| 摘要 |
A heat-expandable laminate contains highly elastic reinforcing fibres like glass fibres in the elastically compressed state and a thermoplastic duromer synthetic material as the binder. To manufacture this laminate, glass fibre mats are first impregnated with a duromer synthetic material (a ''plastic''), one or more of such mats are superimposed and compressed in a press and taken to temperatures at which the plastic softens and the assembly is then cooled in the compressed state so that the plastic re-hardens and forms the finished laminate. The expandable laminate is preferably used for electrically insulating spacers. To this end, for example, a section of laminate (7) is fitted between neighbouring coil parts (5) of a stator of a high-voltage machine. During the subsequent ordinary vacuum-pressure impregnation of the stator to complete the coil insulation, the laminate sections (7) are heated by the hot impregnating agent, whereupon the plastic of the laminate sections softens and expands as the stress on its elastically compressed fibres is relieved, thus completely filling the interstices between the coil parts (5). The impregnating agent filling the pores of the laminate is then cured together with the plastic of the laminate and the stator insulation. |
