How does the change in aluminum powder in the paint bucket affect safety? The paint barrel metal paint reacts with water to form hydrogen during storage, which results in the formation of a protective layer on the outer layer of the aluminum sheet. By treating the aluminum powder, the reactive paint bucket is reduced with water to improve the safety performance of the coating. The commonly used water-based aluminum silver paste modification method is to add a corrosion inhibitor method and a package method. The addition of the corrosion inhibitor method is to physically mix the additives on the surface of the aluminum powder particles, weigh and record the quality at this time, and then place the container in an oven at 40 ° C to investigate the stability of the aluminum powder.
Take 5d as a cycle, take it out and cool to the standard temperature, then gently open the lid of the container. Weigh the mass at this time and finally prevent the reaction of aluminum and water. The corrosion inhibitor includes fatty acid corrosion inhibitor, low molecular corrosion inhibitor, surface activity. The corrosion inhibitor and polymer (polymer) electrolyte corrosion inhibitor package method refers to the physical and chemical treatment of the particle surface, purposefully changing the physicochemical properties of the particle surface, forming a layer of protection on the outside of the aluminum powder. Floor. A commonly used method is chromate treatment of molybdate-treated silicone modification treatment.
Silica-coated aluminum slip is a relatively large class used in waterborne automotive coatings. The advantage is that hydrogen is not generated or the amount of hydrogen generated is very small, but the disadvantages are also obvious - the price is expensive, the compatibility with the organic matter in the coating is poor, the flickering feeling of the aluminum powder is poor, and the variety can be selected.
The difference in appearance flicker between the silica-coated aluminum silver paste before and after coating.
The safety of the coating system was evaluated by evaluating changes in quality. The prepared aqueous coating sample is placed in a closed container, and the pressure in the container is increased and the "bulging barrel" is severe, which may cause an explosion accident. If the pressure inside the barrel is too high when the worker opens the paint bucket during use, the paint may emerge from the packaging drum, and even the phenomenon of "crushing" may occur, causing personal injury to the operator and the quality when it is just placed in the oven. comparing. After 3 cycles, the larger the difference, the greater the amount of aluminum powder released, and the worse the safety and stability of the coating system. The safety of the coating system is rated by the change in system pressure in a closed container. This method is the most common method, and the measuring device is shown in Fig. 3. The measuring principle is that when the aluminum powder in the metal paint in the glass bottle reacts with water to release hydrogen gas, the gas pressure in the glass bottle is increased. As the lower air chamber communicates with the glass bottle, the air pressure in the lower air chamber also increases; due to the upper air chamber and the atmosphere, its air pressure is constant throughout the test, and a pressure difference occurs in the upper air chamber.