scholarly journals Improving the technology of repair painting with powder-coated paints in agro-industrial complex

2021 ◽  
Vol 285 ◽  
pp. 07012
Author(s):  
Andrey Bodrov ◽  
Anton Panichkin ◽  
Denis Lomakin ◽  
Andrew Simushkin
Keyword(s):  
Contact Angle ◽  
Roughness Parameter ◽  
Corrosion Damage ◽  
Industrial Complex ◽  
Powder Coatings ◽  
Chemical Methods ◽  
Painted Surface ◽  
Stain Resistance ◽  
Separation Force ◽  
Contact Angle Of Wetting

The article presents the results of studies to determine the dependence of the degree of adhesion and the separation force of the powder coatings layer on the roughness parameter of the substrate, as well as the contact angle of wetting for various methods of preparing the painted surface by chemical methods. In addition, practical tests for stain resistance were carried out, which showed the absence of corrosion damage, as well as a slight change in color, gloss of coatings, chalking and dirt retention on the studied coating samples.

scholarly journals IMPROVEMENT OF THE METHOD OF MEASURING THE CONTACT ANGLE OF WETTING WITH THE USE OF THE COMPASS-3D PROGRAM

2018 ◽  
Vol 25 (1) ◽  
pp. 77
Author(s):  
G. A. Teptereva ◽  
S. Yu. Shavshukova ◽  
V. G. Konesev ◽  
I. I. Sultanov ◽  
R. R. Rakhimov ◽  
...  
Keyword(s):  
Contact Angle ◽  
Contact Angle Of Wetting

Determination of the wetting angle using gas bubble method

2021 ◽  
Vol 87 (4) ◽  
pp. 38-42
Author(s):  
Yu. F. Patrakov ◽  
S. A. Semenova
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Surface Characterization ◽  
Wetting Angle ◽  
Powdered Sample ◽  
Pressing Pressure ◽  
Gas Bubble ◽  
Working Surface ◽  
Coal Particles ◽  
Contact Angle Of Wetting

Most of the technological processes of coal mining and primary processing (transportation, crushing, and enrichment) depend on the physical and chemical properties of the external surface of coal particles. When determining the wetting angle — the wettability characteristics of the coal surface — the method of preparing the working surface of the sample and the choice of the measurement procedure (a drop of liquid on a solid surface or fixing a gas bubble on the surface of coal placed in water) are of great importance. We present the results of determining the contact angle of wetting using an air bubble. The working surface was prepared by briquetting a powdered sample. Scanning electron microscopy and laser diffraction analysis of the particle size distribution were used for surface characterization and fractional analysis of carbon particles. It is shown that the contact angle of wetting depends on the particle size, mineral composition of coal, and pressing pressure. At the same time, when determining the wetting angle, the optimal particle size and pressing pressure of the briquette are <100 μm and ~500 MPa, respectively. The obtained results can be used to improve technologies for mining, conversion and dressing of coals.

scholarly journals CONTACT ANGLE OF COAL WETTING WITH WATER

2021 ◽  
Vol 1 ◽  
pp. 4-10
Author(s):  
V.M. Kuznichenko ◽  
A.V. Sytnik
Keyword(s):  
Contact Angle ◽  
Moisture Content ◽  
Correlation Coefficient ◽  
Practical Importance ◽  
Polished Surface ◽  
Reasonable Assumption ◽  
Carbon Substrate ◽  
Organic Mass ◽  
Contact Angle Of Wetting

It is known that in the process of coking a compacted coal charge during its ramming in an industrial ramming-loading-pushing machine, the moisture of the charge plays the role of a compaction agent. On the basis of this, the authors put forward a reasonable assumption that the higher the ability of coal grains to hydration, the stronger the contact between them and, accordingly, the greater the density of the formed rammed coal cake. Therefore, the determination of the ability to hydrate the surface of coal used in the charge for ramming is of both theoretical and practical importance. For the numerical determination of this indicator, the authors have chosen the contact angle of wetting, determined by the method of "sessile drop" of water on a carbon substrate. The article presents the results of a study of the ability of various brands of coal to hydrate. The article describes the characteristics of the studied grades of coal and their contact angle of wetting with water (Ɵ) after 1, 2 and 3 minutes of keeping the drop on a polished surface. Since according to the literature data, the organic mass of coal is hydrophobic, and mineral impurities, as a rule, are hydrophilic, the authors investigated the degree of influence of the "ash content of coal" (Аd ) indicator on the value of Ɵ. To determine the influence of the wetting angle and the internal moisture content of coal after 14 hours of moisture saturation in water (Wins) on the strength (ϭss) of the rammed sample, the corresponding graphical dependence was determined. The data obtained indicate that any significant relationship between Аd and Ɵ is absent, the correlation coefficient is insignificant (r = 0.28). Thus, the predominant factor in the hydration of cleaned coal is the properties of its organic matter. The correlation between Ɵ and the yield of volatile substances Vdaf and the content of vitrinite Vt is also insignificant – the correlation coefficient is up to 0,43 and 0,50 respectively. A close relationship of the contact angle was found with the reflection coefficient of vitrinite Ro (r = 0.72), the internal moisture content of coal after 14 hours of saturation in water, Wins (r = 0,65), and the shear strength of the rammed coal sample ϭss (r = 0,68). Keywords: coal, ability to hydration, contact angle of wetting, organic mass of coal, mineral impurities, density, strength. Corresponding author V.M. Kuznichenko, e-mail: : [email protected]

Study on Preparation of PA6 / PDMS Blended Fibers and Fabric Properties

2020 ◽  
Vol 1003 ◽  
pp. 219-227
Author(s):  
Dong Sun ◽  
Guang Li
Keyword(s):  
Contact Angle ◽  
Melt Spinning ◽  
Good Resistance ◽  
Stain Resistance ◽  
Melting Characteristics ◽  
Fabric Surface

PA6 fibers and fabric properties were studied by adding PDMS, and PA6 / PDMS blend fibers were prepared by melt spinning. The experiment found that the addition of PDMS can significantly promote the rheology of the PET / PDMS blend melt. DSC tests show that the addition of PDMS has basically no effect on its crystallization and melting characteristics. With the increase of PDMS content, the contact angle of water on the blended fabric surface increased. KES-FB was used to evaluate fabrics made from PA6 / PDMS blended fibers. It was found that with the increase of PDMS content, the softness and elasticity of the fabrics were improved, and the stain resistance experiments showed that the modified fabrics had good resistance dirty performance.

The Effect of Different Methods of Modification on the Surface Properties and on the Finale Strength of Bonded Joints of Selected Types Thermoplastics

2017 ◽  
Vol 1142 ◽  
pp. 188-193
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Ales Mizera ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Properties ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Wide Range ◽  
Bonded Joint ◽  
Almost All ◽  
Contact Angle Of Wetting

In this study there was compared the effect of different methods of modification (modification by plasma treatment and ionizing beta radiation) on the surface properties (contact angle of wetting and surface free energy) and on the final strength of bonded joints of selected types thermoplastics (low density polyethylene and polycarbonate). At the present time bonding has spread into almost all sectors of practice and it would be very difficult to find an industry in which there is no need to use this technology of joining a wide range of materials. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance.

Protective properties of superhydrophobic coatings on copper and steel obtained by electrochemical method

2021 ◽  
Vol 26 (1) ◽  
Keyword(s):  
Contact Angle ◽  
Copper Substrate ◽  
Copper Plate ◽  
Ethanol Solution ◽  
Cathodic Deposition ◽  
Sem Images ◽  
Protective Properties ◽  
Superhydrophobic Coatings ◽  
Water Wetting ◽  
Contact Angle Of Wetting

Superhydrophobic coatings are obtained by cathodic deposition of copper or nickel on a copper plate with treatment with an ethanol solution of highest carboxylic acids with a long hydrocarbon radical simultaneously or sequentially. They are characterized by a contact angle of water wetting of the order of 155...160°.These coatings protect the copper substrate from corrosion in conditions of 100% humidity for 100...180 days, while maintaining the contact angle within 152…154°. There is no mass loss. The influence of the reversal of the current during electrolysis on the value of the contact angle of wetting is investigated. SEM images of superhydrophobic coatings are presented, indicating multilevel roughness. Superhydrophobic coating on carbon steel is obtained by cathodic deposition of nickel and subsequent surface treatment in an ethanol solution of myristic acid and annealing at 60° for two hours. The influence of the duration of electrolysis on the value of the contact angle of wetting is estimated. Its value is in the range of 151…154°. Exposure of a coated steel plate for 50 days in conditions of 100% humidity is characterized by the absence of weight loss and maintaining the contact angle up to 154°.

scholarly journals Effect of Ionizing Beta Radiation on the Strength of Bonded Joints of Polycarbonate

2014 ◽  
Vol 1025-1026 ◽  
pp. 251-255 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

Strength of Bonded Joints of Linear Low – Density Polyethylene after Radiation Cross – Linking

2014 ◽  
Vol 1025-1026 ◽  
pp. 615-620 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Beta Radiation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Bonded Joints ◽  
Linear Low Density Polyethylene ◽  
Adhesion Properties ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

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