Method for manufacturing shoes using eco-friendly materials

Abstract

The present invention relates to a method for manufacturing shoes using eco-friendly materials, which maximizes the durability, wearability, lightness, and eco-friendly characteristics of shoes and can reduce carbon emissions compared to existing materials. The method comprises the steps of: preparing a bio-based polymer and natural fibers by pulverizing and mixing same; mixing an auxiliary additive with the pulverized bio-based polymer and natural fibers; manufacturing a composite material for shoe uppers by compression molding the mixed material at a high temperature; and cooling and cutting the manufactured composite material to process same into a desired shape.

Description

Method of manufacturing shoes using eco-friendly materials

[0001] The present invention relates to a method for manufacturing shoes using eco-friendly materials, and more specifically, to a method for manufacturing shoes using eco-friendly materials that maximizes the durability, comfort, lightness, and eco-friendly characteristics of the shoes and can reduce carbon emissions compared to existing materials.

[0002] Generally, as environmental issues have recently emerged as a significant global concern, there is a demand for the development of sustainable eco-friendly technologies and materials across various industrial sectors.

[0003] In particular, the footwear manufacturing industry is considered one of the major sectors that consumes significant resources and causes waste problems due to mass production and consumption.

[0004] Conventional shoe manufacturing processes primarily utilize petroleum-based synthetic materials, which cause high carbon emissions during production and have a negative impact on the environment as they do not naturally decompose upon disposal.

[0005] Commonly used synthetic polymers and synthetic fibers are excellent in terms of strength and durability, but they have limitations in terms of environmental sustainability.

[0006] These materials are often difficult to recycle and pose a high risk of threatening the ecosystem by generating microplastics during decomposition. On the other hand, while natural fibers possess biodegradability and eco-friendliness, their lack of durability and elasticity presents technical limitations for their sole use in shoe manufacturing.

[0007] Recent research efforts are being made to develop composite materials suitable for footwear manufacturing by combining natural fibers with bio-based polymers to overcome the shortcomings of existing materials. Bio-based polymers are extracted from renewable resources such as corn, soybeans, and sugarcane, and offer the advantage of significantly reducing carbon emissions compared to conventional petroleum-based materials. These bio-based materials provide recyclability and biodegradability while improving processability, allowing them to be utilized in various manufacturing processes.

[0008] Furthermore, natural fibers offer excellent breathability and moisture absorption, and blending them with bio-based polymers can complement their durability and flexibility. Blended materials provide tangible benefits to both consumers and manufacturers by reducing weight, improving comfort, and increasing design freedom while extending the lifespan of footwear.

[0009] Despite these technological advancements, processing methods to manufacture composite materials homogeneously and secure optimal physical properties remain a challenge. In particular, the mixing ratio of natural fibers and bio-based polymers, molding conditions, cooling, and processing steps have a significant impact on the performance and quality of the shoes.

[0010] Therefore, the development of shoe manufacturing methods that simultaneously satisfy eco-friendliness and functionality is becoming an important research task to meet the tightening of environmental regulations and the increasing consumer preference for eco-friendly products.

[0011] To meet these requirements, the present invention proposes a method for manufacturing eco-friendly shoes using bio-based polymers and natural fibers, and provides a technical solution that ensures an efficient processing process for composite materials and excellent physical properties. Through this, the invention aims to realize an environmentally friendly and high-performance shoe manufacturing technology.

[0012] The present invention has been devised to solve the aforementioned problems, and the objective of the present invention is to provide a method for manufacturing shoes using an eco-friendly material that maximizes the durability, comfort, lightness, and eco-friendly characteristics of the shoes and can reduce carbon emissions compared to existing materials.

[0013] The objectives of the present invention are not limited to those mentioned above, and other unmentioned objectives will be clearly understood by those skilled in the art from the description below.

[0014] To achieve the above objective, the present invention is characterized by comprising the steps of: preparing a mixture of a bio-based polymer and a natural fiber by grinding; mixing an auxiliary additive with the ground bio-based polymer and the natural fiber; manufacturing a composite material for a shoe upper by compression molding the mixed material at a high temperature; and processing the manufactured composite material into a desired shape by cooling and cutting it.

[0015] In addition, the preparation step for grinding and mixing the bio-based polymer and the natural fiber is characterized by including the step of melting the bio-based polymer by heating it to a temperature of 120°C to 160°C, the step of drying the natural fiber to 50°C or lower to control the moisture content to less than 10%, and the step of homogenizing the dried natural fiber and the melted bio-based polymer by mixing them.

[0016] In addition, the step of manufacturing a composite material for a shoe upper by compression molding at a high temperature is characterized by including the step of molding the mixed material by compressing it at a pressure of 5 to 10 MPa and the step of maintaining the molded composite material for at least 10 minutes to ensure uniformity.

[0017] In addition, the step of cooling and cutting the manufactured composite material to process it into a desired shape is characterized by including the step of cooling the compression-molded material to 25°C or lower, and the step of cutting and processing the cooled material into a size and shape suitable for making a shoe upper.

[0018] In addition, the mixing ratio of the bio-based polymer and natural fiber used is characterized by being composed of 60 to 70 weight% of the bio-based polymer, 20 to 30 weight% of the natural fiber, and 5 to 10 weight% of the auxiliary additive.

[0019] The present invention utilizes bio-based polymers to significantly reduce carbon emissions compared to conventional petroleum-based synthetic materials. This contributes to minimizing environmental impact during the production process and realizing a sustainable manufacturing process.

[0020] Furthermore, composite materials combining natural fibers and bio-based polymers offer excellent biodegradability and recyclability. As a result, waste naturally decomposes after use, reducing environmental pollution and enabling resource circulation through the recycling process.

[0021] Furthermore, the composite material of the present invention possesses lightness, durability, and elasticity simultaneously, significantly improving the wearing comfort of the shoe. In particular, the breathability and moisture absorption of natural fibers help maintain a comfortable state for the user's feet, while the strength and flexibility of the bio-based polymer provide durability with minimal deformation or damage even after long-term use.

[0022] FIG. 1 is a flowchart illustrating a method for manufacturing shoes using an eco-friendly material according to a preferred embodiment of the present invention.

[0023] FIG. 2 is a flowchart showing the grinding and mixing preparation steps according to a preferred embodiment of the present invention.

[0024] FIG. 3 is a flowchart showing the step of mixing auxiliary additives according to a preferred embodiment of the present invention.

[0025] FIG. 4 is a flowchart showing the steps for manufacturing a composite material according to a preferred embodiment of the present invention.

[0026] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail 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 merely 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 only by the scope of the claims.

[0027] Specific details for implementing the present invention will be described in detail with reference to the drawings attached below. Regardless of the drawings, identical reference numerals refer to identical components, and "and / or" includes each of the mentioned items and all combinations of one or more.

[0028] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical scope of the present invention.

[0029] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0030] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0032] FIG. 1 is a flowchart showing a method for manufacturing shoes using an eco-friendly material according to a preferred embodiment of the present invention, FIG. 2 is a flowchart showing a grinding and mixing preparation step according to a preferred embodiment of the present invention, FIG. 3 is a flowchart showing a step of mixing an auxiliary additive according to a preferred embodiment of the present invention, and FIG. 4 is a flowchart showing a step of manufacturing a composite material according to a preferred embodiment of the present invention.

[0033] As illustrated in FIGS. 1 to 4, the present invention relates to an eco-friendly shoe manufacturing method for manufacturing a composite material for a shoe upper using a bio-based polymer and natural fibers.

[0034] The present invention provides a composite material that overcomes the disadvantages of existing shoe materials, enhances eco-friendliness, and ensures elasticity and durability.

[0035] The specific details for implementing the invention are as follows.

[0036] First, bio-based polymers and natural fibers are prepared during the material preparation stage. Polylactic acid (PLA) extracted from corn or soybean-based bioresin is used as the bio-based polymer, while bamboo fiber, hemp fiber, or regenerated cellulose fiber is adopted as the natural fiber.

[0037] Bio-based polymers are melted by heating to a temperature between 120°C and 160°C, and natural fibers are dried at 50°C or below to control the moisture content to less than 10%. This drying process is essential to maintain the quality of the fibers and ensure uniformity during the mixing process.

[0038] Next, in the mixing step, the melted bio-based polymer and the dried natural fiber are mixed in a specific weight ratio. The ideal mixing ratio is 60 to 70 weight percent of the bio-based polymer, 20 to 30 weight percent of the natural fiber, and 5 to 10 weight percent of the auxiliary additive.

[0039] Auxiliary additives play a role in supplementing the flexibility and strength of the composite material and use eco-friendly materials that do not compromise biodegradability. The mixing process is carried out uniformly at high temperatures to ensure a homogeneous composite material, and if necessary, mixing equipment is used to ensure that the fibers and polymers are completely bonded.

[0040] In the compression molding step, the mixed material is compressed at a pressure of 5 to 10 MPa to manufacture a composite material for shoe uppers. This step is performed at a temperature of 120°C to 160°C to ensure the uniformity and strength of the composite material, and the compressed material is maintained for about 10 minutes. By maintaining uniform pressure and temperature during the molding process, the physical properties of the composite material are optimized.

[0041] Subsequently, in the cooling and processing stage, the molded composite material is cooled to below 25°C and then cut and processed to adjust it to a shape and size suitable for manufacturing shoe uppers. The cooling process ensures the thermal stability of the material, while the processing stage transforms the composite material into various forms to meet diverse shoe design requirements. The cut composite material is assembled into a shoe upper and used to produce the final product.

[0042] Shoes manufactured according to an embodiment of the present invention exhibit superior lightness and comfort compared to conventional shoe materials, and provide eco-friendly value through the biodegradability and recyclability of the material. Furthermore, sustainable production is possible by reducing carbon emissions and minimizing waste during the manufacturing process.

[0043] The technical effects of the present invention are clearly evident not only in the shoe manufacturing process but also in the quality of the resulting product. The manufactured shoes are highly durable and can maintain performance under various climatic conditions. In particular, the composite material combining bio-based polymers and natural fibers provides both warmth and breathability, ensuring a comfortable fit suitable for both summer and winter.

[0044] This process is applicable to various shoe designs and applications, and sets a new standard for producing high-quality shoes using eco-friendly materials. Through this process, the embodiments of the present invention resolve environmental issues arising from conventional shoe manufacturing processes and realize an innovative technology that satisfies both high performance and eco-friendliness.

[0045] More specifically, first, the material preparation step is an important starting point of the present invention. In this step, bio-based polymers and natural fibers are prepared and pre-treated, respectively, to achieve optimal performance.

[0046] As bio-based polymers, corn-derived polylactic acid (PLA), soybean-based bioresins, or sugarcane-based polymers may be used. These bio-based polymers are manufactured from renewable raw materials and are characterized by biodegradability and low carbon emissions. The polymer is melted using heating equipment at a temperature of 120°C to 160°C and continuously stirred to maintain a uniform state.

[0047] Natural fibers used include bamboo fiber, hemp fiber, or regenerated cellulose fiber. Natural fibers possess excellent hygroscopicity and breathability, as well as eco-friendly characteristics, which provide complementary properties when combined with bio-based polymers. The moisture content of these fibers is controlled to less than 10% using drying equipment at temperatures below 50°C, which is important for preventing non-uniformity during the mixing process and maintaining the quality of the material.

[0048] In the next step, the mixing step, a composite material is manufactured by mixing the prepared bio-based polymer and natural fibers in a certain ratio. The ideal mixing ratio is 60–70% by weight of bio-based polymer, 20–30% by weight of natural fibers, and 5–10% by weight of auxiliary additives. The auxiliary additives serve to complement the flexibility and strength of the composite material and are selected as eco-friendly materials to maintain biodegradability.

[0049] For example, glycerin or natural resin-based additives can be used. The mixing process uses high-temperature mixing equipment to ensure that the molten bio-based polymer and the dried natural fiber are completely combined.

[0050] During this process, the temperature and rotation speed are precisely controlled to ensure homogeneity of the mixture and to ensure that the natural fibers are evenly distributed. This process is carried out for 5 to 10 minutes, and after mixing, the material is adjusted to have a homogeneous state with high viscosity.

[0051] After mixing is complete, the process moves to the compression molding stage. In this stage, the mixed composite material is compressed under high temperature and high pressure conditions to form a material suitable for manufacturing shoe uppers. Compression molding is performed using temperatures ranging from 120°C to 160°C and pressures of 5 to 10 MPa. This process enhances the physical strength and durability of the composite material and provides the manufactured material with the flexibility to be deformed into various shapes.

[0052] During the molding process, the material is maintained in a compressed state for at least 10 minutes to ensure that the internal structure is formed uniformly. In the compression molding stage, maintaining a uniform temperature distribution and pressure is very important, which allows for stable assurance of the material's quality.

[0053] The molds used in this process can be adjusted to fit various shoe designs, and the molded material maintains a smooth surface and high durability.

[0054] The composite material, once molded, undergoes a cooling and processing step. In this step, the molded composite material is cooled to 25°C or lower using cooling equipment. The cooling process ensures the thermal stability of the material and prevents deformation that may occur during subsequent processing.

[0055] The cooled material is adjusted to a size and shape suitable for making shoe uppers using cutting and processing equipment. During the cutting process, precise laser cutting technology is used to minimize damage to the material, and the processed material is ready to be assembled into a shoe upper. The manufactured upper is transformed into a finished product through an assembly process to suit various shoe styles.

[0056] The footwear manufactured according to an embodiment of the present invention exhibits excellent lightness and comfort, and demonstrates superior performance under various climatic conditions.

[0057] In particular, the combination of bio-based polymers and natural fibers provides both warmth and breathability, ensuring a comfortable fit for the user in both summer and winter. Furthermore, the manufactured materials are highly durable and offer reliability with minimal deformation or damage even after prolonged use.

[0058] This technology is applicable not only to the footwear industry but also to various fields such as bags, clothing, and automotive interiors, setting a new standard for products utilizing eco-friendly materials.

[0059] The process of the present invention is compatible with existing manufacturing processes and offers high economic practicality in that it does not require additional large-scale facility investment. Through this, manufacturers gain a competitive edge by providing environmentally friendly products while compensating for the shortcomings of existing processes.

[0060] In conclusion, the present invention proposes a method for manufacturing a composite material that simultaneously satisfies eco-friendliness and functionality in shoe manufacturing, thereby enabling the simultaneous realization of environmental problem solving and sustainable production.

[0061] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. Preparation step for grinding and mixing bio-based polymers and natural fibers; A step of mixing auxiliary additives with pulverized bio-based polymers and natural fibers; A step of manufacturing a composite material for a shoe upper by compression molding the mixed material at a high temperature; and A method for manufacturing shoes using eco-friendly materials, characterized by including the step of cooling and cutting the manufactured composite material to process it into a desired shape.

2. In Paragraph 1, The preparation step for grinding and mixing bio-based polymers and natural fibers is, A step of melting a bio-based polymer by heating it to a temperature of 120°C to 160°C; A step of drying natural fibers at 50°C or below to control the moisture content to less than 10%; and A method for manufacturing shoes using eco-friendly materials, characterized by including the step of mixing and homogenizing dried natural fibers and melted bio-based polymers.

3. In Paragraph 1, The step of manufacturing a composite material for a shoe upper by compression molding at high temperature is, A step of forming the mixed material by compressing it at a pressure of 5 to 10 MPa; and A method for manufacturing shoes using eco-friendly materials, characterized by including a step of maintaining the molded composite material for at least 10 minutes to ensure uniformity.

4. In Paragraph 1, The step of cooling and cutting the manufactured composite material to process it into a desired shape is, A step of cooling the compression-molded material to 25°C or lower; and A method for manufacturing shoes using eco-friendly materials, characterized by including the step of cutting and processing the cooled material into a size and shape suitable for making a shoe upper.

5. In Paragraph 1, The mixing ratio of bio-based polymers and natural fibers used is, 60 to 70 weight% of bio-based polymer; 20 to 30 weight percent natural fibers; and A method for manufacturing shoes using an eco-friendly material, characterized by comprising 5 to 10 weight percent of auxiliary additives.

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