VCI bags are made of VCI vapor rust inhibitor, which can protect metals and other materials anytime and anywhere in the permitted environment.
Good quality VCI bags can last for 2 to 3 years, but the poor quality will not last so long. Then buy When, how to test its anti-rust ability.
The anti-rust function is a key indicator to measure the quality of VCI products. Recognition of the function of rust prevention is the most important step in choosing VCI products.
The anti-rust function test is generally divided into two categories: objective condition test method and artificial accelerated test method.
The objective condition test method is to test in a warehouse or a louver. The former is to pack the metal sample in a vapor rust-proof bag and place it in the warehouse to protect it from acid-base atmosphere and rain and snow, and prevent direct sunlight;
In the latter, the louver box is placed in the field, the air in the box should be communicated with the outside atmosphere, and the sample subjected to vapor phase rust prevention is placed in the middle of the louver box.
Artificial accelerated test methods are divided into dynamic damp heat test, salt spray test, spray compound corrosion test and multi-element cyclic combined corrosion test.
The so-called dynamic damp heat test refers to the condensation of moisture on the surface of the sample under high temperature and high humidity conditions to strengthen the corrosive environment and accelerate the corrosion process of the sample.
The salt spray test is to imitate the protective effect of vapor phase anti-corrosion products on metal samples in the ocean high temperature, high humidity, and high salt environment.
This is also a more commonly used test method, which is more in line with the environmental conditions of the actual application of VCI products.
The spray compound corrosion test refers to adding a monotonous process in the salt spray test process to form a continuous cycle of “wetting-monotonous”, which is closer to the corrosion status of the material in the external environment.
After that, the multi-element cyclic combination corrosion test is to summarize all the elements as much as possible, and reproduce the corrosion in the atmosphere as realistically as possible, such as space humidification, spray, H2S gas, high temperature, cooling, monotonous and other cyclic tests.
