The methods of modern archives insect elimination include a physical method and chemical method, and both are high efficiencies. Physical methods include microwave sterilization, γ-ray radiation sterilization, controlled atmosphere technology and low-temperature methods. Chemical methods include fumigation of formaldehyde, ozone, pyrethroid, ethylene oxide and other chemical agents.
Based on the microwave effect on archival paper, Microwave sterilization kills insects and mildew with thermal and non-thermal methods. The thermal method rapidly heats up and dehydrates the eggs, mold spores and cells, while the non-thermal directly destroys such living substances like proteins and nucleic acids in biological cells, and deprives their activity. These two methods together lead to the death of the eggs and mold cells. The microwave sterilization insecticidal method is economical, low-cost and easy to operate, in addition, its damage to archives is far less than the traditional sun exposure method.
Controlled atmosphere treatment artificially alters the proportions of CO2, O2 and N2 in the treated airspace. This is commonly achieved by enhancing the proportion of N2 and CO2 so that the O2 levels are reduced. By increasing the pressure of the airspace, the activity of insects will be controlled and inhibited, thereby these insects will be suffocated to death.
Freezing insecticidal treatment is to kill insect eggs using a low temperature or ultra-low temperature refrigerator to reduce the archival temperature to -24℃ and maintain it for a period of time. A controlled atmosphere and freezing insect treatment are ineffective for molds and their spores.
There are about 50,000 books in the library that needs insecticidal treatment.
It is required to be environmentally friendly, zero pollution, zero residues, safe, non-toxic and harmless to book collections and the staff member.
Low-oxygen-controlled atmosphere technology is adopted in insecticidal treatments in books.
The library decided to rent relevant equipment to improve efficiency and reduce the cost of insect treatment.
Flexible insecticidal tent, air compressor, nitrogen monitor and controller, bookshelves, oxygen scavenger, dehumidifier.
Oxygen concentration: 0.1%～21%
Humidity: 30%～60%RH
Volume: 29m3×2（set）
Air exchange rate: ≤0.02d-1
