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Aditivne tehnologije niso več namenjene zgolj prototipiranju. Njihova uporaba se je razširila tudi na področje gradbeništva, prehrane, farmacije itd. Z večanjem količine odpadkov se raziskovalci vedno več posvečajo biorazgradljivim materialom tudi v povezavi s 3D-tiskom. Predmet naše raziskave je bila implementacija strojne granulacije v postopek izdelave filamenta iz polivinil alkohola in mikrokristalne celuloze. Razvili in izdelali smo granulacijski boben za strojno granulacijo. Materiala smo ustrezno zmešali, izvedli granulacijo in ekstrudirali. Dobljen filament smo analizirali z merjenjem premera in optično analizo prereza. Pri analizi nismo odkrili nehomogenosti materiala, da bi lahko filament tiskali, pa je nujno potrebna nadgradnja ekstruderja. Additive technologies are no longer used just for prototyping. Their use has also spread to the fields of construction, food, pharmacy, etc. With the increasing amount of waste, researchers are focusing on biodegradable materials, also in connection with 3D-printing. The subject of our research was the implementation of machine granulation in the process of making filament from polyvinyl alcohol and microcrystalline cellulose. We developed and manufactured a granulation drum for machine granulation. The material was properly mixed, granulated and extruded. The resulting filament was analyzed using diameter measurements and cross-sectional analysis. The analysis did not reveal the inhomogeneity of the material. For creating filamet that could be printed, an extruder upgrade is necessary.

V Lavalovi šobi želimo s pomočjo vakuumske črpalke ustvariti nadzvočni tok, katerega udarni val vpliva na filament in omogoči, da se le ta pravilno prereže ob navijanju. S pravilno oblikovano šobo in dovolj velikim podtlakom lahko dosežemo nadzvočne hitrosti in udarne valove, kar je bilo dokazano s CFD simulacijo toka fluida čez Lavalovo šobo. We want to create a sonic flow in Laval nozlle with vacuum. Shock wave caused by the sonic flow is affecting the filament and thus enabling a clean cut at the beginning of winding. With correctly designed shape of the nozzle and great enough vacuum we can achieve a sonic flow and shock waves, which was proofed with CFD simulation of fluid through Laval nozzle.

Uporaba aditivnih tehnologij je v porastu. Ena izmed teh je tudi tehnologija ciljnega nalaganja. 3D tiskalniki, ki delujejo po principu ciljnega nalaganja, uporabljajo filamente iz različnih polimerov. Zaradi svetovnih razmer so v ospredju raziskav biorazgradljivi materiali. V nalogi obravnavamo izdelavo okolju prijaznega filamenta za 3D tiskalnik iz polivinil alkohola z dodatkom mikrokristalne celuloze za izboljšanje mehanskih lastnosti. Izdelali smo testne granule iz polivinil alkohola in mikrokristalne celuloze v različnih koncentracijah. S postopkom ekstruzije smo granule pretvorili v filamente z različnimi vsebnostmi celuloze. Na vzorcih filamentov smo opravili optične analize in dimenzijske meritve. Ugotovili smo, da so filamenti v večini homogeni in dobro strukturirani. Vendar so za uporabo filamenta na 3D tiskalniku še potrebne dodelave. The use of additive manufacturing technologies is on the rise. One of these is also Fused Filament Fabrication. 3D printers, that use FFF technology, use polymer filaments. Due to the global situation, biodegradable materials are at the forefront of research. The aim of the thesis is to make an environmentally friendly filament for 3D printers from polyvinyl alcohol with the addition of microcrystalline cellulose to improve mechanical properties. Test granules from polyvinyl alcohol and microcrystalline cellulose in different concentrations were transformed into filaments with different cellulose contents using extrusion process. Optical analyses and dimensional measurements were carried out on filament samples. We found out that filaments are mostly homogenous and well structured. But for use on a 3D printer out methodology needs some finishing.

Tridimenzijsko (3D) tiskanje je vedno bolj priljubljeno tako kot orodje za hitro prototipiranje kot za tiskanje doma. Za tiskanje kakovostnih izdelkov je potrebno nastaviti ustrezne izdelovalne parametre. Izbrani materiali so bili akrilonitril butadien stiren (ABS), polilaurillaktam (PA12), polietilen tereftalat glikol (PETG), polilaktična kislina (PLA) in termoplastični poliuretan (TPU), saj spadajo med najpogostejše skupine polimernih materialov, ki se uporabljajo za 3D tisk. Zaključna naloga obsega proučevanje vpliva temperature na viskoznost izbranih polimernih materialov za 3D tisk. Viskoznost smo proučili z rotacijskim reometrom znotraj temperaturnega območja, ki ga predpisuje proizvajalec za določen material ter primerjali viskoznost vseh materialov pri isti temperaturi. Ugotovili smo, da temperatura različno vpliva na posamezen material, viskoznost posameznega materiala je bistveno drugačna. Prav tako se razlikuje viskoelastičen odziv. Threedimensional (3D) printing is becoming increasingly popular as a tool for rapid prototyping as well as home printing. To print products of high quality, correct manufacturing parameters need to be set. Selected in the present study acrylonitrile butadiene styrene (ABS), polyurylactamate (PA12), polyethylene terephthalate glycol (PETG), polylactic acid (PLA) and thermoplastic polyurethane (TPU) were selected, as they belong to the most popular groups of polymeric 3D printing materials. In this study we studied the effect of temperature on the viscosity of selected materials. Viscosity was measured with a rotational rheometer within the temperature range specified by the manufacturer for a given material. Viscosities of all materials compared at a selected temperature. The results showed that the temperature has a different effect on each material, ergo the viscosity of each material is significantly different. The viscoelastic response also differed.

Diplomsko delo temelji na osnovi sesalne pištole, ki jo uporabljajo v podjetju AquafilSLO, ki se ukvarjajo s proizvodnjo poliamidnih filamentov in granulatov. Sesalna pištola služi kot pripomoček za navijanje filamenta s pomočjo stisnjenega zraka, ki ga proizvedemo v kompresorski postaji. Zaradi visokih stroškov priprave stisnjenega zraka smo naredili prototipni sesalnik, ki bi z manjšo močjo ter nižjimi stroški obratovanja opravljal enako nalogo. Prototipni sesalnik mora zagotavljati hitrost 100 m/s na vstopu v sesalno pištolo. Nadzvočno hitrost moramo zagotavljati s podtlakom. Izdelali smo prototipni sesalnik ter prototipne De Lavalove šobe, s katerimi smo se hoteli približati trenutnemu delovanju. Za ocenjevanje rezultatov smo izdelali merilno napravo, s katero smo izmerili sile ob sesanju filamenta. Tako smo primerjali rezultate obstoječega sistema z rezultati prototipnega sesalnika. Rezultati so pokazali, da trenutni prototipni sesalnik zagotavlja petkrat manjšo silo, kar pomeni, da se z rešitvijo nismo približali trenutnemu delovanju obstoječega sistema z uporabo stisnjenega zraka. The thesis is based on the suction unit used in AquafilSLO Production of polyamide filaments and granules. It serves as a tool for filament winding. The suction unit is currently powerede by the compressed air produced in the compressor station. Due to the high cost of preparing the compressed air, we made a prototype of a suction unit that would perform the same task with lower power and consequently lower operating costs. It must provide a air sucction velocity of 100 m/s at the inlet of the suction unit. The aim is to achieve near supersonic velocity by vacuum. We have designed a prototype suction unit and prototype of De Laval nozzles to bring us closer to it's current performance. To evaluate the results, a measuring device was designed to measure the forces at which the filament was sucked. Thus, we compared the results of the existing system with the results of the prototype suction system. The results showed that the current prototype vacuum system provides five times less force, which means that the solution did not approximate the current operation of the existing system using compressed air. Further development is needed.