Description:FIELD OF THE INVENTION
The present invention relates to the field of composite materials, specifically to the development and application of natural fiber-reinforced polymer composites. More particularly, it pertains to the fabrication of an epoxy-based composite material reinforced with rice straw fibers, aimed at improving the mechanical properties and sustainability of polymer composites by utilizing agricultural waste as a reinforcing agent.
BACKGROUND OF THE INVENTION
References which are cited in the present disclosure are not necessarily prior art and therefore their citation does not constitute an admission that such references are prior art in any jurisdiction. All publications, patents and patent applications herein are incorporated by reference to the same extent as if each individual or patent application was specifically and individually indicated to be incorporated by reference.
Nowadays in many agricultural regions, the widespread practice of carelessly burning rice straw following the rice harvest is increasing rapidly. Although convenient, this technique poses a substantial environmental risk. Rice straw combustion emits a wide range of harmful greenhouse gases into the environment, including carbon dioxide, methane, and fine particles. These emissions not only increase localized air pollution but also contribute significantly to the global load of greenhouse gases. To address this issue, a sustainable composite material composed of rice straw fiber and epoxy resin can be developed.
Melissa AugustineSaidi, Alexander Gorin, Soon Kok Heng, and Elammaran Jayamani in their paper “Effect of Layout Sequence on the Integrity of Poly-lactic Acid and Rice Straw Fiber Composites” mentioned the development of a composite material from both renewable resources and biodegradable materials: modification of poly-lactic acid (PLA) with rice straw fiber loading.
Xianjun Li, Zhiyong Cai, Jerrold E. Winandy, and Altaf H. Basta in their paper “Effect of oxalic acid and steam pretreatment on the primary properties of UF-bonded rice straw particleboards” evaluated the effect of oxalic acid (OA) and steam-pretreatment on the primary performance of rice straw particleboards as well as the effect of various treatment conditions on carbohydrates released from rice straw particles.
Sabzoi Nizamuddin, Nazia Hossain, Sundus Saeed Qureshi, Amal M. Al-Mohaimeed, Faisal Amri Tanjung, Mohamed S. Elshikh, M.T.H. Siddiqui, Humair Ahmed Baloch, Nabisab Mujawar Mubarak, Gregory Griffin, and Madapusi Srinivasan in their paper “Experimental investigation of physicochemical, thermal, mechanical and rheological properties of polylactide/rice straw hydrochar composite” mentioned about the concept of rice straw hydrochar incorporation at different loadings (5%, 10%, 15%, and 20%), produced from microwave-induced hydrothermal carbonization (HTC) of rice straw to polylactide (PLA) for production of polylactide/hydrochar (PLA/HC) composites
Neenu Poonia, Vinod Kadam, Neelam M. Rose, and Saroj Yadav in their paper “Rice Straw Reinforced Biocomposite: A Sustainable Development” mentioned an Epoxy resin-based composite material made using Rice straw fiber to replace the use of current resources such as wood and at the same time using the rice straw effectively to avoid pollution caused due to its burning.
Mukul Sain in his paper “Production of bioplastics and sustainable packaging materials from rice straw to eradicate stubble burning: A Mini-Review” mentioned a biodegradable rice straw-based plastic material. These rice straw-based bioplastics are great alternatives to synthetic plastics and at the same time solve the issue of pollution caused by the burning of rice straw.
Chikesh Ranjan, Zaid Ahmed, Sonu Raj Kumar, Abhishek Kumar, Abhay Kumar, and Kaushik Kumar in their paper “Fabrication and strength analysis of rice straw fibers reinforced epoxy biodegradable composite” mentioned the study about fabrication and strength analysis of rice straw fiber reinforced epoxy biodegradable composite for the use of the industrial application.
Several patents issued for composites but none of these are related to the present invention. Patent US10639826B2 this invention provides a method for making a conductive pre-impregnated composite sheet includes the steps of joining a nanomaterial composite sheet, a fiber-reinforcing sheet and a resin system to form a combined sheet, heating the combined sheet, compacting the combined sheet, and cooling the combined sheet to form conductive pre-impregnated composite sheet including the fiber-reinforcing sheet, and the nanomaterial composite sheet coupled to the fiber-reinforcing sheet, wherein the fiber-reinforcing sheet and the nanomaterial composite sheet are embedded in the resin system.
Another patent AU2017204658B2 relates to a composite material that includes a layer of reinforcing fibers impregnated with a curable resin matrix and a plurality of electrically conductive composite particles positioned adjacent or in proximity to the reinforcing fibers. Each of the electrically conductive composite particles is composed of a conductive component and a polymeric component, wherein the polymeric component includes one or more polymers that are initially in a solid phase and are substantially insoluble in the curable resin, but is able to undergo at least partial phase transition to a fluid phase during a curing cycle of the composite material.
Another patent US10252505B2 relates to a composite laminate is made by providing at least a first composite ply and a second composite ply, each having longitudinally oriented fibers in a thermoplastic matrix. The second composite ply is disposed on, and in transverse relation to, the first composite ply. Preferably, the second ply is disposed at 90° relative to the first ply. An article can be manufactured by providing a core material and applying a reinforcing material to a portion of the core material. The reinforcing material is a reinforcing composite ply or a composite laminate as described herein. Optionally, the core material is a prepreg that may be a composite laminate
Another patent US11462728B2 This invention includes a method of producing a structured composite material is described. A porous media is provided, an electrically conductive material is deposited on surfaces or within pores of the plurality of porous media particles, and an active material is deposited on the surfaces or within the pores of the plurality of porous media particles coated with the electrically conductive material to coalesce the plurality of porous media particles together and form the structured composite material.
OBJECTS OF THE INVENTION
Main object of the present invention is to development of rice straw fiber-reinforced epoxy composite material.
Another object of the present invention is to enhance the mechanical properties (such as tensile strength, flexural strength, and impact resistance) of epoxy resin through reinforcement with rice straw fibers.
Another object of the present invention is to explore and optimize the processing parameters for effective dispersion and adhesion of rice straw fibers within the epoxy matrix.
Another object of the present invention is to provide a cost-effective and lightweight alternative to conventional synthetic fiber-reinforced composites.
Another object of the present invention is to promote the use of biodegradable and renewable natural fibers in composite manufacturing, reducing dependence on non-renewable and non-biodegradable materials.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention.
This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings.
The present invention provides a novel method for developing a sustainable composite material by reinforcing epoxy resin with rice straw fibers, an abundant agricultural byproduct. This invention addresses the growing demand for environmentally friendly and cost-effective composite materials by utilizing natural fibers as an alternative to conventional synthetic reinforcements. In this invention, rice straw fibers are extracted, treated, and incorporated into an epoxy resin matrix to produce a composite material with enhanced mechanical and physical properties. The reinforcement process improves the composite's tensile strength, flexural strength, and impact resistance while maintaining its lightweight nature. The rice straw fibers contribute to the overall biodegradability and sustainability of the composite, offering an eco-friendly alternative suitable for various industrial applications. The process includes fiber preparation (cleaning, cutting, and optional chemical treatment), proper blending with epoxy resin, curing under controlled conditions, and evaluation of the composite's performance through mechanical and thermal testing. This invention not only promotes the effective use of agricultural waste but also supports sustainable materials engineering, making it applicable in sectors such as automotive parts, building materials, furniture, and packaging.
Herein enclosed a method for preparing a rice straw fiber-reinforced epoxy composite material comprising the steps of:
collecting rice straw fibers;
cleaning the rice straw fibers by immersing them in a sodium chloride (NaCl) solution to remove impurities;
rinsing the fibers with clean water and sun-drying them to eliminate moisture; preparing a resin mixture by combining epoxy resin (LY556) and a hardener in a predetermined ratio;
adding the dried rice straw fibers to the resin mixture with continuous stirring to ensure uniform coating and bonding;
transferring the fiber-resin mixture into a pre-lubricated mold;
sealing the mold to allow undisturbed curing; and
demolding the composite after full solidification to obtain a finished composite material with enhanced mechanical properties.
The method as claimed in claim 1, wherein the rice straw fibers are dried under direct sunlight for a period of 2 to 3 days to ensure complete moisture removal and to preserve the structural integrity of the fibers.
The epoxy resin and hardener are mixed in a weight ratio of 10:1 to form a uniform and reactive composite matrix.
The mold is coated with a release agent or lubricant prior to filling, to facilitate easy removal of the cured composite material.
The cured composite material is post-processed by trimming or sanding to achieve the required dimensions and surface finish.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated embodiments of the subject matter will be understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
Fig.1 Materials Required for the manufacturing process.
Fig.2 The resin is being poured in the laminated and lubed mold.
Fig.3 Rice Straw Composite
DETAILED DESCRIPTION OF THE INVENTION
The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims.
It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a",” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
In addition, the descriptions of "first", "second", “third”, and the like in the present invention are used for the purpose of description only, and are not to be construed as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may include at least one of the features, either explicitly or implicitly.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In some embodiments of the present invention relates to the development of an eco-friendly composite material reinforced with rice straw fibers and bonded using epoxy resin (LY556).
In some embodiments of the present invention, the process begins with the collection of raw materials including rice straw fibers, epoxy resin, hardener, NaCl solution, molds, and supporting tools.
In some embodiments of the present invention, the rice straw fibers, selected for their natural availability and mechanical properties, are first cleaned using a sodium chloride (NaCl) solution to remove dirt and impurities, then rinsed with water and sun-dried to prevent moisture-related defects.
In some embodiments of the present invention, the epoxy resin and hardener are measured in appropriate proportions and mixed thoroughly to form a uniform matrix. The dried fibers are then combined with the resin mixture in a mold that has been lubricated to prevent adhesion.
In some embodiments of the present invention, the mixture is allowed to cure undisturbed for several days, ensuring complete bonding between the resin and fibers.
In some embodiments of the present invention, after curing the solidified composite is demolded, and any excess material is trimmed or sanded to achieve the desired finish.
In some embodiments of the present invention, this process results in a lightweight, cost-effective, and sustainable composite material suitable for a range of industrial applications.
Herein enclosed a method for preparing a rice straw fiber-reinforced epoxy composite material comprising the steps of:
collecting rice straw fibers;
cleaning the rice straw fibers by immersing them in a sodium chloride (NaCl) solution to remove impurities;
rinsing the fibers with clean water and sun-drying them to eliminate moisture; preparing a resin mixture by combining epoxy resin (LY556) and a hardener in a predetermined ratio;
adding the dried rice straw fibers to the resin mixture with continuous stirring to ensure uniform coating and bonding;
transferring the fiber-resin mixture into a pre-lubricated mold;
sealing the mold to allow undisturbed curing; and
demolding the composite after full solidification to obtain a finished composite material with enhanced mechanical properties.
The method as claimed in claim 1, wherein the rice straw fibers are dried under direct sunlight for a period of 2 to 3 days to ensure complete moisture removal and to preserve the structural integrity of the fibers.
The epoxy resin and hardener are mixed in a weight ratio of 10:1 to form a uniform and reactive composite matrix.
The mold is coated with a release agent or lubricant prior to filling, to facilitate easy removal of the cured composite material.
The cured composite material is post-processed by trimming or sanding to achieve the required dimensions and surface finish.
EXAMPLE 1
BEST METHOD
In this Invention, we have proposed a sustainable composite material composed of rice straw fiber and epoxy resin can be developed. The raw materials required for the efficient production of rice straw fiber-reinforced epoxy composite materials are gathered during the first step of the manufacturing process as shown in figure 1. These materials involve rice straw fibers, a mold, epoxy resin as well as a hardener, NaCl solution, a beaker, measuring cylinder, glass rod, plastic sheet as well as, a lubricant. Rice straw fibers from agricultural sources are chosen as reinforcing components due to their natural availability and acceptable mechanical qualities. The NaCl solution acts as a cleaning agent for the rice straw fibers, removing impurities and pollutants to improve the quality of the resulting composite material. Epoxy resin, specifically the LY556 variety, was chosen because it is compatible with rice straw fibers and provides great adhesion and mechanical strength when hardened. Simultaneously, the workspace is carefully set up to allow for safe and efficient manufacturing processes. This includes verifying essential equipment like beakers, molds, and glass rods are available and working properly, as well as safety gear like gloves, goggles, and protective clothes.
The cleaning step is the next stage in the production process. To begin, the rice straw fibers are carefully submerged in a solution containing sodium chloride (NaCl), commonly called salt. The NaCl solution works as a powerful cleaning agent, loosening and removing dirt, dust, oils, and other undesirable particles that could impair the composite material's performance and appearance. After cleaning, the rice straw fibers are rinsed with clean water. This rinsing process is critical for removing any residual salt and contaminants that may remain on the fiber’s surface. The washed fibers are then carefully spread out before being thoroughly dried under sunlight. Typically, this drying process takes several days to eliminate moisture from the fibers. By this step, the structural integrity of the fibers is retained along with reducing the chances of mold formation.
In the Epoxy Resin Preparation stage, the first step is to precisely measure the epoxy resin (LY556) and hardener in the proper ratio. After measuring, the resin and hardener are carefully blended in a mixing container. To create a uniform blend, the mixture must be thoroughly stirred with a continuous and vigorous motion. Proceeding on to the Composite Mixing and Molding stage, the dried rice straw fibers are added to a clean, dry mixing container. The epoxy resin mixture is slowly poured into the laminated mold container containing the rice straw fibers, and constant stirring is maintained.
This guarantees that the resin completely coats and penetrates the fibers, resulting in strong bonding and reinforcing qualities. After the composite mixture has been blended, it is put into a pre-prepared mold that matches the desired shape and dimensions of the finished product. Before pouring the slurry into the mold, lube the inside surfaces. This lubricant prevents the resin mixture from adhering too strongly to the mold’s surface, making demolding easier later in the process.
Finally, once the composite mixture is thoroughly spread throughout the mold, the lid is tightly secured. This phase is essential for avoiding any interruption or contamination during the curing process, which may damage the finished composite material. By maintaining a sealed environment within the mold, the curing process may continue without interruption, allowing the resin to fully solidify and connect with the rice straw fibers, resulting in a high-quality composite material with the appropriate mechanical qualities.
The mold was allowed to remain undisturbed for a few days until the epoxy resin had fully solidified. Firstly, the hardened composite material is carefully and precisely removed from the mold. This method involves careful attention to detail to prevent structural damage or distortion. Following extraction from the mold, any excess material is carefully cut or sanded away to achieve accurate dimensions and the necessary surface smoothness. the composite fresh out of the mold.
ADVANTAGES OF THE INVENTION:
Utilizing rice straw fibers as reinforcement promotes waste reduction and sustainable resource utilization, contributing to environmental conservation.
Incorporating rice straw fibers enhances mechanical properties, providing improved strength, stiffness, and impact resistance to the composite material.
Rice straw fiber-reinforced epoxy composites offer a lightweight alternative without compromising strength, ideal for weight-sensitive applications such as aerospace and transportation.
Epoxy resin provides excellent corrosion resistance, making the composite material suitable for outdoor and marine applications with prolonged exposure to harsh environments.
The mouldability of the composite material allows for complex shapes and customized solutions tailored to specific application requirements.
Rice straw fibers offer inherent thermal insulation properties, making the composite material suitable for applications requiring thermal insulation, such as building insulation and thermal packaging.

, Claims:1. A method for preparing a rice straw fiber-reinforced epoxy composite material comprising the steps of:
a) collecting rice straw fibers;
b) cleaning the rice straw fibers by immersing them in a sodium chloride (NaCl) solution to remove impurities;
c) rinsing the fibers with clean water and sun-drying them to eliminate moisture; preparing a resin mixture by combining epoxy resin (LY556) and a hardener in a predetermined ratio;
d) adding the dried rice straw fibers to the resin mixture with continuous stirring to ensure uniform coating and bonding;
e) transferring the fiber-resin mixture into a pre-lubricated mold;
f) sealing the mold to allow undisturbed curing; and
g) demolding the composite after full solidification to obtain a finished composite material with enhanced mechanical properties.
2. The method as claimed in claim 1, wherein the rice straw fibers are dried under direct sunlight for a period of 2 to 3 days to ensure complete moisture removal and to preserve the structural integrity of the fibers.
3. The method as claimed in claim 1, wherein the epoxy resin and hardener are mixed in a weight ratio of 10:1 to form a uniform and reactive composite matrix.
4. The method as claimed in claim 1, wherein the mold is coated with a release agent or lubricant prior to filling, to facilitate easy removal of the cured composite material.
5. The method as claimed in claim 1, wherein the cured composite material is post-processed by trimming or sanding to achieve the required dimensions and surface finish.