Yosoar——Bronze Powder Manufacturer Worthy Of Your Trust
What is the microscopic morphology of bronze powder?
Observed under the scanning electron microscope, the Gold Powder particles have a scaly structure. Most of the bronze powder’s scales are irregular, with a saw-tooth shape at the edge, and a few are relatively regular round.
Why does bronze powder show golden light?
It has the characteristic of being arranged in parallel with the coating and the purpose is mainly determined by the particle structure. When the carrier containing copper-zinc alloy powder is formed into a film, the copper-zinc alloy powder scales are radially connected to each other to form a continuous metal film. This metal film reflects the outside light presents a golden color light.
What is the granulometric distribution of the bronze powder manufacturer tell you?
The particle size of Gold Powder has a narrow distribution range, and powders of different finenesses have different reflective capabilities and inconsistent hues. Therefore, the particle size and distribution of the powder are almost all specified in the technical requirements. Currently, it is suitable for the printing and packaging industries. The diameter of bronze powder is generally 4 ~ 20 μm, and the particle size distribution range is required to be narrow.
What are the floating characteristics of bronze powder?
The floatability of gold bronze Powder means that the flake gold bronze pigment can float on the binder after being mixed with a suitable binder.
On top, after printing, a metal layer parallels to the substrate, and overlapping each other is formed. The ability of bronze powdery flakes to float in the adhesive is the most important reason for its metallic luster in the adhesive. This is also the difference between metallic pigments and other pigments.
What are the characteristics of the optical performance of bronze powder?
One of the most important characteristics of copper-zinc alloy powder as one of the metallic pigments is the phenomenon of “different colors at different angles”, which refers to an optical phenomenon that can flash with different brightness, saturation, and hue with different viewing angles. It is caused by the different ways of scattering and reflection of the incident light by the pigment.
What are the phenomena of the bronze powder coating film from different angles?
When observed almost perpendicular to the coating film, the coating film shows a strong face color, also called frontal color; when viewed almost parallel to the coating film, the coating film flashes a glancing color; when the viewing angle is between the above two extreme positions at any angle, the coating film flashes with a flash color. This phenomenon is related to the flatness of the gold powder. The flatter the material, the higher the brightness.
What are the factors that affect the glossiness of bronze powder printing gold?
There are a number of factors that affect the gloss of gold bronze printing gold, among which the micro-morphology, sheet thickness, and orientation arrangement of the bronze powder play a vital role in the binder. Different particle diameters have different reflections, diffraction, and scattering effects on light, which makes gold powder with the same alloy composition but different particle diameters have different brightness and hue; the thinner the metal powder, the easier it is to float in the binder. It is easy to align and align, thereby improving the gloss of printed gold; after the surface treatment of the flake pigments, it gives the pigments the ability to align and float in the binder. The orientation arrangement of metallic pigments is closely related to their optical properties (mirror effect, development). Because the gold bronze pigments are arranged in parallel with the substrate, the coating has high reflectivity and thus has a high gold-printed gloss. The more neatly arranged the gold bronze, the more obvious the mirror effect and the higher the gloss of the printed gold.
What is the chemical stability of bronze powder?
The copper-zinc alloy has relatively strong mental activity, and it is prone to oxidation reaction when exposed to the air directly, which makes the color of the metal surface dim and loses its metallic luster. In order to improve the weather resistance of pigments, surface treatment is usually used to reduce the activity of the metal on the one hand, and on the other hand to maintain the original metallic luster. In addition, the surface properties of aluminum, zinc, gold bronze pigments determined by the production process limit the usable media and solvents. If an acidic or alkaline medium and solvent are used, the medium can react with the metallic pigment, making the pigment darker, and even produce bubbles in the paint and change the color of bronze powder. The situation of bronze powder pigments is more complicated. According to the conditions of use or zinc loss or the overall dissolution of the alloy, the medium turns green, and then due to the catalysis of heavy metal ions, polymerization or condensation reaction with the medium occurs (the coating gels and thickens).
What effect does the dispersion of bronze powder pigment have on the quality of the coating film?
Production practice shows that the dispersal of the pigment will directly affect the surface quality of the final coating film. The better the dispersion of the pigment, the more uniform the coating film and the higher the gloss. Therefore, pigment workers are unanimously committed to the research and development of highly dispersible pigments.
What is the dispersing process of bronze powder pigment?
The classic pigment dispersion theory generally divides the pigment dispersion process into three stages: ① the pigment aggregates start to wet; ② the pigment aggregates are broken into small particles, that is, the aggregates are separated; ③ the air on the surface of the particles is replaced with a binder. That is, the water or air attached to the pigment particles is replaced by the wetting medium, and the wetting medium is attached to the surface of the pigment particles.
What is unique about the desirability of bronze powder?
Due to the unique physical properties and application requirements of gold bronze pigments (high floatability and strong metallic luster), the traditional pigment dispersion theory cannot be fully applied to bronze powder pigments. On the one hand, to improve powder dispersion, it is necessary to improve the wettability of the bronze powder pigment in the binder; on the other hand, to improve the floating ability of the powder in the binder, the surface tension of the powder must be reduced. Reduce the degree of wetting between the powder and the binder. For aqueous media, due to its higher polarity, it is different in the conversion of wetting and is also different from solvent-based media in stabilization.
What is the role of bronze powder pigment surface modification?
In the gold bronze processing industry, the surface treatment process is generally the last process. Surface treatment of gold bronze pigments has two main functions. One is that the gold bronze obtained by dry grinding will inevitably have problems such as curling, folding, agglomeration, and low surface finish of the gold bronze. After surface treatment, these curled films can be flattened and polished to show a high metallic luster in the ink; the other main function is: during the polishing process of the gold bronze, an appropriate amount of surface treatment reagent should be added to make it evenly coated on Powder surface, in order to improve the floating performance and dispersion performance of gold bronze in the ink. Therefore, the surface treatment process plays a decisive role in the pigmentation process of metal powder. Improper selection of gold bronze surface treatment process or surface reagents will destroy the performance of bronze powder pigment in ink, reduce the metallic luster and printing adaptability of bronze powder.
The mechanism of the oriented arrangement of bronze powder and its relationship with gloss.
The reason why the powder can be oriented in the binder is that the surface treatment of the flake pigment gives the pigment the ability to align and float in the binder. Specifically, in the process of ball milling and polishing gold bronze, surfactants are generally used as grinding aids.
For example: When using stearic acid as a lubricant, a layer of stearic acid film will be adsorbed on top of the pigment, the polar groups of stearic acid will face the surface of the gold bronze, and the light groups of the non-polar groups will face the gas phase. The surface of the solid surface with the adsorption layer is exposed to light-based groups, which have low-energy surface characteristics. This arrangement makes the gold bronze hydrophobic and lipophilic. When the gold powder is added to the binder, as the solvent continues to evaporate, the wet film shrinks and squeezes the flake pigment to form an orientation parallel to the surface of the substrate.
The orientation arrangement of metallic pigments is closely related to their optical properties (mirror effect, development). Because the bronze powder pigments are arranged in parallel with the substrate, the coating has high reflectivity and thus has a high gold-printed gloss. The more neatly arranged the gold bronze, the more obvious the mirror effect, and the higher the gloss of the printed gold.
What effect does the polishing process have on the glossiness of the bronze powder?
The impact of the polishing process on gloss is mainly manifested in whether the bronze powder scales are completely stretched during the polishing process and the absorption of the reagents. By selecting appropriate polishing process parameters, the gold bronze scales can move and rub against each other, so that they can be stretched, flattened and polished. Under the same conditions, the completely flattened powder scales can enhance specular reflection, reduce light scattering and diffraction, and improve gloss; under the action of polishing mechanochemistry, the more complete the reagent adsorption, the higher the modification efficiency.
What effect does the water-based bronze powder surface modification reagent have on its performance?
Surface modification reagents such as antioxidants and saturated fatty acids and their salts need to be added in the production process of water-based powder. The addition of antioxidants enables the gold bronze to maintain a stable hue in the weakly alkaline environment of water-based binders and high-temperature and high-speed printing operations, thereby providing the possibility to maintain gloss. The addition of saturated fatty acids and their salts and other surface modification reagents can improve the wetting, dispersion, and floating properties of the gold bronze in the water-based binder, thereby affecting the directional arrangement of the gold bronze in the ink layer and then affecting the printing of the water-based gold bronze. Gold gloss and metallic texture. In the production of water-based copper-gold powder, it is necessary to combine the functions of the two, and the glossiness of water-based gold ink is produced by the combination of the two. Therefore, the type and amount of powder surface modifiers, and the type and amount of antioxidants have become important factors affecting the gloss of water-based bronze powder printing.
What factors affect the floating of bronze powder?
The floatability of the gold bronze depends on the surface modifier used in the processing and the arrangement of the outermost groups on the surface of the bronze powder. It affects the surface of the gold bronze by changing the density and wettability of the gold bronze. Properties, which affect the floatability of bronze powder: it is not the point with the worst wettability that corresponds to the highest float rate.
Why should copper-zinc alloy powder be annealed?
The copper-zinc alloy powder has a tendency to harden during the grinding process. Annealing treatment can accelerate the formation of a long fiber structure and make the molecules have good ductility after recrystallization. Therefore, the copper-zinc alloy powder particles also need to be annealed to extend the scale structure. Therefore, the wet-grinded copper-zinc alloy powder must be dried and annealed before it can continue.
Continue to perform finer grinding. The annealing of the copper-zinc alloy powder is carried out in an annealing furnace at a temperature of 500°C. After holding for three hours, the temperature is slowly reduced.
What are the steps for wet pulverization of copper-zinc alloy powder?
After the copper and zinc powder particles are dried, grinding aids and lubricants are added to grind the irregular particles into scales. The surface of the atomized copper powder has an oxide layer, which can also be removed by wet grinding. Adding grinding aids can help the powder to disperse, adding grinding lubricants can increase the viscosity of the grinding materials, prevent the particles from forging and joining together, and at the same time protect the metal surface from being abraded. When the particle fineness reaches the requirement, the material is discharged, and the solvent is removed after filtration through a filter press to obtain a copper-zinc alloy powder filter cake.
How is the dry fine grinding process of copper-zinc alloy powder performed?
The copper-zinc powder after annealing treatment can be finely ground, that is, dry fine grinding so that the copper-zinc powder particles become thin and fine scales. Lubricant needs to be put in dry fine grinding, and the powder is ground and dispersed through continuous friction and collision in the ball mill so that the copper alloy powder is continuously dispersed into fine flakes. The flowing wind blows out the powder with the required particle size and collects it in the container, and the coarse powder that does not meet the requirements is returned to the ball mill to continue grinding and dispersing.
The process of sieving and drying copper-zinc alloy atomized powder.
The atomized copper-zinc alloy powder is sieved and classified according to the particle size in the sieving machine and used in the sieving. Rinse with water to remove mechanical impurities, and then the copper-zinc alloy particles enter the drying oven for drying and dewatering.
Why do we need to add ball milling aids when preparing bronze powder by high-energy ball milling?
The preparation of gold bronze by high-energy ball milling is a special ball milling process that requires the addition of suitable grinding aids. Commonly used grinding aids include antioxidants, lubricants, and corrosion inhibitors. The main function of lubricants is to prevent cold welding of metal powders; antioxidants and corrosion inhibitors are mainly used to prevent further oxidation of metal powders during ball milling. In the process of ball-milling gold bronze, through the grinding and impact of the grinding ball, the diameter of the gold bronze will increase at the beginning, and the thickness will decrease, gradually forming coarse flakes. If there is no ball milling aid at this time when further ball milling is performed, the average flake diameter and thickness of the powder will continue to decrease, but some small flake powders will undergo pressure welding, interlocking, etc., and eventually form some approximations. Spherical aggregates. Adding a grinding aid can solve this problem. The grinding aid is generally a polar substance with a lower melting point. As the average diameter and thickness of the powder decrease, the grinding aid in the molten state will evenly cover the copper. On the surface of the gold powder, a very thin oil film is formed, so that the flake powder can be separated well without being forged. However, if the grinding aid is added too much, the oil film on the surface of the flake powder will be too thick, thereby reducing the gloss of the gold bronze, and at the same time affecting the dispersibility of the bronze powder and reducing the production efficiency of the bronze powder. When the amount of grinding aid added is too small, a continuous and complete oil film cannot be formed, and effective protection and lubrication cannot be achieved.
What influence does the selection of ball-milling ratio have on the preparation of gold bronze by high-energy ball milling?
In the process of ball milling, pay attention to paid to the ratio between the ball and the material, that is, the ratio of ball to the material. If the material is too small, the probability of direct collision between the grinding ball and the grinding ball will increase, which will aggravate the wear of the grinding ball. If the material is too much, the grinding area is not enough, and the powder cannot be finely ground, the ball milling time will be longer, which will increase energy consumption and reduce ball milling efficiency. The filling amount of the material is based on the principle of filling the holes between the grinding balls and slightly covering the grinding surface.
What effect does the choice of stirring shaft speed have on the preparation of bronze powder by high-energy ball milling?
The function of the ball mill to smash the material mainly depends on the work done by the grinding ball on the material, and the amount of energy provided by the grinding ball to the material mainly depends on the speed of the stirring shaft. When the rotating speed of the mixing shaft is fast, the impact force of the grinding ball in the cylinder becomes larger, and the work done on the material increases, which can reduce the time used for crushing the material. However, a too-fast speed will increase the surface energy of the gold bronze, making it easier to be oxidized and reducing its performance; when the stirring shaft speed is slow, the impact force of the grinding ball is smaller, and the time to crush the material becomes longer, and the crushing effect of bronze powder may be reduced due to insufficient energy.
What effect does the choice of milling time have in the process of preparing bronze powder?
In the process of mechanical pulverization, the particles are not infinitely ground, but at the end, the particles are in a reversible dynamic process of pulverization and polymerization. As the milling time passes, the energy on the particle surface or cracks accumulates, and the formation of unsaturated bonds and charged groups will cause the particles to agglomerate.
What kind of influence will the added amount of materials have on the preparation of bronze powder?
Since the production of gold bronze is carried out in a closed environment, in order to obtain a better diameter-to-thickness ratio and stabilize the quality of the gold bronze, the amount of bronze powder added is an extremely important factor. If the amount of material in the grinding cylinder is too much, the grinding will be insufficient, and even part of the powder will not be ground at all. In this case, the performance of the gold bronze obtained must be poor. If the amount of material is too small, the ball milling efficiency will be greatly reduced.