scholarly journals Investigation of the rheological behavior of ABS plastic grades for the production of filaments for 3D printing by layer-by-layer deposition

2021 ◽  
pp. 29-35
Author(s):  
O. I. Abramushkina ◽  
M. I. Uzorina ◽  
P. V. Surikov ◽  
O. B. Ushakova

A comprehensive study of the rheological properties of ABS-plastic grades used for the manufacture of fi laments for 3D printing by the FDM method has been carried out. It is shown that under the printing temperature-speed conditions, the viscous properties of melts of different grades and activation energy of their viscous flow differ significantly. The temporal parameters of the thermal stability of melts at an elevated (250°C) temperature were determined by the rheological method. It is shown that, under printing conditions, the polymer does not undergo noticeable degradation, assessed by the change in its effective viscosity. Viscoelasticity, which determines the dimensional accuracy of products and the thickness of the deposited layer, was evaluated by the degree of swelling of the extrudate under different flow conditions. Criteria for the applicability of ABS-plastic grades for fi lament production are proposed.

2021 ◽  
Vol 2 (2) ◽  
pp. 289-302
Author(s):  
Antreas Kantaros ◽  
Dimitrios Piromalis

Over time, the fabrication of lattice, porous structures has always been a controversial field for researchers and practitioners. Such structures could be fabricated in a stochastic way, thus, with limited control over the actual porosity percentage. The emerging technology of 3D printing, offered an automated process that did not require the presence of molds and operated on a layer-by-layer deposition basis, provided the ability to fabricate almost any shape through a variety of materials and methods under the umbrella of the ASTM terminology “additive manufacturing”. In the field of biomedical engineering, the technology was embraced and adopted for relevant applications, offering an elevated degree of design freedom. Applications range in the cases where custom-shaped, patient-specific items have to be produced. Scaffold structures were already a field under research when 3D printing was introduced. These structures had to act as biocompatible, bioresorbable and biodegradable substrates, where the human cells could attach and proliferate. In this way, tissue could be regenerated inside the human body. One of the most important criteria for such a structure to fulfil is the case-specific internal geometry design with a controlled porosity percentage. 3D printing technology offered the ability to tune the internal porosity percentage with great accuracy, along with the ability to fabricate any internal design pattern. In this article, lattice scaffold structures for tissue regeneration are overviewed, and their evolution upon the introduction of 3D printing technology and its employment in their fabrication is described.


2020 ◽  
Vol 869 ◽  
pp. 466-473
Author(s):  
Kamila T. Shakhmurzova ◽  
Zhanna I. Kurdanova ◽  
Artur E. Baykaziev ◽  
Azamat Zhansitov ◽  
Svetlana Khashirova

The article is a literature review on 3D-printing of crystalline polyether ether ketone by the methods of layer-by-layer deposition of molten polymer filament (FDM) and selective laser sintering (SLS). The influence of printing technological modes and material properties (fluidity, morphology, etc.) on the quality of the products is considered.


2020 ◽  
Vol 3 (01) ◽  
pp. 1-11
Author(s):  
Katia-Emiko Guima ◽  
Felipe L. B. Fialho ◽  
Cauê Alves Martins

Additive manufacturing or 3D-printing is a revolutionary technique for prototyping and building objects for final use. Since the first registers at ~1890 the improved technology has boosted the applications of such technique, decreasing its market price. The most affordable 3D-print technique is Fuse Deposition Modeling (FDM), which is based on a layer-by-layer deposition of a fused polymer on a cooled table. Although FDM has been used by industrials, students and researchers, there are few published protocols dealing with small challenges and daily problems. Here we use a basic object to detail pre- and post-printing steps. This technical note offers the reader tools to model, print and treat the 3D-object. We point out basic challenges, such as positioning the objects on the virtual table of the slicing software, that may lead towards undesirable printed pieces. The protocols described here do not cover the uncountable possibilities of 3D-printing by FDM, but surely help researchers and industrials to start working with it.   DOI: http://dx.doi.org/10.30609/JETI.2020-8625


Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1108 ◽  
Author(s):  
Fengqiang Zhang ◽  
Changhai Li ◽  
Zhenlong Wang ◽  
Jia Zhang ◽  
Yukui Wang

At the core of additive manufacturing (3D printing) is the ability to rapidly print with multiple materials for arbitrary distribution with high resolution, which can remove challenges and limits of traditional assembly and enable us to make increasingly complex objects, especially exciting meta-materials. Here we demonstrate a simple and effective strategy to achieve nano-resolution printing of multiple materials for arbitrary distribution via layer-by-layer deposition on a special deposition surface. The established physical model reveals that complex distribution on a section can be achieved by vertical deformation of simple lamination of multiple materials. The deformation is controlled by a special surface of the mold and a contour-by-contour (instead of point-by-point) printing mode is revealed in the actual process. A large-scale concentric ring array with a minimum feature size below 50 nm is printed within less than two hours, verifying the capacity of high-throughput, high-resolution and rapidity of printing. The proposed printing method opens the way towards the programming of internal compositions of object (such as functional microdevices with multiple materials).


2020 ◽  
Vol 14 (3) ◽  
pp. 7296-7308
Author(s):  
Siti Nur Humaira Mazlan ◽  
Aini Zuhra Abdul Kadir ◽  
N. H. A. Ngadiman ◽  
M.R. Alkahari

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.


Author(s):  
Vokulova Yu.A. Vokulova ◽  
E.N. Zhulev

This article presents the results of studying the dimensional accuracy of the bases of complete removable prostheses made using a 3D printer and the traditional method. Bases of complete removable prostheses were made using an intraoral laser scanner iTero Cadent (USA) and a 3D printer Asiga Max UV (Australia). To study the dimensional accuracy of the bases of complete removable prostheses, we used the DentalCAD 2.2 Valletta software. The Nonparametric Wilcoxon W-test was used for statistical analysis of the obtained data. We found that the average value of the difference with the standard for bases made using digital technologies is 0.08744±0.0484 mm. The average value of the difference with the standard for bases made by the traditional method is 0.5654±0.1611 mm. Based on these data, we concluded that the bases of complete removable prostheses made using modern digital technologies (intraoral laser scanning and 3D printer) have a higher dimensional accuracy compared to the bases of complete removable prostheses made using the traditional method with a significance level of p<0.05 (Wilcoxon's W-test=0, p=0.031). Keywords: digital technologies in dentistry, digital impressions, intraoral scanner, 3D printing, ExoCAD, complete removable dentures.


2021 ◽  
Author(s):  
Kristina Ashurbekova ◽  
Karina Ashurbekova ◽  
Iva Saric ◽  
Evgeny Modin ◽  
Mladen Petravic ◽  
...  

We developed a thin film growth with a radical-initiated cross-linking of vinyl groups in a layer-by-layer manner via molecular layer deposition (MLD). The cross-linked film exhibited improved properties like 12% higher density and enhanced stability compared to the non-cross-linked film.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Amy E. Alexander ◽  
Nicole Wake ◽  
Leonid Chepelev ◽  
Philipp Brantner ◽  
Justin Ryan ◽  
...  

AbstractFirst patented in 1986, three-dimensional (3D) printing, also known as additive manufacturing or rapid prototyping, now encompasses a variety of distinct technology types where material is deposited, joined, or solidified layer by layer to create a physical object from a digital file. As 3D printing technologies continue to evolve, and as more manuscripts describing these technologies are published in the medical literature, it is imperative that standardized terminology for 3D printing is utilized. The purpose of this manuscript is to provide recommendations for standardized lexicons for 3D printing technologies described in the medical literature. For all 3D printing methods, standard general ISO/ASTM terms for 3D printing should be utilized. Additional, non-standard terms should be included to facilitate communication and reproducibility when the ISO/ASTM terms are insufficient in describing expository details. By aligning to these guidelines, the use of uniform terms for 3D printing and the associated technologies will lead to improved clarity and reproducibility of published work which will ultimately increase the impact of publications, facilitate quality improvement, and promote the dissemination and adoption of 3D printing in the medical community.


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