Tesi etd-11112023-103438 |
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Tipo di tesi
Tesi di laurea magistrale
Autore
DI LORETO, LUCA
Indirizzo email
l.diloreto@studenti.unipi.it, luca98diloreto@gmail.com
URN
etd-11112023-103438
Titolo
Analisi di materiali compositi a matrice polimerica per la stampa 3D di endoprotesi ortopediche
Dipartimento
INGEGNERIA DELL'INFORMAZIONE
Corso di studi
INGEGNERIA BIOMEDICA
Relatori
relatore Prof. De Maria, Carmelo
controrelatore Prof. Fortunato, Gabriele Maria
controrelatore Prof. Fortunato, Gabriele Maria
Parole chiave
- ,AM
- 3D Printing
- Additive Manufacturing
- Compositi
- Debinding
- Endoprosthesis
- Endoprotesi
- FDMet
- Protesi
- SIntering
- Stampa3D
Data inizio appello
01/12/2023
Consultabilità
Tesi non consultabile
Riassunto
IT: Ogni anno vengono svolti milioni di interventi articolari sostitutivi in tutto il mondo, a causa di traumi o patologie cartilaginee: l'utilizzo di endoprotesi articolari riesce a ripristinare parzialmente le funzionalità del tessuto leso cin un intervento chirurgico. I dispositivi impiantati, vengono al momento prodotti con tecnologie sottrattive: sono tecniche che mirano alla produzione di dispositivi in serie; quindi, con caratteristiche identiche tra di loro e non basate sulle caratteristiche anatomiche-funzionali del paziente. Una alternativa già abbastanza utilizzata è l’uso di metodi di Additive Manufacturing che prevedono l’utilizzo di polveri che risultano tuttavia costosi e non semplici da gestire. In questo lavoro è stata valutata una nuova tecnologia di Additive Manufacturing che utilizza un filamento a matrice polimerica caricato con nanoparticelle metalliche: viene riscaldato, estruso a formare una struttura tridimensionale tramite una stampante per FDM (Fused Deposition Modeling), quindi processato termicamente e con pressione controllata nelle fasi di Debinding e Sintering. Queste servono per rimuovere dal pezzo ogni traccia di matrice polimerica, ottenendo quindi una struttura interamente metallica. Come le altre tecniche di AM, l’FDMet permette una customizzazione del dispositivo, ma riesce a farlo con costi inferiori di un ordine di grandezza, visto il minor costo sia del materiale che della macchina per la produzione. Per valutare l’utilizzabilità di tale tecnica in ambito endoprotesi, è stata effettuata una caratterizzazione del materiale volta a trovare i corretti parametri di stampa. Successivamente sono stati stampati dei provini da trazione secondo la normativa ASM D638 e delle protesi di caviglia al 50% di infill. Questo valore è stato scelto a partire dalle indicazioni fornite dal produttore del filamento e con l’implementazione di un modello protesico in un software per l’analisi ad elementi finiti testando la resistenza statica della protesi e dei provini. Infine, sono stati valutati gli step da eseguire per completare la approvazione di una protesi costruita tramite l’FDMet.
ENG: Every year, millions of replacement joint surgeries are performed all over the world, due to trauma or cartilage pathologies: the use of joint endoprostheses is able to partially restore the functionality of the injured tissue through surgery. Implanted devices are currently produced with subtractive technologies: these are techniques that aim at the production of devices in series; therefore, with identical characteristics and not based on the anatomical-functional characteristics of the patient. An alternative that is already widely used is the use of Additive Manufacturing methods that involve the use of powders, which are however expensive and not easy to manage. In this work, a new Additive Manufacturing technology using a polymer matrix filament loaded with metal nanoparticles was evaluated: it is heated, extruded to form a three-dimensional structure by means of an FDM (Fused Deposition Modeling) printer, then thermally processed and with controlled pressure in the Debinding and Sintering phases. These are used to remove all traces of polymer matrix from the piece, thus obtaining an all-metal structure. Like other AM techniques, FDMet allows for customization of the device, but it manages to do so with costs that are an order of magnitude lower, given the lower cost of both the material and the machine for production. To evaluate the usability of this technique in the endoprosthesis field, a characterization of the material was carried out in order to find the correct printing parameters. Subsequently, tensile specimens were printed according to ASM D638 and 50% infill ankle prostheses. This value was chosen starting from the indications provided by the filament manufacturer and with the implementation of a prosthetic model in a software for finite element analysis by testing the static strength of the prosthesis and specimens. Finally, the steps to be taken to complete the approval of a prosthesis constructed through the FDMet were evaluated.
ENG: Every year, millions of replacement joint surgeries are performed all over the world, due to trauma or cartilage pathologies: the use of joint endoprostheses is able to partially restore the functionality of the injured tissue through surgery. Implanted devices are currently produced with subtractive technologies: these are techniques that aim at the production of devices in series; therefore, with identical characteristics and not based on the anatomical-functional characteristics of the patient. An alternative that is already widely used is the use of Additive Manufacturing methods that involve the use of powders, which are however expensive and not easy to manage. In this work, a new Additive Manufacturing technology using a polymer matrix filament loaded with metal nanoparticles was evaluated: it is heated, extruded to form a three-dimensional structure by means of an FDM (Fused Deposition Modeling) printer, then thermally processed and with controlled pressure in the Debinding and Sintering phases. These are used to remove all traces of polymer matrix from the piece, thus obtaining an all-metal structure. Like other AM techniques, FDMet allows for customization of the device, but it manages to do so with costs that are an order of magnitude lower, given the lower cost of both the material and the machine for production. To evaluate the usability of this technique in the endoprosthesis field, a characterization of the material was carried out in order to find the correct printing parameters. Subsequently, tensile specimens were printed according to ASM D638 and 50% infill ankle prostheses. This value was chosen starting from the indications provided by the filament manufacturer and with the implementation of a prosthetic model in a software for finite element analysis by testing the static strength of the prosthesis and specimens. Finally, the steps to be taken to complete the approval of a prosthesis constructed through the FDMet were evaluated.
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