| 摘要 |
PROBLEM TO BE SOLVED: To obtain an expanded graphite sheet that is provided with water- and moisture-absorptivity to greatly reduce its coefficient of friction and sliding resistance, and secures an excellent sealing performance, by setting a contact angle of at least one side of the expanded graphite base, consisting of expanded graphite particles pressed mutually to form a monolithic body, with water at a given level or lower. SOLUTION: This expanded graphite sheet allows water dropped thereon to be absorbed in a short time into the sheet, when it has a contact angle θwith water of 85 deg. or smaller. It is therefore possible for water to be absorbed easily into the sheet to realize a frictional condition close to boundary lubrication, so long as the sheet is operated under a condition containing a small quantity of water, thus reducing sliding resistance of the sheet, when it is used as a packing or sliding member. Moreover, the sheet working, e.g. as a sealing material, can absorb water which penetrates into its voids without leaking it, to increase sealing face pressure and stress conversion coefficient by swelling action of the absorbed water, allowing itself to exhibit an excellent sealing performance by a low clamping pressure. |
