Contact angle evaluation for laser cleaning efficiency

2009 ◽  
Vol 45 (11) ◽  
pp. 553
Author(s):  
J.Y. Baek ◽  
H. Jeong ◽  
M.H. Lee ◽  
J.D. Song ◽  
S.B. Kim ◽  
...  
Keyword(s):  
Contact Angle ◽  
Laser Cleaning ◽  
Cleaning Efficiency

scholarly journals Preliminary Study on Enzymatic-Based Cleaning of Cation-Exchange Membranes Used in Electrodialysis System in Red Wine Production

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 114 ◽  
Author(s):  
Bdiri ◽  
Bensghaier ◽  
Chaabane ◽  
Kozmai ◽  
Baklouti ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Contact Angle ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Red Wine ◽  
Exchange Capacity ◽  
Operating Conditions ◽  
Cleaning Efficiency ◽  
Wine Production ◽  
Ion Exchange Capacity

The use of enzymatic agents as biological solutions for cleaning ion-exchange membranes fouled by organic compounds during electrodialysis (ED) treatments in the food industry could be an interesting alternative to chemical cleanings implemented at an industrial scale. This paper is focused on testing the cleaning efficiency of three enzyme classes (β-glucanase, protease, and polyphenol oxidase) chosen for their specific actions on polysaccharides, proteins, and phenolic compounds, respectively, fouled on a homogeneous cation-exchange membrane (referred CMX-Sb) used for tartaric stabilization of red wine by ED in industry. First, enzymatic cleaning tests were performed using each enzyme solution separately with two different concentrations (0.1 and 1.0 g/L) at different incubation temperatures (30, 35, 40, 45, and 50 °C). The evolution of membrane parameters (electrical conductivity, ion-exchange capacity, and contact angle) was determined to estimate the efficiency of the membrane′s principal action as well as its side activities. Based on these tests, we determined the optimal operating conditions for optimal recovery of the studied characteristics. Then, cleaning with three successive enzyme solutions or the use of two enzymes simultaneously in an enzyme mixture were tested taking into account the optimal conditions of their enzymatic activity (concentration, temperatures, and pH). This study led to significant results, indicating effective external and internal cleaning by the studied enzymes (a recovery of at least 25% of the electrical conductivity, 14% of the ion-exchange capacity, and 12% of the contact angle), and demonstrated the presence of possible enzyme combinations for the enhancement of the global cleaning efficiency or reducing cleaning durations. These results prove, for the first time, the applicability of enzymatic cleanings to membranes, the inertia of their action towards polymer matrix to the extent that the choice of enzymes is specific to the fouling substrates.

scholarly journals Imaging Feature Analysis-Based Intelligent Laser Cleaning Using Metal Color Difference and Dynamic Weight Dispatch Corrosion Texture

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 130
Author(s):  
Jiacheng Li ◽  
Haoting Liu ◽  
Limin Shi ◽  
Jinhui Lan
Keyword(s):  
Process Parameters ◽  
Color Difference ◽  
Laser Cleaning ◽  
Support Vector ◽  
Convex Region ◽  
Cleaning Efficiency ◽  
Laser Parameters ◽  
Intelligent Technique ◽  
Online Computation ◽  
Dynamic Weight

To improve the laser cleaning efficiency of Q235 carbon steel, an imaging analysis-based intelligent technique is proposed. Both offline and online computations are designed. Regarding the offline procedure, first, the corrosion images are accumulated to compute the gray-level co-occurrence matrix (GLCM) and the concave-convex region features. Second, different laser cleanings are performed to obtain various cleaned images. Third, a new cleaning performance evaluation method is developed: a metal color difference feature and a dynamic weight dispatch (DWD) corrosion texture are computed. Finally, a particle swarm optimization (PSO)-support vector machine (SVM) is utilized to forecast the laser process parameters. The corresponding laser parameters include power, linear velocity, and line spacing. For the online computation, after the GLCM and the concave-convex region features are computed, an iterative computation is used to tune the process parameters: the random laser parameters are generated constantly, and the iteration is performed and terminated only if the PSO-SVM output is positive. The experimental results have shown that the cleaning efficiency of this method can be improved, and the qualified rate is 92.5%.

Application of micro X-ray fluorescence and micro computed tomography to the study of laser cleaning efficiency on limestone monuments covered by black crusts

Talanta ◽  
2018 ◽  
Vol 178 ◽  
pp. 419-425 ◽  
Author(s):  
Giorgio S. Senesi ◽  
Ignazio Allegretta ◽  
Carlo Porfido ◽  
Olga De Pascale ◽  
Roberto Terzano
Keyword(s):  
Computed Tomography ◽  
Laser Cleaning ◽  
Micro Computed Tomography ◽  
Cleaning Efficiency ◽  
X Ray ◽  
Black Crusts

A Theoretical Model for Steam Laser Cleaning

1998 ◽  
Vol 526 ◽  
Author(s):  
Y. F. Lu ◽  
Y. Zhang ◽  
W. D. Song ◽  
T. S. Low
Keyword(s):  
Theoretical Model ◽  
Liquid Film ◽  
Solid Surface ◽  
Laser Fluence ◽  
Adhesion Force ◽  
Thin Liquid Film ◽  
Laser Cleaning ◽  
Superheated Liquid ◽  
Cleaning Efficiency ◽  
The Difference

AbstractA theoretical model for removal of tiny particles from solid surface covered with a thin liquid film by laser cleaning is established by taking adhesion force and cleaning force into account. When pulsed laser irradiates on the solid surface coated with a thin liquid film, a sheet of liquid near the liquid/substrate interface can be superheated through thermal diffusion. The rapid growth of vapor bubbles inside the superheated liquid can generate transient stress wave with high pressure, large enough to expel micron and sub-micron particles from the contaminated surface. By calculating the adhesion force and cleaning force, the cleaning threshold of laser fluence can be predicted from this theoretical model. The difference between cleaning force and adhesion force increases quickly along with the laser fluence and leads to higher cleaning efficiency.

scholarly journals Laser cleaning of paper: Cleaning efficiency and irradiation dose

2015 ◽  
Vol 60 (sup1) ◽  
pp. S97-S105 ◽  
Author(s):  
Saira Arif ◽  
Wolfgang Kautek
Keyword(s):  
Irradiation Dose ◽  
Laser Cleaning ◽  
Cleaning Efficiency

Laser Cleaning of Nanoparticles from Solid Surfaces

2001 ◽  
Vol 704 ◽  
Author(s):  
Y.F. Lu ◽  
W.Y. Zheng ◽  
L. Zhang ◽  
B. Luk'yanchuk ◽  
W.D. Song ◽  
...  
Keyword(s):  
Incident Angle ◽  
Near Field ◽  
Mie Theory ◽  
Laser Wavelength ◽  
Laser Cleaning ◽  
Experimental Result ◽  
Original Position ◽  
Material Surface ◽  
Cleaning Efficiency ◽  
Optical Resonance

AbstractThe experimental analysis of dry laser cleaning efficiency is done for certified spherical particle (SiO2, 5.0, 2.5, 1.0 and 0.5 μm) from different substrates (Si, Ge and NiP). The influence of different options (laser wavelength, incident angle, substrate properties, i.e. type of material, surface roughness, etc.) on the cleaning efficiency is presented in addition to commonly analyzed options (cleaning efficiency versus laser fluence and particle size). Found laser cleaning efficiency demonstrates a great sensitivity to some of these options (e.g. laser wavelength, angle of incidence, etc.). Partially these effects can be explained within the frame of the Mie theory of scattering. Other effects (e.g. influence of roughness) can be explained along the more complex line, related to examination of the problem “particle on the surface” beyond the Mie theory. 0.5 μm spherical silica particles were placed on Silicon (100) substrate. After laser irradiation with a 248 nm KrF excimer laser, hillocks with size of about 100 nm were obtained at the original position of the particles. Mechanism of the formation of the sub-wavelength structures were investigated and found to be the near-field optical resonance effect induced by particles on surface. Theoretical prediction of the near-field light intensity distribution was presented, which was in agreement with the experimental result.

scholarly journals Research on mechanism and process of paint removal with pulsed fiber laser

2018 ◽  
Vol 189 ◽  
pp. 01008
Author(s):  
Xiaodi Zeng ◽  
Wenbin Qin ◽  
Jing Li ◽  
Zhiyong Wang
Keyword(s):  
Energy Density ◽  
Fiber Laser ◽  
Laser Energy ◽  
Steel Substrate ◽  
Paint Layer ◽  
Laser Cleaning ◽  
Laser Energy Density ◽  
Cleaning Efficiency ◽  
Pulsed Fiber Laser ◽  
Paint Removal

Compared with the traditional cleaning technology, laser cleaning, as a new type of industrial technology, has the advantages of high cleaning rate, green pollution-free and low cost. So laser cleaning is widely used in the fields of paint removal. This paper analyzes that the mechanism of paint removal and heat transfer process in the paint layer and substrate, also determines the process parameters of affect the laser paint removal. The removal of paint from steel substrate with fiber laser of frequency adjustable 20 to 500kHz at 1064nm is reported, researching impact that laser energy density,scanning speed and line width on the paint removal effect. The results show that, the 100μm paint layer can be removed completely while keeping the substrate undamaged with the laser energy density of 10.19J/cm2 and speed of 4200mm/s and width of 0.02mm. In order to get better results, the cleaning efficiency can be improved by increasing the power, speed and spot size under the right energy density.

Sign in / Sign up

Export Citation Format

Share Document