In the fields of food packaging, drug storage, electronic equipment moisture-proofing, etc., we often see a white spherical desiccant - alumina air desiccant. It does not change color like silica gel desiccant, nor is it as dangerous as quicklime desiccant, but it has become a moisture-proof expert widely used in industrial and civil fields due to its high moisture absorption rate and safe and stable characteristics.
What is alumina desiccant?
The main component of alumina desiccant is activated alumina. It is not ordinary alumina powder, but a porous material treated by a special process, with the following features:
High specific surface area, capable of absorbing a large amount of water
Rich microporous structure, capable of efficiently capturing water molecules in the air
Stable chemical properties, insoluble in water, non-corrosive
Why is alumina suitable as a desiccant?
1. Strong moisture absorption capacity
At 25℃ and 60% relative humidity, the moisture absorption can reach 20% of its own weight (far exceeding the 30% moisture absorption rate of silica gel)
Stable moisture absorption even in high or low temperature environments
2. Safe and reliable
Non-toxic and odorless, meets FDA standards, and can be used for food and drug packaging
Non-flammable and non-explosive, safer than quicklime (quicklime releases heat when in contact with water)
PH neutral, will not corrode metal or plastic
3. Reusable
After moisture absorption, it can be regenerated by heating and recycled 5-8 times
After regeneration, the moisture absorption capacity can still maintain more than 80% of the initial
Application scenarios in life
1. Moisture-proof electronic equipment
Common in the packaging of optical equipment such as camera lenses and telescopes to prevent the lenses from mildewing.
2. Medical packaging
Maintain a dry environment during the transportation of medicine bottles and medical reagents.
3. Industrial gas purification
Used to remove moisture from compressed air pipelines, oxygen generators, etc. (dew point can reach -40℃).
4. Home mildew prevention
Place in closed spaces such as wardrobes, safes, and musical instrument boxes.
Interesting facts
Application in the aerospace field: The International Space Station uses alumina desiccant to regulate the humidity in the cabin
Historical origin: It was used to store penicillin in a moisture-proof manner during World War II
Special form: Some high-end desiccants are made into a "honeycomb shape" to increase the contact area