Recently, the Ministry of Science and Technology officially issued the 2022 National Key Research and Development Plan "Cultural Science and Technology and Modern Service Industry" key special project approval notice. "The project was approved.

This is the first national key research and development project approved by Nanjing Museum during the "14th Five-Year Plan" period.

Recently, a reporter from the Yangzi Evening News walked into the Nanbo laboratory to find out.

　　Yangtze Evening News/Ziniu News reporter Zhang Nan

　　Why should paper documents be "deacidified"

　　The Ministry of Culture and Tourism Key Laboratory of Deacidification and Protection Technology for Modern Paper Documents (Nanjing Museum) is located in the Wenbao Building of Nanjing Museum.

　　"Trial production and demonstration of large-scale deacidification equipment for ancient Chinese books and modern paper documents in the collection" sounds abstract, but in fact it means that the paper documents in our country's collections generally face acidification problems. However, the existing deacidification technology can only meet the processing needs of small batches. It is far from realizing large-scale deacidification protection.

　　Why should paper be deacidified?

According to Zhang Jinping, the project leader and vice president of Nanjing Museum, the collection of paper documents in my country is very large, the types are also very rich, and the value of documents is very high, but there are acidification phenomena to varying degrees, and acidification has become a cause of damage to paper documents. biggest killer.

　　Prescription for medical examination and reexamination

　　Let's walk into the laboratory and see how to "deacidify"?

According to Zhang Yuzhi, an associate researcher, "First of all, we need to conduct a physical examination of the literature, test its pH value, and understand the degree of acidification."

　　In the paper cultural relics analysis room, technicians are systematically understanding the mechanical strength of paper through a series of experiments such as folding endurance, tensile strength, and tearing degree; The measurement of contact angle can understand the weight of sizing in the papermaking process, which will directly affect the rate of deacidification liquid entering the interior of paper fibers.

　　The magnification of an ordinary microscope is several hundred times, and the magnification of an electron microscope can reach one or two thousand times, or even 5000 times. You can clearly see the arrangement of paper fibers, the gaps between fibers, the aging and fracture of fibers, etc., and the energy spectrum analyzer ( EDS) combined, it is possible to know the type and relative content of the filler in the paper.

　　How to treat symptomatically?

Engineer Jiang Bi said that according to the characteristics of the paper, the books are placed in the soaking pool, and a special process is used to allow the deacidification liquid to enter the interior of the paper.

Then put it in a constant temperature and humidity laboratory. After the state is stable, a series of re-examinations will be carried out to verify the deacidification results.

In the laboratory, technicians are using a series of operations such as ultraviolet light, damp heat, and dry heat to make the paper sample quickly reach the aging state of 10 years, 20 years, or even 100 years later, and through simulated accelerated aging experiments and long-term hanging samples in the natural state In the experiment, the performance parameters of the paper were compared to test the deacidification effect.

　　It is reported that Nanjing Museum is one of the earliest units dedicated to paper deacidification in China, and has obtained a number of independent research and development patents. The solid and comprehensive preliminary research work has laid the foundation for the declaration of the 14th Five-Year key research and development plan project.

Zhang Jinping said, "Based on the characteristics of Chinese paper documents, we will solve the problem of acidification of Chinese paper documents as soon as possible."

　　Yangzi Evening News