Effects of processing conditions on mechanical properties of PLA printed parts

Purpose With recent advances in additive manufacturing (AM), polymer-based three-dimensional (3D) printers are available for relatively low cost and have found their way even in domestic and educational uses. However, the optimum conditions for processing and post-processing of different materials are yet to be determined. The purpose of this paper is to examine the effects of printing temperature, pattern and annealing conditions on tensile strength and modulus of samples printed with polylactic acid (PLA). Design/methodology/approach This study focuses on fused deposition modelling according to ISO/ASTM 52900 material extrusion AM. To print parts with maximum mechanical properties, the printing variables must be optimised. To determine the printing and annealing condition on physical and mechanical properties of PLA-based parts, dogbone-shaped tensile samples were printed at four different nozzle temperatures and five different filling patterns embedded in a 3D printing software. The samples were further annealed at three different temperatures for three different time intervals. The mechanical properties were evaluated and the changes in mechanical properties were analysed with the help of rheometrical measurements. Findings The results showed that printing condition has a significant influence on final properties, for example, the strain at break value increases with increasing nozzle temperature from 34 to 56 MPa, which is close to the value of the injected sample, namely, 65 MPa. While tensile strength increases with printing temperature, the annealing process has negative effects on the mechanical properties of samples. Originality/value The authors observed that traditional findings in polymer science, for example, the relationship between processing and annealing temperature, must be re-evaluated when applied in 3D printing because of major differences in processing conditions resulting from the layer-by-layer manufacturing.

Download Full-text

Investigation of a Short Carbon Fibre-Reinforced Polyamide and Comparison of Two Manufacturing Processes: Fused Deposition Modelling (FDM) and Polymer Injection Moulding (PIM)

Materials ◽

10.3390/ma13030672 ◽

2020 ◽

Vol 13 (3) ◽

pp. 672 ◽

Cited By ~ 7

Author(s):

Elena Verdejo de Toro ◽

Juana Coello Sobrino ◽

Alberto Martínez Martínez ◽

Valentín Miguel Eguía ◽

Jorge Ayllón Pérez

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Injection Moulding ◽

New Technologies ◽

Mechanical Response ◽

Fused Deposition Modelling ◽

Layer By Layer ◽

Polymer Injection ◽

Fused Deposition

New technologies are offering progressively more effective alternatives to traditional ones. Additive Manufacturing (AM) is gaining importance in fields related to design, manufacturing, engineering and medicine, especially in applications which require complex geometries. Fused Deposition Modelling (FDM) is framed within AM as a technology in which, due to their layer-by-layer deposition, thermoplastic polymers are used for manufacturing parts with a high degree of accuracy and minimum material waste during the process. The traditional technology corresponding to FDM is Polymer Injection Moulding, in which polymeric pellets are injected by pressure into a mould using the required geometry. The increasing use of PA6 in Additive Manufacturing makes it necessary to study the possibility of replacing certain parts manufactured by injection moulding with those created using FDM. In this work, PA6 was selected due to its higher mechanical properties in comparison with PA12. Moreover, its higher melting point has been a limitation for 3D printing technology, and a further study of composites made of PA6 using 3D printing processes is needed. Nevertheless, analysis of the mechanical response of standardised samples and the influence of the manufacturing process on the polyamide’s mechanical properties needs to be carried out. In this work, a comparative study between the two processes was conducted, and conclusions were drawn from an engineering perspective.

Download Full-text

Parameters Affecting the Mechanical Properties of Three-Dimensional (3D) Printed Carbon Fiber-Reinforced Polylactide Composites

Polymers ◽

10.3390/polym12112456 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2456

Author(s):

Demei Lee ◽

Guan-Yu Wu

Keyword(s):

Mechanical Properties ◽

Carbon Fiber ◽

3D Printing ◽

Three Dimensional ◽

Fused Deposition Modelling ◽

Layer By Layer ◽

Fused Deposition ◽

Bed Temperature ◽

3D Printed ◽

The Impact

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.

Download Full-text

Influence of ABS print parameters on a 3D open-source, self-replicable printer

Rapid Prototyping Journal ◽

10.1108/rpj-10-2019-0267 ◽

2020 ◽

Vol 26 (10) ◽

pp. 1733-1738

Author(s):

André Luiz Alves Guimarães ◽

Vicente Gerlin Neto ◽

Cesar Renato Foschini ◽

Maximiliano dos Anjos Azambuja ◽

Luiz Antonio Vasques Hellmeister

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Open Source ◽

Layer Thickness ◽

Acrylonitrile Butadiene Styrene ◽

Influential Factor ◽

Fused Deposition Modelling ◽

Content Type ◽

Fused Deposition ◽

Printing Parameters

Purpose The purpose of this paper is to investigate and discuss the influence of printing parameters on the mechanical properties of acrylonitrile butadiene styrene (ABS) print by fused deposition modelling (FDM). The mechanical properties of ABS are highly influenced by printing parameters, and they determine the final product quality of printed pieces. Design/methodology/approach For the paper’s purpose, five main parameters (extrusion temperature, infill pattern, air gap, printing speed and layer thickness) were selected and varied during ABS printing on an open-source and self-replicable FDM printer. Three different colors of commercially available ABS were also used to investigate color and printing parameter’s influence on the tensile strength. Findings The research results suggest that two parameters (infill pattern and layer thickness) were most influential on the mechanical properties of print ABS, being able to enhance its tensile strength. Another key influential factor was material color selected prior to printing, which influenced the tensile strength of the print specimen. Originality/value This study provides information on print parameters’ influence on the tensile strength of ABS print on replicable open-source three-dimensional (3D) printers. It also suggests the influence of materials’ color on print pieces’ tensile strength, indicating a new parameter for materials selection for 3D printing.

Download Full-text

Mechanical properties comparison of PLA, tough PLA and PC 3D printed materials with infill structure – Influence of infill pattern on tensile mechanical properties

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1208/1/012019 ◽

2021 ◽

Vol 1208 (1) ◽

pp. 012019

Author(s):

Adi Pandzic ◽

Damir Hodzic

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

3D Printing ◽

Material Testing ◽

Fused Deposition Modelling ◽

Fused Deposition ◽

3D Printed ◽

Printed Materials ◽

Product Weight

Abstract One of the advantages provided by fused deposition modelling (FDM) 3D printing technology is the manufacturing of product materials with infill structure, which provides advantages such as reduced production time, product weight and even the final price. In this paper, the tensile mechanical properties, tensile strength and elastic modulus, of PLA, Tough PLA and PC FDM 3D printed materials with the infill structure were analysed and compared. Also, the influence of infill pattern on tensile properties was analysed. Material testing were performed according to ISO 527-2 standard. All results are statistically analysed and results showed that infill pattern have influence on tensile mechanical properties for all three materials.

Download Full-text

The influence of the 3D-printing technology on the physical and mechanical properties of polyphenylene sulfone

Rapid Prototyping Journal ◽

10.1108/rpj-03-2017-0045 ◽

2018 ◽

Vol 24 (7) ◽

pp. 1124-1130 ◽

Cited By ~ 3

Author(s):

Azamat Ladinovich Slonov ◽

Azamat Askerovich Khashirov ◽

Azamat Aslanovich Zhansitov ◽

Elena Viktorovna Rzhevskaya ◽

Svetlana Yuryevna Khashirova

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

3D Printing ◽

Impact Strength ◽

Orientation Angle ◽

Physical And Mechanical Properties ◽

Air Gap ◽

Content Type ◽

Fused Deposition ◽

The Impact

Purpose This paper aims to examine the impact of three-dimensional (3D) printing technological modes (using fused deposition modelling [FDM]) on physical and mechanical properties of samples from polyphenylenesulfone. Design/methodology/approach For this study, the standard test samples were printed using the FDM method at different filament orientation angles, the gaps between them and a different width. The basic physical and mechanical properties, such as the strength, the elastic modulus and the impact strength, were studied. Findings The authors found that the basic mechanical properties strongly depend on the printing settings. In particular, the elastic modulus generally depends on the air gap between rasters, and it is practically independent of the filament orientation angle. In contrast, the impact strength depends on the orientation and the degree of adhesion between filaments: the highest values are reached at the longitudinal orientation of rasters in the sample (0°) and the minimum value of the air gap (−0.025 mm). However, in selecting the optimal mode of 3D printing, it is necessary to take into account the specific geometry of the printing products and the direction of the stress that it will experience. Originality/value The paper presents the results of the investigation of the influence of FDM printing modes on the mechanical properties of samples from polyphenylenesulfone, including impact strength. The authors studied the mechanisms of the destruction under impact loading and revealed the optimal printing settings for making samples with properties which are not inferior to the injection molded samples.

Download Full-text

Experimental testing of PLA biodegradable thermoplastic in the frame of 3D printing FDM technology

MATEC Web of Conferences ◽

10.1051/matecconf/201815706001 ◽

2018 ◽

Vol 157 ◽

pp. 06001

Author(s):

Juraj Beniak ◽

Peter Križan ◽

Miloš Matúš ◽

Michal Šajgalík

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

3D Printing ◽

Experimental Testing ◽

3D Models ◽

Fused Deposition Modelling ◽

Suitable Material ◽

Fused Deposition ◽

Plastic Materials ◽

Melted Material

In the present time there are many different plastic materials and composite materials suitable for 3D printing by deposition of semi-melted material. The proper selection of correct material with suitable material properties is dependent on the situation how the produced 3D model should be used. If we need to take into account just the visual look of used material or also the mechanical properties as strength is important for loaded models for final use. The aim of this paper is to publish outputs of experimental testing for 3D models from selected materials with regards to mechanical properties of produced testing parts. Produced 3D models are from PLA biodegradable thermoplastic. Models are prepared on Fused Deposition Modelling (FDM) 3D printer. Testing is based on prepared full factors experiment with four factors on its two levels. Measured values are Tensile strength of PLA testing 3D models. In the same time there are gathered information regarding the 3D printing process and compared to measured tensile strength values for each sent of testing parts. All the measured data are statistically evaluated also by Analysis of Variance (ANOVA method).

Download Full-text

Effect of process parameters on tensile strength of FDM printed PLA part

Rapid Prototyping Journal ◽

10.1108/rpj-06-2017-0134 ◽

2018 ◽

Vol 24 (8) ◽

pp. 1317-1324 ◽

Cited By ~ 20

Author(s):

Shilpesh R. Rajpurohit ◽

Harshit K. Dave

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Process Parameters ◽

Fused Deposition Modelling ◽

Type I ◽

Content Type ◽

Layer Height ◽

Fused Deposition ◽

Anisotropic Mechanical Properties ◽

Raster Angle

PurposeThe purpose of this paper to study the tensile strength of the fused deposition modelling (FDM) printed PLA part. In recent times, FDM has been evolving from rapid prototyping to rapid manufacturing where parts fabricated by FDM process can be directly used for application. However, application of FDM fabricated part is significantly affected by poor and anisotropic mechanical properties. Mechanical properties of FDM part can be improved by proper selection of process parameters.Design/methodology/approachIn the present study, three process parameter, namely, raster angle, layer height and raster width, have been selected to study their effect on tensile properties. Parts are fabricated as per ASTM D638 Type I standard.FindingsIt has been observed that the highest tensile strength obtained at 0° raster angle. Lower value of layer height is observed to be good for higher tensile strength because of higher bonding area between the layers. At higher value of raster width, tensile strength is improved up to certain extent after which presence of void reduces the tensile strength.Originality/valueIn the present investigation, layer height and raster width have been also varied along with raster angle to study their effect on the tensile strength of FDM printed PLA part.

Download Full-text

Development of 3D Printing Raw Materials from Plastic Waste. A Case Study on Recycled Polyethylene Terephthalate

Applied Sciences ◽

10.3390/app11167338 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7338

Author(s):

Alaeddine Oussai ◽

Zoltán Bártfai ◽

László Kátai

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

3D Printing ◽

Tensile Test ◽

Polyethylene Terephthalate ◽

Fused Deposition Modelling ◽

Additive Process ◽

Recycled Pet ◽

Fused Deposition ◽

Test Pieces

Fused Deposition Modelling (FDM) is the most common 3D printing technology. An object formed through continuous layering until completion is known as an additive process while other processes with different methods are also relevant. In this paper, mechanical properties were analysed using two distinct kinds of printed polyethylene terephthalate (PET) as tensile test specimens. The materials used consist of recycled PET and virgin PET. An assessment of all the forty test pieces of both kinds of PET was undertaken. A comparison of the test samples’ tensile strength values, difference in stress-strain curves, and elongation at break was also carried out. The reasoning behind the fracturing of test pieces that printed with different settings is presented in part by the depiction of the fractured specimens following the tensile test. An optimal route was revealed to be 3D printing with recycled PET, as per the mechanical testing. The hardness of the recycled filament decreased to 6%, while the tensile strength and shear strength increased to 14.7 and 2.8%, respectively. Nonetheless, no changes occurred to the tensile modulus elasticity. Despite notable differences being observed in the results of the recycled PET filament, no substantial differences were found prior or post-recycling in the mechanical properties of the PET filament. In conclusion, the demand for improved recycled 3D printing filament technologies is heightened due to the comparable mechanical features of the specimens of both the 3D printed recycled and virgin materials. With tensile strength figures reaching as high as 43.15MPa at Recycled PET and 3.12% being the greatest elongation at 40% Recycled PET, 100% Recycled is the ideal printing setting.

Download Full-text

Use of polymer concrete for large-scale 3D printing

Rapid Prototyping Journal ◽

10.1108/rpj-12-2019-0316 ◽

2021 ◽

Vol 27 (3) ◽

pp. 465-474

Author(s):

Martin Krčma ◽

David Škaroupka ◽

Petr Vosynek ◽

Tomáš Zikmund ◽

Jozef Kaiser ◽

...

Keyword(s):

3D Printing ◽

Large Scale ◽

Mechanical Performance ◽

Construction Material ◽

Polymer Concrete ◽

Fused Deposition Modelling ◽

Cast State ◽

Content Type ◽

Fused Deposition ◽

3D Printed

Purpose This paper aims to focus on the evaluation of a polymer concrete as a three-dimensional (3D) printing material. An associated company has developed plastic concrete made from reused unrecyclable plastic waste. Its intended use is as a construction material. Design/methodology/approach The concrete mix, called PolyBet, composed of polypropylene and glass sand, is printed by the fused deposition modelling process. The process of material and parameter selection is described. The mechanical properties of the filled material were compared to its cast state. Samples were made from castings and two different orientations of 3D-printed parts. Three-point flex tests were carried out, and the area of the break was examined. Computed tomography of the samples was carried out. Findings The influence of the 3D printing process on the material was evaluated. The mechanical performance of the longitudinal samples was close to the cast state. There was a difference in the failure mode between the states, with cast parts exhibiting a tougher behaviour, with fractures propagating in a stair-like manner. The 3D-printed samples exhibited high degrees of porosity. Originality/value The results suggest that the novel material is a good fit for 3D printing, with little to no degradation caused by the process. Layer adhesion was shown to be excellent, with negligible effect on the finished part for the longitudinal orientation. That means, if large-scale testing of buildability is successful, the material is a good fit for additive manufacturing of building components and other large-scale structures.

Download Full-text

Tensile and Bending Strength Improvements in PEEK Parts Using Fused Deposition Modelling 3D Printing Considering Multi-Factor Coupling

Polymers ◽

10.3390/polym12112497 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2497 ◽

Cited By ~ 1

Author(s):

Yao Li ◽

Yan Lou

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Tensile Properties ◽

Bending Strength ◽

Utilization Rate ◽

Fused Deposition Modelling ◽

Fused Deposition ◽

Molded Parts ◽

Injection Molded ◽

Printing Direction

Compared with laser-based 3D printing, fused deposition modelling (FDM) 3D printing technology is simple and safe to operate and has a low cost and high material utilization rate; thus, it is widely used. In order to promote the application of FDM 3D printing, poly-ether-ether-ketone (PEEK) was used as a printing material to explore the effect of multi-factor coupling such as different printing temperatures, printing directions, printing paths, and layer thicknesses on the tensile strength, bending strength, crystallinity, and grain size of FDM printed PEEK parts. The aim was to improve the mechanical properties of the 3D printed PEEK parts and achieve the same performance as the injection molded counterparts. The results show that when the thickness of the printed layer is 0.1 mm and the printing path is 180° horizontally at 525 °C, the tensile strength of the sample reaches 87.34 MPa, and the elongation reaches 38%, which basically exceeds the tensile properties of PEEK printed parts reported in previous studies and is consistent with the tensile properties of PEEK injection molded parts. When the thickness of the printed layer is 0.3 mm, the printing path is 45°, and with vertical printing direction at a printing temperature of 525 °C, the bending strength of the sample reaches 159.2 MPa, which exceeds the bending performance of injection molded parts by 20%. It was also found that the greater the tensile strength of the printed specimen, the more uniform the size of each grain, and the higher the crystallinity of the material. The highest crystallinity exceeded 30%, which reached the crystallinity of injection molded parts.

Download Full-text