scholarly journals Design guidelines for plastic casting using 3D printing

2020 ◽  
Vol 15 ◽  
pp. 155892502091603 ◽  
Author(s):  
Paweł Zmarzły ◽  
Damian Gogolewski ◽  
Tomasz Kozior
Keyword(s):  
Surface Layer ◽  
3D Printing ◽  
Textile Industry ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Design Guidelines ◽  
Design Stage ◽  
Technological Inheritance ◽  
Finished Sample

The main aim of the presented tests was to assess the possibility of using 3D printing and casting material to produce casting molds and prototypes, especially in production of existing models. The analysis was based on the assessment of dimensional accuracy and quality of the surface layer of a finished prototype and the intermediate elements made during the production process. The mold was made using the PolyJet Matrix additive technology, and then a silicone mold was cast which was used to prepare a finished sample for testing in accordance with the design assumptions. Based on the results of metrological measurements, the phenomenon of technological inheritance in terms of error transfer in the foundry industry was evaluated. The measurements obtained suggest that in case of casting process, the hereditary features are transferred from individual casting processes, which is especially prominent in the case of surface texture quality. This confirms the occurrence of the phenomenon of the so-called technological inheritance and the need to analyze it. The results of the tests can be a guide for technologists who design molds, core boxes, and casting models, concerning the corrections (shrinkage) that need to be introduced at the design stage in order to obtain a product (casting) of satisfactory dimensional accuracy and quality of the surface layer. The result can also be useful for casting materials reinforced with glass fiber, carbon fiber, which are common materials in 3D printing and textile industry.

THE INFLUENCE OF ADDITIVE TECHNOLOGY ON THE QUALITY OF THE SURFACE LAYER AND THE STRENGTH STRUCTURE OF PROSTHETIC CROWNS

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 13-22
Author(s):  
Łukasz BOJKO ◽  
Wojciech RYNIEWICZ ◽  
Anna M. RYNIEWICZ ◽  
Marcin KOT ◽  
Paweł PAŁKA
Keyword(s):  
Surface Layer ◽  
Layer Structure ◽  
Casting Process ◽  
Additive Technology ◽  
Cocrmo Alloy ◽  
Casting Technology ◽  
Stomatognathic System ◽  
Cad Cam ◽  
Hard Structures

Prosthetic crowns reproduce the damaged hard structures of the patient’s own teeth and take over their natural functions, thus securing the correct reconstruction of the stomatognathic system. The aim is to evaluate the crowns for premolars and molars produced by casting, milling, and Selective Laser Melting technologies, in terms of the accuracy of reproducing the degree against the prosthetic pillar, the analysis of the surface layer structure of the step, and the micromechanical parameters of the alloy. The study material included CoCrMo alloy crowns. The conducted study allowed finding that the tightness of prosthetic crowns made using traditional casting technology as well as in SLM milling and technology is comparable and meets clinical requirements. Structural crown analyses confirmed the very good quality of the surface layer obtained with milling technology and SLM technology using the CAD/CAM method. SLM and digital milling allow the formation of precise and durable structures constituting the foundation of crowns in a time much shorter than the casting process.

scholarly journals Possibilities of using 3D printing for surface layers

2018 ◽  
Vol 183 ◽  
pp. 02005
Author(s):  
Agnieszka Dulska
Keyword(s):  
Surface Layer ◽  
Cast Iron ◽  
3D Printing ◽  
Abrasive Wear ◽  
Composite Layer ◽  
Casting Process ◽  
Grey Cast Iron ◽  
Titanium Layer ◽  
Mould Cavity ◽  
Grey Cast

This article describes how to improve the tribological properties of cast iron by local strengthening by titanium layer, directly in the casting process. The research comprised test molds with a titanium (composite) layer. The insert with titanium was made basing on proprietary development of geometric assumptions. The innovation relies on application the 3D printing insert obtaining in SLM (selective laser melting) method. The tests included measurement of resistance to abrasive wear and carried out metallographic, microhardness measurements as the presents detailed geometry of the insert as well. On the basis of obtaining results was stated that there is a possibility of reinforcing surface layer of the grey cast iron casting by using 3D printing scaffold insert in the method of mould cavity preparation. Moreover there was a local increase in hardness and abrasive wear resistance in spite of the precipitation of titanium carbides in surface layer of grey cast iron.

scholarly journals THE EFFECT OF 3D PRINTING MACHINE PARAMETERS IN EXTRUSION PROCESS OF BIOCOMPOSITE MATERIALS (PMMA AND HA) ON DIMENSIONAL ACCURACY

SINERGI ◽  
2018 ◽  
Vol 22 (2) ◽  
pp. 83
Author(s):  
Raeshifa Diani Almy ◽  
Alva Edy Tontowi
Keyword(s):  
3D Printing ◽  
Operation Time ◽  
Dimensional Accuracy ◽  
Extrusion Process ◽  
Medical Procedures ◽  
Bone Implants ◽  
Dimensional Error ◽  
Complex Shapes ◽  
Printing Machine

Bone implants are medical procedures involving replacement or reconstruction of missing or damaged bones with the patient's ones, natural substitutes or artificial substitutes. The widely used bone cement is a polymethylmethacrylate (PMMA) based composite material. To improve bioactivity, PMMA is combined with hydroxyapatite (HA). The manual formation can make bone implants during surgery. However, the method requires a longer operation time and raises the possibility of a higher error. Therefore, 3D printing technology is used to improve the quality of bone implants. One of the machines that can be used is the 3D printing machine, the property of the Product Design and Development Laboratory of Universitas Gadjah Mada. This machine needs to be tested to determine the accuracy of the prints, which is one indicator of product quality. Several machine parameters can be set in this machine setting. This study aims to determine the effect of three parameters, those are perimeter speed or edge print speed (20-40 mm / s), infill speed or inner print speed (50 - 70 mm / s), and fill angle or inner slope of inner printing (45 - 90 ° C). Before printing complex shapes, the machine was tested in advance with a more straightforward specimen design, which is a specimen design of flexural strength test. Response surface experiment design is used to determine the effect of three parameters on the dimensional accuracy which is measured through dimensional error. The results show that these three factors have no significant impact on the dimensional error, but the resulting error is still high. Therefore, it is necessary to adjust the design size before printing.

An investigation on energy consumption and part quality of stereolithography apparatus manufactured parts

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jizhuang Hui ◽  
Zhiqiang Yan ◽  
Jingxiang Lv ◽  
Yongsheng Liu ◽  
Kai Ding ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Energy Consumption ◽  
Layer Thickness ◽  
Laser Power ◽  
Dimensional Accuracy ◽  
Electrical Energy ◽  
Design Stage ◽  
Content Type ◽  
Part Quality

Purpose This paper aims to investigate the influences of process parameters on part quality, electrical energy consumption. Moreover, the relationship between part quality and energy consumption of UTR9000 photosensitive resin fabricated by stereolithography apparatus (SLA) was also assessed. Design/methodology/approach Main effect plots and contour maps were used to analyze the interactions and effects of various parameters on energy consumption and part quality, respectively. Then, a growth rate was used defined as the percentage of the value of energy consumption (or the part quality) of the sample compared to the minimum value of the energy consumption (or the same part quality), to jointly analyze relationships between part quality and energy consumption on a specific process parameter. Findings The part qualities can be improved with increased energy consumption via adjusting layer thickness, without further increasing energy consumption through adjusting laser power, over-cure and scanning distance. Energy consumption can be highly saved while slightly decreasing the tensile strength by increasing layer thickness from 0.09 mm to 0.12 mm. Energy consumption and surface roughness can be decreased when setting laser power near 290 mW. Setting an appropriate over-cure of about 0.23 mm will improve tensile strength and dimensional accuracy with a little bit more energy consumption. The tensile strength increases nearby 5% at a scanning distance of 0.07 mm compared to that at a scanning distance of 0.1 mm while the energy consumption only increases by 1%. Originality/value In this research, energy consumption and multiple part quality for SLA are jointly analyzed first to accelerate the development of sustainable additive manufacturing. This can be used to assist designers to achieve energy-effective fabrication in the process design stage.

Computational and experimental study of lattice structured patterns for casting process

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ablyaz Timur Rizovich ◽  
Muratov Karim Ravilevich ◽  
Алексей Aleksey Шумков ◽  
Evgeniy Shlykov ◽  
Sahil Dhiman ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Dimensional Accuracy ◽  
Casting Process ◽  
Content Type ◽  
Cell Parameters ◽  
Alloy Casting ◽  
Ni Alloy ◽  
Porosity Coefficient ◽  
Ceramic Shell Mold

Purpose The quality of lost foam casted engineering components is directly influenced by the characteristics of the respective ceramic shell mold (CSM) and hence casting pattern. In this present work, rapid prototyping (RP) was used to fabricate the lattice structured patterns (LSPs) to reduce the defects and cracks in CSM during the heating stage. Design/methodology/approach The quality of the LSPs was accessed by measuring the dimensional accuracy. Further, the thermal stress in the CSM during the heating of porosity varied LSPs was analyzed using ANSYS software package 16.0. The Ni-alloy casting was fabricated by using the designed LSP and compared with its respective CAD model to access its quality. Findings The obtained results revealed that the Wigner–Seitz LSPs retained high accuracy and minimized the stress for defect-free CSM. Also, the thermal stress generated in the CSM depends upon the porosity coefficient of the LSP. Hence the interplay with porosity coefficient of LSPs leads to the formation of defect free CSM and hence high quality casting. Originality/value RP was used to develop LSPs and investigated the dependency of unit cell parameters on the accuracy of the final casting.

scholarly journals Non-Contact Multiscale Analysis of a DPP 3D-Printed Injection Die for Investment Casting

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6758
Author(s):  
Arkadiusz Kroma ◽  
Michał Mendak ◽  
Michał Jakubowicz ◽  
Bartosz Gapiński ◽  
Paweł Popielarski
Keyword(s):  
3D Printing ◽  
Investment Casting ◽  
Measurement Techniques ◽  
Dimensional Accuracy ◽  
Printing Technology ◽  
Measurement Systems ◽  
Contact Measurement ◽  
3D Printing Technology ◽  
3D Printed

The investment casting method supported with 3D-printing technology, allows the production of unit castings or prototypes with properties most similar to those of final products. Due to the complexity of the process, it is very important to control the dimensions in the initial stages of the process. This paper presents a comparison of non-contact measurement systems applied for testing of photopolymer 3D-printed injection die used in investment casting. Due to the required high quality of the surface parameters, the authors decided to use the DPP (Daylight Polymer Printing) 3D-printing technology to produce an analyzed injection die. The X-ray CT, Structured blue-light scanner and focus variation microscope measurement techniques were used to avoid any additional damages to the injection die that may arise during the measurement. The main objective of the research was to analyze the possibility of using non-contact measurement systems as a tool for analyzing the quality of the surface of a 3D-printed injection die. Dimensional accuracy analysis, form and position deviations, defect detection, and comparison with a CAD model were carried out.

scholarly journals Evaluation and optimisation of a slurry-based layer casting process in additive manufacturing using multiphase simulations and spatial reconstruction

2021 ◽  
Author(s):  
P. Erhard ◽  
A. Seidel ◽  
J. Vogt ◽  
W. Volk ◽  
D. Günther
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
Fine Particles ◽  
High Surface ◽  
Casting Process ◽  
Spatial Reconstruction ◽  
Novel Method ◽  
Slurry Layer ◽  
High Level

AbstractSlurry-based 3D printing allows ceramic green bodies to be fabricated at high packing densities. In contrast to powder-based binder jetting, full densification of printed parts can be achieved in a subsequent sintering step as fine particles dispersed in a suspension are cast and compacted. Slurry-based 3D printing is thus expected to overcome the application limits of the powder-based alternative in metal casting in terms of unfavorable properties like high surface roughness, low density and low mechanical strength. To ensure stress-free drying and therefore high qualities of the compounds made in layers, it is crucial to fabricate single layers with a high level of homogeneity. This paper presents a CFD model based on the open-source simulation environment OpenFOAM to predict the resulting homogeneity of a cast slurry layer with defined parameter sets or coater geometries using the Volume-Of-Fluid method. Moreover, a novel method of spatial reconstruction is proposed to evaluate the surface quality of layers on a minimised computional demand. By comparing the results of the simulation with the real macroscopic behaviour determined in experiments, the approach is found to be a useful tool for suggesting suitable parameters and coater geometries for processing slurries. A precise reconstruction of the outline of the coating area with different process parameters and an approximate prediction of the effect on surface roughness was achieved.

Effect of High-Pressure Hot Airflow On Interlayer Adhesion Strength of 3D Printed Parts

2021 ◽  
Author(s):  
Huangxiang Xu ◽  
Jianhua Xiao ◽  
Xiaojie Zhang ◽  
Xiaobo Liu
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Surface Layer ◽  
3D Printing ◽  
Adhesion Strength ◽  
Gas Flow ◽  
Dimensional Accuracy ◽  
Lubrication Layer ◽  
3D Printed ◽  
Printing Method

Abstract The characteristics of FDM 3D printed parts depend largely on the process used to make them. This paper demonstrates the design of an FDM 3D printing gas-assisted molding printing head, which is used to eliminate the effect of swelling away from the mold and improve the dimensional accuracy. Meanwhile, the high-pressure hot airflow instantly heats and pressurizes the printing surface layer to enhance the interlayer adhesion strength and its mechanical properties. A stable gas lubrication layer can be formed on the inner wall of gas-assisted nozzle to smoothly deposit filaments when the gas flow (Qgas) is set to 1.75 L/min and the gas pressure (Pgas) is set to 0.4 MPa. The interlayer adhesion strength of the printed parts is enhanced by more than 50% compared with that without gas assistance, and the volumetric shrinkage rate of the optimal group is only 0.13%. The proposed printing method can significantly improve the performance of thermoplastic parts and provide new capabilities for biomedical printing, automotive, aerospace and functional device printing in the future.

3D Printed Injection Molds Using Various 3D Printing Technologies

2020 ◽  
Vol 1005 ◽  
pp. 150-156 ◽  
Author(s):  
John Ryan Cortez Dizon ◽  
Arnaldo D. Valino ◽  
Lucio R. Souza ◽  
Alejandro H. Espera ◽  
Qiyi Chen ◽  
...  
Keyword(s):  
3D Printing ◽  
Injection Molding ◽  
Polylactic Acid ◽  
Dimensional Accuracy ◽  
Damage Mechanism ◽  
Molding Machine ◽  
Fused Filament Fabrication ◽  
Commercial Software ◽  
3D Printed

This paper explores the possibility of using different 3d printing methods and materials in the production of polymer molds for injection molding applications. A mold producing a cube was designed using a commercial software. Following the standard 3d printing process, injection molds which could produce a cube were printed using different 3d printing materials and 3d printing technologies. The 3d printing technologies used were Stereolithography (SLA), Polyjet and Fused Filament Fabrication (FFF). A bench-top injection molding machine was used to inject polylactic acid (PLA) in these molds. The quality of the injected parts in terms of dimensional accuracy has been investigated. In some cases, the damage mechanism of the polymer molds has also been observed.

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