| 摘要 |
Encapsulating- or bulkhead- wall resistant to arcing and used for enclosing electrical switchgear. The wall has a laminated structure consisting of >=1 outer carrying layer (a) with a noncombustible, fire-protection layer (b) of mica with a binder.Layer (b) pref. used expanded mica, esp. expanded muscovite mica with grain size of 1-10 mm, the binder being a material which evolves a noncombustible gas on heating, e.g. a melamine resin, or a pressure-setting plastic. Layer (b) is pref. thicker than layer (a), which is pref. Al; an Al alloy; steel sheet; or hard paper.This wall causes the arc to wander, and layer (b) evolves gases which cause rapid extinction of the arc.
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