet wipes, refreshing tissues, probiotic towels), as a stimulant aid or protective film, for disinfection (filled with disinfectant), and for medical purposes. Furthermore, nonwoven materials made of nanocellulose gel can be used as massage gloves, towels, or as a means for applying cosmetics (lotions, creams, oils) over large areas. There is an increasing demand for nanocellulose gels that can be individually filled by the user after gel synthesis, rather than entirely. Unfilled nanocellulose gel is required for post-modification. The synthesized hydrogel must be free as much as possible of bacterial residues that may have adhered during the synthesis of the gel or been retained in the fiber mesh. In addition, other impurities, especially those harmful to health, must be at least below a limit. At the same time, since the hydrogel is an organic material, the cleaning procedure must be appropriately gentle to obtain the desired properties. The problem to be solved

[0016] Therefore, the objective of the present invention is to provide a method for manufacturing a nonwoven material consisting of bacterial nanocellulose with almost no foreign substances in the manufactured hydrogel. At the same time, the manufacturing method must be quick and easy to implement, inexpensive, and environmentally friendly.

[0017] In addition, the objective of the present invention is to provide a dimensionally stable hydrogel made of bacterial nanocellulose that can be manufactured in a fast, inexpensive, and environmentally friendly manner with almost no foreign substances. means of solving the problem

[0018] This objective is achieved by a method for manufacturing a nonwoven material composed of bacterial nanocellulose according to claim 1. Beneficial embodiments of the present invention are described in dependent claims. Specific details for implementing the invention

[0019] A method for manufacturing a nonwoven material composed of bacterial nanocellulose consists of four process steps: In the first process step, a sugar-containing solution is provided. Fructose or sucrose can act as a carbon source, and in the case of the simplest glucose, crystalline D-glucose is dissolved in water with sodium hydrogen phosphate and citric acid in an aqueous and acid-buffered nutrient medium at a concentration of, for example, 2% to 20% by weight. This results in a pH value buffered in a weakly acidic range. In the second process step, the sugar-containing solution is inoculated with a bacterial strain. The nanocellulose gel is preferably synthesized using microbial strains such as Gluconacetobacter, Enterobacter, Agrobacterium, Pseudomonas, and Lysphobium. In addition, a strain of the bacterium Gluconacetobacter xylinus, known as Komagataeibacter xylinus, is particularly suitable for the preparation of nanocellulose gels. Additionally, usable bacterial strains include Gluconacetobacter kombucha, Komagataeibacter hansenii, Gluconobacter oxidans, Saccharomyces ludwigii, Saccharomyces apiculatus, and Saccharomyces cerevisiae. In the third process step, the solution is cultured; that is, conditions are created and maintained to ensure that the bacteria can metabolize nutrients. Culture takes place for a period of 2 to 25 days. Dimensionally stable hydrogels are produced by microorganisms at the interface between air and a nutrient medium. Bacteria extrude cellulose in the form of fibrils, and these fibrils aggregate to form fibers at the interface between the culture medium and air. This creates a three-dimensional interwoven fiber network consisting of about 99% water and 1% nanocellulose.In the fourth process step, the hydrogel produced through the culture process is washed to obtain a purity level harmless to health. According to manufacturing processes using various culture media and bacterial strains, the cultivation of bacterial nanocellulose induces impurities, which are treated in the purification process step after cultivation. Such process steps are necessary to utilize bacterial nanocellulose as a fillable carrier for use in nonwoven materials, raw materials, molded bodies, or on the skin.

[0020] Additional components for selective filling or alternative culture of the hydrogel include an organic acid selected from the group consisting of gluconic acid, glucuronic acid, dextrorotatory (L+) lactic acid, tartaric acid, folic acid, oxalic acid, usnic acid, succinic acid, malic acid, malonic acid, and citric acid, at a concentration of 0.1% to 5% by weight, and additionally include trace elements (e.g., potassium, calcium, copper, zinc, manganese, cobalt) at a concentration of 1 ppm to 100 ppm. In addition, the solution may include at least one vitamin (e.g., vitamin B1, vitamin B2, vitamin B3, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E, vitamin K).

[0021] According to the present invention, a hydrogel produced by a culture process is cleaned in an alkali containing 5% to 50% by weight of alkali for 5 minutes to 400 minutes at a temperature of 37°C to 142°C. The temperature interval for the cleaning procedure is preferably 90°C to 142°C, particularly preferably 100°C to 142°C. The duration of the cleaning procedure is preferably 60 minutes to 400 minutes, and more preferably 120 minutes to 400 minutes. The hydrogel produced by this method according to the present invention can be cleaned very easily due to its surface structure and is particularly insensitive to cleaning agents (soap, dishwashing detergent, etc.) that are used on the skin in its pure synthetic form. The hydrogel can be boiled in water or sterilized with hot steam without deformation and can be washed in a dishwasher. Therefore, the hydrogel is reusable and completely biodegradable when properly disposed of.

[0022] In an improved embodiment of the present invention, the alkali is a 5% to 50% by weight solution of caustic soda (sodium hydroxide). Caustic soda solution, i.e., an aqueous solution of NaOH (sodium hydroxide), is available and inexpensive as it is a standard material in the chemical industry. Since NaOH is a solid in its pure state, it is easy to transport. It can be easily disposed of by neutralizing it with an acid or by diluting it sufficiently strongly. Cleaning with a caustic soda solution at a concentration and duration suited to the strength and properties of the hydrogel makes the cell structure of the hydrogel more flexible, soft, and smooth without significantly reducing stability and water retention capacity as intended.

[0023] In further development of the present invention, relative movement occurs between the cleaning solution and the hydrogel during the cleaning process. Due to this relative movement, impurities attached to or embedded in the hydrogel are removed more quickly and thoroughly than in a static cleaning process.

[0024] In another embodiment of the present invention, the cleaning procedure is carried out in two stages. The two stages of the cleaning procedure differ particularly in the concentration of the cleaning solution, the temperature of the cleaning solution, and the duration of the cleaning procedure, or in at least one of the mentioned parameters. In the first stage (preliminary cleaning), a 40 wt% to 50 wt% caustic soda solution is used at a temperature 15°C or lower than the boiling point of the caustic soda solution used. The boiling point of a 45 wt% caustic soda solution is 142°C. The duration of the first stage of the cleaning procedure is 1 minute to 150 minutes, preferably 100 minutes to 140 minutes. In the second stage, a cleaning solution with a lower concentration, a lower temperature, and a longer duration is used. The concentration of the caustic soda solution is in the range of 0.4 wt% to 8 wt%, and the temperature is 37°C to 100°C, which is lower than the boiling point of the cleaning solution used. The duration is 1 hour to 400 minutes.

[0025] In an improved embodiment of the present invention, the cleaning solution is replaced between the first and second steps of the cleaning procedure. When the cleaning procedure is performed with the same cleaning solution, it is reasonable to replace the solution to reduce the concentration of unnecessary foreign substances.

[0026] In a beneficial embodiment of the present invention, following the cleaning procedure, multiple rinsing with distilled water at 80°C for 30 to 120 minutes and sterilization (of the hydrogel) are optionally performed. The cleaning procedure may optionally be completed with sterilization to kill other microorganisms and ensure the shelf life of the packaging to the maximum extent. Sterilization may be performed in an autoclave.

[0027] In an improved embodiment of the present invention, the sterilization is performed using high-temperature steam. The cleaning procedure may optionally be completed with high-temperature steam at, for example, 121°C for 20 minutes to kill other microorganisms and ensure the longest possible shelf life in the packaging. Sterilization may be performed at least partially in an autoclave.

[0028] In addition, the objective of the present invention is achieved by a nonwoven material made of a hydrogel according to claim 8.

[0029] The nonwoven fabric material according to the present invention, made of bacterial nanocellulose, has a moisture content of 80% to 99.5% by weight and a cellulose content of 0.5% to 20% by weight. According to the present invention, the nonwoven fabric material has a foreign substance content of 0.1% to 15% by weight. In the context of this specification, the foreign substance is an unusual component that is intentionally or unintentionally a component of the nonwoven fabric material.

[0030] In an improved embodiment of the present invention, foreign substances include impurities and fillers. Impurities are unintended components and are mostly removed from the nonwoven material during the washing process. On the other hand, fillers are intentional components and are applied to and introduced into the nonwoven material during or after the synthesis process of the nonwoven material. Such nonwoven materials can be found, for example, in the form of skin pads and active ingredient carriers in cosmetics fortified with active ingredients and vitamins.

[0031] Depending on the bacterial strain, nutrient medium, culture temperature and duration, and other parameters, the nonwoven material may contain various proportions of the corresponding nutrient solution and may include various acids and chemical additives, yeast, vitamins, or organic residues (e.g., from plants such as tea, flowers, fruits, or coconut). In certain cases, such as when the nonwoven material is filled with an active acidic-probiotic (see kombucha culture) or an active plant component (equivalent to CBD from in-situ cannabis instead of post-modification), this may be desirable.

[0032] In a further embodiment of the present invention, the impurity has a content of 0.05% to 1% by weight. In a further configuration of the present invention, the impurity has a content of 0.1% to 0.5% by weight. In a further embodiment of the present invention, the impurity contains one or more substances from the group consisting of the aforementioned acids, trace elements, yeast, vitamins, and organic or inorganic coloring particles, probiotics, antifungals, disinfectants, alcohols, aloe vera, hyaluronic acid, essential oils, extracts from leaves, roots and fruits, skin particles, or body fluids (after use on the skin).

[0033] In another embodiment of the present invention, the impurities include biological impurities and / or chemical impurities. The use of Gram-negative bacterial strains during the synthesis of the nonwoven fabric material entails a risk of contamination of the final product, namely, endotoxin from the degradation products of the bacterial outer cell membrane, which can cause undesirable reactions in the human body. These exist only in harmless concentrations in the nonwoven fabric material according to the present invention.

[0034] The manufacturing method according to the present invention also optionally comprises the following steps:

[0035] A step of forming a buffer pH between pH 4 and pH 7 by dissolving crystalline glucose, sodium hydrogen phosphate, and citric acid in water at concentrations between 2% and 20% by weight in a flat-bottomed container; a step of introducing a dry mixture of peptone and yeast extract, each having a concentration between 0.1% and 5% by weight, into the buffered aqueous solution; a step of stirring the solution until the peptone is completely dissolved and the yeast extract is completely suspended; a step of sterilization by autoclaving at 121°C for 20 minutes; a step of inoculating the bacterium Gluconacetobacter xylinus; a step of culturing the solution for 2 to 25 days until a hydrogel is formed at the interface between the nutrient medium and air; a step of decanting the aqueous solution; a step of washing and purifying the hydrogel; and then, optionally, immersing the hydrogel in an aqueous solution containing a dye, fragrance, perfume, and active ingredient for 30 minutes to 30 days, and finally, at a high temperature Steam sterilization step.

[0036] In another method, instead of adding glucose, peptone, yeast, sodium hydrogen phosphate, and citric acid, it is carried out in the following steps:

[0037] A step of introducing a powder containing 2-10% by weight of black tea, green tea and / or hemp tea extract, 90-98% by weight of sucrose and / or glucose, fruit or vegetable powder, dried leaves and flowers, dried herbal flavoring, and 1-5% by weight of an active ingredient.

[0038] Inoculation is carried out by adding one or more dried microorganisms selected from the group consisting of Gluconacetobacter xylinus, Gluconacetobacter kombuchae, Comagataibacter hanseni, Gluconobacter oxidans, Saccharomyces rudwig, Saccharomyces apiculatus, or Saccharomyces, or a liquid solution containing them. In addition, one or more other organic acids selected from the group consisting of gluconic acid, glucuronic acid, right-rotating (L+) lactic acid, tartaric acid, folic acid, oxalic acid, usnic acid, succinic acid, malic acid, malonic acid, and citric acid are added at a concentration of 0.1% to 5% by weight. The sum of the weight-based ratios of the components is 100% by weight.

[0039] Alternatively, instead of introducing glucose, peptone, yeast, sodium hydrogen phosphate, and citric acid, the following step may be performed: introducing a solution of 300g of white refined beet sugar or sugarcane sugar and 120ml of concentrated anhydrous acetic acid into 2L of coconut water.

[0040] In an additional configuration of the process, instead of introducing glucose, peptone, yeast, sodium hydrogen phosphate, and citric acid and inoculating with Comagataibacter xylinus, the following step is carried out:

[0041] Steps for introducing a solution of 5g of dried cannabis flowers or leaves boiled in 1000ml of water with the addition of 1 teaspoon of coconut oil for 60 minutes, step of adding 100g of sugar (white refined beet sugar or sugarcane sugar), step of cooling to room temperature, and step of introducing 250ml of acidic kombucha tea (pH 2.2~pH 3.5) containing an active kombucha culture (e.g., living Gluconacetobacter kombucha).

[0042] A set for using one of the aforementioned manufacturing processes comprises 2% to 10% by weight of black tea, green tea and / or hemp extract, 90% to 98% by weight of sucrose and / or glucose, fruit or vegetable powder, dried leaves and flowers, dried herbal flavorings and active ingredients, and 1% to 5% by weight of at least one type of dried microorganism selected from the group consisting of Gluconacetobacter xylinus, Gluconacetobacter kombuchae, Comagataibacter hanseni, Gluconacetobacter oxidans, Saccharomyces ludwiggii, Saccharomyces apiculatus or Saccharomyces cerevisiae.

[0043] The above set also has one or more other organic acids selected from the group consisting of acetic acid, gluconic acid, glucuronic acid, dextrous (L+) lactic acid, tartaric acid, folic acid, oxalic acid, usnic acid, succinic acid, malic acid, malonic acid, and citric acid, at a concentration of 0.1% to 5% by weight. In this case, the sum of the weight-based ratios of the components is 100% by weight. The above set is configured such that the pH value in an aqueous solution is 3.5 to 7.

[0044] A method for producing bacterial nanocellulose using a dry instant mixture or the two-component solution described below is novel. Important manufacturing parameters are standardized herein, resulting in very simple and planable results. Furthermore, since this method eliminates the process steps of brewing and cooling tea and maintains a constant mixing ratio between the components, it can be used in the food sector (such as kombucha beverages) or textiles (manufacturing of bacterial nanocellulose-based vegan leather or fabrics). The instant mix offers significant simplicity, particularly for home users.

[0045] Kombucha, a traditional domestic brewing and fermentation culture, is often seen as an undefined culture but generally contains a desirable probiotic composition of bacterial and yeast strains. However, this can vary significantly due to the nature of wild fermentation. Known components include Gluconoacetobacter xylinus, Gluconoacetobacter kombucha, Gluconoacetobacter hanseni, Acetobacter xylinoides, Gluconobacter oxidans, Saccharomyces rudwigie, Saccharomyces apiculatus, and Saccharomyces cerevisiae.

[0046] Organic acids must be prepared using acetic acid, gluconic acid, glucuronic acid, dextrous (L+) lactic acid, tartaric acid, folic acid, oxalic acid, usnic acid, and trace amounts of succinic acid, malic acid, malonic acid, and citric acid. Trace elements and minerals include iron, magnesium, sodium, potassium, calcium, copper, zinc, manganese, cobalt, and other minerals.

[0047] The list of vitamins includes Vitamin B1, Vitamin B2, Vitamin B3, Vitamin B6, Vitamin B12, Vitamin C, Vitamin D, Vitamin E, and Vitamin K. It also includes various amino acids, enzymes, tannins, enzyme invertase, amylase, catalase, saccharase, rennet and proteolytic enzymes, antibiotics, alcohol, and carbonic acid.

[0048] Kombucha bacterial cultures possess special characteristics that allow them to assert themselves against foreign bacteria threatening the system in sufficiently acidic liquids. When provided with nutrients, natural dyes, active ingredients, and flavors, the growing bacterial cellulose acquires additional properties such as high water absorption (approximately 99% water, 1% cellulose) and water retention capacity.

[0049] The active nanocellulose gel contains live probiotic strains of bacteria; in the passive nanocellulose gel, the bacterial strains were killed and removed by a purification process step, and the hydrogel was sterilized by autoclaving (121°C steam for 15-20 minutes) or an electron beam process.

[0050] A combination of 250 ml of acidic kombucha tea ["FairmentKombucha - Original" pH 2.5-2.8] or a nanocellulose gel strain defined by an appropriate active bacterial culture (pH 2.2-3.5) and 25 g of instant powder is suitable for producing one or more kombucha-based nanocellulose gels with a total mass of more than 50 g in 2-25 days under hygienic conditions and with oxygen supply. The inorganic properties of the kombucha-based nanocellulose gel are similar to those of the synthetic biopolymer mentioned above.

[0051] The liquid byproduct is an acidic tea solution (pH 2.3-4) of a conventional kombucha composition of bacterial and yeast cultures having proportions of organic flavors, dyes, fragrances, and active ingredients (from fruit or vegetable, tea, herbal flavors, and active ingredients according to the composition of instant powders). This solution is suitable for inoculation and dyeing, as well as for the storage, modification, and maintenance of nanocellulose gels. It can be used to activate manual nonwoven materials sterilized by probiotic culture.

[0052] Due to the high water absorption rate and the ability to release moisture under mechanical shock, the weight specifications are highly variable and can be used only as a guide in this invention. Growth is also critically influenced by the container. Shape, surface, fill level, and material are factors that determine the characteristics. Ceramic, plastic, and glass containers are most suitable for growing nanocellulose gels at home.

[0053] In addition to the synthesized passive nanocellulose nonwoven material and probiotic active hydrogel, there is a third process for producing a coconut-based nanocellulose gel, which in turn has material properties similar to the nanocellulose gel mentioned above and can be filled in-situ or subsequently. Here, the production process of fermentation in a culture of 2 to 25 days is suitable, and the nutrient medium (pH 2.3 - 3.5) is composed as follows: namely, 120 ml of concentrated acetic anhydride (glacial acetic acid), 300 g of sugar [Naturata Bio-Beet Sugar] (white sugar, refined sugar, or raw sugarcane sugar), 300 ml of Nata Starter (bacterial strain Gluconacetobacter xylinus), alternatively kombucha starter or unpasteurized kombucha beverage ["FairmentKombucha - Original"] may be used, and 2 liters of coconut water ["Coco Juice Pure Organic"].

[0054] A fourth variation for producing bacterial nanocellulose involves using medicinal cannabis. For this purpose, a nutrient solution is prepared by boiling 5g of cannabis leaves or flowers in 1 liter of water and 1 teaspoon of coconut oil for 60 minutes, and adding 100g of sugar [Naturata Organic Beet Sugar] (white, refined, or raw cane sugar). Adding 250ml of acidic kombucha tea [FairmentKombucha - Original pH 2.5-2.8] or a defined nanocellulose gel strain (pH 2.2-3.5) initiates the production of nanocellulose containing effective cannabinoids, in addition to the properties mentioned above. There are many receptors for cannabinoids in the skin and mucous membranes. For example, cannabidiol (CBD), a medically active ingredient, can increase sensitivity by promoting blood circulation within tissues.

[0055] Nanocellulose gels produced in various ways are preferably used in the following product variations: wet wipes or protective films with dimensions of 150-300mm x 150-300mm and a thickness of 0.1-3mm have a drainage net weight of 12-180g. Towels (or massage sponges or tactile stimulators) with dimensions of 120-180mm x 120-180mm and a thickness of 3-10mm have a drainage weight of 60-180g.

[0056] Two construction methods (rounded corners, or grown or cut into a rectangular shape) can be combined with glass or plastic cylinders that can be filled with hot water or skin care products. Laundry gloves are formed by combining two pieces of cloth (e.g., square, rectangular, hand-shaped, etc.) that can be cut, sewn, folded, or pressed in a manner similar to fabric.

[0057] As a material unit for individual additional processing, the nonwoven material has a length of 150-400 mm and a width of 120-300 mm when not rolled. In the rolled form, a cylindrical shape with an outer diameter of 30-120 mm and a net weight of 100-1200 g is obtained depending on a specific length and material thickness (0.5-25 mm). In the rolled form, a cylindrical shape with an outer diameter of 30-120 mm and a net weight of 100-1200 g is obtained depending on a specified length and material thickness (0.5-25 mm). The size specifications vary because all products are industrially assembled and can also be individually adapted to consumer requirements. Foldable and rolled flaps (e.g., circular, oval, rectangular, square, diamond-shaped, triangular) with varying thicknesses depending on the fermentation period, temperature, and addition of nutrients can be manufactured by culturing in containers of suitable shape made of glass or food-safe plastic. Various components such as cylinders, hose-shaped covers, and protectors may also be designed using the described process by utilizing suitable devices and containers.

[0058] Shapes from solidly grown blocks or thin films can be modeled using cutting and milling tools (knife, scissors, die cutter, laser, hole punch) or 3D printing processes that do not result in purely organic growth. This results in a large number of different components in modular systems.

[0059] These nanocellulose gel components can be connected to each other using rubber bands, cords, cuffs, rings, clamps, staples, or sewing techniques. They can be combined to provide shape and stability to containers such as massage tools, bags, glasses, bottles, or tubes, or to be used for storage.

[0060] Tools such as templates made of plastic, glass, cork, etc., can be used in culture to form bacterial nanocellulose gels growing on a surface while still growing. This can represent the final shape or individual components for specific designs of more complex nanocellulose gel-based models. Using lasers, stamping irons, embossing tools, and branding irons, model numbers, production dates, or other information can be provided or designs can be applied to objects made of bacterial nanocellulose.

[0061] The reduction of plastic waste and the use of non-renewable materials represent ecological opportunities for the growth of technology when applied to the skin. The potential for resource-saving individual domestic production and the availability of choices in various production processes to access locally produced and readily available raw materials on an industrial scale mean that packaging, shipping routes, and associated emissions can be avoided.

[0062] The ideal purification duration based on culture and NaOH concentration depends on the exact composition of the nutrients and bacteria used, regardless of whether it is a complex, hybrid, or pure culture.

[0063] In one embodiment of the method according to the present invention, a single-step purification method is used. For each millimeter of thickness of the nonwoven material, 85 in 100 ml of a 0.8 wt% NaOH solution per cubic meter (cm³) of cellulose Exposure for 2 hours ensures that all bacterial activity in all mentioned processes is reliably stopped. Depending on the desired purity, this process step can be repeated by replacing the sodium hydroxide solution or run in a dynamic flow until the NaOH solution absorbs no or only a small amount of detectable impurities from the prepared cellulose. The nonwoven material is then rinsed with distilled water and, depending on the intended use, the pH is adjusted to a desired value between pH 4 and pH 7, preferably to a skin-neutral pH of about 7, so that it can be easily readjusted later by appropriate filling. Optionally, citric acid may also be used in addition to distilled water in this neutralization step.

[0064] The nonwoven material cleaned in this manner contains 8 wt% (intended) filler and 1.5 wt% impurities. Purification kills other microorganisms and ensures the longest possible shelf life in the packaging, for example, 121 It can be optionally completed by sterilization with high-temperature steam for 20 minutes.

[0065] For optimal shelf life for retailers, packaging should ideally be vacuum-sealed with an impermeable film without an air supply to the liquid (distilled water or filling solution); for sustainability, bacterial nanocellulose should be vacuum-sealed in reusable and lockable cylindrical containers or in water-repellent or waterproof packaging for later expansion.

[0066] In an additional embodiment of the one-step cleaning process, the nonwoven material is 45 wt% NaOHIt is washed with a solution at 110°C for 240 minutes. The amount of NaOH solution is 100 ml per cubic meter of cellulose. After washing, the nonwoven fabric is also rinsed with distilled water and optionally citric acid. The nonwoven fabric washed in this way contains 9.5% by weight of filler and 0.8% by weight of impurities.

[0067] In a further embodiment of the method according to the present invention, a two-step cleaning method is used. In the first step (pre-cleaning), an NaOH solution containing 50 wt% NaOH is used, the operating time is 135 minutes, and the temperature is 127°C. In the second cleaning step, the nonwoven fabric material is cleaned with an 8 wt% NaOH solution at a temperature of 85°C for 240 minutes. The nonwoven fabric material cleaned in this way contains 10.5 wt% of filler and 0.27 wt% of impurities.

Claims

Claim 1 A method for preparing a hydrogel composed of bacterial nanocellulose, comprising the following steps: - providing a sugar-containing solution; - inoculating the sugar-containing solution with a bacterial strain selected from Gluconacetobacter, Enterobacter, Agrobacterium, Pseudomonas, or Rhizobium; - culturing the solution; and - washing the hydrogel produced in the culturing step, wherein the washing step comprises a first step (preliminary washing) and a second step, wherein in the first step (preliminary washing), a caustic soda solution of 40% to 50% by weight is used, the temperature is at least 15°C lower than the boiling point of the caustic soda solution, and the washing is sustained for 1 minute to 150 minutes; wherein in the second step, the concentration of the caustic soda solution used is lower, the temperature is lower, and the washing A method for preparing a hydrogel composed of bacterial nanocellulose, characterized in that the duration is longer, wherein the concentration of the caustic soda solution is in the range of 0.4% by weight to 8% by weight, the temperature is 37°C to 100°C, and the washing is sustained for 1 hour to 400 minutes. Claim 2 A method for manufacturing a hydrogel according to claim 1, characterized in that relative movement between the cleaning solution and the hydrogel occurs during the cleaning procedure. Claim 3 A method for manufacturing a hydrogel according to claim 2, characterized in that the cleaning solution is replaced between the first and second steps of the cleaning step. Claim 4 A method for manufacturing a hydrogel according to claim 1, characterized in that sterilization is performed after the above-mentioned cleaning procedure. Claim 5 A method for manufacturing a hydrogel according to claim 4, characterized in that the sterilization is performed with steam. Claim 6 A nonwoven fabric material made of a hydrogel, wherein the hydrogel is manufactured by the manufacturing method of claim 1, the hydrogel comprises moisture and cellulose with a content of 0.5% to 20% by weight, the nonwoven fabric material has a foreign substance content between 0.01% and 15% by weight, the foreign substance contains impurities and fillers, and the impurities have a content of 0.01% to 2% by weight. Claim 7 A nonwoven fabric material made of a hydrogel according to claim 6, characterized in that the above-mentioned impurities have a content of 0.05% to 1% by weight. Claim 8 A nonwoven fabric material made of a hydrogel, characterized in that, in claim 6, the above-mentioned impurities have a content of 0.1% to 0.5% by weight. Claim 9 A nonwoven material made of hydrogel according to claim 6, characterized in that the impurities include biological impurities and / or chemical impurities. Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete