Laminate electrical insulation part
View Patent ↗This invention relates to a laminate electrical insulation part for an electrical device comprising a thermoplastic film positioned between, adjacent to, and attached to two nonwoven sheets. Each of the nonwoven sheets consists of multicomponent polymeric fibers comprising at least a first polymer and a second polymer, the first polymer having a melting point that is at least 15 degrees Celsius lower than both the melting point of the second polymer and the melting point of the thermoplastic film, and the film is attached to the nonwoven sheets by the first polymer in the nonwoven sheets. The electrical insulation part has a breakdown voltage of at least 3 kilovolts, and a surface having a dynamic frictional coefficient of 0.25 or less. This invention also relates to an electrical device component comprising the laminate electrical insulation part.
1. A laminate electrical insulation part for an electrical device
comprising:
a thermoplastic film positioned between, adjacent to, and attached to two nonwoven sheets, each of the nonwoven sheets consisting of multicomponent polymeric fibers comprising:
at least a first polymer and a second polymer, the first polymer having a melting point that is at least 15 degrees Celsius lower than both the melting point of the second polymer and the melting point of the thermoplastic film; the thermoplastic film attached to the nonwoven sheets by the first polymer in the nonwoven sheets, and
wherein, the electrical insulation part has a breakdown voltage of at least 3 kilovolts, and a surface having a dynamic frictional coefficient of 0.25 or less, with the proviso that a fiber of the multicomponent polymer fibers is a bicomponent fiber and contains the first polymer and the second polymer in either:
(i) a sheath core arrangement with the sheath including the first polymer and the core including the second polymer or,
(ii) a side-by-side arrangement.
2. The laminate electrical insulation part of claim 1 , having a Normalized Stiffness Index of at least 30.
3. The laminate electrical insulation part of claim 1 wherein, the thermoplastic film is attached to each of the two nonwoven sheets to the same degree.
4. The laminate electrical insulation part of claim 1 , in the form of a slot liner.
5. The laminate electrical insulation part of claim 1 , in the form of a closure, a wedge or a stick.
6. The laminate electrical insulation part of claim 1 wherein, the thermoplastic film is a polyester film.
7. The laminate electrical insulation part of claim 1 wherein, the thermoplastic film has an initial modulus of at least 0.8 GPa.
8. The laminate electrical insulation part of claim 1 wherein, the first or second polymer is polyester.
9. The laminate electrical insulation part of claim 1 wherein, the first polymer is a copolymer or terpolymer and the second polymer is a homopolymer.
10. The laminate electrical insulation part of claim 1 wherein, the multicomponent polymeric fibers have a sheath/core construction with the sheath including the first polymer and the core including the second polymer.
11. The laminate electrical insulation part of claim 1 wherein, the multicomponent polymeric fibers have a side-by-side construction with one side including the first polymer and the other side including the second polymer.
12. The laminate electrical insulation part of claim 1 wherein, the multicomponent polymeric fibers are continuous filaments.
13. An electrical device comprising the laminate electrical insulation part of claim 1 .