| 摘要 |
<p>A stopper (20, 44) for holding fluid (31, 43) in a container (30, 40) comprising: (a) a body of vulcanized elastomer having a convex surface (23, 45) and (b) a thin layer of thermoplastic (26) providing a surface for contacting the fluid (31, 43) and a part of the container (30, 40) and laminated without adhesive to a surface of the vulcanized elastomer (47). Also a method for making a stopper (20, 44) to hold fluid (31, 43) in a container (30, 40), said stopper (20, 44) having a thin layer of thermoplastic (26) laminated without adhesive to form a surface intended to contact the fluid (31, 43), comprising: (a) providing a first mold half (10) having a concavity (11, 11") and a second mold half (14) opposite the concavity (11, 11"), (b) disposing a sheet of thermoplastic (16) between the mold halves (10, 14) and vulcanizable elastomer (17) between the thermoplastic (16) and one of the mold halves (10 or 14), the thermoplastic (16) having an elongation of at least 450% and a crystalline melting point higher than the minimum vulcanizing temperature of the elastomer (17), (c) heating the mold halves (10, 14) to a temperature that is within the softening range and below the crystalline melting point of the thermoplastic (16) and above the minimum vulcanizing temperature of the elastomer (17), (d) pressing the heated mold halves (10, 14) toward each other with pressure sufficient to force elastomer (17) into the concavity (11, 11") while simultaneously forming thermoplastic (16) against the surface of one mold half (10 or 14), (e) holding the mold halves (10 and 14) in pressed position for a time sufficient to vulcanize the elastomer (17), and (f) removing the so-formed stopper (20, 44) from the mold. </p> |
