Formulation of UV Curable Resins Utilized in Vat Photo Polymerization for the Additive Manufacturing of Gun Propulsion Charge in 3D Printers (Update)

Author(s):  
D. Bird ◽  
J. Laquidara ◽  
E. Caravaca ◽  
K. Luhmann ◽  
N. M. Ravindra
1996 ◽  
Vol 425 ◽  
Author(s):  
H. Takatsu ◽  
H. Hasebe

AbstractSome classes of liquid crystalline monoacrylates having no methylene spacers in a side chain have been prepared. The liquid crystalline monoacrylates have effects to reduce the driving voltage and the hysteresis for a light scattering display of Polymer Network liquid crystals prepared by photo-polymerization-induced phase separation.By photo-polymerization of a chiral monoacrylate monomer in a nematic liquid crystalline host including a black dichroic dye, a polarizer free reflective Spiral Polymer Aligned Nematic (SPAN) Guest Host (GH) LCD exhibiting a low driving voltage has been fabricated. The effect of the spiral polymers made of some kinds of chiral monoacrylates for a Super Twisted Nematic (STN) LCD using SPAN liquid crystals is discussed.UV-curable liquid crystals showing nematic phases at room temperature have been developed. By in situ photo-polymerization, the UV-curable liquid crystals can be utilized for the retardation film with high quality and good thermal stability. The fabrication of various kinds of retardation film using the UV-curable liquid crystals is discussed.UV-curable liquid crystals having isotropic-nematic-smectic A phase sequence have been developed and the photo-polymerization at the state of their uniaxially oriented smectic A phases at room temperature is discussed. The polymerized film is optically uniaxial and transparent without light scattering.


2020 ◽  
Vol 17 (01) ◽  
pp. 2050005 ◽  
Author(s):  
Harm-Jan Steenhuis ◽  
Xin Fang ◽  
Tolga Ulusemre

Additive manufacturing can be considered an innovative and high-technology and one of its characteristics is that it has limited dependency on the location. The purpose of this study is to examine this aspect by investigation how additive manufacturing is spreading globally. The focus is on established manufacturers of industrial additive manufacturing machines. It was found that the early-stage diffusion of this technology is primarily in advanced economies. Furthermore, many of the currently established companies that manufacture industrial 3D printers come from already existing companies that expanded into AM or that led to spin-off companies. The complexity of AM which requires expert knowledge across a range of fields may be the key reason for this finding. Recommendations for further research are provided.


2019 ◽  
Vol 39 (13) ◽  
pp. 3797-3803 ◽  
Author(s):  
Mario Borlaf ◽  
Albert Serra-Capdevila ◽  
Carles Colominas ◽  
Thomas Graule

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Hauke Prüß ◽  
Thomas Vietor

The continuously decreasing life cycle of modern products leads to new challenges for product development. Additive manufacturing (AM) processes are able to support faster development by rapid production of samples and prototypes. However, the material properties of components produced by common (plastic-) 3D-printers are often insufficient for functional prototyping. A well-established way to improve the properties of plastics is the embedding of reinforcing fibers. Thus, this paper shows a method for fiber-reinforced 3D-printing. Through this combination, several restrictions of conventional composite production can be eased and additional freedoms of design are gained. To support the design of such parts, an adapted design methodology for fiber-reinforced 3D-printing is developed.


Author(s):  
Leonardo Portilha Gomes da Costa ◽  
Stephanie Isabel Díaz Zamalloa ◽  
Fernando Amorim Mendonça Alves ◽  
Renan Spigolon ◽  
Leandro Yukio Mano ◽  
...  

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.


2021 ◽  
Vol 11 (18) ◽  
pp. 8545
Author(s):  
So-Ree Hwang ◽  
Min-Soo Park

Additive manufacturing, commonly called 3D printing, has been studied extensively because it can be used to fabricate complex structures; however, polymer-based 3D printing has limitations in terms of implementing certain functionalities, so it is limited in the production of conceptual prototypes. As such, polymer-based composites and multi-material 3D printing are being studied as alternatives. In this study, a DLP 3D printer capable of printing multiple composite materials was fabricated using a movable separator and structures with various properties were fabricated by selectively printing two composite materials. After the specimen was fabricated based on the ASTM, the basic mechanical properties of the structure were compared through a 3-point bending test and a ball rebound test. Through this, it was shown that structures with various mechanical properties can be fabricated using the proposed movable-separator-based DLP process. In addition, it was shown that this process can be used to fabricate anisotropic structures, whose properties vary depending on the direction of the force applied to the structure. By fabricating multi-joint grippers with varying levels of flexibility, it was shown that the proposed process can be applied in the fabrication of soft robots as well.


Fourth Industrial Revolution gave birth to few different technologies, not known until now. One of them is 3D printing. If subtracting manufacturing is part of Industrial Revolution 3, Additive manufacturing is for sure part of Industrial Revolution 4.0. 3D printing has the potential to transform science and technology by creating bespoke, low-cost appliances that previously required dedicated facilities to make. 3D printers are used to initiate chemical reactions by printing the reagents directly into a 3D reactionware matrix, and so put reactionware design, construction and operation under digital control. Some models of 3D Printers can print uniquely shaped sugar confections in flavors such as chocolate, vanilla, mint, cherry, sour apple and watermelon. They can also print custom cake toppers–presumably in the likeness of the guest of honor.


Author(s):  
Jim Flowers

Is the primary purpose of a 3D printer to manufacture a product? Yes, but students and teachers can also use 3D printers to learn about and engage in research and experimentation. This could begin with product research and development, then expand to technical areas based on additive manufacturing technologies, the physical and mechanical properties of additive manufacturing materials, and the properties of 3D printed products. Student inquiry can take the form of formal or informal experimentation and observational studies. Although dedicated testing equipment can facilitate more demanding investigations, it is possible for quite a bit of experimentation to be done with little or no dedicated testing equipment. It is hoped that the reader will identify different educational experiences with experimentation that might fit their learners' needs and see 3D printers as tools for conducting and teaching about research, including product research and development and research into process engineering and materials.


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