The present invention proposes a B1-class
halogen-free, low-
smoke,
flame-retardant special cable and its preparation method. The cable comprises: a cable core formed by wrapping a control core and a power core, a
flame-retardant filling
rope, a wrapping layer, a
flame-retardant tape layer, a total shielding layer, a
ceramic fireproof layer, and an outer sheath. The present invention uses a cross-linked
polyethylene sheath to form an outer layer of protection, a
ceramic fireproof layer to form an intermediate shell flame-retardant
insulation layer, and a flame-retardant tape layer combined with expandable
graphite as an inner layer of buffer insulation, thereby achieving multiple flame-retardant insulation for the cable core, inhibiting the release of burning drips and toxic
smoke with
corrosion, and meeting and exceeding the B1-class flame-retardant requirements. By using low-
smoke,
halogen-free materials, the release of toxic gases can be reduced during
combustion. At the same time, a double-layer
hardness flame-retardant filling
rope is twisted in the core to make the cable more round as a whole, and to allow the flame-retardant material to be fully filled into the cable core, achieving a better flame-retardant effect, and having certain buffering, compression resistance, torsional resistance, and
fatigue resistance effects, thereby improving the mechanical properties of the cable.