Title Optimiranje rada ekstrudera za proizvodnju filamenata cikloolefinskog kopolimera Title (english) Optimizing the operation of extruders for the production of cycloolefin copolymer filaments Author Iva Pavičić Mentor Domagoj Vrsaljko (mentor)Committee member Domagoj Vrsaljko (predsjednik povjerenstva)Committee member Dajana Kučić Grgić (član povjerenstva)Committee member Helena Otmačić Ćurković (član povjerenstva)Granter University of Zagreb Defense date and country 2019-09-25, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Aditivna proizvodnja (poznatija pod nazivom 3D-ispis) je tehnologija koja omogućava izradu željenog oblika dodavanjem materijala sloj po sloj. Jedna od najraširenijih tehnologija aditivne proizvodnje je proizvodnja rastaljenim filamentom (FFF). FFF je tehnologija kojom se rastaljeni filamenti polimernog materijala pomoću pokretne dizne nanose sloj po sloj na radnu podlogu. Vrlo je važno koristiti filamente odgovarajućeg promjera kako bi sustav funkcionirao te kako bi se dobio kvalitetan krajnji proizvod. Filamenti koji se pritom koriste mogu biti promjera 1,75 mm ili 3 mm. U ovom se radu optimirao proces rada jednopužnog ekstrudera Noztek Pro za proizvodnju filamenata cikloolefinskog kopolimera (COC). COC se odlikuje svojstvima kao što su velika transparentnost, odlična barijerna svojstva za vlagu, dobra otpornost na vodu i polarna otapala, biokompatibilnost. COC je materijal dobrih mehaničkih svojstava, čime je pogodan za proizvodnju rastaljenim filamentom (FFF). Optimiranje je provedeno u računalnom programu Design-Expert te su dobiveni optimalni uvjeti za dobivanje idealnog promjera vrijednosti 1,75 mm i minimalne standardne devijacije. Pronađeno je deset različitih kombinacija uvjeta pri kojima su dobivene željene vrijednosti promjera i male standardne devijacije. Kombinacija najveće poželjnosti daje promjer vrijednosti 1,75 mm uz malu standardnu devijaciju koja iznosi 0,06 mm, a ostvaruje se pri temperaturi od 197,93 °C, brzini izvlakača 51,22 mm/s te udaljenosti izvlakača 44,43 cm. U ovom su se radu također pripremili kompoziti COC-a dodatkom funkcionalnih punila netretiranog kalcijevog karbonata i kalcijevog karbonata predtretiranog stearinskom kiselinom. Navedeni su kompoziti pripravljeni kako bi se ispitala mogućnost modifikacije mehaničkih, toplinskih, površinskih svojstava i otpornosti na otapala (vodu, aceton i etanol). Provedenom analizom mjerenja kontaktnog kuta utvrđeno je da funkcionalna punila ne utječu na površinska svojstva hidrofobnosti kompozita te je ustanovljeno da ne dolazi do značajnih promjena mehaničkih i toplinskih svojstava. Također, provedenim testom bubrenja se pokazalo da su pripravljeni kompoziti, kao i čisti COC, dobre otpornosti na korištena otapala: vodu, aceton i etanol.
Abstract (english) Additive manufacturing (better known as 3D-printing) is a technology which enables creating a wanted object by adding the material layer by layer. One of the most wide-spreaded technologies of additive manufacturing is fused filament fabrication (FFF). FFF is a technology in which the deposited polymer material filaments are applied to the working surface, layer by layer, by means of a mobile nozzle. In order for the technology to function and to obtain a quality finished product, it is very important to prepare the filaments of an appropriate diameter. Filaments which are used during the process ought to be 1.75 mm or 3 mm in diameter. In this paper the process of cycloolefin copolymer (COC) filaments extrusion was optimized. The experiment was carried out in Noztek Pro single screwed extruder. COC exhibits unique combination of properties such as: high transparency, great water vapour barrier properties, excellent resistance to water and other polar solvents, and biocompatibility. It is a material with good mechanical properties which makes it appropriate for Fused Filament Fabrication. The optimization was carried out in the Design-Expert computer program and optimal conditions were achieved for obtaining an ideal diameter of 1.75 mm and a minimum standard deviation. Ten different combinations of desired conditions were found in which the desired diameter values and small standard deviations were obtained. Combination with the highest desirability gives an ideal diameter of 1.75 mm with a minimum standard deviation of 0.06 mm, and it is achieved at a temperature of 197.93 °C, puller speed of 51.22 mm/s and puller distance of 44.43 cm. In this paper was also carried out the fabrication of COC composites. They were fabricated using functional fillers: precipitated calcium carbonate and calcium carbonate pretreated with stearic acid. The mentioned composites were fabricated in order to research the possibility to modify mechanical, thermal, surface properties and resistance to solvents (water, acetone and ethanol). By carried out contact angle analysis it is determined that the functional fillers do not affect the hidrofobic surface properties of the composites and it is established that there were no significant modifications in terms of mechanical and thermal properties. In addition, the fabricated composites and COC itself have shown excellent resistance to water, acetone and ethanol.
Keywords
aditivna proizvodnja
cikloolefinski kopolimer
filamenti
optimiranje
Keywords (english)
additive manufacturing
cycloolefin copolymer
filaments
optimization
Language croatian URN:NBN urn:nbn:hr:149:675229 Project Number: UIP-2014-09-3154 Study programme Title: Environmental Engineering - Graduate study Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2022-02-26 20:01:34
