Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

2018 ◽  
Vol 919 ◽  
pp. 222-229
Author(s):  
Jiří Šafka ◽  
Filip Veselka ◽  
Martin Lachman ◽  
Michal Ackermann

The article deals with the topic of 3D printing of pressure vessels and their testing. The main focus of the research was on a 3D model of the pressure vessel, which was originally designed for a student formula racing car project. The described virtual 3D model was designed with regard to 3D printing. The physical model was manufactured using several additive manufacturing technologies. The first technology was FDM using ULTEM 1010 material. The next technology was SLS (Selective Laser Sintering) using polyamide materials (PA3200GF and PA2220). The last technology was SLA (Stereolithography) using a polypropylene material (Durable). Experimental evaluation of the vessels was carried out by a pressure test, which verified the compactness of the 3D printed parts and their possible porosity. At the end of the article, a comparison of each printed model is made in terms of their final price and weight, together with pressure and thermal resistance.


2018 ◽  
Vol 10 (461) ◽  
pp. eaan6521 ◽  
Author(s):  
Laura M. Ricles ◽  
James C. Coburn ◽  
Matthew Di Prima ◽  
Steven S. Oh

Additive manufacturing [also known as three-dimensional (3D) printing] is the layer-wise deposition of material to produce a 3D object. This rapidly emerging technology has the potential to produce new medical products with unprecedented structural and functional designs. Here, we describe the U.S. regulatory landscape of additive manufactured (3D-printed) medical devices and biologics and highlight key challenges and considerations.


Author(s):  
V. Kovan ◽  
G. Altan ◽  
E.S. Topal ◽  
H.E. Camurlu

Three-dimensional printing or 3D printing (also called additive manufacturing) is any of various processes used to make a three-dimensional object. Fused deposition modelling (FDM) is an additive manufacturing technology commonly used for modelling, prototyping, and production applications. It is one of the techniques used for 3D printing. FDM is somewhat restricted in the size and the variation of shapes that may be fabricated. For parts too large to fit on a single build, for faster job builds with less support material, or for parts with finer features, sectioning and bonding FDM parts is a great solution. The strength of adhesive bonded FDM parts is affected by the surface roughness. In this study, the layer thickness effect on bonding strength is experimentally studied and the results are discussed.


2020 ◽  
Vol 26 (10) ◽  
pp. 1783-1788
Author(s):  
Asif Ur Rehman ◽  
Vincenzo M. Sglavo

Purpose Three-dimensional (3D) printing technology allows geometric complexity and customization with a significant reduction in the structural environmental impact. Nevertheless, it poses a serious threat to the environment when organic binders are used. Binder jet printing of alkali-activated geopolymer precursor can represent a successful and environmental-friendly alternative. Design/methodology/approach The present work reports about the successful 3D printing of metakaolin-based alkali-activated concrete, with dimensional integrity and valuable mechanical behavior. Findings The geometric behavior was studied as a function of alkali activator flow rate, and the minimum geometric deviation with complete saturation was recorded at 103 mg/s. The printed specimen is characterized by a modulus of rupture as high as 4.4 MPa at 135 mg/s. Practical implications The 3D printed geopolymer-based concrete can be potentially used in a wide range of structural applications from construction to thermal insulation elements. Originality/value The analysis of the 3D geopolymer-based concrete printing system and material conducted in this paper is original.


2018 ◽  
Vol 16 (2) ◽  
pp. 104-107
Author(s):  
Veronica Verlan ◽  
Marcela Irovan

The usage of innovative technologies has become one of the most widespread ways of diversifying the current supply of clothing and footwear products. Therefore, using the 3D printing technologies in the garment production is a remarkable example of the symbiosis of creativity and technology, which creates unusual and fashionable clothing pieces. Although the 3D printing technology is a relatively new technology and allows creating unique garments it must not neglect important features of clothing products such as cost-accessibility, comfort and aesthetic appearance. The research on these aspects is prior to implement this technology in the manufacturing process. The study includes the analysis of the current 3D printing technologies which are used for obtaining three-dimensional objects, the current directions of implementing this technology in the industry, as well as the opportunities of applying this technology in the process of clothing’s creation. Therefore, this paper concludes the study with the creation of a clothing product – a blouse for women, which is including a 3D printed part confirming this way the possibility of creation of clothing products, which would integrate innovative elements which were obtained by implementing the advanced technology of additive manufacturing.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoyu Zhao ◽  
Ye Zhao ◽  
Ming-De Li ◽  
Zhong’an Li ◽  
Haiyan Peng ◽  
...  

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.


Lab on a Chip ◽  
2021 ◽  
Author(s):  
Liang Wu ◽  
Stephen Beirne ◽  
Joan-Marc Cabot Canyelles ◽  
Brett Paull ◽  
Gordon G. Wallace ◽  
...  

Additive manufacturing (3D printing) offers a flexible approach for the production of bespoke microfluidic structures such as the electroosmotic pump. Here a readily accessible fused filament fabrication (FFF) 3D printing...


Author(s):  
Yanyan Ma ◽  
Peng Ding ◽  
Lanlan Li ◽  
Yang Liu ◽  
Ping Jin ◽  
...  

AbstractHeart diseases remain the top threat to human health, and the treatment of heart diseases changes with each passing day. Convincing evidence shows that three-dimensional (3D) printing allows for a more precise understanding of the complex anatomy associated with various heart diseases. In addition, 3D-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical interventions. We introduce examples of the clinical applications of different types of 3D printing based on specific cases and clinical application scenarios of 3D printing in treating heart diseases. We also discuss the limitations and clinically unmet needs of 3D printing in this context.


Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 353
Author(s):  
Yanting Han ◽  
Qianqian Wei ◽  
Pengbo Chang ◽  
Kehui Hu ◽  
Oseweuba Valentine Okoro ◽  
...  

Hydroxyapatite (HA) and HA-based nanocomposites have been recognized as ideal biomaterials in hard tissue engineering because of their compositional similarity to bioapatite. However, the traditional HA-based nanocomposites fabrication techniques still limit the utilization of HA in bone, cartilage, dental, applications, and other fields. In recent years, three-dimensional (3D) printing has been shown to provide a fast, precise, controllable, and scalable fabrication approach for the synthesis of HA-based scaffolds. This review therefore explores available 3D printing technologies for the preparation of porous HA-based nanocomposites. In the present review, different 3D printed HA-based scaffolds composited with natural polymers and/or synthetic polymers are discussed. Furthermore, the desired properties of HA-based composites via 3D printing such as porosity, mechanical properties, biodegradability, and antibacterial properties are extensively explored. Lastly, the applications and the next generation of HA-based nanocomposites for tissue engineering are discussed.


2020 ◽  
Vol 6 (1) ◽  
pp. 57-69
Author(s):  
Amirhosein Fathi ◽  
Farzad Kermani ◽  
Aliasghar Behnamghader ◽  
Sara Banijamali ◽  
Masoud Mozafari ◽  
...  

AbstractOver the last years, three-dimensional (3D) printing has been successfully applied to produce suitable substitutes for treating bone defects. In this work, 3D printed composite scaffolds of polycaprolactone (PCL) and strontium (Sr)- and cobalt (Co)-doped multi-component melt-derived bioactive glasses (BGs) were prepared for bone tissue engineering strategies. For this purpose, 30% of as-prepared BG particles (size <38 μm) were incorporated into PCL, and then the obtained composite mix was introduced into a 3D printing machine to fabricate layer-by-layer porous structures with the size of 12 × 12 × 2 mm3.The scaffolds were fully characterized through a series of physico-chemical and biological assays. Adding the BGs to PCL led to an improvement in the compressive strength of the fabricated scaffolds and increased their hydrophilicity. Furthermore, the PCL/BG scaffolds showed apatite-forming ability (i.e., bioactivity behavior) after being immersed in simulated body fluid (SBF). The in vitro cellular examinations revealed the cytocompatibility of the scaffolds and confirmed them as suitable substrates for the adhesion and proliferation of MG-63 osteosarcoma cells. In conclusion, 3D printed composite scaffolds made of PCL and Sr- and Co-doped BGs might be potentially-beneficial bone replacements, and the achieved results motivate further research on these materials.


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