| 摘要 |
PROBLEM TO BE SOLVED: To provide a silk burned product for various electromagnetic wave shielding materials which has flexibility, bulkiness, strength, and easiness to fabricate and is obtained by the carbonization of an industrial waste such as a waste cocoon, a silk rubbish and a silk nonwoven fabric or a powder for use only as a food additive produced by hydrolyzing a silk. SOLUTION: The silk burned product can be obtained by a method comprising a first low temperature vacuum burning and a second high temperature vacuum burning, wherein the first low temperature vacuum burning is carried out by a process that a raw material is held in a burning furnace for allowing a vacuum degassing method and burned under a vacuum degree of 1.8 Torr-10<-5> Torr at 285-420 deg.C for 60-480 min to eliminate a gas included within the raw material followed by cooling down to room temperature; and the second high temperature vacuum burning is carried by a process that the material thus obtained is burned again under the same vacuum degree at 1,000-2,300 deg.C for 60-1,200 min followed by cooling down to room temperature. |
