The production of composite materials is growing more than ever. Carbon fibre reinforced polymer (CFRP) demand sees an annual growth of 11 %, and glass fibre reinforced polymers (GFRP) a growth of 2.5 %. Due to the high percentage of resultant scrap from production, and the increasing disposal of End-of-Life products, there is more composite material waste than ever before. Governments around the world are trying to reduce the amount of composite material waste that is ending up as landfill scrap by increasing the taxes levied on this type of disposal. Several recycling processes exist today; from commercially active methods to lab-scale trials. Reclaimed fibres cannot be re-incorporated into the same applications from which they originated. This is due to change in mechanical properties and bonding capabilities of the fibre during the recycling process. As a result, development of new use-applications are necessary to achieve a circular-economy for the fibres, in single or multiple levels. This research focuses on the available recycling methods and the mechanical properties that can be achieved by re-incorporating the reclaimed fibres into new composite materials. The analysis defines the most appropriate recycling method according to the typology of fibre. Results suggest that a simple and efficient recycling method such as mechanical grinding is the best solution for GFRP because of the fibres low value. Due to the high value of carbon fibre (CF), reclaiming the material with more advanced thermal and chemical methods can be economically justified. Possible future applications have been proposed; highlighting areas and industries where the use of reclaimed fibres could be a valid alternative to more traditional material options. Reclaimed GFRP material is proposed as wall structures in the marine sector. Recycled CF can replace virgin CF in composite compound materials for semi-structural and aesthetical applications.
La produzione di materiali composti cresce più che mai. La domanda di CFRP (carbon fibre reinforced polymer) aumenta annualmente dell’11 %, mentre quella per il GFRP (glass fibre reinforced polymer) del 2,5%. Siccome la percentuale di sfridi è alta durante la produzione, e così l’aumento dello smaltimento di prodotti a fine vita, ci troviamo con più scarti di composito che mai. Le istituzioni statali in tutto il mondo tentano di ridurre la quantità di composito smaltito in discarica con un aumento delle tasse di smaltimento. Sul mercato sono presenti diversi metodi di riciclo, sia attivi commercialmente, sia ad uno stadio pilota. Le fibre recuperate da un processo di riciclo risultano più deboli dal punto di vista meccanico e con una capacità legante inferiore. Per questo motivo non possono essere reinseriti nelle stesse applicazioni dalle quali sono stati originati. Di conseguenza, nuove applicazioni di riutilizzo devono essere sviluppate per permettere un’economia circolare su uno o più livelli. Questa ricerca tratta i vari metodi di riciclo disponibili e le proprietà meccaniche ottenibili quando le fibre riciclate sono re-incorporate in nuovi materiali compositi. L’analisi definisce il metodo più appropriato di riciclo rispetto alla tipologia di fibra. Siccome il valore del GF (glass fibre) è molto basso, un metodo semplice ed efficiente come la macinazione meccanica sarebbe più adatto per compositi con queste fibre. Dall’altro lato, il valore più alto del CF (carbon fibre) giustifica un metodo di riciclo più avanzato come quello chimico o termico. Possibili applicazioni future vengono proposte, evidenziando aree e industrie dove le fibre riciclate incorporate in nuovi compositi potrebbero essere una valida alternativa alla scelta di materiali più tradizionali. Il GFRP recuperato viene proposto come materiale per pareti parzialmente strutturali nel settore nautico. Il CF riciclato potrebbe essere usato per sostituire il CF vergine in materiali come SMC e BMC, per poi essere applicati a componenti estetici e semi-strutturali.
Recycling of fibre reinforced polymers technologies, materials and future applications
MYKLEBUST, KIM JOAR
2015/2016
Abstract
The production of composite materials is growing more than ever. Carbon fibre reinforced polymer (CFRP) demand sees an annual growth of 11 %, and glass fibre reinforced polymers (GFRP) a growth of 2.5 %. Due to the high percentage of resultant scrap from production, and the increasing disposal of End-of-Life products, there is more composite material waste than ever before. Governments around the world are trying to reduce the amount of composite material waste that is ending up as landfill scrap by increasing the taxes levied on this type of disposal. Several recycling processes exist today; from commercially active methods to lab-scale trials. Reclaimed fibres cannot be re-incorporated into the same applications from which they originated. This is due to change in mechanical properties and bonding capabilities of the fibre during the recycling process. As a result, development of new use-applications are necessary to achieve a circular-economy for the fibres, in single or multiple levels. This research focuses on the available recycling methods and the mechanical properties that can be achieved by re-incorporating the reclaimed fibres into new composite materials. The analysis defines the most appropriate recycling method according to the typology of fibre. Results suggest that a simple and efficient recycling method such as mechanical grinding is the best solution for GFRP because of the fibres low value. Due to the high value of carbon fibre (CF), reclaiming the material with more advanced thermal and chemical methods can be economically justified. Possible future applications have been proposed; highlighting areas and industries where the use of reclaimed fibres could be a valid alternative to more traditional material options. Reclaimed GFRP material is proposed as wall structures in the marine sector. Recycled CF can replace virgin CF in composite compound materials for semi-structural and aesthetical applications.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/131856