scholarly journals Investigation of the Performance of Fumed Silica as Flow Additive in Polyester Powder Coatings

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 977
Author(s):  
Junqing Xie ◽  
Haiping Zhang ◽  
Yuanyuan Shao ◽  
Danni Bao ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Fumed Silica ◽  
Powder Coating ◽  
Angle Of Repose ◽  
Powder Coatings ◽  
Inclined Plate ◽  
Coating Application ◽  
Blending Method ◽  
Distinctness Of Image ◽  
A Minor ◽  
Bed Expansion

Fumed silica is one of the most commonly used flow additives in the powder coating industry. To investigate the influence of the properties of fumed silica on powder coatings, three different types of fumed silica, Aerosil R812, R972, and R8200, were selected and introduced to an ultra-high-gloss powder paint by the dry-blending method with preset mixing conditions and times. Their effect on the powder flowability, coating application related properties and film properties were carefully studied. The angle of repose (AOR) and bed expansion height data, which represent the semi-dynamic and dynamic flowability of powders respectively, show a strong flowability enhancement for the powders with additives, and R812 exhibits the best performance compared to 8200 and R972, mainly due to its high hydrophobicity and specific surface area. For the ultra-high-gloss powder paint, all the flow additives cause slight gloss reductions, surface roughness increase and a significant effect on the distinctness of image (DOI). The addition of R972 is beneficial to the transfer efficiency of powders compared with the other two, while the additives impose only a minor influence in the Faraday cage effect. The melting and curing dynamics, i.e., gel time, and inclined plate flow, are not affected by the flow additives.

scholarly journals EFFICIENCY OF MODIFYING ADDITIVES IN POWDER COATING MATERIALS

2021 ◽  
pp. 47-57
Author(s):  
V.І. Gots ◽  
◽  
О.V. Lastivka ◽  
О.О. Tomin ◽  
◽  
...  
Keyword(s):  
Surface Tension ◽  
Silicon Dioxide ◽  
Mechanical Characteristics ◽  
Powder Coating ◽  
Coating Film ◽  
Powder Coatings ◽  
High Effectiveness ◽  
Modifying Additives ◽  
Polymer Resin ◽  
Technical Specifications

Rapid rates of development in production of powder coatings are, in comparison to liquid paint-and-lacquer materials, evidence of their importance, high effectiveness and prospectivity. The increase in popularity of powder coatings can be explained by their environmental adequacy and attractiveness from the perspective of the environmental protection as well as high effectiveness related to the possibility of obtaining high quality protective and decorative coatings during the one-layer application. At the same time, it is obvious that during modern powder coating-and-lacquer materials have not exhausted all possibilities of improving pharmaceutical compositions and expanding the assortment as well as modernizing their production technology the relatively short period of their development. The composition of the thermosetting powder coating contains five key components: polymer resin, hardener, pigments, fillers and functional additives. In general, the polymer resin and hardener play a key role in ensuring necessary mechanical characteristics and lifespan of the powder coating. In this case, the role of functional (modifying) additives is extremely important to obtain characteristics that are often fundamentally required to meet predetermined technical specifications of the products and needs of end users. Additives play an important role in forming properties of powder coatings and coatings based on them as they have become their integral part for several main reasons: because of control of rheological properties, surface defects as well as light and temperature stabilization of coatings. The study deals influence of modifying additives on properties of the powder coating. The authors using rheological and degassing modifying additives with different nature of the main active substance. It was found that the additives based on the acrylate polymer adsorbed on the silicon dioxide in the form of Byk-3900P and on the polyoxyethylene derivative of the castor oil in the form of Luvotix R400 decreasing the surface tension in the coating film, which, in its turn, contributes to the increase in the wettability of base during the melting of the powder coating, decrease the ‘orange peel’ effect during the cross-linking, reduction in pinholes on the obtained surface and improvement of mechanical characteristics of the coating. At the same time, rheological additives based on the bentonite in the form of Luvogel 4B and on the hydrophilic silicon dioxide in the form of Cab-o-sil M5 cause the increase in the surface tension in the coating film, which, in its turn, leads to the worsening of flow, appearance and mechanical characteristics of the powder coating.

Study of rheological behaviours of electrostatic thermoset powder coatings

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Morteza Ehsani ◽  
Ali Akbar Yousefi ◽  
Saeed Samiei Yeganeh
Keyword(s):  
Mechanical Properties ◽  
Dynamic Viscosity ◽  
Physical And Mechanical Properties ◽  
Powder Coating ◽  
Curing Temperature ◽  
Design Parameters ◽  
Powder Coatings ◽  
Gel Time ◽  
Rheological Measurements ◽  
The Impact

AbstractThe use of dynamic viscosity/time (temperature) cure curves is seen as a powerful technique to quantify formulation and resin design parameters. The behaviour of different thermoset powder coating systems, epoxy/polyester (50/50, 40/60 and 30/70) as well as the impact of the filler, the curing temperature and the frequency upon gel-time have been examined based upon the rheological measurements and compared with PE/TGIC systems. Two disparate methodologies have been utilized to determine gel-time. The behaviour of dissimilar systems bearing different formulations has been compared by means of the non-isothermal DSC test. The effects of resin percentage and the formulation on physical and mechanical properties of coating have been studied.

scholarly journals Comparative Study of the Performances of Al(OH)3 and BaSO4 in Ultrafine Powder Coatings

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 316 ◽  
Author(s):  
Weihong Li ◽  
Diego Cárdenas Franco ◽  
Marshall Shuai Yang ◽  
Xinping Zhu ◽  
Haiping Zhang ◽  
...  
Keyword(s):  
High Surface ◽  
Expansion Ratio ◽  
Ultrafine Powder ◽  
Angle Of Repose ◽  
Organic Polymer ◽  
Inorganic Filler ◽  
Differential Scanning Calorimetric ◽  
Powder Coatings ◽  
Coating Films ◽  
The Impact

Ultrafine powder coatings are one of the development directions in the powder coating industry, as they can achieve thin coatings with good leveling and high surface smoothness comparable to liquid coatings. Compared to regular coatings, they experience a higher sensitivity to any incompatibilities, e.g., filler from coating components. The properties of fillers play a great role in the performance of coating films. Aluminum trihydrate (Al(OH)3) is a well-known filler in solvent-based coatings and other polymer industries. To study and evaluate the performances of Al(OH)3 in ultrafine powder coatings, a popular filler, barium sulfate (BaSO4) is used for comparison. Both fillers are added in ultrafine powder coatings based on two of the most commonly used resin systems (polyester-epoxy and polyester). The differences of physical and chemical properties between both fillers have significant influences on several properties of powder paints and coating films. The polar groups (hydrogen bond) in Al(OH)3 result in the strong interaction between inorganic filler and organic polymer matrix, thus decreasing the molecular network mobility and influencing the chain formation, which is verified by differential scanning calorimetric (DSC). The bed expansion ratio (BERs) of powder paints incorporated with Al(OH)3 are much higher than those with BaSO4, which indicate more uniform gas-solid contact during the spraying process. Samples with Al(OH)3 exhibit much lower specular gloss at 60°, which are expected to achieve remarkable matting effects. Superior corrosion resistances can be observed for almost all the coated panels incorporated with Al(OH)3 in contrast to those with BaSO4. Other aspects are slightly influenced by the difference between the two fillers, such as the angle of repose values (AORs) of powder paints, the impact resistance and flexibility of coating films.

Influence of cathodic polarization on the properties of epoxy powder coatings

2019 ◽  
Vol 24 (4) ◽  
pp. 7-14
Author(s):  
D.N. Zapevalov ◽  
A.Р. Sazonov ◽  
E.V. Sheverdenkin ◽  
A.V. Latyshev ◽  
N.I. Savostina ◽  
...  
Keyword(s):  
Mechanical Load ◽  
Large Diameter ◽  
Powder Coating ◽  
Operational Reliability ◽  
Powder Coatings ◽  
Active Centers ◽  
Cathode Polarization ◽  
Epoxy Coatings ◽  
Large Diameter Pipes ◽  
The Impact

The article discusses the effect of cathode polarization on the protective properties of powder epoxy coatings, assesses their operational reliability, statistics of failures and describes the problems found during their operation. In the process of applying commercially available pipes with epoxy powder coating on the existing gas pipeline, a not previously manifested defect was observed - the formation of dome-shaped swellings. This led to some restrictions on the use of epoxy powder coatings. With the advent of a new generation of epoxy materials, as well as in connection with the revision of the regulatory documentation GOST R 51164-98, the issue of removing these restrictions on their use for insulating large diameter pipes (up to 1,420 mm). Without additional protection has become topical. As a result, it became necessary to estimate the probability of the appearance of defects of this type when using modern powder coatings. We carried out laboratory studies of the effect of cathode polarization on the properties of modern two-layer epoxy coatings after exposure to them of shock loads of a certain size. The results indicate that the impact of such a mechanical load may cause the appearance of microdefects of the coating, which are not determined by the existing methods of control. Due to the penetration of electrolyte under the coating and the occurrence of certain physicochemical and electrochemical processes that are enhanced by imposing the potential of cathodic protection and increasing the operating temperature, these microdamages can serve as active centers for the formation of a cupola-shaped swelling.

Wear tests of modified powder coatings at low climatic temperatures

2021 ◽  
pp. 442-446
Author(s):  
N.F. Struchkov ◽  
D.I. Lebedev ◽  
K.N. Bol’shev ◽  
G.G. Vinokurov
Keyword(s):  
Friction Surface ◽  
Sliding Friction ◽  
Powder Coating ◽  
Powder Coatings ◽  
Ambient Temperatures ◽  
Special Stand ◽  
Wear Tests

The results of comparative wear tests for sliding friction of modified powder coatings with metal counterbodies at room and low climatic temperatures are presented. For this, a special stand has been developed and manufactured for testing the wear of powder coatings in conditions of low climatic ambient temperatures. The temperature of the friction pairs "powder coating — metal counterbody" and the profiles of the friction surface of coatings and counterbodies were measured.

scholarly journals Characterization of Surface Coating Techniques for Improved Performance

2020 ◽  
Vol 5 (9) ◽  
pp. 5-9
Keyword(s):  
Surface Coating ◽  
Research Work ◽  
Hardness Test ◽  
Powder Coating ◽  
Load Force ◽  
Wood Block ◽  
Powder Coatings ◽  
Coating Technology ◽  
Scratch Hardness ◽  
Coated Materials

Surface coating has evolved with time, tracking the demands of the processing industry. This research activity, studies the significance of powder coatings in the evolution of existing conventional surface coating technology for their practical applications in the field of metal coating, particularly office and home appliances. The first objective of this work involves a systematic comparison between polymer powder coatings with liquid-based coatings. In the second objective, a comparison between the polymer coatings with additive filled powder coating was performed. Various conventional substrates (such as copper, aluminium, galvanized iron, brass, cement plank, wood block) were used for this study. The materials were first dry scuffed and then dipped in 3 in 1 chemical (zinc phosphate chemical and magnesium phosphate) for the primer coat. The prepared substrates were surface coated with liquid paint (on one side of the panel) using spray gun and powder paint (on another side of panel) using electrostatic spraying. The coated panels are then subjected to various standard (ISO) characterization techniques such as Scratch hardness test, Flexibility test, Thickness test, Adhesion test, Impact resistance test etc to analyze the effectiveness of the coatings applied. The quantitative and qualitative results thus obtained using powder coatings were promising (e.g: As the load progressively kept increasing i.e. 1000-2000 gm, mild scratches were noticeable on liquid coated substrates whereas powder coated metal panels have shown a greater resistance to scratch damage) as the test values determined high strength quality and durability (in-line with the standards) in comparison with liquid coatings. Also, the doping of additive (graphene) in small quantity has improved characteristics and qualities of the powder coated materials (e.g: graphene based powder coating has endured scratch hardness test beyond 2500 gms load force compared to simple powder coating). The findings of the current research study has confirmed the advantage of the powder coating technology and also deliberated the effect of fine powder flow ability. The important future prospects of this research work is that., powder coatings will stand on the threshold of exciting breakthroughs thus opening new frontiers by being able to coat thick steel components and even non-metal substrates. Also, the recent advances in powder coating technology with anticorrosive additives will result in bonded metallic coatings that deliver a unique, quality appearance.

scholarly journals Evaluation of corrosion resistance of powder coatings after various surface chemical pre-treatment

2017 ◽  
Vol 61 (2) ◽  
pp. 80-85
Author(s):  
D. Draganovská ◽  
J. Brezinová
Keyword(s):  
Corrosion Resistance ◽  
Protective Layer ◽  
Powder Coating ◽  
Conversion Coating ◽  
Powder Coatings ◽  
Surface Protection ◽  
Pre Treatment ◽  
Respective Surface ◽  
System Selection

Abstract The surface treatment by a powder coating is one of the progressive technologies. Such coatings are resistant to corrosion and mechanical wearing. The quality of surface protection is affected primarily by a layer pre-treatment, the type of surface tretment, the system selection and the method and quality of application. Taking into account all the surface pre-tretment methods, the chemical pre-modification is a leading method. One of the methods is pre-treatment using a conversion coating which was developed on the nanotechnology basis - BONDRITE NT. That non-phosphate chemical pre-treatment is utilized at a surrounding temperature. It creates nano-ceramic protective layer on steel, zinc and aluminium surfaces, and as the result the coating has a significant adhesion. In the paper, the possibilities for the improvement of corrosion resistance of powder coatings using the subject conversion coating are presented at the current pasivation of respective surface.

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