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1

Wytrzymałość mieszaniny skrobia termoplastyczna/polilaktyd

Garbarski Jacek, Fabijański Mariusz

Przemysł Chemiczny

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2024

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T. 103, nr 3

381--386

PL

Przedstawiono wyniki badań mieszaniny TPS/PLA o różnych proporcjach składników. Wykonano próby rozciągania statycznego dla każdej z badanych mieszanin. Wielkościami mierzonymi były wytrzymałość, odkształcenie oraz moduł Younga.

EN

Granules of thermoplastic starch (TPS), polylactide (PLA) and their mixts. in mass proportions of 25, 50, 75% were formed using a injection molding machine. Static tensile tests were performed for each of the tested mixts. The measured values were force, strain and Young’s modulus. TPS/PLA blends showed much higher strength parameters than each of the component materials separately.

2

Otrzymywanie i degradacja kompozytów na bazie polilaktydu i paździerzy konopnych modyfikowanych stearyną

Biniaś Dorota, Drabek Weronika

Polish Journal of Materials and Environmental Engineering

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2024

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Vol. 7 (27)

63--73

EN

As a result of the work carried out, composites were obtained whose matrix was polylactide (PLA) and the filler was hemp shives with the addition of stearin. Using a heating press, composites with different shares of both PLA and hemp shives were obtained. The amount of stearin was always 15% in relation to the mass of hemp shives used. Samples were prepared from the obtained composites to test the biodegradation process, which were measured and weighed. The biodegradation process was carried out in the environment, placing the appropriately prepared batches of composites in compost derived from grass. Samples were taken at monthly intervals to analyze changes in mass and thickness and morphological assessment. The degradation process of the obtained composites was carried out for 3 months. The mass of the samples after the first month of biodegradation did not change significantly, however, with the biodegradation time, the masses of the tested composite samples decrease. The thickness of composite samples after the first month of biodegradation increased in relation to the initial value, which may be caused by the adsorption of water from the substrate. However, after three months of biodegradation, a decrease in thickness was observed for all samples in comparison to the initial value. Analysis of the surface morphology of the composite samples carried out using a stereoscopic microscope and a scanning electron microscope confirmed the biodegradation process for the obtained composites. Stearin, which is a mixture of fatty acids, used as a composite modifying additive turned out to be a nutrient for microorganisms present in the compost, which accelerated the decomposition of the samples. As a result of the conducted research, it can be stated that the obtained composite has properties that support ecological processing, which is in line with the assumptions of a circular economy.

3

Study of cellular structures built from self-similar models and repeatable structures manufactured by FDM/FFF technology

Rudnik Mateusz

Polimery

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2024

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Vol. 69, nr 3

173--178

EN

Appropriate recursive formulas were obtained for generating repeatable and self-similar cel-lular structures obtained from PLA using the FDM/FFF method. The H1s, H2s self-similar models show mechanical self-similarity relationships based on simulation and compression test. In addition, the H1s models show higher displacement values than the H1i recurrent models. For the results of the H2s models, it is not conclusive whether they show higher displacement values.

PL

Uzyskano odpowiednie formuły rekurencyjne do generowania powtarzalnych i samopodobnych struktur komórkowych otrzymanych z PLA metodą FDM/FFF. Zbadano wytrzymałość na ściskanie otrzymanych w ten sposób struktur. Modele samopodobne H1s, H2s wykazują zależności mechanicznego samopodobieństwa na podstawie symulacji i testu ściskania. Ponadto modele H1s wykazują wyższe wartości przemieszczeń niż modele rekurencyjne H1i. Dla wyników modeli H2s nie jest jednoznaczne, czy wykazują one wyższe wartości przemieszczeń.

4

Liquid heat capacity of an amorphous poly(lactic acid)

Skotnicki Marcin, Czerniecka-Kubicka Anna, Zarzyka Iwona, Pyda Marek

Polimery

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2024

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Vol. 69, nr 5

238--291

EN

The experimental and computed liquid heat capacity of an amorphous PLA was presented. The liquid heat capacity of PLA above the glass transition 333 K (60°C) is linked to the molecular motions and computed as the sum of vibrational, external (anharmonic), and conformational contributions. The largest contribution to the liquid heat capacity, Cp(liquid) of PLA comes from the vibrational motions calculated as the group and skeletal vibrational heat capacity. The external contribution to Cp(liquid) was calculated as a function of temperature from experimental data of the thermal compressibility and expansivity of the liquid state. The contribution of conformational heat capacity to the total heat capacity of an amorphous liquid PLA was calculated by fitting the experimental liquid heat capacity, after subtracting the vibrational and external parts, to the obtained heat capacity based on a one-dimensional Ising-type model with two discrete states. The parameters described in these states can characterise the macromolecule’s stiffness, cooperativity, and degeneracy. The computed and experimental data of Cp(liquid) showed good agreement at the investigated temperature region.

PL

W pracy przedstawiono eksperymentalna i obliczoną pojemność cieplną ciekłego amorficznego PLA. Pojemność cieplna cieczy PLA powyżej temperatury przejścia szklistego 333 K (60°C) jest powiązana z ruchami molekularnymi i została obliczona jako suma składników wibracyjnych, zewnętrznych (nieharmonicznych) i konformacyjnych. Największy wkład w pojemność cieplną cieczy, Cp(liquid) PLA, pochodzi z ruchów wibracyjnych, obliczonych jako pojemność cieplna wibracji grupowych i szkieletowych. Zewnętrzny wkład do Cp(liquid) został obliczony jako funkcja temperatury na podstawie danych eksperymentalnych z użyciem parametrów ściśliwości i rozszerzalności cieplnej cieczy. Wkład konformacyjnej pojemności cieplnej do całkowitej pojemności cieplnej amorficznego ciekłego PLA został obliczony przez dopasowanie eksperymentalnej pojemności cieplnej cieczy, po odjęciu części wibracyjnych i zewnętrznych, do otrzymanej pojemności cieplnej opartej na jednowymiarowym modelu typu Ising z dwoma dyskretnymi stanami. Parametry opisane w tych stanach mogą charakteryzować sztywność, kooperatywność i degenerację makrocząsteczki. Obliczone dane Cp(liquid) wykazały zgodność z danymi eksperymentalnymi w badanym zakresie temperatury.

5

Effect of shells number and machining on selected properties of 3D-printed PLA samples

Kowalska Natalia, Szczygieł Paweł, Skrzyniarz Michał, Błasiak Sławomir

Polimery

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2024

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Vol. 69, nr 3

186--190

EN

Effect of shells number (1–5) on tensile properties of PLA samples printed using the FDM/FFF technique was investigated. The crack surface was also analyzed. The best properties were obtained for 4-shell sample. However, due to the large coefficient of variation (>> 10%) in the case of elongation, 3-shell sample was selected for testing the machining impact. Such a large coefficient of variation can be explained by the presence of voids between the layers. The greater the number of layers, the greater the structure defects. Machining increases surface smoothness while reducing tensile strength and practi¬cally unchanged elongation at break.

PL

Zbadano wpływ liczby warstw (1–5) na właściwości mechaniczne przy rozciąganiu próbek PLA otrzymanych techniką FDM/FFF. Analizie poddano także powierzchnie pęknięć. Najlepsze właściwości uzyskano dla próbki 4-warstwowej. Jednak, ze względu na duży współczynnik zmienności (>> 10%) w przypadku wydłużenia, do badań wpływu obróbki skrawaniem wytypowano próbkę 3-warstwową. Tak duży współczynnik zmienności można wyjaśnić obecnością pustych przestrzeni pomiędzy warstwami. Im większa liczba warstw, tym większe defekty struktury. Obróbka skrawaniem zwiększa gładkość powierzchni przy jednoczesnym zmniejszeniu wytrzymałości na rozciąganie i praktycznie niezmienionym wydłużeniu przy zerwaniu.

6

Influence of size on the compressive properties of cellular structures manufactured by additive technologies

Rudnik Mateusz

Mechanik

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2024

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R. 97, nr 4

6--15

EN

This article is a continuation of research on hexagonal cell structures. Previous research has dealt with cell structures in normalized models, where it was shown that cell structures should be studied from a single cell to a suitably generated iterative model based on recursive formulas. The aim of this paper was to compare manufactured cell structures with an appropriately defined formula. Printed models of the hexagonal structure subjected to compression showed that, in the case of the Polylactic Acid Blue material, as the size of the side length of the hexagonal cells increased, the quality of the generated diagrams also increased, which informed the undesired effects of the compressive force in the tests. In the case of cells manufactured from the PA2200 material, it was noted that the maximum force acting on the cell structure decreased with increasing cell side length, however, no undesirable situations occurred during testing in contrast to structures manufactured from Polylactic Acid base materials. In the case of Polylactic Acid materials, special attention had to be paid to the Polylactic Acid Gray material. The models were printed with the same parameters, from the same Stereolitography language file, had a slightly higher mass and were subjected to the same compression test, yet showed significant differences in the tests carried out compared to the other models.

PL

Artykuł jest kontynuacją badań dotyczących struktur komórkowych heksagonalnych. Poprzednie badania dotyczyły struktur komórkowych w modelach znormalizowanych. Wykazano, że struktury komórkowe należy badać od pojedynczej komórki do odpowiednio wygenerowanego modelu iteracyjnego opartego na wzorach rekurencyjnych. Celem pracy było porównanie wytworzonych struktur komórkowych o odpowiednio zdefiniowanym wzorze. Wydrukowane modele struktury heksagonalnej poddanej ściskaniu wykazały, że w przypadku materiału Polylactic Acid Blue wraz ze wzrostem długości boku komórek heksagonalnych wzrastała także jakość generowanych diagramów, co informowało o niepożądanych efektach działania siły ściskającej. W przypadku struktur komórkowych wykonanych z materiału PA2200 zauważono, że maksymalna siła działająca na strukturę komórkową zmniejszała się wraz ze wzrostem długości boku struktury komórkowej, jednakże podczas badań nie wystąpiły żadne niepożądane sytuacje w porównaniu ze strukturami wytwarzanymi z materiałów na bazie kwasu polimlekowego. W przypadku materiałów z polikwasu mlekowego szczególną uwagę należało zwrócić na materiał z szarego kwasu polimlekowego. Modele zostały wydrukowane z tymi samymi parametrami, z tego samego pliku, który został zapisany w języku stereolitograficznym, a jednak miały nieco większą masę i zostały poddane temu samemu testowi ściskania, a mimo to wykazały istotne różnice w przeprowadzonych testach w porównaniu z pozostałymi modelami.

7

Investigate the Effect of Chemical Post Processing on the Surface Roughness of Fused Deposition Modeling Printed Parts

Abdulridha HInd Hadi, Abbas Tahseen Fadhil, Bedan Aqeel Sabree

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

47--60

EN

Fused deposition modeling (FDM) technology is one of the rapidly growing techniques used for producing various complicated configurations without the need for any tools or continuous human intervention. However, a low quality of surfaces results for the layered production used in FDM. It is essential to investigate a suitable method for enhancing the accuracy and quality associated with FDM parts. This study aims to investigate the impact of different parameters such as the percentage of infill density, the shell thickness, layer thickness, and the number of top/bottom layers, as well as the percentage of infill overlap on part quality and the improvement of surface finish for printed specimens achieved through post-processing. Polylactic acid (PLA) material is used in building test specimens through the FDM approach. The experiments are carried out based on the Taguchi design of experiment method using (L25) orthogonal array. Using an analysis-of-variance approach (ANOVA), it is possible to understand the significance of the FDM parameters in order to find optimal parameter combinations. The results indicate that the application of the vapour smoothing procedure (VSP) treatment enhances the surface quality of FDM components to a microstage with minimal dimensional variation. The dichloromethane chemical has been found to exhibit excellent surface finish at an infill density of 50%, a layer thickness of 0.1 mm, a shell thickness of 2.8 mm, five top/bottom layer numbers, and 0.25 infill overlap.

8

Wpływ sposobu przechowywania filamentu ABS, PLA, PET-G na właściwości wyrobów wytwarzanych przyrostowo metodą FDM

Góralski Błażej, Siergiej Joanna

Zarządzanie Przedsiębiorstwem

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2023

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Vol. 26, nr 1

7--11

EN

The subject of the article is the influence of filament moisture on the quality of products manufactured using the additive method using the Fused Deposition Modelling (FDM) method. Three types of thermoplastic polymers were tested: ABS, PLA and PET-G. The polymers were stored in environments with different humidity. The moisture content of the filament was determined as the water content in the material expressed as a percentage by weight. To obtain the expected humidity of the samples, they were conditioned for 7 days in tightly closed containers with constant humidity of 40%, 60% and 80%. After the sample conditioning process was completed, they were removed from the container and subjected to further tests. The influence of filament humidity on selected properties of manufactured products is presented, such as: surface quality of the obtained samples, tensile strength and dimensional repeatability. To sum up, the method of storing the filament affects the moisture content of the filament. The humidity of the filament, in turn, affects the quality of products manufactured using the FDM method, including: on: mechanical properties, dimensional stability, Surface appearance. Therefore, it is important in what conditions the filament is stored before the production process begins.

9

Właściwości fizyczne mieszaniny polilaktyd/skrobia termoplastyczna

Fabijański Mariusz, Garbarski Jacek

Przemysł Chemiczny

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2023

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T. 102, nr 9

954--958

PL

Przedstawiono wyniki badań właściwości mieszaniny PLA/TPS. Granulki polilaktydu (PLA) i skrobi termoplastycznej (TPS) w proporcjach masowych 25, 50 i 75% mieszano w mieszalniku bębnowym, a następnie mieszano w stanie stopionym i formowano we wtryskarce ślimakowej. Próbki polimerów analizowano pod kątem udarności, twardości i nasiąkliwości. Mieszaniny PLA/TPS wykazywały istotnie większą udarność niż każdy z materiałów składowych z osobna. Udarność była nawet dwukrotnie większa, co wskazywało na występowanie zjawiska synergizmu.

EN

Polylactide (PLA) and thermoplastic starch (TPS) granules in mass proportions of 25, 50, 75% were mixed in a drum mixer, and then meltmixed and shaped using a screw injection molding machine. Polymer samples were analyzed for impact strength, hardness and water absorption. The PLA/TPS mixts. showed a significantly higher impact strength than each of the component materials separately. The impact strenght was even twice as high, which indicated the occurrence of the synergism phenomenon.

10

The use of PLA filled with fibrillar nanocellulose from wastepaper as an expansion joint material

Szafraniec Małgorzata, Grabias-Blicharz Ewelina, Droździel-Jurkiewicz Magda, Tor-Świątek Aneta

Polimery

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2023

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Vol. 68, nr 2

93--98

EN

The effect of nanocellulose (3 or 5 wt%) on the PLA properties was investigated. Moreover, the possibility of using such composites as an expansion joint material was considered. Nanocellulose was obtained from wastepaper by mechano-chemical treatment. The structure, impact strength, tensile strength of the composites and the adhesion to the cement were studied. It was observed that with the increasing nanocellulose content, the impact strength and tensile strength decreased because of weak interactions at the interface and formation of agglomerates.

PL

W pracy zbadano wpływ nanocelulozy (3 oraz 5% mas.) na właściwości PLA. Dodatkowo rozważono możliwość zastosowania tego typu kompozytów jako materiału dylatacyjnego. Nanocelulozę otrzymano z makulatury poprzez obróbkę mechano-chemiczną. Zbadano strukturę, udarność i wytrzymałość kompozytów na rozciąganie oraz adhezję do cementu. Zaobserwowano, że wraz ze wzrostem zawartości nanocelulozy udarność i wytrzymałość na rozciąganie zmniejszały się jako efekt słabych oddziaływań na granicy faz i tworzenia się aglomeratów.

11

Polymer and composite materials used in medicine – an overview

Oleksy Małgorzata, Dynarowicz Klaudia, Aebisher David

Polimery

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2023

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Vol. 68, nr 7-8

363--370

EN

The article is a review of the literature on the use of polymers in medicine as biomaterials. Examples of the preparation of the most commonly used synthetic polymers in medicine, such as: polylactide (PLA), polyglycolide (PGA), polyhydrobutyrate (PHB), polycaprolactone (PCL) are described. The characteristics of ceramic materials: hydroxyapatite (HAp) and tricalcium phosphate (TCP) are also presented in terms of the use of synthetic biodegradable polymers as biofillers. The last part of article is devoted to the functional properties of composites based on PLA with the addition of HAp and TCP.

PL

Artykuł stanowi przegląd literatury dotyczący zastosowania polimerów w medycynie jako biomateriałów. Opisano przykłady otrzymywania najczęściej stosowanych syntetycznych polimerów w medycynie takich jak: polilaktyd (PLA), poliglikolid (PGA), polihydromaślan (PHB), polikaprolakton (PCL). Przedstawiono także charakterystykę materiałów ceramicznych: hydroksyapatytu (HAp) i trójfosforanu wapnia (TCP) pod kontem stosowania jako bionapełniacze syntetycznych biodegradowalnych polimerów. Ostatnia część artykułu jest poświęcona właściwościom użytkowym kompozytów na osnowie PLA z dodatkiem HAp i TCP.

12

Mechanical properties of sandwich products obtained by 3D printing from PLA-PLA/Al2O3

Subramaniyan Madheswaran, Karuppan Sivakumar

Polimery

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2023

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Vol. 68, nr 11-12

646--651

EN

The mechanical properties of samples made by 3D printing from poly(lactic acid) (PLA) and PLA filled with 20, 40, 60 and 80 wt% PLA/Al2O3 (85/15) was evaluated. Addition of PLA/Al2O3 improved mechanical properties of PLA. Tensile strength increased by approx. 19%, tensile modulus by 27%, com¬pression modulus by approx. 42%, flexural modulus by 70%, impact strength by 20% and hardness by approx. 14% compared with pure PLA.

PL

Zbadano właściwości mechaniczne kształtek wykonanych metodą druku 3D z poli(kwasu mlekowego) (PLA) napełnionego 20, 40, 60 i 80% mas. PLA/Al2O3 (85/15). Wytrzymałość na rozciąganie zwiększyła się o ok. 19%, moduł sprężystości przy rozciąganiu o 27%, moduł przy ściskaniu o ok. 42%, moduł sprężystości przy zginaniu o 70%, udarność o 20%, a twardość o ok. 14% w porównaniu z czystym PLA.

13

Durability of chain transmission obtained using FFF technology

Budzik Grzegorz, Dziubek Tomasz, Sobolewski Bartłomiej, Borek Karol, Gontarz Małgorzata

Polimery

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2023

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Vol. 68, nr 11-12

617--624

EN

Durability of polymer (PCTG, ABS, PLA) chain gears with a modular chain obtained by 3D printing (FFF - Fused Filament Fabrication) was tested under static and dynamic conditions. An analysis was performed using finite element modeling (FEM). The PLA gear showed the highest tensile strength, and the PCTG gear the lowest. However, in dynamic conditions (rotational speed 750 min-1), the ABS gear was characterized by the smallest deformation and the longest operating time. Chain links were damaged at the point of connection during both static and dynamic tensile tests. Probably the surface of the hole where the chain links were joined was not smooth enough, which could lead to their damage.

PL

W warunkach statycznych i dynamicznych zbadano wytrzymałość na rozciąganie polimerowych (PCTG, ABS, PLA) przekładni łańcuchowych z łańcuchem o budowie modułowej otrzymanych metodą druku 3D. Przeprowadzono analizę metodą modelowania elementów skończonych (MES). Największą wytrzymałość wykazywała przekładnia wykonana z PLA, a najmniejszą z PCTG. Natomiast w warunkach dynamicznych (prędkość obrotowa 750 min-1) przekładnia z ABS charakteryzowała się najmniejszym odkształceniem i najdłuższym czasem pracy. Ogniwa łańcucha zarówno podczas statycznych, jak i dynamicznych testów rozciągania ulegały uszkodzeniu w miejscu ich łączenia. Prawdopodobnie powierzchnia otworu w miejscu łączenia ogniw łańcucha nie była wystarczająco gładka, co mogło prowadzić do ich uszkodzenia.

14

PLA filament is not equal to PLA filament: Experimental studies of the influence of the type of pigment on the mechanical and thermal properties of poly(lactic acid) products

Iwko Jacek, Jaruga Tomasz, Trzaska Oliwia, Stachowiak Tomasz

Materials Science Poland

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2023

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Vol. 41, No. 1

177-190

EN

The correct manufacture of products using FDM printers is not an easy task, taking into account the value and repeatability of material properties. The properties of elements manufactured in this way depend on many factors, both technological and material. Poly(lactic acid) PLA is one of the most willingly used materials in additive techniques. It is sold in a very wide range of colours. This work was intended to answer the question of how the type of pigment affects the mechanical and thermal properties of products obtained from PLA. The correlation between the material properties and the structure of the material as well as the macroscopic structure of the product has also been investigated. The paper analyses the mechanical and thermal properties of products made of PLA filaments in 12 basic colours obtained from one supplier. Bending, impact strength, HDT and Vicat softening point tests were carried out. The percentage content of residues after calcination the samples was determined. Additional analysis (DSC) was performed to interpret the obtained tests results. They indicate that the mechanical properties differ significantly between different types of PLA with differences of up to 45%. Vicat softening point tests indicate differences of 5°C between the extreme values of these parameters. The DSC interpretive study did not clearly show the reasons for these differences in the properties of the filaments.

15

Study of selected properties of PLA used in 3D printing

Sośniak K., Biela D., Szalaty D., Ścieszka M., Polok-Rubiniec M., Włodarczyk-Fligier A., Kania A.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 116, nr 2

72--79

EN

Purpose: This study focuses on determining the best possible structure of the orthosis made with FDM 3D printing technology. To produce the samples, a thermoplastic PLA material was selected that met the conditions of biodegradability, biocompatibility and non-toxicity. The samples produced were subjected to a tensile strength test and corrosion resistance. Design/methodology/approach: Studies based on FEM analysis were carried out using the advanced engineering software CAE - Inventor. The samples were designed in the CAD system, while the G-Code path was generated using the PrusaSlicer 2.5.0 program dedicated to the Prusa i3 MK3S+ printer, which was used to create the models. Surface morphology observations of PLA were carried out with a Zeiss SUPRA 35 scanning electron microscope (SEM). The static tensile test was performed on the Zwick/Roell z100 device based on the PN-EN ISO 527:1 standard. Electrochemical corrosion tests were carried out using the Autolab PGSTAT302N Multi BA potentiostat in Ringer solution at a temperature of 37ºC. Findings: The research allowed the appropriate structure of the orthosis made of PLA polymer material using 3D FDM printing technology. The static tensile test, SEM and corrosion tests confirmed the correct application of this material for the selected purpose. It was possible to determine that samples with holes of 10 mm had the highest strength properties. Due to the tensile tests, the average tensile strength of those samples was around 61 MPa. The corrosion parameters of PLA were determined using Tafel analysis. Research limitations/implications: The research methodology proposed in work can be used to study other biomedical materials. The results presented can be the basis for further tests in order to search for the best orthopaedic stabiliser. Originality/value: The innovative part of the article are three different versions of structures intended for making orthoses used in medicine.

16

Post-processing in multi-material 3D printing

Brancewicz-Steinmetz E., Sawicki J.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 117, nr 1

5--14

EN

Purpose: This study aims to investigate the adhesion of combining two materials with different properties (PLA-TPU and TPU-PLA) printed in FFF (fused filament fabrication) with post-processing treatments. Design/methodology/approach: The scope of the study includes making variants of samples and subjecting them to three different post-printing treatments. After processes, shear tests were conducted to determine the adhesion. Findings: The post-printing treatment results in a stronger inter-material bond and increased adhesion strength; the best average shear strength results were achieved for annealing without acetone and for PLA/TPU samples for treatment in cold acetone vapour. Research limitations/implications: In the study, adhesion was considered in the circular pattern of surface development. Practical implications: Reinforcement of the biopolymer broadens the possibilities of using polylactide. Examples of applications include personalised printing items, where the elastomer will strengthen the polylactide. Originality/value: These studies aim to promote the use and expand the possibilities of using PLA biopolymer. The strength properties of printouts from different materials are often insufficient, hence the proposal to use post-printing processing.

17

Mechanical properties of recycled PLA and PETG printed by FDM/FFM method

Dobrzańska-Danikiewicz A. D., Siwczyk B., Bączyk A., Romankiewicz A.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 119, nr 2

49--59

EN

Purpose: The aim of this paper is to compare the mechanical properties of selected recycled thermoplastics against their equivalents made from new raw materials manufactured using the FDM/FFF additive method. Design/methodology/approach: Two materials were tested: recycled polylactide (R-PLA) and recycled poly(ethylene terephthalate) with the addition of glycol (R-PETG). Reference materials are their equivalents made from new raw materials. Both types of materials are widely available on the market. In order to compare their mechanical properties and to check whether recycled materials do not differ in quality from their equivalents made from new raw materials, tensile strength tests were performed. In addition, the Vickers microhardness was measured, and the structure of printed samples using optical microscopy was observed. Findings: The paper presents the results of the static tensile strength test of samples made by the FDM/FFF technology from the tested materials in accordance with the ISO-00527-2-2012 standard. The samples were manufactured at the average temperature recommended by the producer ±10°C. The results of tensile strength tests indicate that the samples printed at the average temperature show the best tensile strength for both methods of filament deposition. Research limitations/implications: The recycled materials are not significantly different from the reference materials in terms of tensile strength, microhardness and structure. It is reasonable to test other polymeric materials further and check materials from several consecutive recycling cycles. Practical implications: Closing the cycle of plastic used in 3D printing. The ability to quickly transform waste products, e.g. PET bottles, into filaments and reuse them to produce full-value products. Originality/value: The paper presents the results of strength and microhardness tests as well as microscopic investigations of two recycled thermoplastics commonly used in the industry manufactured using the FDM/FFF technology against the background of reference materials made from new raw materials.

18

Analysis of the quality of printed PLA samples using various 3D printers and print preparation programs

Tomczyk Karolina, Raczkiewicz Albert, Paśnikowska-Łukaszuk Magdalena

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

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2023

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T. 13, nr 3

43--46

EN

The article presents the impact of individual settings of both 3D printers and software dedicated to the preparation of printouts. 3D printing methods are discussed. The individual methods and tools necessary for the implementation of 3D prints are described. Materials that are used in 3D printing technology are also discussed. In addition, the construction of printers on which the samples for the tests described in this work were prepared was discussed. The advantages and disadvantages of using individual slicers for 3D printing are presented. The obtained measurement results of samples made of polylactide (PLA) are presented. The work was summarized with final conclusions.

PL

W artykule przedstawiono wpływ poszczególnych ustawień zarówno drukarek 3D oraz oprogramowania dedykowanego do przygotowania wydruków. Omówiono metody druku 3D. Opisano poszczególne metody i narzędzia niezbędne do realizacji wydruków 3D. Omówiono także materiały, które są wykorzystywane w technologii druku 3D. Ponadto omówiono budowę drukarek, na których zostały przygotowane próbki do badań opisanych w tejże pracy. Przedstawiono wady i zalety korzystania z poszczególnych slicerów do druku 3D. Zaprezentowano otrzymane wyniki pomiarowe próbek wykonanych z polilaktydu (PLA). Pracę podsumowano wnioskami końcowymi.

19

Effect of the Surface modification of Cellulose nanofibers on the Mechanical Properties and Disintegrability of Specific PLA/Cellulose Composites

Wietecha Justyna, Kazimierczak Janusz, Jeziorna Agata

Fibres & Textiles in Eastern Europe

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2023

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Vol. 31, no. 6

15--29

EN

PLA/nanofibrillar cellulose (NFC) composite films were produced by solution casting. Before use, the cellulose fibers were modified with various types of surface active agents – cationic, anionic and non-ionic surfactants. The structure and morphology of samples of the cellulose fillers and composite films with polymer were analyzed by means of scanning electron microscopy and PXRD diffraction. Thermal parameters of the composite films were characterized by differential scanning calorimetry and thermogravimetric analysis. The tensile strength and elongation at break of the films were evaluated in mechanical tests. The ability to disintegrate of all PLA/NFC composites under composting conditions was also determined and compared.

20

Experimental study of the fracture of CT specimens printed in PLA as a function of the raster width

Aourik O., Othmani M., Chouaf A.

Archives of Materials Science and Engineering

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2023

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Vol. 122, nr 2

78--85

EN

Purpose: The FDM (Fused Deposition Modelling) additive manufacturing process is characterised by a large number of process variables that determine the mechanical properties and quality of the manufactured parts. When printing layer by layer, the filaments constituting the layer are welded on the one hand between them in the same layer and on the other hand between the superimposed layers, this welding develops on the contact surfaces (raster width) along the deposited filaments. The quality of this welding determines the resistance to crack propagation between filaments and between layers. This article aims to study the effect of the width of the raster on the resistance to crack propagation in a structure obtained by FDM. Design/methodology/approach: We have developed an experimental approach from CT specimens to determine the tensile strength of polylactic acid (PLA) polymers, considering the J-Integral method. And given the complexity of the problem, three cases of raster width (l=0.42 mm, l=0.56 mm and l=0.68 mm) have been treated. Findings: According to the results obtained (J, ∆a), the resistance to crack propagation in the parts printed by FDM seems to be better when the width of the filament is small. Indeed, the energy necessary to break the specimen is relatively greater than in the case of a larger width. This finding was confirmed by comparing the values of J for a given advancement of the crack for the three cases studied. Research limitations/implications: In order to present an exhaustive study, we focused on the effect of raster widths (including 0.42 mm, 0.56 mm to 0.68 mm) on the crack propagation of printed PLA. This study is in progress for other printing parameters. To highlight the cracking mechanisms, microscopic observations will be developed in greater depth at the SEM. Practical implications: Our analysis can be used as decision support in the design of FDM parts. In effect, we can choose the raster width that would provide the resistance to crack propagation desired for a functional part. Originality/value: In this article, we analysed the damage mechanism of CT specimens printed by FDM. This subject represents a new direction for many lines of research. For our study, we used the J-Integral theoretical approach to study the fracture behaviour of these parts by determining the resistance curves (J-∆a).