| 摘要 |
337,200. Brßzay, Z. Dec. 5, 1928, [Convention date]. Tobacco pipes etc.; cigarettes.-A filtering-wad for use in tobacco pipes and cigar or cigarette holders, or for insertion into the tip of a. cigarette, is produced by subjecting cellulose, cottonwool, filter paper, or other fibrous material to diluted sulphuric acid, heating sufficiently to carbonize the fibres on the outer surface, and then impregnating with a heavy-metal salt, such as iron chloride, or other material adapted to bind the nicotine, for example citric, tartaric, or tannic acid. Small cylindrical bodies are then formed of the material to constitute the wad. The sulphuric acid remaining after carbonizing is neutralized by a current of ammonia gas. |
