| 摘要 |
Recoverability is induced into a material by a first expansion which is unidirectional but uniform, and then by a second expansion which produces pleats, and may increase in extent across the surface of the material. The material can be used to form pipe branch-offs, pipe bends or used as a tape for sealing pipe branch-offs or splice cases. A material for producing a branch-off comprises a first portion 1, and a second portion 2 which has been differentially expanded by pleating. The material is wrapped-around to form a tube; the portion 2 splays out to form a collar which can overly a hole in a main conduit, the portion 1 serving as a branch-off conduit. |
