How do researchers know about aerosol filter plates?

At first, the researchers hoped to improve the June 4th gas mask, but the gas mask developed was only equivalent to the M-9 gas mask finalized in the United States in the 1940s. The researchers are not satisfied with this result, and think that it is necessary to catch up with the level of American M- 17 gas masks and equip the troops with satisfactory light gas masks.

However, how can we uncover the secret of American "vapor-aerosol filter plate"?

1962 One day at the end of August, Gao Fang of the Institute of Chemical Defense was looking for information in the library of the Chinese Academy of Sciences, looking for information from bundles of American patent specifications.

Suddenly, a title touched his sensitive nerve, "No gas mask".

Is this the patent of American M- 17 gas mask?

Gao Fang rubbed his dry eyes and looked at them carefully. "U.S. Patent No.29 10979", he quickly opened the page carefully and read it word by word.

With the accumulated rich knowledge, Gao Fang immediately decided that this was the patent of M- 17 gas mask just announced by the United States. In this patent specification, only the core part of the "vapor-aerosol filter plate" is briefly described.

However, from this extremely simple explanation, Gao Fang learned that it is a plate-like material, which is made by using the new technology of "non-woven fabric" developed rapidly abroad at that time, dispersing fine particles of activated carbon between cotton fibers, and then mixing and bonding chemical fibers with hot-melt fibers "Vesso" by hot pressing.

You can't find a place to get it, and it doesn't take much effort to get it!