scholarly journals Theoretical Uniformity Analysis and Improvement of Spray Deposition by Mixing Nozzles with Heating Conditions

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Xuran Dong ◽  
Xiaolong Pan ◽  
Xianxian Gao ◽  
Haisheng Fang
Keyword(s):  
High Speed ◽  
Heating Temperature ◽  
Spray Deposition ◽  
Low Cost ◽  
Spray Coating ◽  
Deposition Process ◽  
Test Method ◽  
Large Area ◽  
Orthogonal Test Method ◽  
Experimental Trials

Spray coating is widely used in the manufacture of deposited layers of electronic devices due to its unique advantages of high-speed deposition over a large area. To improve the spray deposition process for further low-cost and uniform production, the uniformity of the spray deposition should be systematically investigated. The current study, however, mainly focuses on the experimental trials with few numerical directions especially for the mixing nozzle sprayers with heating conditions. In the paper, we conduct a theoretical study on the uniformity of the internal and external mixing nozzles. The influencing factors include the initial angle, the total ink flow rate, the transporting gas velocity and the distance from the nozzle to the substrate. Then, the orthogonal test method is adopted to obtain the optimal combination of the parameters. Finally, the effects of different heating modes on the uniformity have been further studied. The results show that these factors influence the uniformity with the two types of nozzles to a different degree. The evaporation of the atomized droplets can effectively improve the uniformity in a certain temperature range. The heating temperature with the highest uniformity is various depending on the heating modes, which should be carefully addressed during the actual production.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

scholarly journals Superhydrophobicity and Durability in Recyclable Polymers Coating

2021 ◽  
Vol 13 (15) ◽  
pp. 8244
Author(s):  
Francesca Cirisano ◽  
Michele Ferrari
Keyword(s):  
Thermal Treatment ◽  
Superhydrophobic Surface ◽  
Low Cost ◽  
Spray Coating ◽  
Large Area ◽  
Average Roughness ◽  
Water Contact ◽  
Alkaline Environments ◽  
Fine Control ◽  
Recycle And Reuse

Highly hydrophobic and superhydrophobic materials obtained from recycled polymers represent an interesting challenge to recycle and reuse advanced performance materials after their first life. In this article, we present a simple and low-cost method to fabricate a superhydrophobic surface by employing polytetrafluoroethylene (PTFE) powder in polystyrene (PS) dispersion. With respect to the literature, the superhydrophobic surface (SHS) was prepared by utilizing a spray- coating technique at room temperature, a glass substrate without any further modification or thermal treatment, and which can be applied onto a large area and on to any type of material with some degree of fine control over the wettability properties. The prepared surface showed superhydrophobic behavior with a water contact angle (CA) of 170°; furthermore, the coating was characterized with different techniques, such as a 3D confocal profilometer, to measure the average roughness of the coating, and scanning electron microscopy (SEM) to characterize the surface morphology. In addition, the durability of SH coating was investigated by a long-water impact test (raining test), thermal treatment at high temperature, an abrasion test, and in acidic and alkaline environments. The present study may suggest an easy and scalable method to produce SHS PS/PTFE films that may find implementation in various fields.

An Investigation onto Polydimethylsiloxane (PDMS) Printing Plate of Multiple Functional Solid Line by Flexographic

2013 ◽  
Vol 844 ◽  
pp. 158-161 ◽  
Author(s):  
M.I. Maksud ◽  
Mohd Sallehuddin Yusof ◽  
M. Mahadi Abdul Jamil
Keyword(s):  
Laser Ablation ◽  
Line Width ◽  
High Speed ◽  
Printed Electronics ◽  
Low Cost ◽  
Flexible Substrates ◽  
Large Area ◽  
Printing Plate ◽  
Roll To Roll ◽  
Printing Processes

Recently low cost production is vital to produce printed electronics by roll to roll manufacturing printing process like a flexographic. Flexographic has a high speed technique which commonly used for printing onto large area flexible substrates. However, the minimum feature sizes achieved with roll to roll printing processes, such as flexographic is in the range of fifty microns. The main contribution of this limitation is photopolymer flexographic plate unable to be produced finer micron range due to film that made by Laser Ablation Mask (LAMs) technology not sufficiently robust and consequently at micron ranges line will not be formed on the printing plate. Hence, polydimethylsiloxane (PDMS) is used instead of photopolymer. Printing trial had been conducted and multiple solid lines successfully printed for below fifty microns line width with no interference between two adjacent lines of the printed images.

Numerical Simulation of the Cold Spray Deposition Process for Aluminium and Copper

2012 ◽  
Author(s):  
Jing Xie ◽  
Daniel Nelias ◽  
Hélène Walter-le Berre ◽  
Yuji Ichikawa ◽  
Kazuhiro Ogawa
Keyword(s):  
Reference Frame ◽  
Cold Spray ◽  
High Speed ◽  
Gas Flow ◽  
Heat Dissipation ◽  
Spray Deposition ◽  
Deposition Process ◽  
Arbitrary Lagrangian Eulerian ◽  
Systematic Analysis ◽  
The Impact

Cold spray is a rapidly developing coating technology for depositing materials in the solid state. In this deposition process, the spray particles are accelerated to a high velocity by a high-speed gas flow, and then form a dense and high quality coating due to plastic deformation of particles impinged upon the solid surface of substrate. 2D and 3D modelling of particle impacting behaviours in cold spray deposition process by using ABAQUS/Explicit was conducted for four couples of materials (i.e. impacting particle/impacted substrate): copper/aluminium, aluminium/copper, copper/copper, and aluminium/aluminium. A systematic analysis of a single impact was carried out considering different parameters, such as the initial impact velocity, initial temperature and contact angle, which affect the deposition process and subsequently the mechanical properties of coating. Three numerical methods have been evaluated and their performances are discussed for various simulation settings: (i) modelling in a Lagrangian reference frame; (ii) modelling using adaptive remeshing in an Arbitrary Lagrangian Eulerian (ALE) reference frame; and (iii), modelling in a CEL reference frame. It is found that the Coupled Eulerian Lagrangian (CEL) method has more advantages to simulate the large deformation of materials, and is also more efficient to prevent the excessive distortion of the mesh. A comparison between simulation results and experimental data from the literature was performed. Nevertheless, the CEL method is implicitly isothermal for ABAQUS v6.10, whereas the modelling in the classical Lagrangian reference frame does include coupled thermo-mechanical effects with a local increase of the temperature near the interface — due to friction — and for the highly plastically deformed elements — due to the heat dissipation linked to plasticity. A local rise of temperature at the impact surface may also be observed for oblique impacts. Finally a first attempt to simulate the deposition of several particles is made with a 3D CEL model, resulting in the creation of porosity at the interface between particles.

Study on the Cement-Improved Loess under the Vibratory Load by Dynamic Tests

2013 ◽  
Vol 838-841 ◽  
pp. 1302-1308 ◽  
Author(s):  
Jia Ding Wang ◽  
Shu Jun Peng ◽  
Wan Li Xie
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Deformation ◽  
Damping Ratio ◽  
Test Method ◽  
Dynamic Elastic Modulus ◽  
Dynamic Tests ◽  
Long Time ◽  
Orthogonal Test Method

In this paper based on the foundation construction of Datong Xian high-speed railway, a large number of test samples have been taken. The order and contribution rate of every experiment factor like cement commingle ratio, depths, water dipping conditions, compacting factor and vibration frequency on the dynamic characteristics of cement-improved loess such as dynamic elastic modulus, dynamic deformation, damping ratio by dynamic triaxial test, which orthogonal test method has been applied to. The dynamic load was calculated according to the train vibration attenuation rule of different depth. The dynamic characteristics of cement-improved loess such as dynamic deformation, dynamic elastic modulus, damping ratio were got form the dynamic tests of long time and large number of cycles. The results showed that with the increase of cement ratio, the dynamic characteristics of cement-improved loess are more better, there is no optimal ratio of cement.

Optimization of the Process Conditions Based on Depositing Rate and Micro-Hardness for Electroless Ni-P-Nano SiC Composite Plating

2011 ◽  
Vol 339 ◽  
pp. 483-486 ◽  
Author(s):  
Hong Wang
Keyword(s):  
High Speed ◽  
Test Method ◽  
Complexing Agents ◽  
Process Conditions ◽  
Micro Hardness ◽  
Technological Parameters ◽  
Composite Plating ◽  
Sic Particles ◽  
Orthogonal Test Method ◽  
Electroless Ni

The orthogonal test method has been used to study the effects of the concentration of SiC, the speed of mixing, the temperature and the surfactants on depositing rate and micro-hardness, and obtained the optimized technological scheme and fine Ni-P-SiC composite coating. The results showed that using citric acid-acetic acid as complexing agents can obtain high speed of depositing and homogeneous coating with SiC well-distributed. Among the technological parameters, the effects of temperature on depositing rate is biggest, and the surfactants is next; the effects of the concentration of SiC particles on micro-hardness is biggest, and the surfactants is next. Give consideration to depositing rate and stability of the liquid, the temperature should be controlled at 82±2°C, the concentration of SiC particles and surfactants should be controlled in 4g/L and 60mg/L.

Preparation of a New Unburned Brick from Ti-Bearing Blast Furnace Slag and PVA Modified by Epikote

2013 ◽  
Vol 785-786 ◽  
pp. 328-331 ◽  
Author(s):  
Xiang Wen Kong ◽  
Li Li Ren ◽  
Xia Ai ◽  
Jing Zhang
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Low Cost ◽  
Mixing Time ◽  
Cementitious Materials ◽  
Test Method ◽  
Process Conditions ◽  
Curing Time ◽  
Orthogonal Test Method ◽  
Furnace Slag

A new unburned brick was prepared from the Ti-bearing blast furnace slag as an aggregate and PVA modified by epikote as cementitious materials. The effects of modified PVA and auxiliaries on compressive strength of unburned brick were studied by the orthogonal test method. The results show that samples have better properties and low cost when the samples have a composition of slag dosage 72 %, modified PVA dosage 6%, auxiliary 1 dosage 6%, auxiliary 2 dosage 10%, water 6% and the process conditions of preparing the brick sample were mixing time 1 h, forming time 10 min, forming pressure 40 MPa, and curing time 7 d. The study reveals that the samples properties can meet the standard requirements of excellent grade products (MU20) in GB11945-1999.

A Novel Low-Cost Stereolithography Process Based on Vector Scanning and Mask Projection for High-Accuracy, High-Speed, High-Throughput and Large-Area Fabrication

2014 ◽  
Author(s):  
Chi Zhou ◽  
Hang Ye ◽  
Feng Zhang
Keyword(s):  
Surface Quality ◽  
High Speed ◽  
Laser Scanning ◽  
Low Cost ◽  
High Surface ◽  
Hybrid Process ◽  
Surface Finishing ◽  
Layer By Layer ◽  
Large Area ◽  
Vector Scanning

Photopolymerization based process is one of the most popular additive manufacturing processes. Two primary configurations for this process are laser based vector by vector scanning (0D) and projection based layer by layer exposing (2D). With the highly focused fine laser, the scanning based process can accomplish very high surface finishing and precision, however, due to the serial nature of scanning, this process suffers from the problem of slow speed. In contrast with laser scanning, projection based process can form the whole layer in one exposure, which leads to higher fabrication efficiency. However, due to the limited resolution of projection device and various optical defects, the surface quality will be significantly deteriorated for large area fabrication. To solve this problem, a novel hybrid process by integrating vector scanning and mask projection has been presented. In this process, laser is focused into a fine spot and used to scan the boundary of the layer, whereas the projector is focused onto a large platform surface and used to form the interior area of the layer. An efficient slicing method is proposed for extracting the contour for laser scanning. A slice to image conversion algorithm is also developed to convert the offset contour to grayscale image for mask projection. Experimental results have verified that the proposed hybrid process can significantly improve the fabrication speed without losing the surface quality.

Continuous Process for Large-Area Flexible MEMS

2012 ◽  
Vol 81 ◽  
pp. 9-14
Author(s):  
Toshihiro Itoh
Keyword(s):  
High Speed ◽  
Spray Deposition ◽  
Continuous Process ◽  
Electrical Contact ◽  
Functional Materials ◽  
Micro Machining ◽  
Large Area ◽  
Conductive Films ◽  
Touch Sensor ◽  
Process System

A novel fabrication process for large area flexible MEMS, having been developed in BEANS project, Japan, is introduced. The process consists of continuously high-speed coating for functional film materials, 3-D nano/micro-machining of the films on fibers, and weaving the functional fibers into large-area integration. In the coating process, functional materials, e.g., organic semiconductor, piezoelectric, conductor and insulator films could be formed on fibers with a speed of 20 m/min. In the 3-D nano/micro-machining, a compound reel-to-reel process system including both thermal roller imprint and photolithography functions was developed. In addition, the microfabrication of the 3-D exposure module and the spray deposition of thin resist films on the fibers were demonstrated. For the weaving assembly, a round-projection microspring contact structure was developed for the electrical contact between weft and warp fibers in a large area of woven textile. Evaluation of the durability showed that the microspring contact structures made of silicon elastomer and PEDOT:PSS are applicable to a movable contact. Weaving assembly process was verified by prototyping 1 × 1 m² or larger flexible touch sensor sheets using functional fibers with organic insulating/conductive films.

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