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Post treatment effect on mechanical properties of Reclaimed fiberglass

Luca Damiano

Post treatment effect on mechanical properties of Reclaimed fiberglass.

Rel. Marco Sangermano. Politecnico di Torino, Corso di laurea magistrale in Ingegneria Dei Materiali, 2023

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Composite materials, formed by combining two or more materials with distinct properties, have revolutionized industries by offering unique characteristics not found in individual components. In the marine sector, composites are employed to reduce weight and enhance corrosion resistance. Their applications in the marine sector are diverse, from sports equipment to naval vessels and offshore structures. While composites offer many advantages, they also face challenges, including fatigue behavior and limited recyclability. To address environmental concerns, recycling strategies for Glass Fiber-Reinforced Polymers (GFRPs) are crucial, especially as the demand for composites grows. It is challenging, particularly for thermoset matrices, and requires effective strategies to reduce environmental impact and comply with regulations. The project focus on the recycling of old boat thermoset composite fragments. The procedure is made by several steps. The first step involves thermal recycling, specifically pyrolysis, to break down the organic components of the waste composites into molecular substances. After pyrolysis, calcination is performed to remove remaining char and prepare the fiberglass for further processing. The calcinated fibers are cleaned to remove any remaining particles and impurities. Then the fibers are manually arranged into mats using a steel mesh as a foundation. Chemical treatments are applied to restore the mechanical properties of the recycled fiberglass and re-establish the sizing layer. This includes surface activation, sizing, and optional binding with a binder. To conclude these mats are used in a vacuum Infusion of new Composite where different resins, such as polyester and epoxy, are used. The project focuses on visualizing and analyzing the results of the mechanical tests conducted to understand the efficiency, repeatability, and consistency of the procedure, then to compare the structural and mechanical properties of the Recycled Glass Fiber (RGF) composite with two other types of composites: Virgin glass fiber thermoset composite and 30% recycled glass fiber thermoset composite. The key characteristics examined include volume Fraction of Fibers, fracture Behavior and mechanical properties, such as Flexural Modulus and Flexural Strength, using the ASTM D790 Standard. Volume Fraction of Fibers of RGF composites, whether manually developed or treated with a binder, have a significantly lower fiber volume fraction (between 15% and 20%) compared to virgin fiber composites (around 37%). The failure behavior of RGF composites during testing differs from that of virgin fiber composites. RGF composites tend to exhibit more brittle behavior, similar to ceramic materials, after the yield load. Virgin fiber composites generally have superior mechanical properties. However, Normalizing mechanical properties to a common fiber volume fraction (0.35) reveals some interesting trends. Flexural modulus tends to increase for most samples after normalization, except those with binder-treated mats. Flexural strength shows improvements, especially in samples with fibers treated with sizing. Binder-treated samples generally exhibit lower properties. Overall, the project highlights the challenges and complexities of recycling glass fiber composites, particularly in replicating the fiber distribution seen in industrial mats. The results suggest that the application of sizing to recycled fibers is crucial for improving mechanical properties, but achieving consistency remains a challenge.

Relators: Marco Sangermano
Academic year: 2023/24
Publication type: Electronic
Number of Pages: 78
Corso di laurea: Corso di laurea magistrale in Ingegneria Dei Materiali
Classe di laurea: New organization > Master science > LM-53 - MATERIALS ENGINEERING
Ente in cotutela: EPFL (SVIZZERA)
Aziende collaboratrici: EPFL-STI-IMX-PBL
URI: http://webthesis.biblio.polito.it/id/eprint/28210
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