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The aim of this study is to investigate the relationship between the fusion temperature and dimensional accuracy of the 3D printed components. The Computer Aided Design (CAD) model of specimens were prepared using Autodesk Inventor Software. Then the models were exported to STL file format for rapid prototyping. Prusa İ3 desktop type 3D printer with 90-300 microns layer height manufacturing capacity was used to produce the samples. The printer settings were prepared with Simplified3D software. Infill density and layer height of specimens were determined as 20% and 200 microns, respectively. The heated bed temperature was selected as 60 °C to increase the bonding and surface quality. The specimens were produced as sphere with the diameter of 10 mm. The samples were manufactured with five different extruder temperatures (185, 195, 205, 215, and 220 °C) that directly affect the fusing temperature and process. Three samples spheres were produced for each fusion temperature. After the design and manufacturing processes the dimensions of produced samples were measured with image processing techniques. The obtained results were compared with each other to find the relationship between the dimensional accuracy and fusion temperatures. The results showed that the minimum dimensional error was obtained from the fusion temperature of 185 °C with the value of 0.290797 mm and percentage of 3%.
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Sigma J Eng & Nat Sci 38 (1), 2020, 21-28
Research Article
THE RELATIONSHIP BETWEEN THE FUSION TEMPERATURE AND
DIMENSIONAL ACCURACY OF 3D PRINTED PARTS
Pinar DEMIRCIOGLU
*
1, Ismail BOGREKCI2, H. Saygin SUCUOGLU3,
Emrah GUVEN4
1Aydın Adnan Menderes University, Mechanical Eng. Department, AYDIN; ORCID: 0000-0003-1375-5616
2Aydın Adnan Menderes University, Mechanical Eng. Department, AYDIN; ORCID: 0000-0002-9494-5405
3Aydın Adnan Menderes University, Mechanical Eng. Department, AYDIN; ORCID: 0000-0002-2136-6015
4Aydın Adnan Menderes University, Mechanical Eng. Department, AYDIN; ORCID: 0000-0002-4161-1989
Received: 15.05.2019 Revised: 08.07.2019 Accepted: 24.10.2019
ABSTRACT
The aim of this study is to investigate the relationship between the fusion temperature and dimensional
accuracy of the 3D printed components. The Computer Aided Design (CAD) model of specimens were
prepared using Autodesk Inventor Software. Then the models were exported to STL file format for rapid
prototyping. Prusa İ3 desktop type 3D printer with 90-300 microns layer height manufacturing capacity was
used to produce the samples. The printer settings were prepared with Simplified3D software. Infill density and
layer height of specimens were determined as 20% and 200 microns, respectively. The heated bed temperature
was selected as 60 °C to increase the bonding and surface quality. The specimens were produced as sphere
with the diameter of 10 mm. The samples were manufactured with five different extruder temperatures (185,
195, 205, 215, and 220 °C) that directly affect the fusing temperature and process. Three samples spheres
were produced for each fusion temperature. After the design and manufacturing processes the dimensions of
produced samples were measured with image processing techniques. The obtained results were compared with
each other to find the relationship between the dimensional accuracy and fusion temperatures. The results
showed that the minimum dimensional error was obtained from the fusion temperature of 185 °C with the
value of 0.290797 mm and percentage of 3%.
Keywords: Bonding and surface quality, coordinate measurement machine, dimensional accuracy, fusion
temperature, image processing.
1. INTRODUCTION
Additive manufacturing technologies have developed significantly in order to integrate
manufacturing companies with Industry 4.0 technologies. For this purpose, several techniques are
used to improve the manufacturing processes in additive manufacturing. Rapid Prototyping
Technologies that is the one of the additive manufacturing method, has been investigated in many
academic studies.
3D printing important technique among the Rapid Prototyping methods has commonly
preferred for many different application areas such as automotive, aerospace, food, medicine and
*
Corresponding Author: e-mail: pinar.demircioglu@adu.edu.tr, tel: (256) 213 75 03
Sigma Journal of Engineering and Natural Sciences
Sigma Mühendislik ve Fen Bilimleri Dergisi
22
biomechanical industry because of its fast and low cost manufacturing ability. 3D Printing creates
the geometries and structures from 3D dimensional model data. According to ASTM Committee
F12, “3D printing is the fabrication of objects through the deposition of a material using a print
head, nozzle, or other printing technologies. 3D printing is a process of using successive layers of
printed material to form solid 3D objects of virtually any shape from a digital model” [1]. This
technique was first developed by Charles Hull in 1986 as stereolithography (SLA) and it had a
great deal of developments, such as inkjet printing, fused deposition modeling (FDM), powder
bed fusion, contour crafting (CC) etc. [2].
Most commonly used method of 3D printing is known as Fused Deposition Modelling
(FDM). FDM brings parts onto a base plate material with deposition of the stream of hot viscous
material. Solidification of the molten material is obtained by natural cooling; so theoretically any
thermoplastic or heat fusible material can be used in this process [3]. It has some advantages
advantages such as high manufacturing speed, low cost and simplicity beside this there are some
disadvantages such as weak mechanical properties, layer-by-layer appearance and poor surface
quality. Although mechanical properties of the produced parts with FDM can be improved using
fiber-reinforced composites, there are some factors that should be taken into account such as fiber
orientation, bonding between the fiber and matrix and void formation in 3D printed parts [2]. The
surface quality and dimensional accuracy of parts with high surface roughness cause to the
dimensional errors. For these parts, it is much more significant to reach the sufficient dimensional
accuracy on the top part of the surface [4]. There is a thermal energy of the extruded material
because of the melting solidification mechanism of FDM and the formation of bonds among
filaments. Bonding quality is changed significantly with this thermal energy [5, 7]. Sun et al.
found in their study that the nozzle & environment temperatures and cooling condition had
important effects on bonding & surface quality and dimensional accuracy [5, 6].
Image Processing provides different forms of an image to get improved forms or extracting
some convenient features from it. Image Processing Systems enclose handling images with two
dimensional signals even as applying already set signal processing methods to them [8]. Image
processing techniques can be implemented for measurements, determining data such as particles
and shape identification, and size distribution [9].
Some important applications of processing are summarized below [8]:
Visualization; to observe the invisible objects.
Image sharpening and restoration; to generate a better image.
Image retrieval; to seek for the image of interest.
Pattern measurement; to measure several objects in the image.
Image Recognition; to differentiate the objects in the image.
In this study; the relationship between the fusion temperature and dimensional accuracy of the
3D printed components was investigated. The specimens were produced as sphere with the
diameter of 10 mm. The samples were manufactured with five different extruder temperatures
(185, 195, 205, 215, and 220 °C) that directly affect the fusing temperature and process. Three
samples spheres were produced for each fusion temperature. The images of the specimens were
acquired using 20.2 Megapixels high resolution CCD camera. The obtained images were
processed by different image processing techniques such as binarizing, edge detection, edge
enhancement and image correlation.
P. Demircioglu, I. Bogrekci, H.S. Sucuoglu, E. Guven / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
23
2. METHODOLO GY
2.1. Design and Producing of Specimens
The dimensional accuracy measurement samples were printed using Prusa İ3 desktop type 3D
printer with 90-300 microns layer height manufacturing capacity with the 1.75 mm diameter PLA
filament. The printer parameters were set with Simplified3D software (Figure 1).
Figure 1. Printer settings of measurement samples.
The technical specifications of Prusa İ3 desktop type Printer were given in Table 1.
Table 1. Technical specifications of Prusa İ3 3D Printer [10].
Properties
Unit
Value
Layer Resolution
µm
90-300
Build Volume
mm
200 x 200 x 180
XY Positioning Precision
µm
12
Z Positioning Precision
µm
4
Filament Diameter
mm
1.75
Extruder Temperature
0C
170-275
Print Material
-
PLA , ABS
The Prusa İ3 3D printer has ability to produce the parts with PLA and ABS material. The
dimensional accuracy measurement specimens were designed using a CAD software (Autodesk
Inventor 2018). The samples were designed and produced as sphere with the diameter of 10 mm
(Figure 2). The designed models were exported to STL file format for 3D printing. In the printing
process; the heated bed temperature was selected as 60 °C increase the bonding and surface
quality. The samples were manufactured with five different extruder temperatures (185, 195, 205,
215, and 220 °C) that directly affect the fusing temperature and process. Shell of the specimens
were created with the thickness of 0.8 mm Layer heights were selected as 0.2 mm. Number of
shells were used as 2 and print speed was determined as 80 mm/s.
The Relationship Between the Fusion Temperature / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
24
Figure 1. The produced sphere shape samples.
2.2. Image Processing for the Measurement of Dimensional Accuracy
In the digital image processing, an edge can be the result of the changes in light, color and
texture. The changes can be used to define the depth, size orientation and surface properties of the
image. To filter the unnecessary information to select the edge points, digital analysis of the
image can be used. Edge detection is a basic and important tool in the main areas of image
processing such as feature detection and feature extraction [11]. The flowchart of the edge
detection in image processing is shown in Figure 3.
Figure 2. Flowchart of edge detection.
The Prewitt operator was in this study for edge detection. It is a discrete differentiation
operator to calculate the relation of the gradient of intensity. The results of Prewitt operator is the
gradient vector or the norm of this at each point in the image. Mathematically, the operator uses
two 3×3 kernels that are convolved with the original image to calculate approximations of the
derivatives one for horizontal changes, and one for vertical as shown in Figure 4.
P. Demircioglu, I. Bogrekci, H.S. Sucuoglu, E. Guven / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
25
Figure 4. 3x3 kernels used in Prewitt operator.
The roundness errors of the samples were calculated using single trace roundness design.
According to the approach, the measured diameter of the sample images were normalized to the
designed diameter as 10 mm from the pixel values. The differences of the diameter from design
and produced samples were found horizontally and vertically. The mean and standard deviation
values were also found.
3. RESULTS AND DISCUSSION
The images obtained from image processing (RGB, Gray scale and edge detected) are shown
in Figure 5.
(a) (b)
(c)
Figure 5. The obtained images from image processing (a) RGB (b) Gray scale (c) Edge detected.
The obtained diameter values from the image processing are given in Table 2.
The Relationship Between the Fusion Temperature / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
26
Table 1. The obtained results from the image processing for dimensional accuracy.
Temperature
(°C)
Ruler
Pixel
Horizontal
Diameter
(Pixel)
Vertical
Diameter
(Pixel)
Normalized
Horizontal
Diameter
(mm)
Normalized
Vertical
Diameter
(mm)
Mean of Vertical
and Horizontal
Diameters (mm)
Difference
185
582
597
603
10.25773196
10.36082474
10.30927835
0.309278
585
601
601
10.27350427
10.27350427
10.27350427
0.273504
587
607
601
10.3407155
10.23850085
10.28960818
0.289608
Mean
0.290797
Standard
Deviation
0.017917
195
585
610
609
10.42735043
10.41025641
10.41880342
0.418803
587
612
616
10.42589438
10.49403748
10.45996593
0.459966
589
615
612
10.44142615
10.39049236
10.41595925
0.415959
Mean
0.431576
Standard
Deviation
0.024627
205
593
621
615
10.47217538
10.37099494
10.42158516
0.421585
591
619
615
10.47377327
10.40609137
10.43993232
0.439932
587
617
613
10.51107325
10.44293015
10.4770017
0.477002
Mean
0.446173
Standard
Deviation
0.028230
215
589
617
617
10.475382
10.475382
10.475382
0.475382
585
605
611
10.34188034
10.44444444
10.39316239
0.393162
591
625
619
10.57529611
10.47377327
10.52453469
0.524535
Mean
0.464360
Standard
Deviation
0.066376
220
581
617
609
10.61962134
10.48192771
10.55077453
0.550775
583
611
609
10.48027444
10.44596913
10.46312178
0.463122
581
607
607
10.4475043
10.4475043
10.4475043
0.447504
Mean
0.487134
Standard
Deviation
0.055665
The means of differences of the diameters between the designed and produced specimens
were computed as, respectively;
0.290797 mm for 185 °C fusion temperature,
0.431576 mm for 195 °C fusion temperature,
0.446173 mm for 205 °C fusion temperature,
0.464360 mm for 215 °C fusion temperature,
0.487134 mm for 220 °C fusion temperature.
In this study; the nozzle temperature to produce the measurement samples were selected in the
range between 185 °C and 220 °C as the processing temperature of the PLA was around 180 °C to
P. Demircioglu, I. Bogrekci, H.S. Sucuoglu, E. Guven / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
27
220 °C [12]. For the dimensional accuracy the minimum diameter error was obtained from 185 °C
fusion temperature with the value of 0.290797 mm. It was also observed that the diameter error
reached to 0.487134 mm for 220 °C fusion temperature environment. The dimensional error was
about 3% for 185 °C while it was 4.8% for 220 °C.
The fusion temperature has effect on the elasticity and strength of the produced object with
PLA material. While the increasing fusion temperature is resulting with higher ultimate strength,
it decreases the elasticity [13]. It can be also understood from the measurement results in
dimensional accuracy that the increasing fusion temperature causes to more dimensional errors.
The reason of these results can be that higher level of the fusion temperature helps to material to
fill the gaps caused from air void and increase the level of ultimate strength. However, it leads to
the dimensional errors.
4. CONCLUSION
In this research, the relationship between the fusion temperature and dimensional accuracy of
the 3D printed components have been studied. Results showed that:
1. The minimum dimensional error was obtained from the fusion temperature of 185 °C with
the value of 0.290797 mm and percentage of 3%.
2. The specimens were produced with the maximum dimensional error with the value of
0.487134 mm and percentage of 4.8% for fusion temperature of 220 °C.
3. It could be concluded from the results that the fusion temperature has important effect for
the dimensional accuracy of 3D printed components.
Further researches are planned to understand the effect of the other producing parameters such
as infill type, environmental conditions and heated bed temperature effects to the dimensional
accuracy of 3D printed components.
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P. Demircioglu, I. Bogrekci, H.S. Sucuoglu, E. Guven / Sigma J Eng & Nat Sci 38 (1), 21-28, 2020
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Standard Specification for Additive Manufacturing File Format, F2915-11
ASTM, Standard Specification for Additive Manufacturing File Format, F2915-11, ASTM International, West Conshohocken, PA. 2011.
Investigation of bond formation in FDM process, 13th Solid freeform fabrication symposium
  • L Li
  • Q Sun
  • C Bellehumeur
  • P Gu
Li, L., Sun, Q., Bellehumeur, C., Gu, P.,(2002) Investigation of bond formation in FDM process, 13th Solid freeform fabrication symposium, Solid Freeform Fabrication Proceedings, Pages 400-407, Austin, Texas..
Structure, Surface and Permanence Properties of Three Dimensional Printing Materials
  • M Stanic
Stanic, M., (2010) Structure, Surface and Permanence Properties of Three Dimensional Printing Materials", Doctoral Thesis in Faculty of Graphic Arts University of Zagreb, Zagreb.