Highly flame-retardant UTP cable
A highly flame-retardant UTP cable may have a plurality of pair units formed by a plurality of conductive wires twisted together, wherein each conductive wire includes a conductor, an insulator surrounding the conductor, an outer jacket surrounding the plurality of pair units, and a separator including one or more partition walls disposed between the plurality of pair units, wherein any cross-section of the cable has a cross-sectional limited oxygen index, of 57% or more.
1 . A highly flame-retardant UTP cable comprising:
a plurality of pair units formed by a plurality of conductive wires twisted together, each including a conductor and an insulator surrounding the conductor;
an outer jacket surrounding the plurality of pair units; and
a separator including one or more partition walls disposed between the plurality of pair units,
wherein any cross-section of the cable has a cross-sectional limited oxygen index, as defined by Equation 1 below, of 57% or more,
Cross-sectional limited oxygen index (%)= a /( a+b+c )×α+ a /( a+b+c )×β+ a /( a+b+c )×γ [Equation 1]
In Equation 1 above,
a is a cross-sectional area (mm′) of an insulator,
b is a cross-sectional area (mm′) of a separator,
c is a cross-sectional area (mm′) of an outer jacket,
α is a limited oxygen index (LOI) of a material that forms the insulator,
β is a limited oxygen index (LOI) of a material that forms the separator, and
γ is a limited oxygen index (LOI) of a material that forms the outer jacket.
2 . The highly flame-retardant UTP cable of claim 1 , wherein the cable has a maximum combustion length of 1.52 m or less, a maximum smoke density of 0.5 or less, and an average smoke density of 0.15 or less as measured by a plenum flame-retardant test for which certification is given by UL based on NFPA 262 standard.
3 . The highly flame-retardant UTP cable of claim 1 , wherein the cross-sectional limited oxygen index as defined by Equation 1 is 57 to 68%.
4 . The highly flame-retardant UTP cable of claim 1 , wherein the insulator includes a fluoropolymer having a limited oxygen index (LOI) of 90% or more.
5 . The highly flame-retardant UTP cable of claim 4 , wherein the insulator includes a fluorinated ethylene propylene (FEP) resin.
6 . The highly flame-retardant UTP cable of claim 1 , wherein the separator is formed from a flame-retardant polyolefin resin composition having a limited oxygen index (LOI) of 38 to 45%.
7 . The highly flame-retardant UTP cable of claim 6 , wherein the flame-retardant polyolefin resin composition includes a polyolefin resin and a thermoplastic polyolefin elastomer resin as a base resin, and includes a metal hydroxide as a flame retardant.
8 . The highly flame-retardant UTP cable of claim 7 , wherein the content of the flame-retardant is 200 to 270 parts by weight, based on 100 parts by weight of the base resin.
9 . The highly flame-retardant UTP cable of claim 1 , wherein the outer jacket is formed from a flame-retardant polyvinyl chloride (PVC) resin composition having a limited oxygen index (LOI) of 44 to 57%.
10 . The highly flame-retardant UTP cable of claim 1 , further comprising:
a ripcord inside the outer jacket to facilitate removal of the outer jacket.