China Aluminum Industry Network 1. Aluminum powder exhibits a silvery-white metallic luster, which is why it is commonly referred to as aluminum silver or silver powder. However, its chemical composition is purely "aluminum," not "silver." It is widely used in powder coatings, inks, plastic masterbatches, printing, imitation gold paper, gold cards, and textiles. However, it tends to oxidize and turn black when exposed to water-based paints or environments with acid and alkali. Therefore, it is not recommended for applications that require resistance to acidic or alkaline conditions, especially in outdoor settings where rain is common.
2. Ultra-fine silver powder: The surface area of ultra-fine floating silver is large, so it quickly forms a protective passive layer when exposed to air, leading to oxidation and darkening. Proper sealing measures are essential. Floating silver is not suitable for applications requiring alkali resistance. If such resistance is needed, consider using silver white pearlescent powder instead. Batch variations can occur due to differences in production processes and spraying techniques, so maintaining consistent production is crucial. It's advisable to conduct trial runs first to avoid unnecessary losses. Adding 1-2% of ultra-fine silver and 0.6%-1.5% of high-gloss wax AW500B can help cover the base and create a strong metallic sheen. The less the amount, the more blueish the effect. Insufficient amounts may result in dark spots, known as "flies," or overall darkness.
3. Floating silver particles tend to rise to the surface of the coating, which slightly reduces their hardness and anti-oxidation performance. To improve hardness, adding printing agents and hardeners like AS501, POL16, or POL09 is recommended. Avoid using high-gloss wax, gold and silver powder dispersants, or polyethylene wax. Longer mixing times generally yield better results.
4. Floating silver: Smaller particle sizes enhance the metallic feel and hiding power, but too much can cause issues like "spit powder" or clogging. Insufficient amounts may lead to black spots, hair-like lines, or stripes. Special effect silver dispersants like R18 and R01 use SIO2 as a carrier, allowing uniform dispersion regardless of the silver powder quantity. This helps reduce black spots and adjust color effects based on background tone. These dispersants are added to the flake, not directly, to prevent clumping and white spots. R01 offers better performance without dry particles when mixed properly.
5. The sheet-like structure of floating aluminum powder can be damaged during grinding or extrusion, causing discoloration. Dry mixing is typically preferred. Non-floating silver is evenly distributed within the coating, offering better oxidation and abrasion resistance, along with improved weathering and acid/alkali resistance. It doesn’t leave fingerprints, provides good gloss, and allows color adjustment from the base. However, it requires a higher dosage than floating silver, resulting in a less intense metallic effect. PCRDIS aluminum powder is ideal for outdoor products due to its inorganic coating, which provides excellent water and chemical resistance. Despite silicon coatings, exposure to light and humidity can cause oxidation, reducing the metal effect and leading to dark gray patches. To prevent this, using transparent powder for coverage is recommended.
6. Testing the amount of transparent base powder for bottom coverage is important. Flash silver can be added up to around 10%. The mixing and spraying process significantly affects the final appearance, so ensuring uniformity is key. Larger particle sizes produce a better flicker effect. Due to differences in shape, density, and charge between silver powder and other powders, separation may occur. Bonding technology can enhance adhesion and improve overall performance. Lastly, aluminum powder can withstand temperatures up to 600°C without changing color.
Rotary lobe pumps for Food and Beverage
Sanitary grade lobe pump is one of the products specially developed by Durrex pumps company to meet the customers in the production process of high hygiene requirements. Working chamber has sanitary rotor, rotor locking nut O - ring, pump body without sanitary dead angle and Higher hygienic grade. Support CIP, SIP. The surface roughness is 0.2--0.8um, in accordance with 3A, FDA standards. Can be widely used food, medicine and other materials with high requirements for hygiene level.
We are specialized in the production of rotor pumps and homogeneous pumps. The production capacity reaches 18,000 units/year.Our pumps can transfer medium with viscosity up to 1,000,000cps, with a maximum flow rate of 400m3 / h (Capacity of 30L / R).
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