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1

The effect of printing velocity on the temperature and viscosity of the polymer thread at the nozzle exit in 3D printers

Baeza-Campuzano Alberto, Castaño Victor M.

Polimery

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2021

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T. 66, nr 2

127--138

EN

Fused Deposition Modelling (FDM) is a powerful method for advanced additive manufacturing of polymeric materials, due to its simplicity and low cost. However, the process implies complex phenomena which are not fully understood yet. In particular, the effect of viscosity on the printed thread is a key parameter to control if good quality products are to be obtained. Experimental data of two grades of acrylonitrile-butadiene- styrene copolymer (ABS) was employed to analyse, by using ANSYS Fluent simulation package, six printing velocities at a temperature of 230°C. A drastic temperature change was observed as the printing velocity increases, confirming the effect of viscosity on the shear created on the wall of the nozzle transversal to the printing bed. The polymers analysed present different viscosity behavior even under the same angular frequency range (0.1 to 100 rad/s), and testing temperature (230°C), which could lead to inhomogeneities. Our results allow taking into account these parameters as part of the design criteria.

PL

Technologia druku 3D – FDM (Fused Deposition Modelling), dzięki prostocie i niskiemu kosztowi, stanowi skuteczną zaawansowaną metodę przyrostowego wytwarzania elementów z materiałów polimerowych. Jednak występujące w tym procesie złożone zjawiska nie są jeszcze w pełni poznane. Kluczowym parametrem determinującym możliwość uzyskania produktów dobrej jakości jest lepkość stopionego polimeru, zależna od prędkości druku. Na podstawie wyników badań dwóch odmian kopolimeru akrylonitryl-butadien-styren (ABS), za pomocą programu symulacyjnego ANSYS Fluent, przeanalizowano zależności dla sześciu prędkości drukowania w temperaturze 230°C. Zaobserwowano istotną zmianę temperatury polimerowej nici wraz ze wzrostem prędkości druku, co potwierdza wpływ lepkości na naprężenia ścinające występujące na ściance dyszy, poprzecznie do stołu drukującego. Analizowane polimery wykazywały różną lepkość, nawet w tym samym zakresie częstotliwości kątowej (0,1 do 100 rad/s) i w takiej samej temperaturze (230°C), co może prowadzić do niejednorodności stopionego tworzywa. Uzyskane wyniki wskazują, że parametry te należy uwzględnić przy projektowaniu procesu druku.

2

Influence of post-processing on the accuracy of fdm products

Kuczko W., Górski F., Wichniarek R., Buń P.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 2

172--179

EN

This paper presents the assessment of the rapid prototyping finishing techniques for printed components. The aim of the study was to compare the element printed with FDM technology before and after the treatment, using 3D scanning techniques. The object was scanned right after manufacturing, then it was subjected to finishing treatment and 3D-scanned again. The assessment of the results was performed using the GOM Inspect software, based on a comparison between scans and nominal model.

3

Application of additively manufactured polymer composite prototypes in foundry

Kuczko W., Wichniarek R., Górski F., Buń P., Zawadzki P.

Advances in Science and Technology. Research Journal

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2015

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Vol. 9, nr 26

20--27

EN

The paper presents a method, developed by the authors, for manufacturing polymer composites with the matrix manufactured in a layered manner (via 3D printing – Fused Deposition Modeling) out of a thermoplastic material. As an example of practical application of this method, functional prototypes are presented, which were used as elements of foundry tooling – patterns for sand molding. In case of manufacturing prototype castings or short series of products, foundries usually cooperate with modeling studios, which produce patterns by conventional, subtractive manufacturing technologies. If patterns have complex shapes, this results in high manufacturing costs and significantly longer time of tooling preparation. The method proposed by the authors allows manufacturing functional prototypes in a short time thanks to utilizing capabilities of additive manufacturing (3D printing) technology. Thanks to using two types of materials simultaneously (ABS combined with chemically hardened resins), the produced prototypes are capable of carrying increased loads. Moreover, the method developed by the authors is characterized by manufacturing costs lower than in the basic technology of Fused Deposition Modeling. During the presented studies, the pattern was produced as a polymer composite and it was used to prepare a mold and a set of metal castings.