Hydrophilic and anti-corrosion properties of aluminium foil bags

Hydrophilic and anti-corrosion properties of aluminium foil bags

After a period of use, the hydrophilicity of the surface of the aluminium foil is affected by various environmental factors. Therefore, hydrophilic properties are generally divided into initial hydrophilic and hydrophilic properties after environmental tests. The hydrophilicity is mainly measured by the size of the a-angle. The initial hydrophilicity of a<100 and the hydrophilicity after environmental testing requires a<250. The contact angle a can be measured with a special contact angle measuring instrument or calculated by the size of the area occupied by a certain volume of water droplets on the surface of the aluminium foil.

Corrosion resistance of aluminium foil.

Corrosion resistance is mainly reflected in three aspects: firstly, alkali resistance, as the lubricating oil on the surface of the heat exchanger flush needs to be removed with alkaline cleaning agents, so the functional coating on the surface of the aluminium foil must have a certain degree of alkali resistance, generally requiring 3 minutes of immersion in a 20% NaOH solution without blistering; secondly, salt spray corrosion resistance, generally in the test conditions of 35 oC, 3% salt water spray environment requires 500 hours can not have corrosion spots.

The good or bad salt spray corrosion resistance is directly related to the length of service life of the heat exchanger. In coastal areas, due to the high salt content in the air, so the heat exchanger piece of salt spray corrosion resistance has higher requirements; three is the resistance to heat and humidity performance, that is, in a certain temperature, a certain humidity placed under a long time corrosion resistance. This performance is also an important indicator of the heat exchanger's ability to withstand the weather.