Neoprene Frozen Drum-rotating 's Manufacture

　　The neoprene is a aging-fast, heat-resistant, burningproof and cauterzation-resitant material, it is also the sealed cable's main material of leather products, electronic, telecom, automobile, spaceflight, shipbuilding and other new and high-tech field. With the economic development, the demand for neoprene becomes larger and larger, at present, the price is increasing and the parts of them have to import.

　　Frozen drum-rotating is the key part of neoprene's after process, it is made by pure nickel so the material is expensive. The part's size is big, the diameter reaches +ф2740mm, the length is 2740mm, the precision requirement is quite high.

　　At present, only Shangxi Chemical Plant, Changshou Chemical Factory and Tsingdao Chemical Branch Plant respectively introduced the frozen neoprene producing method from American Dupont from 1985 to 1986. According to the investigation made by Shanxi Chemical Plant and the information we master, the frozen technique and equipment of Dupont is still taking the leading position, the importing price is over RMB 6,000,000yuan, the customs duties and freightage is not included.

　　Three years ago, the Eighth Design Institute of the Ministry has analyzed the technical requirement of drum technique and made a national and international investigation, a conclusion is made that our nation still can not make frozen drum so it has to be imported.

　　In December, 1994, we formally accepted the commission of Shanxi Chemical Plant to trial-manufacture frozen drum-rotating.

　　During the manufacture process of the drum-rotating, not only the molding, but also the jointing, the processing is quite difficult. Since the drum did not reach the technical request, for example, the surface jointing is visible, so it has to be processed finish machining, because there is no grinder in our nation can reach the 3m diameter grinding so the grinding can not be made. Guanjie Company took the project to process the surface's finish machining, to improve the surface's coarseness degree as well as to ensure its geometrical precision, through Guangjie's effort and repeating experiments, it has been passed the Shangxi Chemical Plant's spot inspection, Guangjie earned precious experience in doing the high precision big article polishing work.

Technology Development Department, Beijing Chemical Machinery Factory 　　　　　　　　　　　 October, 1995

Beijing Guangjie Machinery Co., Ltd.:

　　The biggest vacuum container inside surface polishing project, heavy task, short time limit, high technical difficult, it is the key equipment to develop our nation's spacefight technique. We retain your company to attend the project container polishing project, there are almost 3,000 square meters polishing, seal's research and development task. The project is made in short time and the quality requirement is high You company joined the battle, accomplish the task successfully and got high praise from the leaders of Commission of Science, Technology and Industry for National Defense, the Spaceflight Industry Company. Especially the principal, Mr. Gao Chao, puts up his dedication spirit to our nation's defense cause, leads the company's stuff working day and night and fulfill the task in time.

　　As the general contractor and research unit, we give our sincere appreciation to your company. At March 19, 1997, it has passed the first taking out inspection, it is the first time for such big project that passed the inspection at the first time, this proved that the quality is perfect. The achievement belongs not only to us, but also to you, so here we give our congratulation and appreciation to you!

　　　　　　　　　　　　　　　　　　　　Harbin Institute of Technology