scholarly journals A Simplified 2D Numerical Simulation of Photopolymerization Kinetics and Oxygen Diffusion–Reaction for the Continuous Liquid Interface Production (CLIP) System

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 875
Author(s):  
Kentaro Taki
Keyword(s):  
Numerical Simulation ◽  
Oxygen Diffusion ◽  
Uv Light ◽  
Dead Zone ◽  
Liquid Interface ◽  
Diffusion Reaction ◽  
Uv Curable ◽  
Oxygen Inhibition ◽  
Continuous Liquid Interface Production ◽  
Photopolymerization Kinetics

Additive manufacturing is a versatile technology for producing customized 3D products. In 2015, the Continuous Liquid Interface Production (CLIP) system was developed as a part of projection-type, UV-curable resin 3D printers. The CLIP system utilized the dead zone where oxygen inhibition occurs and prevents the UV-cured product from adhering to the UV illumination window. The CLIP system successfully produced complex shapes in a short time. This study investigated how the relationship between the photopolymerization rate, oxygen inhibition rate, and oxygen diffusion rate affects the shape of the product by means of a numerical simulation of the photopolymerization kinetics with oxygen diffusion and reaction. The results indicate that the vertical production speed and transmittance of UV light are crucial to controlling the conversion and shape precision of products.

scholarly journals Fast Fabrication of Nanostructured Films Using Nanocolloid Lithography and UV Soft Mold Roller Embossing: Effects of Processing Parameters

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 405
Author(s):  
Demei Lee ◽  
Ya-Ling Tang ◽  
Shih-Jung Liu
Keyword(s):  
Uv Light ◽  
Processing Parameters ◽  
Polymeric Films ◽  
Step Motor ◽  
Silicon Substrates ◽  
Casting Method ◽  
Uv Curable ◽  
Soft Mold ◽  
Uv Curable Resin ◽  
Spin Coater

We report the fabrication of nanofeatured polymeric films using nanosphere lithography and ultraviolet (UV) soft-mold roller embossing and show an illuminative example of their application to solar cells. To prepare the nanofeatured template, polystyrene nanocolloids of two distinct sizes (900 and 300 nm) were overlaid on silicon substrates using a spin coater. A lab-made soft-mold roller embossing device equipped with a UV light source was adopted. A casting method was employed to replicate the nanofeatured template onto polydimethylsiloxane, which was used as the soft mold. During the embossing procedure, the roller was driven by a step motor and compressed the UV-curable resin against the glass substrate to form the nanofeatured layer, which was subsequently cured by UV radiation. Polymer films with nanoscaled features were thus obtained. The influence of distinct processing variables on the reproducibility of the nanofeatured films was explored. The empirical outcomes demonstrate that UV soft-mold roller embossing offers a simple yet potent way of producing nanofeatured films.

scholarly journals Numerical simulation of the crossing of a liquid-liquid interface by a droplet

2020 ◽  
Vol 5 (9) ◽  
Author(s):  
Hassan El Itawi ◽  
Benjamin Lalanne ◽  
Gladys Massiera ◽  
Nathalie Le Sauze ◽  
Olivier Masbernat
Keyword(s):  
Numerical Simulation ◽  
Liquid Interface

Self-Assembly of Monolayers of Submicron Sized Particles on Thin Liquid Films

2013 ◽  
Author(s):  
Shriram Pillapakkam ◽  
N. A. Musunuri ◽  
P. Singh
Keyword(s):  
Electric Field ◽  
Self Assembly ◽  
Uv Light ◽  
Capillary Forces ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Liquid Interfaces ◽  
Uv Curable ◽  
Particle Monolayer ◽  
Uv Curable Resin

In this paper, we present a technique for freezing monolayers of micron and sub-micron sized particles onto the surface of a flexible thin film after the self-assembly of a particle monolayer on fluid-liquid interfaces has been improved by the process we have developed where an electric field is applied in the direction normal to the interface. Particles smaller than about 10 microns do not self-assemble under the action of lateral capillary forces alone since capillary forces amongst them are small compared to Brownian forces. We have overcome this problem by applying an electric field in the direction normal to the interface which gives rise to dipoledipole and capillary forces which cause the particles to arrange in a triangular pattern. The technique involves assembling the monolayer on the interface between a UV-curable resin and another liquid by applying an electric field, and then curing the resin by applying UV light. The monolayer becomes embedded on the surface of the solidified resin film.

Enhanced continuous liquid interface production with track-etched membrane

2019 ◽  
Vol 25 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Wenxiong Lin ◽  
Huagang Liu ◽  
Haizhou Huang ◽  
Jianhong Huang ◽  
Kaiming Ruan ◽  
...  
Keyword(s):  
Pure Oxygen ◽  
Inhibition Layer ◽  
High Permeability ◽  
Content Type ◽  
Oxygen Inhibition ◽  
Speed Up ◽  
Continuous Liquid Interface Production ◽  
Track Etched Membrane ◽  
Printing Speed ◽  
Etched Membrane

PurposeThe purpose of this paper is to explore the possibility of an enhanced continuous liquid interface production (CLIP) with a porous track-etched membrane as the oxygen-permeable window, which is prepared by irradiating polyethylene terephthalate membranes with accelerated heavy ions. Design/methodology/approachExperimental approaches are carried out to characterize printing parameters of resins with different photo-initiator concentrations by a photo-polymerization matrix, to experimentally observe and theoretically fit the oxygen inhibition layer thickness during printing under conditions of pure oxygen and air, respectively, and to demonstrate the enhanced CLIP processes by using pure oxygen and air, respectively. FindingsOwing to the high permeability of track-etched membrane, CLIP process is demonstrated with printing speed up to 800 mm/h in the condition of pure oxygen, which matches well with the theoretically predicted maximum printing speed at difference light expose. Making a trade-off between printing speed and surface quality, maximum printing speed of 470 mm/h is also obtained even using air. As the oxygen inhibition layer created by air is thinner than that by pure oxygen, maximum speed cannot be simply increased by intensifying the light exposure as the case with pure oxygen. Originality/valueCLIP process is capable of building objects continuously instead of the traditional layer-by-layer manner, which enables tens of times improvement in printing speed. This work presents an enhanced CLIP process by first using a porous track-etched membrane to serve as the oxygen permeable window, in which a record printing speed up to 800 mm/h using pure oxygen is demonstrated. Owing to the high permeability of track-etched membrane, continuous process at a speed of 470 mm/h is also achieved even using air instead of pure oxygen, which is of significance for a compact robust high-speed 3D printer.

UV-Curable organic-inorganic hybrid films based on tetraethylorthosilicate oligomer and special acrylated polyester

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Jianyun He ◽  
Jinping Xiong ◽  
Bingqian Xia
Keyword(s):  
Uv Light ◽  
Uv Curing ◽  
Organic Matrix ◽  
Dynamic Mechanical Properties ◽  
Hybrid Films ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Dynamic Mechanical ◽  
H Nmr ◽  
Uv Curing Process

AbstractOrganic-inorganic hybrid films were prepared using tetraethylorthosilicate (TEOS) oligomer and special acrylated polyester (SAP) via a UV-curing process. TEOS oligomers were prepared in the presence of water and ethanol using hydrochloric acid as the catalyst and characterized using 1H NMR, 29Si NMR and MALDI-TOF mass spectra. Special acrylated polyester was synthesized by 1,4-cyclohexane dimethanol, neopentyl glycol, 1,4-butanediol, maleic anhydride, adipic acid, and acrylic acid. Hybrid films were cured by UV light and the thermal properties, dynamic mechanical properties, and tensile properties of the hybrid films were evaluated as the function of TEOS oligomer content. The morphology of the hybrid films was examined using atomic force microscopy (AFM). The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. The results indicated that after incorporating the TEOS oligomer, the strength and thermal stability of the hybrid films were enhanced.

Impact of Process Parameters on the Tensile Properties of DLP Additively Manufactured ELAST-BLK 10 UV-Curable Elastomer

2021 ◽  
Author(s):  
Asma Ul Hosna Meem ◽  
Kyle Rudolph ◽  
Allyson Cox ◽  
Austin Andwan ◽  
Timothy Osborn ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
Tensile Properties ◽  
Process Parameters ◽  
Uv Light ◽  
Uv Curable ◽  
Build Orientation ◽  
Static Tensile ◽  
The Impact

Abstract Digital light processing (DLP) is an emerging vatphotopolymerization-based 3D-printing technology where full layers of photosensitive resin are irradiated and cured with projected ultraviolet (UV) light to create a three-dimensional part layer-by-layer. Recent breakthroughs in polymer chemistry have led to a growing number of UV-curable elastomeric photoresins developed exclusively for vat photopolymerization additive manufacturing (AM). Coupled with the practical manufacturing advantages of DLP AM (e.g., industry-leading print speeds and sub-micron-level print resolution), these novel elastomeric photoresins are compelling candidates for emerging applications requiring extreme flexibility, stretchability, conformability, and mechanically-tunable stiffness (e.g., soft robotic actuators and stretchable electronics). To advance the role of DLP AM in these novel and promising technological spaces, a fundamental understanding of the impact of DLP manufacturing process parameters on mechanical properties is requisite. This paper highlights our recent efforts to explore the process-property relationship for ELAST-BLK 10, a new commercially-available UV-curable elastomer for DLP AM. A full factorial design of experiments is used to investigate the effect of build orientation and layer thickness on the quasi-static tensile properties (i.e., small-strain elastic modulus, ultimate tensile strength, and elongation at fracture) of ELAST-BLK 10. Statistical results, based on a general linear model via ANOVA methods, indicate that specimens with a flat build orientation exhibit the highest elastic modulus, ultimate tensile strength, and elongation at fracture, likely due to a larger surface area that enhances crosslink density during the curing process. Several popular hyperelastic constitutive models (e.g., Mooney-Rivlin, Yeoh, and Gent) are calibrated to our quasi-static tensile data to facilitate component-level predictive analyses (e.g., finite-element modeling) of soft robotic actuators and other emerging soft-matter applications.

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