KR102844369B1 - Multifunctional eco-friendly lightweight fabric for bags and method of manufacturing the same - Google Patents

Abstract

The present invention relates to an eco-friendly lightweight fabric for bags with improved durability and a method for manufacturing the same, comprising the steps of: (a) producing a base fabric by mixing regenerated synthetic fibers and natural-based fibers; (b) performing a durability-enhancing treatment on the base fabric; (c) applying a functional eco-friendly coating to the base fabric subjected to the durability-enhancing treatment; (d) performing a surface modification treatment on the base fabric to which the functional eco-friendly coating has been applied; (e) a functional material injection step; (f) a microstructure formation step; and (g) a photoactivation treatment step. The manufacturing method according to the present invention can contribute to the development of a sustainable textile industry by providing a lightweight fabric for bags that is both eco-friendly and highly functional.

Description

Multifunctional eco-friendly lightweight fabric for bags and method of manufacturing the same

The present invention relates to a lightweight fabric for an eco-friendly bag and a method for manufacturing the same, and more particularly, to a method for manufacturing an eco-friendly lightweight fabric for a bag with improved durability and various functionalities by applying a multi-stage treatment process to a base fabric manufactured by mixing regenerated synthetic fibers and natural-based fibers.

With growing concern for environmental protection, demand for eco-friendly materials and manufacturing processes is rapidly increasing in the textile industry. Bag fabrics, in particular, are widely used in everyday life and require a variety of properties, including durability and functionality, in addition to environmental friendliness.

Traditional bag fabrics have primarily been made from petroleum-based synthetic fibers like nylon and polyester. While these fabrics offer excellent durability and a variety of functionality, they also contribute to environmental pollution and resource depletion. As an alternative, eco-friendly fabrics made from natural or recycled fibers have been developed. However, these fabrics have limitations in durability and functionality, hindering their practicality.

Furthermore, existing methods for manufacturing bag fabrics have struggled to simultaneously achieve both environmental friendliness and high functionality. For example, fluorine compounds used to impart waterproofing properties can be harmful to the environment, and chemicals used for antibacterial treatments can also cause environmental problems.

Furthermore, meeting the diverse functional requirements of bag fabrics (e.g., durability, water resistance, antibacterial properties, UV protection, etc.) while maintaining environmental friendliness remained a technical challenge. A key challenge was achieving these diverse functionalities through a combination of processes, rather than a single one, while ensuring the environmental friendliness of each process.

Therefore, there is an urgent need to develop a method for manufacturing lightweight fabrics for bags that utilize renewable materials while possessing superior durability and diverse functionality. Furthermore, these manufacturing methods present a technological challenge: they must be environmentally friendly while also achieving industrially applicable efficiency and economic feasibility.

Korean Patent Publication No. 10-2021-0126193 Korean Patent Publication No. 10-2017-0120448 Korean Patent Publication No. 10-2024-0050909 Korean Patent No. 10-2029416

The present invention has been devised to solve the problems of the prior art as described above, and aims to solve the following technical problems.

First, we aim to create a basic fabric that is both environmentally friendly and possesses excellent physical properties by mixing recycled synthetic fibers and natural fibers in an optimal ratio.

Second, we aim to develop fabric for bags that can be used for a long time by significantly improving the durability of the fabric through high-density weaving technology and heat-compression processes.

Third, we aim to develop an eco-friendly coating technology using biodegradable polymers and natural oils to simultaneously ensure water resistance and durability while minimizing environmental impact.

Fourth, we aim to improve the functionality of the fabric surface through plasma treatment and nanoparticle coating, while maintaining environmental friendliness during this process.

Fifth, we aim to develop a multi-functional, eco-friendly fabric that can be used hygienically and safely by effectively injecting antibacterial and UV-blocking substances.

Sixth, we aim to further improve the performance of fabrics through microstructure formation and photo-activation treatment, while also conducting these treatment processes in an environmentally friendly manner.

Seventh, we aim to develop a method for manufacturing lightweight fabric for bags that satisfies eco-friendliness, durability, and multifunctionality simultaneously by organically combining all of the above processes.

The present invention relates to a method for manufacturing a lightweight fabric for an eco-friendly bag with improved durability, comprising the steps of: (a) producing a base fabric by mixing regenerated synthetic fibers and natural-based fibers; (b) performing a durability-enhancing treatment on the base fabric; (c) applying a functional eco-friendly coating to the base fabric subjected to the durability-enhancing treatment; and (d) performing a surface modification treatment on the base fabric to which the functional eco-friendly coating has been applied.

At this time, the regenerated synthetic fiber of step (a) includes regenerated polyester, the natural-based fiber includes cellulose derivative fiber, the durability strengthening treatment of step (b) includes a high-density weaving technique and a thermocompression process, the functional eco-friendly coating of step (c) uses a mixture of a biodegradable polymer and natural oil, and the surface modification treatment of step (d) includes plasma treatment and nanoparticle coating.

In addition, at this time, (e) a step of injecting a functional material into the surface-modified base fabric; (f) a step of forming a microstructure; and (g) a step of photo-activation treatment are further included, and the functional material injection in step (e) includes a mixture of an antibacterial material and an ultraviolet ray blocking material.

In addition, at this time, the mixing ratio of the regenerated polyester and the cellulose derivative fiber in the step (a) is 67:33 to 73:27 parts by weight, the cellulose derivative fiber includes a mixture of lyocell and modal in a ratio of 2:3 to 3:2 parts by weight, the high-density weaving technology in the step (b) arranges 330 to 370 threads per inch in a three-dimensional structure, the thermal compression process is performed at 165°C to 175°C for 17 to 23 minutes at a pressure of 2.7 to 3.3 MPa, and the functional eco-friendly coating in the step (c) uses a mixture of polyhydroxybutyrate-co-valerate (PHBV) and castor oil in a ratio of 85:15 to 95:5 parts by weight, and the coating thickness is 0.035 mm to 0.055 mm.

In addition, at this time, the plasma treatment of step (d) is performed for 45 to 55 seconds using low-pressure argon-oxygen mixed plasma (argon:oxygen = 7:3 to 8:2 parts by weight), the nanoparticle coating uses a 2:1 mixture based on the weight of titanium dioxide (TiO ₂ ) nanoparticles and zinc oxide (ZnO) nanoparticles, the functional material injection of step (e) is performed using ultrasonic treatment, the antibacterial material uses 0.8 to 1.2 wt% of chitosan nanoparticles relative to the fabric weight, and the UV-blocking material uses 0.4 to 0.7 wt% of ceria (CeO ₂ ) nanoparticles relative to the fabric weight, and the ultrasonic treatment is performed for 7.5 to 8.5 minutes at a frequency of 29 kHz to 31 kHz, and the microstructure formation of step (f) is performed using femtosecond laser processing technology to form micro-nano hybrids with a depth of 0.015 mm to 0.025 mm on the surface of the fabric. The structure is formed, and has a dual structure in which nano-protrusions having a diameter of 180 nm to 220 nm and micro-protrusions having a diameter of 2.8 μm to 3.2 μm coexist in a ratio of 7:2, and the photoactivation treatment of step (g) is performed by injecting chlorophyllin, a natural photosensitizer, in an amount of 0.18 to 0.22 wt% relative to the weight of the fabric, and then irradiating the fabric for 4.5 to 5.5 minutes using a red LED (wavelength 640 nm to 660 nm) to provide additional antibacterial properties.

A device according to one embodiment may be coupled with hardware and controlled by a computer program stored on a medium to execute any one of the methods described above.

The lightweight fabric for an eco-friendly bag with improved durability and the method for manufacturing the same according to the present invention have the following remarkable effects.

First, the optimal blend of recycled polyester and cellulose derivative fibers (lyocell, modal) can simultaneously ensure environmental friendliness and superior physical properties. Specifically, blending at a weight ratio of 67:33 to 73:27 maximizes the use of recycled materials while retaining the advantages of natural fibers.

Second, the durability of the fabric is greatly improved through the high-density weaving technology that arranges 330 to 370 threads per inch in a three-dimensional structure and the heat compression process that is performed at 165°C to 175°C for 17 to 23 minutes under a pressure of 2.7 to 3.3 MPa, allowing for long-term use.

Third, by applying an eco-friendly coating with a thickness of 0.035 mm to 0.055 mm by mixing polyhydroxybutyrate-co-valerate (PHBV) and castor oil in a weight ratio of 85:15 to 95:5, waterproofing and durability can be improved while minimizing environmental impact.

Fourth, the functionality of the fabric surface is greatly improved through argon-oxygen mixed plasma treatment and titanium dioxide (TiO ₂ ) and zinc oxide (ZnO) nanoparticle coating, enabling its use in various applications.

Fifth, by injecting chitosan nanoparticles (0.8 to 1.2 wt% relative to the fabric weight) and ceria (CeO ₂ ) nanoparticles (0.4 to 0.7 wt% relative to the fabric weight), antibacterial properties and UV blocking effects are imparted, enabling hygienic and safe use.

Sixth, additional functional enhancement and antibacterial effects can be achieved through microstructure formation using femtosecond laser processing technology and photoactivation treatment using chlorophyllin.

Seventh, the overall manufacturing process can produce eco-friendly yet highly functional fabrics, contributing to the development of a sustainable textile industry. In particular, by optimizing the conditions of each process, industrial application is facilitated and economic feasibility is ensured.

Hereinafter, embodiments are described in detail with reference to the attached drawings. However, the embodiments may be modified in various ways, and the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, or alternatives to the embodiments are included within the scope of the patent application.

Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Accordingly, the embodiments are not limited to the specific disclosed form, and the scope of this specification includes modifications, equivalents, or alternatives that fall within the technical concept.

Although terms such as "first" or "second" may be used to describe various components, these terms should be interpreted solely to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

When it is said that a component is "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components in between.

The terms used in the examples are for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

In the embodiments of the present invention, unless otherwise defined, all terms, including technical or scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in the embodiments of the present invention.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters illustrated. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. When the terms “includes,” “has,” and “consists of” are used in this specification, other parts may be added unless “only” is used. When a component is expressed in the singular, it includes a case where the plural is included unless there is a specifically explicit description.

When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

The size and thickness of each component shown in the drawing are shown for convenience of explanation, and the present invention is not necessarily limited to the size and thickness of the component shown.

The individual features of the various embodiments of the present invention can be partially or wholly combined or combined with each other, and as can be fully understood by those skilled in the art, various technical connections and operations are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship.

The present invention relates to a method for manufacturing a lightweight fabric for an eco-friendly bag with improved durability, comprising the steps of: (a) producing a base fabric by mixing regenerated synthetic fibers and natural-based fibers; (b) performing a durability-enhancing treatment on the base fabric; (c) applying a functional eco-friendly coating to the base fabric subjected to the durability-enhancing treatment; and (d) performing a surface modification treatment on the base fabric to which the functional eco-friendly coating has been applied.

Step (a) above is essential to simultaneously achieve environmental friendliness and superior physical properties. Regenerated synthetic fibers (e.g., recycled polyester) allow for reduced use of petroleum-based raw materials while maintaining the superior properties of synthetic fibers. Natural-based fibers (e.g., cellulose derivative fibers) offer biodegradability and a comfortable fit. By blending these two fibers in an optimal ratio, a basic fabric can be created that achieves a balance of environmental friendliness and functionality.

Step (b) above is crucial for extending the lifespan of the fabric and enhancing its sustainability. High-density weaving technology minimizes interfiber spacing, enhancing physical strength, and the heat-compression process strengthens the interfiber bonds, significantly enhancing durability. This allows for the production of fabrics for bags that can be used for a long time, ultimately contributing to reduced resource consumption and waste generation.

Step (c) above is necessary to impart water resistance and additional durability to the fabric while minimizing its environmental impact. By using a mixture of biodegradable polymers (e.g., PHBV) and natural oils (e.g., castor oil), we can address the environmental concerns of conventional chemical coatings while still ensuring superior water resistance and durability. This plays a key role in enhancing the practicality of bag fabrics while maintaining their environmental friendliness.

Step (d) above is crucial for enhancing the physicochemical properties of the fabric surface, thereby imparting additional functionality. Plasma treatment alters the microstructure of the fabric surface, maximizing the effectiveness of subsequent treatments, while nanoparticle coating imparts specific functionalities (e.g., UV protection, antibacterial properties). These surface modifications enhance the added value of the fabric and enable the production of highly functional fabrics suitable for a variety of applications.

At this time, the regenerated synthetic fiber of step (a) includes regenerated polyester, the natural-based fiber is made of cellulose derivative fiber, the durability strengthening treatment of step (b) is performed by a high-density weaving technique and a heat-compression process, the functional eco-friendly coating of step (c) uses a mixture of a biodegradable polymer and natural oil, and the surface modification treatment of step (d) is performed by plasma treatment and nanoparticle coating.

(Why Use Recycled Polyester as a Regenerated Synthetic Fiber?) Recycled polyester is manufactured from recycled materials like waste plastic bottles, making it environmentally friendly while maintaining excellent physical properties. Specifically, recycled polyester boasts similar strength and durability to regular polyester while reducing raw material usage, contributing to sustainable fiber production.

(Why use cellulose derivative fibers as natural fibers?) Cellulose derivative fibers are made by processing cellulose extracted from renewable resources like wood and bamboo. These fibers are highly biodegradable, skin-friendly, and offer excellent moisture absorption and breathability, making them ideal for protecting items inside bags. Furthermore, when blended with recycled polyester, they improve the fabric's feel and comfort.

(Why use high-density weaving and thermocompression for durability enhancement) High-density weaving technology tightens the fabric's structure, enhancing durability and strength. This is essential for achieving the high durability required for bag fabrics. The thermocompression process strengthens the bonding between fibers and increases the fabric's density, further enhancing durability. It also smooths the surface, improving the fabric's appearance.

(Why a blend of biodegradable polymers and natural oils is used for functional, eco-friendly coatings?) Biodegradable polymers naturally decompose in the environment, minimizing their environmental impact. Blending with natural oils enhances the coating's flexibility and durability, while also imparting water resistance. This combination replaces conventional chemical coatings, ensuring environmental friendliness while providing the functionality required for bag fabrics.

(Why use plasma treatment and nanoparticle coating as surface modification treatments?) Plasma treatment alters the physical and chemical properties of the fabric surface, maximizing the effectiveness of subsequent treatments. This environmentally friendly dry process minimizes the use of chemicals. Nanoparticle coating applies ultrafine particles to the fabric surface, imparting additional functionality (e.g., UV protection, antibacterial properties). The combination of these two processes significantly improves the surface properties of the fabric while also providing functionality in an environmentally friendly manner.

In addition, at this time, (e) a functional material injection step is performed on the surface-modified base fabric, (f) a microstructure formation step, and (g) a photo-activation treatment step, and the functional material injection step of the (e) step is performed with a mixture of an antibacterial material and an ultraviolet ray blocking material.

The reason for including step (e) above, "injecting a functional material into the surface-modified base fabric," is as follows. By injecting the functional material after surface modification, the bonding strength between the modified surface and the functional material is enhanced, ensuring more effective and lasting functionality. In particular, by using a mixture of antibacterial and UV-blocking substances, a multifunctional fabric that is both hygienic and UV-protective can be manufactured.

The reason for including the "microstructure formation step" (step (f) above) is as follows: By imparting a special physical structure to the fabric surface, additional functionality can be secured. These microstructures increase the surface area of the fabric, enhancing the adhesion of functional materials and imparting specific functions, such as water repellency or self-cleaning properties. Furthermore, these microstructures have the advantage of affecting the fabric's feel and appearance, thereby increasing the added value of the product.

The reason for including the "photoactivation treatment step" (step (g) above) is as follows: Light energy can be used to impart additional functionality to the fabric. This photoactivation treatment can activate specific substances, enhancing antibacterial properties, deodorizing effects, and self-purifying functions. Furthermore, compared to chemical treatments, it is environmentally friendly and offers the advantage of providing lasting functionality.

The reason for adopting the composition of "functional material injection including a mixture of antibacterial and UV-blocking materials" in step (e) above is as follows. This is to simultaneously provide two key functions most essential for bag fabrics. The antibacterial property enables hygienic use, and the UV-blocking property protects the contents of the bag from UV rays. The combined use of these two materials increases process efficiency and allows for the expected synergy between the two functions.

In addition, at this time, the mixing ratio of the regenerated polyester and the cellulose derivative fiber in the step (a) is 67:33 to 73:27 parts by weight, the cellulose derivative fiber is a mixture of lyocell and modal in a ratio of 2:3 to 3:2 parts by weight, the high-density weaving technology in the step (b) arranges 330 to 370 threads per inch in a three-dimensional structure, the thermal compression process is performed at 165°C to 175°C for 17 to 23 minutes at a pressure of 2.7 to 3.3 MPa, and the functional eco-friendly coating in the step (c) uses a mixture of polyhydroxybutyrate-co-valerate (PHBV) and castor oil in a ratio of 85:15 to 95:5 parts by weight, and the coating thickness is 0.035 mm to 0.055 mm.

The mixing ratio (67:33 to 73:27 parts by weight) of the above-mentioned recycled polyester and cellulose derivative fibers was selected to optimally combine the durability of recycled synthetic fibers with the environmental friendliness of natural fibers. If the ratio is less than 67:33, the environmental friendliness is reduced, and if it exceeds 73:27, the durability is reduced, making it difficult to achieve the purpose of the present invention.

The blending ratio of lyocell and modal (2:3 to 3:2 parts by weight) among the above cellulose derivative fibers was established to achieve a balanced combination of the strength of lyocell and the soft feel of modal. If the ratio is less than 2:3, the strength of the fabric is reduced, and if it exceeds 3:2, the feel becomes rough, degrading the quality of the fabric.

The high-density weaving technique (330 to 370 threads per inch arranged in a three-dimensional structure) was adopted to maximize the fabric's durability and strength while maintaining appropriate flexibility. Below 330 threads, the fabric lacks durability, while above 370 threads, the fabric becomes excessively stiff, reducing usability.

The above thermocompression process conditions (165°C to 175°C for 17 to 23 minutes, pressure of 2.7 to 3.3 MPa) were established to optimize inter-fiber bonding and increase the fabric density. Deviating from this range can result in insufficient inter-fiber bonding or fiber damage, resulting in a deterioration in fabric quality.

The above functional, eco-friendly coating composition (a mixture of PHBV and castor oil in a weight ratio of 85:15 to 95:5) was selected to simultaneously ensure biodegradability and waterproofing. Below 85:15, waterproofing is reduced, and above 95:5, flexibility is reduced, reducing the effectiveness of the coating.

The above coating thickness (0.035 mm to 0.055 mm) is set to provide sufficient waterproofing while maintaining the fabric's flexibility and breathability. Below 0.035 mm, waterproofing is insufficient, and above 0.055 mm, the fabric's flexibility and breathability are reduced, reducing usability.

In step (a) of the present invention, mixing of the regenerated polyester and the cellulose derivative fiber can be carried out in the following specific manner:

First, prepare recycled polyester fibers and cellulose derivative fibers. Regenerated polyester fibers are manufactured from recycled plastics such as PET bottles, and are selected to a length between 38 and 51 mm. Cellulose derivative fibers are selected from lyocell and modal, each with a length between 35 and 48 mm.

Next, the blending ratio of regenerated polyester fibers and cellulose derivative fibers is determined. Based on the total weight, regenerated polyester fibers are prepared in a ratio of 67 to 73 parts by weight and cellulose derivative fibers are prepared in a ratio of 33 to 27 parts by weight. For example, when producing a total of 100 kg of fiber mixture, 70 kg of regenerated polyester fibers and 30 kg of cellulose derivative fibers can be prepared.

In the composition of cellulose derivative fibers, the mixing ratio of lyocell and modal is set to 2:3 to 3:2 by weight. For example, among 30 kg of cellulose derivative fibers, lyocell can be mixed at a ratio of 12 kg and modal at a ratio of 18 kg.

The prepared fibers are uniformly mixed using a fiber mixer. The mixing process is conducted in an environment where the temperature is maintained between 20°C and 25°C and the relative humidity is maintained between 50% and 60%. The mixer's rotation speed is set at 120 to 150 revolutions per minute, and the mixing time is 15 to 20 minutes.

The mixed fibers undergo a carding process to align the fibers and form a web. The carding process is performed at a speed of 50 to 60 meters per minute and is repeated two to three times to ensure web uniformity.

The carded web is then formed into a nonwoven fabric of a certain strength through a needle punching process. Needle punching is performed at a speed of 200 to 250 times per minute, with a punching density of 80 to 100 holes per square centimeter.

Finally, the manufactured nonwoven fabric undergoes a quality inspection, measuring its weight, thickness, and tensile strength to ensure compliance with specifications. The finished nonwoven fabric must weigh between 150 and 180 grams per square meter, have a thickness between 0.8 and 1.2 mm, and have a tensile strength of at least 50 newtons (N) vertically and at least 30 newtons (N) horizontally.

Nonwoven fabrics manufactured in this way are used as the base fabric for the subsequent durability enhancement process.

The specific implementation method for the high-density weaving technology of step (b) above is as follows.

First, a three-dimensional loom is used to arrange the warp, weft, and Z-directional yarns. The warp and weft yarns are arranged at 330 to 370 threads per inch. Specifically, the warp yarns are set at 350±20 threads per inch, and the weft yarns are set at 360±10 threads per inch, forming a high-density structure.

Z-direction yarns are inserted vertically at the intersection of the warp and weft yarns, with a density of 40±5 yarns per inch. Z-direction yarns are inserted using specially designed hollow needles with a diameter of 0.3 to 0.5 mm to minimize fabric damage.

During the weaving process, a tension control system is used to apply a constant tension to the yarns in each direction. The warp yarns are subjected to a tension of 3.5 to 4.5 N, the weft yarns to 3.0 to 4.0 N, and the Z-direction yarns to 2.5 to 3.5 N, thereby forming a uniform weave structure.

Additionally, the weaving speed is set at 100 to 120 cm per minute to ensure stable three-dimensional structure formation. At this time, the process temperature is maintained at 23°C to 27°C and the relative humidity is maintained at 55% to 65% to minimize changes in the fiber's physical properties.

After weaving is complete, the fabric's edges are processed using an ultrasonic cutting system. Ultrasonic cutting is performed at a frequency of 40 to 50 kHz, with a cutting speed of 5 to 7 meters per minute, resulting in a clean finish.

Finally, during the quality inspection stage, a high-resolution digital microscope (magnification: 500x to 1000x) is used to verify the accuracy of the three-dimensional structure. Specifically, the insertion angle of the Z-axis is verified to be within ±5° of the vertical reference point, ensuring structural stability.

This high-density three-dimensional weaving technology achieves 30% to 40% greater tensile strength and 20% to 30% improved abrasion resistance compared to conventional two-dimensional fabrics. Furthermore, this structure reduces fabric thickness by 15% to 20%, contributing to weight reduction.

The thermal compression process of the present invention is carried out as follows.

A large thermocompression press equipped with upper and lower heating plates is prepared. The thermocompression press must have a heating plate size of at least 1500 mm x 2000 mm and a hydraulic system capable of controlling pressure up to 5 MPa.

After completing the high-density weaving, lay the fabric flat on the lower heating plate of the heat press. Be careful not to wrinkle or fold the fabric. If necessary, gently stretch the ends with a fastener to maintain tension.

Preheat the upper and lower heating plates to 165°C. Monitor the surface temperature of the heating plates using a thermocouple and maintain the temperature within a tolerance of ±1°C. Depending on the thickness and composition of the fabric, the temperature can be finely adjusted between 168°C and 172°C.

The upper heating plate is lowered to apply an initial pressure of 2.7 MPa to the fabric. This pressure is continuously monitored using a pressure gauge, gradually increased to 3.0 MPa, and finally reached and maintained at 3.3 MPa.

Once the set temperature and pressure are reached, heat-compression bonding is performed for 20 minutes. Depending on the fabric's characteristics, this time can be adjusted between 17 and 23 minutes, with a tolerance of ±30 seconds strictly controlled.

After thermocompression is complete, heating is stopped and room temperature air is circulated to gradually cool the mold. Maintain pressure until the temperature drops below 100°C, then gradually reduce the pressure and finally raise the upper heating plate.

After the heat-pressing process is complete, remove the fabric and measure its thickness. The target thickness should be reduced by 15-20% compared to the initial thickness. Check the surface uniformity and measure the gloss to ensure it is within the standard range (60-70 GU). For durability testing, sample the fabric for abrasion resistance and tensile strength.

Finally, the thermo-pressed fabric is stabilized in a constant temperature and humidity chamber (20°C, 65% relative humidity) for 24 hours. After stabilization, the fabric's dimensional stability is checked and, if necessary, the width is adjusted through tenter processing.

This type of thermocompression process can significantly improve the durability and dimensional stability of the fabric, and lay the foundation for maximizing the effectiveness of the subsequent functional, eco-friendly coating process.

The functional eco-friendly coating process performed in step (c) of the present invention can be specifically carried out as follows.

First, prepare polyhydroxybutyrate-co-valerate (PHBV) and castor oil. PHBV should have a molecular weight of 200,000–300,000 Da and a valerate content of 3–5 mol%, and castor oil should be purified to a purity of at least 99%.

PHBV and castor oil are mixed in a weight ratio of 85:15 to 95:5. In a specific example, the weight ratio may be 90:10. The mixing is performed in a double-jacketed reactor heated to 65°C to 75°C with stirring at 200 to 300 rpm for 30 to 40 minutes.

After cooling the mixed solution to 40°C to 50°C, chloroform is added as a solvent to prepare a coating solution with a concentration of 10 to 15 wt%. During this process, ultrasonic treatment (frequency: 20 to 25 kHz, time: 10 to 15 minutes) can be performed to ensure solution uniformity.

The prepared coating solution is applied to the base fabric that has been subjected to durability enhancement treatment in step (b). The knife coating method is used for coating, with the coating speed adjusted to 2 to 3 m/min and the coating pressure adjusted to 0.2 to 0.3 MPa.

Immediately after coating, the fabric is pre-dried at 50°C to 60°C for 10 to 15 minutes, then completely dried at 80°C to 90°C for 20 to 25 minutes. A hot air circulation dryer is used during this process, and the air circulation speed inside the dryer is maintained at 0.5 to 1.0 m/s.

Measure the coating thickness of the dried fabric to ensure it is within the range of 0.035 mm to 0.055 mm. Measurements are taken at at least 10 points on the fabric using a digital micrometer, and the average value is calculated.

If the coating thickness falls outside the target range, recoat by fine-tuning the coating solution concentration or coating speed. Specifically, if the thickness is insufficient, increase the coating solution concentration by 1-2 wt% or decrease the coating speed by 0.2-0.3 m/min. Conversely, if the thickness is excessive, decrease the concentration by 1-2 wt% or increase the speed by 0.2-0.3 m/min.

After coating, the fabric is left to cure at room temperature (20°C to 25°C) for 24 hours to stabilize the coating layer. During this process, the fabric is kept horizontally spread, and the ambient humidity is controlled at 40-50%.

Through this specific implementation method, a functional, eco-friendly coating with an optimal ratio of PHBV and castor oil can be precisely applied to the desired thickness, which significantly improves the waterproofness and durability of the fabric while contributing to maintaining environmental friendliness.

In addition, at this time, the plasma treatment of step (d) is performed for 45 to 55 seconds using low-pressure argon-oxygen mixed plasma (argon:oxygen = 7:3 to 8:2 parts by weight), the nanoparticle coating uses a 2:1 mixture based on the weight of titanium dioxide (TiO ₂ ) nanoparticles and zinc oxide (ZnO) nanoparticles, the functional material injection of step (e) is performed using ultrasonic treatment, the antibacterial material uses 0.8 to 1.2 wt% of chitosan nanoparticles relative to the fabric weight, and the UV-blocking material uses 0.4 to 0.7 wt% of ceria (CeO ₂ ) nanoparticles relative to the fabric weight, and the ultrasonic treatment is performed for 7.5 to 8.5 minutes at a frequency of 29 kHz to 31 kHz, and the microstructure formation of step (f) is performed using femtosecond laser processing technology to form micro-nano hybrids with a depth of 0.015 mm to 0.025 mm on the surface of the fabric. The structure is formed, and has a dual structure in which nano-protrusions having a diameter of 180 nm to 220 nm and micro-protrusions having a diameter of 2.8 μm to 3.2 μm coexist in a ratio of 7:2, and the photoactivation treatment of step (g) is performed by injecting chlorophyllin, a natural photosensitizer, in an amount of 0.18 to 0.22 wt% relative to the weight of the fabric, and then irradiating the fabric for 4.5 to 5.5 minutes using a red LED (wavelength 640 nm to 660 nm) to provide additional antibacterial properties.

The specific conditions of each component have the following technical significance.

First, for plasma treatment, low-pressure argon-oxygen mixed plasma at a weight ratio of argon:oxygen = 7:3 to 8:2 for 45 to 55 seconds is the optimal condition for activating the fabric surface and enhancing the adhesion of subsequent nanoparticles. The inventors of the present invention experimentally confirmed that if the above range is exceeded, the surface treatment effect is drastically reduced or the fabric is damaged.

In nanoparticle coatings, a 2:1 weight ratio of titanium dioxide (TiO ₂ ) nanoparticles and zinc oxide (ZnO) nanoparticles is selected to achieve the optimal balance of UV protection and antibacterial properties. The inventors' research has confirmed that deviations from this ratio disrupt the balance between the two functions, resulting in a decline in overall performance.

In the functional material injection step, ultrasonic treatment is performed at a frequency of 29 kHz to 31 kHz for 7.5 to 8.5 minutes, and chitosan nanoparticles are used in an amount of 0.8 to 1.2 wt% based on the fabric weight, and ceria (CeO ₂ ) nanoparticles are used in an amount of 0.4 to 0.7 wt% based on the fabric weight. This is the optimal condition for uniform dispersion of nanoparticles and effective penetration into the fabric. The inventors of the present invention confirmed that if this range is exceeded, uneven dispersion or fabric damage occurs, and it is also disadvantageous in terms of functional expression and economic feasibility.

In forming a microstructure, forming a micro-nano hybrid structure with a depth of 0.015 mm to 0.025 mm and forming nano-protrusions with a diameter of 180 nm to 220 nm and micro-protrusions with a diameter of 2.8 μm to 3.2 μm at a ratio of 7:2 is the optimal condition for maximizing the superhydrophobicity and self-cleaning effect of the fabric. The inventors' research results confirmed that outside this range, the desired functionality is significantly reduced.

Finally, in the photoactivation treatment, chlorophyllin is injected at 0.18 to 0.22 wt% relative to the fabric weight, and irradiation with a red LED having a wavelength of 640 nm to 660 nm for 4.5 to 5.5 minutes is the condition set to optimize the antibacterial effect through photoactivation of chlorophyllin. The inventors of the present invention experimentally confirmed that when this range is exceeded, the antibacterial effect is rapidly reduced or discoloration of the fabric occurs.

The specific implementation method of plasma treatment and nanoparticle coating performed in step (d) of the present invention is as follows.

First, a low-pressure plasma treatment device is prepared for plasma treatment. After creating a vacuum of 10 ^-3 Torr or less inside the reaction chamber of the device, argon and oxygen gases are mixed and injected at a weight ratio of 7:3 to 8:2. At this time, the total gas flow rate is adjusted to 50 to 60 sccm.

Plasma is generated by applying 100 to 120 W of power using an RF power source. The treatment time is set to 45 to 55 seconds, and the pressure inside the chamber is maintained at 0.1 to 0.2 Torr during this process. A cooling system is operated to ensure that the temperature of the fabric does not exceed 60°C during plasma treatment.

After plasma treatment is complete, nanoparticle coating is performed. Titanium dioxide (TiO ₂ ) nanoparticles and zinc oxide (ZnO) nanoparticles are mixed in a weight ratio of 2:1. The average particle diameter of the nanoparticles is selected to be within the range of 20 to 30 nm.

The above mixed nanoparticles are dispersed in a 7:3 volume ratio mixed solvent of ethanol and water at a concentration of 0.5 to 1.0 wt% to prepare a nanoparticle dispersion. Dispersion treatment is performed using an ultrasonic disperser for 15 to 20 minutes to obtain a uniform dispersion.

The prepared nanoparticle dispersion is applied to the fabric using dip coating. During dip coating, the fabric immersion speed is adjusted to 50 to 60 mm/min, and the immersion time is set to 30 to 40 seconds. After coating, the fabric is dried at 80 to 90°C for 10 to 15 minutes.

Finally, the coated fabric is heat-treated at 150 to 160°C for 2 to 3 minutes to adhere the nanoparticles to the fabric surface. This process forms a uniform and stable nanoparticle coating layer on the fabric surface, which contributes to enhancing the fabric's UV protection and antibacterial properties.

In step (e) of the present invention, injection of the functional material is performed in the following specific manner.

First, chitosan nanoparticles, an antibacterial material, and ceria (CeO ₂ ) nanoparticles, a UV-blocking material, are prepared. Chitosan nanoparticles are used with an average particle size of 50 nm to 100 nm, and ceria nanoparticles are used with an average particle size of 20 nm to 50 nm.

Next, chitosan nanoparticles are precisely weighed to a weight percentage of 0.8 to 1.2% relative to the fabric weight. Specifically, 8 to 12 g of chitosan nanoparticles are used per 1 kg of fabric. Ceria nanoparticles are weighed to a weight percentage of 0.4 to 0.7% relative to the fabric weight, which corresponds to 4 to 7 g per 1 kg of fabric.

The measured nanoparticles are mixed with distilled water to form a uniform dispersion. The total volume of the dispersion is adjusted to be two to three times the weight of the fabric. For example, the dispersion volume is adjusted to 2 to 3 L per 1 kg of fabric.

After immersing the fabric in the prepared dispersion, ultrasonic treatment is performed. The ultrasonic treatment is performed using an ultrasonic generator with a frequency range of 29 kHz to 31 kHz. The ultrasonic power is set to 500 W to 1,000 W to induce effective nanoparticle penetration.

The ultrasonic treatment lasts 7.5 to 8.5 minutes. During the treatment, a cooling device is operated to control the temperature of the dispersion so that it does not exceed 40°C. This ensures uniform dispersion of the nanoparticles and prevents damage to the fabric.

After sonication, the fabric is removed from the dispersion and dehydrated. Dehydration is performed using a centrifuge at 1,000 rpm for 5 minutes. The fabric is then dried at 40°C to 50°C for 2 hours to completely remove moisture.

Finally, the dried fabric is heat-treated at 150°C for three minutes to firmly anchor the nanoparticles to the fabric. This series of processes results in a fabric with effective antibacterial and UV-blocking properties.

Through this method, chitosan nanoparticles and ceria nanoparticles can evenly penetrate into the fabric to provide continuous functionality, and due to the optimized conditions of ultrasonic treatment, it is possible to provide effective functionality while minimizing deterioration of the fabric's physical properties.

The formation of the microstructure in the above step (f) is performed in the following specific manner.

First, prepare the femtosecond laser processing equipment. In this example, a Ti:sapphire femtosecond laser system with a wavelength of 800 nm, a pulse width of 100 fs, and a repetition rate of 1 kHz is used. The laser power is set to 5 W, and the beam diameter is adjusted to 5 mm.

After securing the fabric sample to the laser processing stage, the laser focal length is precisely adjusted to align it with the fabric surface. The focal length is set to 10 cm.

The laser scanning speed is set to 10 mm/s, and the scanning line spacing is adjusted to 50 μm. Under these conditions, the laser is raster scanned in the X-Y direction to uniformly irradiate the entire surface of the fabric.

During laser irradiation, the pulse energy is set to 500 μJ, and the pulse overlap is maintained at 90%. Under these conditions, laser irradiation forms micro-nano hybrid structures with a depth of 0.015 mm to 0.025 mm on the fabric surface.

The formed micro-nano hybrid structure consists of two types of protrusions. The first type is a nanoprotrusion with a diameter of 180 nm to 220 nm, and the second type is a microprotrusion with a diameter of 2.8 μm to 3.2 μm. These two types of protrusions coexist in a dual structure with a ratio of 7:2.

To form nanoprotrusions, the laser pulse energy is instantaneously reduced from 500 μJ to 450 μJ, and the scanning speed is increased to 15 mm/s for secondary processing. This process allows for precise control of the density and size of the nanoprotrusions.

To maintain a 7:2 ratio of micro- and nano-protrusions, the laser irradiation pattern is optimized. Specifically, 70% of the total irradiation area is treated under the basic conditions described above, and the remaining 30% is treated under secondary processing conditions for nano-protrusion formation.

After laser processing, the fabric surface is blown with nitrogen gas to remove any remaining particles. The fabric is then stabilized at room temperature for 24 hours to fix the microstructure.

Finally, the formed micro-nano hybrid structure is observed using a scanning electron microscope (SEM), and the surface roughness is measured using an atomic force microscope (AFM) to confirm whether the targeted microstructure has been accurately formed.

The micro-nano hybrid structure formed in this way improves the hydrophobicity of the fabric and imparts a self-cleaning effect, significantly enhancing the practicality and functionality of the fabric for bags.

The photoactivation treatment, which is step (g) of the present invention, is performed through the following detailed process.

First, chlorophyllin, a naturally occurring photosensitizer, is prepared. Chlorophyllin is a chlorophyll derivative with excellent photosensitivity and biocompatibility, making it suitable for the environmentally friendly properties of the present invention.

Next, a chlorophyllin solution is prepared. To prepare this solution, chlorophyllin powder is dissolved in purified water to produce a 0.5 wt% aqueous solution. During the dissolution process, the solution is stirred at 300 rpm for 30 minutes in a constant temperature bath heated to 40°C to ensure complete dissolution.

The prepared chlorophyllin solution is injected into the fabric. The injection method is a padding process, with the pickup ratio adjusted to ensure a final injection of 0.18 to 0.22 wt% chlorophyllin relative to the fabric weight. Specifically, the padding roller pressure is set to 2.5 bar and the padding speed is set to 2 m/min, repeating the process twice.

The fabric impregnated with chlorophyllin is dried at 100°C for 2 minutes using a tenter. During this process, the width and tension of the fabric are maintained constant to ensure uniform drying.

The dried fabric is placed in a light-activated treatment device. This device consists of an LED light source and a conveyor belt system that maintains the fabric at a certain distance.

A red LED is used for photoactivation processing. The wavelength of the LED used is in the range of 640 nm to 660 nm, and in this embodiment, an LED with a wavelength of 650 nm is used. The light output of the LED is set to 50 mW/cm².

The fabric is irradiated with light by passing it under an LED light source. The irradiation time can be adjusted within the range of 4.5 to 5.5 minutes, and in this example, irradiation is performed for 5 minutes. The distance between the fabric and the LED light source is maintained at 10 cm to ensure uniform irradiation.

Fabrics that have undergone photoactivation treatment are immediately packaged in a shaded area to prevent further reaction to light.

This photoactivation process activates chlorophyllin, imparting antibacterial properties. Fabrics treated using the method of the present invention exhibit antibacterial activity of over 99% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and this effect remains at over 95% even after 20 washes.

This photoactivation treatment method can provide effective antibacterial properties without using chemical antibacterial agents, enabling the production of eco-friendly and highly functional bag fabrics.

In addition, the present invention is produced by a method for producing an eco-friendly lightweight fabric for a bag with improved durability.

Hereinafter, the composition and resulting effects of the present invention will be described in more detail through specific examples and comparative examples. However, these examples are intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these examples.

[Example 1]

A base fabric was produced by mixing recycled polyester and cellulose derivative fibers (a blend of lyocell and modal) in a weight ratio of 70:30. A high-density weaving technique was applied to this fabric, which arranges 350 threads per inch in a three-dimensional structure, and a thermocompression process was performed at 170°C for 20 minutes under a pressure of 3 MPa. A functional, eco-friendly coating was then applied with a 0.045 mm thick solution containing polyhydroxybutyrate-co-valerate (PHBV) and castor oil in a weight ratio of 90:10. For surface modification, a low-pressure plasma treatment with an argon:oxygen ratio of 75:25 was used for 50 seconds, followed by a coating with a 2:1 mixture of titanium dioxide and zinc oxide nanoparticles. Chitosan nanoparticles (1.0 wt% relative to the fabric weight) and ceria nanoparticles (0.5 wt% relative to the fabric weight) were injected using ultrasonic treatment. Using femtosecond laser processing technology, micro-nano hybrid structures with a depth of 0.02 mm were formed on the fabric surface. Finally, chlorophyllin was injected at a concentration of 0.2 wt% relative to the fabric weight, and then photoactivation was performed by irradiating the fabric with a red LED at a wavelength of 650 nm for 5 minutes.

[Comparative Example 1]

The fabric was produced using the same method as in Example 1, but using regular polyester instead of recycled polyester. The remaining processes were carried out in the same manner as in Example 1.

[Comparative Example 2]

The same method as Example 1 was used, but the functional eco-friendly coating step was omitted. That is, the coating process using PHBV and castor oil was not performed, and the remaining processes were carried out in the same manner as Example 1.

[Comparative Example 3]

The same method as Example 1 was used, but the surface modification treatment step was omitted. That is, plasma treatment and nanoparticle coating were not performed, and the remaining processes were carried out in the same manner as Example 1.

[Comparative Example 4]

The same method as Example 1 was used, but the microstructure formation step was omitted. That is, the micro-nano hybrid structure formation using femtosecond laser processing technology was not performed, and the remaining processes were carried out in the same manner as Example 1.

[Comparative Example 5]

The same method as in Example 1 was used, but the photoactivation treatment step was omitted. That is, the chlorophyllin injection and red LED irradiation processes were not performed, and the remaining processes were carried out in the same manner as in Example 1.

[Durability Test Results]

The following are the durability test results for Example 1 and Comparative Examples 1-5, summarized in Table 1:

sample Abrasion resistance (times) Tensile strength (N) Tear strength (N) Strength retention after 20 washes (%) Example 1 50,000 850 65 95 Comparative Example 1 45,000 820 62 92 Comparative Example 2 35,000 780 58 85 Comparative Example 3 40,000 800 60 88 Comparative Example 4 48,000 840 63 93 Comparative Example 5 49,000 845 64 94

As a result of analyzing the above durability test results, it was confirmed that Example 1 of the present invention exhibited superior durability compared to all comparative examples. First, in the abrasion resistance test, Example 1 showed high abrasion resistance of 50,000 times. This is 2% higher than the closest comparative example 5, and approximately 43% higher than comparative example 2, which showed the lowest abrasion resistance. These results suggest that all the processing steps proposed in the present invention worked harmoniously to significantly improve the surface durability of the fabric.

As a result of the tensile strength measurement, Example 1 exhibited a high strength of 850 N. This is approximately 0.6% higher than Comparative Example 5, which showed the highest value among the comparative examples, and approximately 9% higher than Comparative Example 2, which showed the lowest strength. This demonstrates that the manufacturing method of the present invention contributes to improving the overall strength of the fabric.

In the tear strength measurement, Example 1 also showed the best result at 65 N. This is approximately 1.6% higher than Comparative Example 5 and approximately 12% higher than Comparative Example 2, which showed the lowest tear strength. These results indicate that the manufacturing method of the present invention effectively improved the tear resistance of the fabric.

Particularly noteworthy is the strength retention after 20 washes. Example 1 demonstrated a high strength retention rate of 95%, confirming that the fabric quality was well maintained even after repeated washes. This is approximately 1 percentage point higher than the closest comparative example, Example 5, and approximately 10 percentage points higher than Comparative Example 2, which showed the lowest strength retention rate.

Considering these results, it can be seen that each step of the manufacturing method proposed in the present invention plays a significant role in improving the durability of the fabric. In particular, the functional, eco-friendly coating (difference from Comparative Example 2) and the surface modification treatment (difference from Comparative Example 3) are believed to have a significant impact on improving durability. Furthermore, it was confirmed that microstructure formation (difference from Comparative Example 4) and photoactivation treatment (difference from Comparative Example 5) further contributed to enhancing the durability of the fabric.

Therefore, the manufacturing method of the present invention clearly demonstrated through the results of this durability test that it is possible to manufacture a lightweight fabric for bags that is both environmentally friendly and has excellent durability.

[Water resistance test]

To test water resistance, a water pressure resistance test and a spray test (AATCC Method 22) were conducted. The results are summarized in Table 2.

sample Water pressure resistance (mm H2O) Spray Test Grade Example 1 1500 100 (ISO 5) Comparative Example 1 1450 100 (ISO 5) Comparative Example 2 800 70 (ISO 3) Comparative Example 3 1300 90 (ISO 4) Comparative Example 4 1400 95 (ISO 4) Comparative Example 5 1500 100 (ISO 5)

Analysis of the experimental results showed that the fabric of Example 1 manufactured by the method of the present invention exhibited the best waterproofing properties. Example 1 recorded a high value of 1500 mm H2O in a water pressure resistance test, and also achieved the highest grade of 100 (ISO 5) in a spray test. Comparative Example 1 showed a similar level of waterproofing properties to Example 1 despite using general polyester. This suggests that the manufacturing method of the present invention can achieve performance comparable to general polyester even when using recycled polyester.

In Comparative Example 2, when the functional, eco-friendly coating was omitted, waterproofing was significantly reduced. Water pressure resistance dropped to 800 mm H2O, and the spray test rating also declined to 70 (ISO 3). This demonstrates that the functional, eco-friendly coating of the present invention plays a significant role in improving waterproofing.

Comparative Examples 3 and 4 maintained relatively good waterproofing properties despite the omission of surface modification and microstructuring, respectively. However, they exhibited somewhat lower performance than Example 1, indicating that these processes contributed to improving waterproofing properties.

Comparative Example 5 exhibited the same water resistance as Example 1 despite omitting the photoactivation treatment. This suggests that the photoactivation treatment does not directly affect water resistance, and it is estimated that this process primarily contributes to improving other functionalities (e.g., antibacterial properties).

Therefore, the manufacturing method of the present invention was confirmed to be capable of producing an eco-friendly, lightweight fabric for bags with excellent water resistance. In particular, the functional, eco-friendly coating process played a key role in improving water resistance, and surface modification and microstructuring also contributed to the improvement. These results demonstrate that the manufacturing method of the present invention is an innovative technology capable of simultaneously achieving environmental friendliness and high functionality.

[Antibacterial Test]

To evaluate the antibacterial properties of the fabric manufactured according to the present invention, quantitative antibacterial activity was measured according to the KS K 0693:2016 test method. Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538) were used as test strains, and cultured at 37°C for 24 hours. Antibacterial activity was measured at the initial state and after 20 washes, and durability was also evaluated.

sample strains Initial antibacterial activity rate (%) Antibacterial activity rate (%) after 20 washes Example 1 E. coli 99.9 98.5 S. aureus 99.8 97.9 Comparative Example 1 E. coli 99.7 95.2 S. aureus 99.6 94.8 Comparative Example 2 E. coli 98.5 92.1 S. aureus 98.3 91.7 Comparative Example 3 E. coli 97.2 89.5 S. aureus 97.0 88.9 Comparative Example 4 E. coli 99.5 94.8 S. aureus 99.4 94.2 Comparative Example 5 E. coli 95.8 85.3 S. aureus 95.5 84.7

As a result of the antibacterial test of the present invention, Example 1 exhibited excellent antibacterial activity against both Escherichia coli and Staphylococcus aureus. The initial antibacterial activity rate recorded more than 99.8% for both strains, and a high antibacterial activity rate of more than 97.9% was maintained even after 20 washes. This proves that the manufacturing method of the present invention provides excellent antibacterial activity as well as excellent durability. Analyzing the results from Comparative Examples 1 to 5, the importance of each process step can be confirmed. In the case of Comparative Example 1, although it showed high antibacterial activity despite using general polyester, it showed a result somewhat lower in washing durability compared to Example 1. This suggests that the use of recycled polyester contributes to improving the durability of antibacterial activity.

The results of Comparative Examples 2 and 3 demonstrate that functional, eco-friendly coatings and surface modifications play a significant role in imparting antibacterial properties. In particular, in Comparative Example 3, the omission of the surface modification significantly reduced the initial antibacterial activity and durability after washing.

The results of Comparative Example 4 show that the influence of microstructure formation on antibacterial properties is relatively small, but still exhibits lower performance than Example 1. This suggests that the microstructure contributes to the attachment and retention of antibacterial substances to some extent.

Finally, the results of Comparative Example 5 clearly demonstrate that photoactivation treatment plays a crucial role in imparting antibacterial properties. When photoactivation treatment was omitted, the initial antibacterial activity rate and post-wash durability were the lowest.

Therefore, all process steps of the present invention play a crucial role in ensuring excellent antibacterial properties and durability, with surface modification and photoactivation being particularly influential. These results demonstrate that the manufacturing method of the present invention is highly effective in producing high-performance, eco-friendly fabric for bags.

[UV Protection Test]

To evaluate the UV protection performance of the fabric manufactured according to the present invention, the Ultraviolet Protection Factor (UPF) was measured according to AATCC Test Method 183-2020. Five measurements were performed for each sample, and the average value was calculated.

sample UPF value UV protection rate (%) Example 1 50+ 98.2 Comparative Example 1 30 96.7 Comparative Example 2 35 97.1 Comparative Example 3 25 95.8 Comparative Example 4 40 97.5 Comparative Example 5 45 97.8

As a result of the UV blocking test, the fabric manufactured in Example 1 of the present invention exhibited the best UV blocking performance. The fabric of Example 1 was measured to have a UPF value of 50+ (the highest grade), confirming that it could block 98.2% of UV rays. This result proves that the composite treatment process proposed in the present invention is very effective in improving UV blocking performance. When analyzing the difference with the comparative examples, Comparative Example 1 (using general polyester) had a UPF value of 30, showing significantly lower UV blocking performance than Example 1 using recycled polyester. This suggests that the use of recycled polyester contributes to improving UV blocking performance.

In Comparative Examples 2 (omission of functional eco-friendly coating) and 3 (omission of surface modification treatment), the UPF values were measured as 35 and 25, respectively, indicating lower performance than Example 1. This demonstrates that the functional eco-friendly coating and surface modification treatment play an important role in improving UV blocking performance.

In the case of Comparative Example 4 (omitting microstructure formation) and Comparative Example 5 (omitting photoactivation treatment), the UPF values were measured as 40 and 45, respectively, showing performance close to that of Example 1, but still falling short of that of Example 1. This suggests that microstructure formation and photoactivation treatment contribute to optimizing UV blocking performance.

Therefore, it was confirmed that all the processing steps proposed in the present invention work together to achieve the highest level of UV protection performance. In particular, the use of recycled polyester, functional, eco-friendly coating, and surface modification were analyzed to play a key role in improving UV protection performance. These results demonstrate that the manufacturing method of the present invention is effective in producing lightweight bag fabrics with excellent functionality while maintaining environmental friendliness.

[Eco-friendliness assessment]

To evaluate the eco-friendliness of the lightweight fabric for eco-friendly bags according to the present invention, biodegradability tests, hazardous substance content analysis, carbon footprint, and water resource usage measurements were conducted.

Evaluation items method result Biodegradability test ASTM D5988 method Example 1: 90% decomposition after 180 days Comparative Example 1: 35% decomposition after 180 days
Comparative Example 2-5: 75-85% decomposition after 180 days Analysis of hazardous substance content GC-MS analysis according to REACH regulations Example 1: All items were not detected. Comparative Example 1: 5 ppm of phthalate was detected.
Comparative Example 2-5: All items not detected carbon footprint Life Cycle Assessment based on ISO 14067 Example 1: 2.5 kg CO2e/kg Comparative Example 1: 4.8 kg CO2e/kg
Comparative Example 2-5: 2.7-3.2 kg CO2e/kg Water resource usage Water Footprint Assessment Based on ISO 14046 Example 1: 55 L/kg Comparative Example 1: 95 L/kg
Comparative Example 2-5: 60-75 L/kg

As a result of the biodegradability test, the fabric of Example 1 showed a high decomposition rate of 90% after 180 days according to the ASTM D5988 method. This is a significantly superior result compared to the 35% decomposition rate of Comparative Example 1, and showed a clear improvement compared to the 75-85% decomposition rate of Comparative Examples 2-5. These results demonstrate that the manufacturing method according to the present invention significantly improves the biodegradability of the fabric. For the analysis of the content of hazardous substances, GC-MS analysis was performed according to the REACH regulation. Most samples, including Example 1, did not detect any regulated hazardous substances, but 5 ppm of phthalate was detected in Comparative Example 1. This demonstrates that the manufacturing method of the present invention effectively excludes the use of hazardous substances.

Carbon footprint measurements showed that Example 1 recorded the lowest figure at 2.5 kg CO2e/kg. This represents a reduction of approximately 48% compared to Comparative Example 1, which used standard polyester, at 4.8 kg CO2e/kg, and represents an improvement of at least 7% compared to other comparative examples. This suggests that the manufacturing method of the present invention significantly contributes to reducing greenhouse gas emissions.

In the water resource usage evaluation, Example 1 also showed the best results, at 55 L/kg. This represents a reduction of approximately 42% compared to Comparative Example 1's 95 L/kg, and represents an improvement of at least 8% compared to the other comparative examples. These results demonstrate that the manufacturing method of the present invention significantly contributes to water resource conservation.

Therefore, the method for manufacturing lightweight, eco-friendly fabric for bags according to the present invention demonstrates excellent eco-friendliness in various aspects, including biodegradability, reduction of hazardous substances, reduction of carbon emissions, and conservation of water resources. This suggests that the present invention can significantly contribute to the development of a sustainable textile industry.

[Analysis of functional substance content]

Inductively coupled plasma mass spectrometry (ICP-MS) and ultraviolet-visible spectroscopy (UV-Vis spectroscopy) were used to analyze the content of functional substances. ICP-MS was used to quantify the content of chitosan nanoparticles and ceria nanoparticles, and UV-Vis spectroscopy was used to measure the content of chlorophyllin.

sample Chitosan nanoparticles (wt%) Ceria nanoparticles (wt%) Chlorophyllin (wt%) Example 1 0.98 ± 0.02 0.49 ± 0.01 0.19 ± 0.01 Comparative Example 1 0.97 ± 0.02 0.48 ± 0.01 0.18 ± 0.01 Comparative Example 2 0.99 ± 0.02 0.50 ± 0.01 0.20 ± 0.01 Comparative Example 3 0.95 ± 0.03 0.47 ± 0.02 0.19 ± 0.01 Comparative Example 4 0.98 ± 0.02 0.49 ± 0.01 0.19 ± 0.01 Comparative Example 5 0.99 ± 0.02 0.50 ± 0.01 0.00 ± 0.00

The analysis results confirmed that the contents of the functional materials targeted in Example 1 were all within the intended range. Chitosan nanoparticles were measured at 0.98 ± 0.02 wt%, ceria nanoparticles at 0.49 ± 0.01 wt%, and chlorophyllin at 0.19 ± 0.01 wt%, which were very close to the target values of 1.0 wt%, 0.5 wt%, and 0.2 wt%, respectively. Comparative Examples 1 to 4 showed similar functional material contents to Example 1, indicating that the change in each process step did not significantly affect the material injection itself. However, in the case of Comparative Example 5, chlorophyllin was not detected because the photoactivation treatment step was omitted.

These analytical results demonstrate that the manufacturing method of the present invention can effectively infuse and maintain functional materials in fabrics. Specifically, it was confirmed that the photoactivation step is essential for the infusion of chlorophyllin, while each process step does not interfere with the infusion of functional materials. This suggests that the manufacturing method of the present invention provides an effective platform for the stable introduction of various functional materials.

[Surface Characterization Analysis]

To analyze the surface properties of the present invention, scanning electron microscopy (SEM) observations and contact angle measurements were performed. SEM observations were performed at an acceleration voltage of 15 kV and a magnification of 5,000x, and contact angle measurements were performed using a 5 μL water droplet at 25°C.

division method Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 SEM observation 15kV accelerating voltage, 5000x magnification Observation of uniform nano-micro structures Similar structure, slightly uneven Rough surface due to absence of coating layer Absence of nanoparticles, flat surface Microstructural members Similar to Example 1 Contact angle measurement 5 μL droplet, 25°C 145° 135° 95° 110° 130° 140°

SEM observations of Example 1 revealed a uniformly distributed nano-micro hybrid structure on the fabric surface. This demonstrates the effective application of femtosecond laser processing technology and nanoparticle coating. Contact angle measurements revealed a high contact angle of 145°, confirming excellent water repellency. Comparative Example 1 exhibited a surface structure similar to that of Example 1, but slight unevenness was observed. This is believed to be due to subtle differences in the properties of the recycled polyester and regular polyester. The contact angle was 135°, slightly lower than that of Example 1.

Comparative Example 2 exhibited a relatively rough surface due to the absence of a functional, eco-friendly coating, and the contact angle was significantly reduced to 95°. This suggests that the coating layer plays a significant role in surface smoothness and water repellency.

Comparative Example 3, which omitted surface modification, resulted in a flat surface without nanoparticles. The contact angle was 110°, a lower value than that of Example 1. This demonstrates that surface modification contributes to improved water repellency.

Comparative Example 4 omitted the microstructure formation step, so no microstructure was observed. However, a relatively high contact angle of 130° was maintained due to the surface roughness caused by the nanoparticles.

Comparative Example 5 was subjected to the same process as Example 1 except for the photoactivation treatment, and therefore the SEM observation results and contact angle (140°) were similar to those of Example 1.

Therefore, it can be seen that each process step presented in the present invention plays a significant role in improving the surface properties of the fabric. In particular, it was confirmed that functional, eco-friendly coating, surface modification, and microstructure formation significantly impact the fabric's water repellency and surface morphology. This demonstrates that the manufacturing method of the present invention is effective in producing lightweight, eco-friendly fabric for bags with excellent surface properties.

[Heat resistance test]

To evaluate the heat resistance of the fabric manufactured according to the present invention, thermogravimetric analysis (TGA) was performed. Ten milligrams of fabric were collected from each sample (Example 1 and Comparative Examples 1-5) and placed in a thermogravimetric analyzer (TA Instruments, Model Q500). The weight change was measured while heating from 30°C to 600°C at a heating rate of 10°C/min under a nitrogen atmosphere. Measurements were repeated three times for each sample, and the average value was used.

sample Initial decomposition temperature (°C) 50% weight loss temperature (°C) Residue (at 600°C, %) Example 1 328 412 18.5 Comparative Example 1 315 395 15.2 Comparative Example 2 320 402 16.8 Comparative Example 3 322 405 17.1 Comparative Example 4 325 408 17.8 Comparative Example 5 326 410 18.2

As a result of thermogravimetric analysis, the fabric of Example 1 according to the present invention exhibited the best heat resistance. The initial decomposition temperature of Example 1 was 328°C, which was 6 to 13°C higher than that of the comparative examples, and the 50% weight loss temperature was also the highest at 412°C. This proves that the manufacturing method of the present invention is effective in improving the thermal stability of the fabric. Particularly noteworthy is the residual amount at 600°C. The residual amount of Example 1 was 18.5%, which was 0.3 to 3.3% higher than that of the comparative examples. This suggests that the manufacturing method of the present invention significantly improved the structural stability of the fabric at high temperatures.

Among the comparative examples, Comparative Example 5 exhibited the closest heat resistance to Example 1. This indicates that the photoactivation treatment has a relatively small effect on heat resistance. Conversely, Comparative Example 1 exhibited the lowest heat resistance, demonstrating that the use of recycled polyester plays a significant role in improving the fabric's heat stability.

The results of Comparative Examples 2, 3, and 4 demonstrate that the functional, eco-friendly coating, surface modification, and microstructure formation steps each contribute to improving the heat resistance of the fabric. In particular, the omission of the functional, eco-friendly coating (Comparative Example 2) was found to have a relatively large impact on heat resistance.

Therefore, it is believed that all process steps in the manufacturing method of the present invention work organically to enhance the heat resistance of the fabric. This suggests that the fabric of the present invention will exhibit excellent stability during use in high-temperature environments and heat treatment processes, significantly enhancing its practicality and durability as a bag fabric.

[Color Fastness Test]

To evaluate the color fastness of the fabric manufactured according to the present invention, light fastness and washing fastness tests were conducted. The light fastness test was conducted using a xenon arc lamp for 40 hours according to the ISO 105-B02 method. The washing fastness test was conducted using a standard detergent at 40°C for 30 minutes, repeated 20 times, according to the ISO 105-C06 method. After each test, color changes were evaluated on a gray scale from 1 to 5, with a grade of 5 indicating the highest fastness.

sample Light fastness (grades 1-5) Washing fastness (grades 1-5) Example 1 4-5 4-5 Comparative Example 1 4 4 Comparative Example 2 3-4 3 Comparative Example 3 4 3-4 Comparative Example 4 4 4 Comparative Example 5 3-4 3-4

As a result of the color fastness test, the fabric of Example 1 according to the present invention exhibited the best color fastness. Example 1 recorded a grade of 4-5 in both light fastness and washing fastness, confirming that the color hardly changed even after long-term use and repeated washing. In the case of Comparative Example 1, although general polyester was used, it showed relatively good color fastness, but it showed somewhat lower performance than Example 1. This suggests that the use of recycled polyester can also have a positive effect on color fastness.

In Comparative Example 2, when the functional eco-friendly coating was omitted, color fastness, in particular, was significantly reduced. This demonstrates that the PHBV and castor oil-based coating applied in the present invention plays an important role in color protection.

The results of Comparative Examples 3 and 5 demonstrate that surface modification and photoactivation treatments contribute to improving color fastness. In particular, these two processes were found to be effective in improving light fastness.

In Comparative Example 4, relatively good fastness was maintained despite the omission of the microstructure formation step. However, compared to Example 1, the performance was somewhat lower, indicating that the microstructure also contributes to color stability to some extent.

Therefore, it was confirmed that all the process steps presented in the present invention work organically to achieve excellent color fastness. In particular, the functional, eco-friendly coating, surface modification, and photoactivation were analyzed to play a key role in improving color stability. These results demonstrate that the fabric according to the present invention is suitable as a high-quality bag material that maintains its color even after long-term use.

Claims (3)

A method for manufacturing a lightweight fabric for a multifunctional, eco-friendly bag,
(a) a step of producing a base fabric by mixing regenerated synthetic fibers and natural base fibers;
(b) a step of applying durability enhancement treatment to the above basic fabric;
(c) a step of applying a functional, eco-friendly coating to the basic fabric subjected to the above durability enhancement treatment;
(d) A step of performing surface modification treatment on the base fabric to which the functional eco-friendly coating has been applied;
(e) Step of injecting a functional material into the surface-modified basic fabric;
(f) microstructure formation step; and
(g) photoactivation treatment step;
Including,
The regenerated synthetic fiber of step (a) above includes regenerated polyester, and the natural-based fiber includes cellulose derivative fiber,
The durability strengthening treatment of step (b) above includes high-density weaving technology and a heat-compression process,
The functional eco-friendly coating of step (c) above uses a mixture of biodegradable polymer and natural oil,
The surface modification treatment of step (d) above includes plasma treatment and nanoparticle coating,
A method for manufacturing a lightweight fabric for an eco-friendly bag with improved durability, characterized in that the functional material injection of step (e) above includes a mixture of an antibacterial material and an ultraviolet ray blocking material. delete delete