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Fabrication and Characterization of Bamboo—Epoxy Reinforced Composite for Thermal Insulation

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Open Journal of Composite Materials 2024年第1期14卷 15-32页

作者： Nandavardhan Reddy Kopparthi jens schuster Yousuf Pasha Shaik Institute of Polymer Technology West Palatine University of Applied Sciences Kaiserslautern Pirmasens Germany

As global warming intensifies, researchers worldwide strive to develop effective ways to reduce heat transfer. Among the natural fiber composites studied extensively in recent decades, bamboo has emerged as a prime candidate for reinforcement. This woody plant offers inherent strengths, biodegradability, and abundant availability. Due to its high cellulose content, its low thermal conductivity establishes bamboo as a thermally resistant material. Its low thermal conductivity, enhanced by a NaOH solution treatment, makes it an excellent thermally resistant material. Researchers incorporated Hollow Glass Microspheres (HGM) and Kaolin fillers into the epoxy matrix to improve the insulating properties of bamboo composites. These fillers substantially enhance thermal resistance, limiting heat transfer. Various compositions, like (30% HGM + 25% Bamboo + 65% Epoxy) and (30% Kaolin + 25% Bamboo + 45% Epoxy), were compared to identify the most efficient thermal insulator. Using Vacuum Assisted Resin Transfer Molding (VARTM) ensures uniform distribution of fillers and resin, creating a structurally sound thermal barrier. These reinforced composites, evaluated using the TOPSIS method, demonstrated their potential as high-performance materials combating heat transfer, offering a promising solution in the battle against climate change.

关键词： Thermal Insulator Rooftiles Hollow Glass Microspheres Bamboo Kaolin Epoxy VARTM Process Thermal Conductivity Mechanical Properties

Enhancing Stress Intensity Factor Reduction in Cracks Originating from a Circular Hole in a Rectangular Plate under Uniaxial Stress through Piezoelectric Actuation

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Materials Sciences and Applications 2024年第1期15卷 1-14页

作者： Gopi Krishna Konda jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

Circular holes are commonly employed in engineering designs;however, they often serve as locations where cracks initiate and propagate. This paper explores a novel approach to structural repair by utilizing piezoelectric actuators. The primary focus of this study is to investigate the influence of an adhesively bonded piezoelectric actuator patch placed above a circular hole on the stress intensity factor (SIF) in an aluminium plate. The plate is subjected to uniaxial tensile stress, while the piezoelectric actuator is excited with varying voltage levels. The analysis is conducted using the finite element method (FEM), a powerful numerical technique for simulating complex structures. The study assesses the stress distribution and employs the SIF as an adequate criterion for evaluating the impact of different patch configurations. The results indicate a strong correlation between the applied voltage and the SIF. Whether the SIF increases or decreases depends on the polarization of the piezoelectric actuator. Particularly noteworthy is the finding that rectangular patches in a horizontal orientation significantly reduce the SIF compared to other patch geometries. Moreover, double-sided patches exhibit a pronounced decrease in the SIF compared to single-sided patches. In summary, this research underscores the potential of piezoelectric actuators in mitigating stress intensity in structures with circular hole with crack initiation. It offers valuable insights into the influence of applied voltage, patch geometry, and patch placement on the SIF, thereby contributing to developing effective strategies for enhancing structural integrity.

关键词： Piezoelectric Actuators Stress Intensity Factor (SIF) Aluminium Plate Voltage Finite Element Method (FEM)

Development of Kaolin and Glass Fiber Reinforced Composites for Thermal Insulating Panels

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Open Journal of Composite Materials 2024年第1期14卷 44-59页

作者： Jagadiswar Reddy Tippi Reddy jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

In our modern world, where conserving energy is highly valued, thermal insulation panels play a crucial role in reducing heat transfer between two spaces, surfaces, or materials. They are used to enhance the energy efficiency of various industrial applications by minimizing heat loss and temperature control. These panels function as silent protectors, aiding in reducing energy consumption and making things more sustainable and better for the environment. This is where composite materials come in;they are known for their lightweight nature, high strength-to-weight ratio, and excellent thermal insulation properties and have gained significant attention. Researchers are actively engaged in various studies aimed at enhancing these materials further. This research project focuses on the development of kaolin and glass fiber-reinforced composites for thermally insulating panels, to which natural strengthening materials like corn husk and bamboo fibers are added. The aim is to create cost-effective and efficient composite materials for thermal insulation applications by incorporating these components with a binder consisting of potassium silicate, hydroxide, and distilled water. This project involves conducting compression tests, bending tests, impact tests, thermal conductivity measurements, and microscopic analysis to evaluate the mechanical and thermal properties of the developed composites. The profound impact of these engineered composites on thermal insulation panels stands to revolutionize energy conservation efforts, offering a potent avenue to minimize heat loss and enhance overall energy efficiency across an array of industrial sectors.

关键词： Kaolin Glass Fiber Corn Husk Bamboo Potassium Silicate Potassium Hydroxide

Development of Morus alba Reinforced Poly-Lactic Acid with Elevated Mechanical and Thermal Properties

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Materials Sciences and Applications 2024年第7期15卷 186-200页

作者： Girish Kumar Reddy Madda jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

This research investigates the mechanical and thermal properties of Morus alba combined with polylactic acid in comparison with other natural fibers. The study uses three different fiber and PLA compositions - 20%, 30%, and 40% respectively - to produce composite materials. In addition, another composite with the same fiber volume is treated with a 4% NaOH solution to improve mechanical properties. The composites are processed by twin-screw extrusion, granulation, and injection molding. Tensile strength measurements of raw fibers and NaOH-treated fibers were carried out using a single-fiber tensile test with a gauge length of 40 mm. It was observed that the NaOH surface treatment increases the resistance against tensile loading and exhibited improved properties for raw fiber strands. The diameter of the fibers was measured using optical microscopy. During this research, flexural tests, impact tests, differential scanning calorimetry (DSC), and heat deflection temperature measurements (HDT) were conducted to evaluate the mechanical and thermal properties of the developed composite samples. The results indicate that the mechanical properties of NaOH-treated Morus alba-reinforced polylactic acid outperform both virgin PLA samples and untreated Morus alba samples.

关键词： Morus Alba Fiber (MAF) White Mulberry Polylactic Acid (PLA) Sodium Hydroxide (NaOH) Solution Single Fiber Tensile Test Thermal Stability Optical Microscopy

Increased Elongation at Breaking Point with Improved Mechanical Characteristics in PLA

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Open Journal of Composite Materials 2023年第2期13卷 13-28页

作者： Vishal Atnurkar jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

The main goal of this research was to increase the strength of Polylactic acid (PLA), an entirely biodegradable thermoplastic polyester, and an increase in elongation at the breaking point compared to neat PLA. To this end, S1, S2, and S3 were melt blended with various percentages of Zeolite, Glycerol, White vinegar, green camphor, Eucalyptus, and Carom seed oils. Here, the addition of glycerol, eucalyptus, and carom seed oils demonstrated an average improvement in impact and tensile strength of 13.44% and 14.55% respectively. Zeolite and glycerol work together as binding agents to improve stress transfer in the matrix, which increases tensile and flexural modulus as well as toughness elongation (>10%). The addition of the aforementioned materials led to an increase in the glass transition temperature and melting temperature, according to further DSC investigation. The thermal stability increased gradually, according to TGA data.

关键词： Polylactic Acid Biodegradable Thermoplastic Polyester Elongation Zeolite Glycerol Toughness Elongation Thermal Stability

Exploring the Potential to Uniquely Manufacture Curved VARTM Epoxy Composites Using Cost-Effective FDM Molds

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Open Journal of Composite Materials 2020年第3期10卷 45-65页

作者： Syed Monis Raza Kazmi jens schuster Johannes Lutz Hochschule Kaiserslautern University of Applied Sciences Pirmasens Germany

The Resin Infusion or the VARTM (Vacuum Assisted Resin Transfer Molding) process has significant potential to be used to manufacture curved composites. Another way to produce curved or complex geometry is to use 3D printers. 3D or FDM (Fused Deposition Modelling) printers are now being used to produce relatively cheaper curved parts using thermoplastics such as PLA. However, the strength and mechanical performance of these parts is limited and can be enhanced if the polymer is reinforced with a type of fiber for instance. Research is being carried out to produce fiber rein-forced thermoplastic composites but that process is expected to be more expensive than the alternative methods such as injection or compression molding. Furthermore, to understand the manufacture of a hybrid composite using thermoplastics, fibers and epoxy resin, research and investigation need to be carried out. In this research, there are single-sided, double-sided, reusable, disposable and consumable molds. Most of the molds were created either using an FDM printer or manually. These molds were then used to manufacture flat and curved composite structures via the resin injection process, i.e. VARTM with epoxy resin system and glass/carbon/flax fiber reinforcement. By replacing the costly metallic molds by significantly cheaper molds, the cost of production was expected to further reduce. Furthermore, using double-sided PLA molds was not expected to be a threat to the overall cost of the composite part in question compared to double-sided matched molds used in compression molding. Shear

关键词： 3D Printing FDM VARTM Curved Composites 3D Molds Reusable Molds Consumable Molds Disposable Molds

Manufacturing and Product Analysis of Non-Woven and Paper Based Epoxy Composites

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Open Journal of Composite Materials 2023年第2期13卷 29-45页

作者： Vinay Kumar Kotike jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

Fiber-reinforced polymer composites are used in a wide variety of applications due to their many advantages, such as relatively low production costs, ease of fabrication, and superior strength compared to pure polymer resins. Polymer reinforcement can be either synthetic or natural. Synthetic fibers such as carbon have high specific strength, but their application fields are limited due to their high manufacturing cost. Recently, interest in recycled fiber-based composites has increased due to their many advantages. In this context, research has been carried out to better utilize non-woven and paper-based materials to make value-added products. The aim of the current research work is to compare the mechanical performance of non-woven and paper-based reinforced epoxy composites manufactured by the VARTM process. Mechanical properties such as tensile strength, flexural strength (using three-point bending), impact strength, hardness strength, and water absorption were measured. A multi-criteria decision approach called TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) was used to select the best alternative from the investigated materials.

关键词： Recycled Fibers Nonwovens and Papers VARTM Mechanical Properties TOPSIS

Development of Ecological Absorbent Core Sanitary Pads in Combination of Kenaf and Chitosan Fibers

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Materials Sciences and Applications 2023年第7期14卷 363-381页

作者： Desh Maruthi Jeyakanthan jens schuster Yousuf Pasha Shaik Department of Applied Logistics and Polymer Sciences University of Applied Sciences Kaiserslautern Institute for Plastics Engineering West Pfalz (IKW) Pirmasens Germany

The menstrual cycle is always considered as a big nightmare by many women. This research aims to make this process smooth and safe by developing natural sanitary pads which are used to absorb and retain menstrual blood from the body. Some existing sanitary pads contain 90% plastics made of non-woven polypropylene/polyethylene sheets, super absorbent polymers, and polyethylene back sheets that will take up to 600 - 800 years to decompose. So, biodegradable sanitary pads using natural fibers are the best alternative to eliminate the pads which contain non-biodegradable materials. In this research, nonwoven bamboo will be used as the top layer, nonwoven cotton will be used as the second layer, the absorbent core is to be made by the combination of kenaf and chitosan fibers as the third layer, cotton as the fourth layer, and cornstarch-based bioplastic sheets as the bottom layer. These biodegradable natural materials will change the menstrual process into a healthy one as well as create a robust ecological community.

关键词： Sanitary Pads Biodegradable Kenaf Chitosan Bamboo Cotton Corn-Based Polylactic Acid

Prediction of the Enhanced Out-of-Plane Thermal Conductivity of Carbon Fiber Composites Produced by VARTM

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Open Journal of Composite Materials 2016年第4期6卷 100-111页

作者： jens schuster Martin Schütz Johannes Lutz Laura Lempert Institut für Kunststofftechnik Westpfalz University of Applied Sciences Kaiserslautern Pirmasens Germany

The thermal conductivity of epoxy resin can be increased by a factor of eight to ten by loading with highly conductive particles. However, higher loadings increase the viscosity of the resin and hamper its use for liquid composite molding processes. Thus, the enhancement of the out-of-plane thermal conductivity of carbon composites manufactured by VARTM and accomplished by matrix filling is limited to about 250%. In order to derive higher increases in out-of-plane thermal conductivity, additional measures have to be taken. These consist of introducing thermally conductive fibers in out-of-plane direction of the preform using a 3D-weaving process. Measured out-of-plane thermal conductivities of 3D-woven fabric composites are significantly increased compared to a typical laminated composite. It has been shown that if introducing highly conductive z-fibers, the use of a particle filled resin is not necessary and furthermore should be avoided due to the manufacturing problems mentioned above. An existing analytical model was altered to predict the effective thermal conductivity as a function of the composite material properties such as the thermal conductivities and volume contents of fibers in in-plane and out-of-plane directions, the thermal conductivity of the loaded resin, the grid-density of the out- of-plane fibers, and material properties of the contacting material. The predicted results are compared with measured data of manufactured samples.

关键词： Thermal Conductivity Vacuum Assisted Resin Transfer Molding (VARTM) 3D-Weaving Modeling Woven Fabric Composites