Industry News

The aluminum powder has lightweight, high buoyancy, strong hiding power

Views : 25
Update time : 2021-02-20 13:48:55
What is aluminum powder?
Aluminum powder, commonly referred to as "silver powder", is a silver metallic pigment. It is made by adding a small amount of powder to pure aluminum foil, crushing it into scaly powder, and then polishing it. The aluminum powder has lightweight, high buoyancy, strong hiding power, and good reflection and heat. After treatment, it can also become non-floating aluminum powder. Aluminum powder can be used to identify fingerprints and can also be used as fireworks. Aluminum powder has become a class of metallic pigments due to its wide range of uses, high demand, and a wide variety.

What is an aluminum powder used for?
The aluminum powder particles used in the pigment are scaly. It is precise because of this scaly particle state that the aluminum powder has a metallic color and shielding function. The industrial production of metal aluminum powder has existed for a long time ago. The early production method was the ramming method. The aluminum crumbs were placed in the groove of the punching machine. The ramming pestle was driven by the machine to continuously punch the aluminum crumbs in the groove. The ductile aluminum gradually becomes flakes and shatters under the impact. After the aluminum becomes very thin and small, it is screened, and the aluminum powder that meets the requirements is taken out as a product. The production efficiency of the ramming method is very low, the product quality is not easy to grasp, and there is a lot of dust in the production process, which is very easy to catch fire and explode.
In 1894, German Hamtag used a ball mill to produce the aluminum powder. Steel balls, aluminum scraps and lubricants were put into the ball mill, and the aluminum scraps were crushed by flying steel balls to become scaly aluminum powder, which was filled with inertness in the ball mill and the pipeline. Gas, this method is still used, is called "dry production." In 1910, J. Hall in the United States invented the addition of petroleum solvent to the ball mill to replace the inert gas, and the produced aluminum powder was mixed with the solvent into a slurry to become a slurry aluminum pigment. This method is simple in equipment, safe in the process, and very convenient to use, and it is quickly adopted by countries all over the world. Most modern aluminum powder pigments use this method, which is also called the "wet method". Aluminum powder can be used to produce many types of explosives and fireworks. It is also used to manufacture certain types of electronic products. Many paints and sealants contain aluminum powder.

Is aluminum powder dangerous?
Exposure to fine dust can cause scarring of the lungs (pulmonary fibrosis), accompanied by coughing and shortness of breath. Aluminum powder is a flammable solid, which may cause a fire hazard.
The safety risk of powder coating is lower than that of ordinary paint. Compared with solvent/air mixture, the ignition energy of powder/air mixture is 50-100 times. However, all flammable powder or dust will form an explosive mixture with air, which is a potential source of danger. But if corresponding measures are taken in advance, safe transportation, storage and processing can be carried out. For safety reasons, the powder concentration of the various powders mentioned above cannot exceed 10g/m3. In the spray area, this concentration is often exceeded. Because there is always sufficient oxygen content, it is necessary to avoid sparks that exceed this energy.
Compared with resin powder without pigment, when 5-6% aluminum powder is added, the so-called powder constant (Dust Constant, a measure of explosive power) and maximum explosion pressure increase by 10%. When the aluminum powder content continues to increase, the explosive power will also increase. When the aluminum powder content is greater than 25%, it will reach the explosive power of pure metal powder. However, this dependence on aluminum powder pigments does not contribute to the lowest initiation of combustion energy. Regardless of the dispersion method used, pure resin powder cannot reach the initiation energy. If the aluminum powder pigment content is >10% and the use of fine particle size and uncoated aluminum powder, the lowest ignition energy may be reduced.
Aluminum powder-containing powder coatings are the same as ordinary pigmented powder coatings. As long as they do not exceed the specified limit, there is no danger of fire or explosion.
To ensure the safety of the entire spraying process, it is necessary to avoid the separation, accumulation and concentration of aluminum powder in the factory. These basic requirements also apply to solvent-based coatings containing copper and gold powder. However, the explosion hazard directly caused by copper-zinc alloy powder is smaller than that of aluminum powder.
Characteristics of aluminum powder
The aluminum powder used for the pigment refers to the aluminum powder whose particles are in the form of scales, the surface is coated with a treatment agent, and is suitable for pigments. Aluminum powder paste is a mixture of pigment aluminum powder and solvent. Its use and characteristics are roughly the same as aluminum powder. Because it is easy to use, the output and dosage are larger. Compared with other pigments, aluminum powder for pigments has more characteristics in the following aspects:
1. The characteristics of scaly covering
The aluminum powder particles are scaly, and the ratio of the diameter to the thickness is about (40:1)-(100:1). After the aluminum powder is dispersed in the carrier, it has the characteristic of being parallel to the substrate. Numerous aluminum powders are connected. The particles fill each other to form a continuous metal film, which covers the substrate and reflects the light outside the coating film. This is the unique hiding power of aluminum powder. The hiding power of aluminum powder depends on the surface area, which is the ratio of diameter to thickness. Aluminum is stretched during the grinding process, the diameter-to-thickness ratio continues to increase, and the hiding power also increases.
2. Shielding characteristics of aluminum powder
The aluminum powder dispersed in the carrier floats, and the result of its movement always makes itself parallel to the substrate coated by the carrier to form a continuous aluminum powder layer, and this aluminum powder layer is arranged in multiple layers in the carrier film in parallel. The pores between each layer of aluminum powder are staggered, cutting off the capillary pores of the carrier film, and external moisture and gas cannot pass through the pores to reach the substrate. This feature is the good physical shielding of aluminum powder.
3. Optical properties of aluminum powder
The aluminum powder is made of aluminum with light color and high metallic luster. Its surface is smooth and can reflect 60%-90% of visible light, ultraviolet light and infrared light. The object is coated with paint containing aluminum powder, and its surface is silvery and bright. This is the characteristic of aluminum powder reflecting light.
4. The "two-color effect" characteristics of aluminum powder
Aluminum powder has the characteristics of metallic luster and parallel to the coated object. In the carrier containing transparent pigments, the gloss and color depth of aluminum powder change with the incident angle and viewing angle of the incident light. The characteristic is called the "two-color effect". The aluminum powder is arranged in different levels in the coating film. When the incident light illuminates each layer of aluminum flakes, the coating film of different thicknesses is weakened differently, and the reflected light is different in brightness. When light enters the film containing transparent pigments and aluminum powder, the incident light passes through the pigment particles to become colored light and then is reflected by different levels of aluminum powder, and changes in color tone and metallic light occur, incident light and viewing angle The angular position shifts gradually from vertical, and the light passes through pigments of different particle numbers and aluminum powders of different particle sizes, and the color tone and metallic light of the reflected light also undergo infinite changes. This characteristic of aluminum powder has been widely used in coatings as hammer paint or metallic paint.
5. Floating characteristics of aluminum powder
A large type of aluminum powder and aluminum paste for pigments is the floating type, which is characterized by scaly floating on the surface of the coating film.
This fully functional electric motorcycle is 3D printed with aluminum powder
Airbus, known for its giant aircraft, has now entered the field of producing 3D motorcycles! This electric bicycle called 3D printing is called Light Rider, which is not only the future of electric cars but also the future of 3D printed cars.
This 3D bike was launched by APWorks, a subsidiary of Airbus, and was described by them as "corrosion-resistant, combined with lightweight aluminum and almost specific strength titanium." These special qualities are derived from the use of Scalmalloy, which is specialized for APWorks. Researched aluminum powder.
So, how to use powder to print something as strong as a bicycle? Well, Airbus explained that Light Rider's parts have thousands of thin layers, about 60 microns thick. The hollow frame of the 3D printed electric bicycle adds another feather to its lid. Compared with other bicycles, the total weight of the frame is reduced by 30%. Airbus APWorks GmbH CEO Joachim Zettler (Joachim Zettler) explained that traditional welding or milling techniques cannot be applied to this bicycle. Therefore, they decided to adopt a branched, complex hollow structure. Therefore, each 3D printed Light Rider now weighs only about 35kg!
You might think of Light Rider as a toy, but it has all the practicality you might need. Although it is not Harley, its top speed can reach 49m/h. The company's goal is to use 3D printed electric bicycles mainly for urban driving. Airbus claims that after each charge, its battery can travel 37 miles.
TRUNNANO (aka. Luoyang Tongrun Nano Technology Co. Ltd.) is a trusted global chemical material supplier & manufacturer with over 12 years' experience in providing super high-quality chemicals and Nanomaterials. Currently, our company has successfully developed a series of materials. The aluminum powder produced by our company has high purity, fine particle size and impurity content. Send us an email or click on the needed products to send an inquiry.
Calcium Nitride | Nitride Powder | Boride Powder | 3D Printing Powder | Carbide Powder | Oxide Powder | Silicide Powder