A Light, Durable and Flexible Core
Modernized material science x Sophisticated stranding technology. CFCC‘s characteristics far exceed conventional cables, such as high strength, high elasticity, light weight, high corrosion resistance, non-magnetism, and low linear expansion plus practical handling performance and flexibility.
What Is CFCC made of?
CFCC stands for Carbon Fiber Composite Cable and is produced by forming a compound of carbon fibers (of approx. 7µm dia.) and thermosetting epoxy resin into a stranded shape. The resins used in CFCC are among the toughest available and can resist operation temp. up to 200° .
  • Uni-directional carbon fibers stranded in a themoset epoxy resin matrix.
  • Carbon fiber grade is T-700 or higher. Each strand consists of 12,000 filaments.
  • Protection layer:overlapping wraps of polyester yarn cover each strand for mechanical and electrical protection
  • CFCC has almost no thermal expansion with increased temperature, resulting in much lower sag of ACFR conductors at high temperature operation as compared to standard conductors.
High Grade Carbon Fiber
Carbon Fiber Composite Cable
Aluminum Conductor Fiber Reinforced
Cross-section of CFCC® by digital microscope
Protection layer: overlapping wraps of polyester yarn (0.05㎜)
Why is CFCC® stranded?
The stranded construction has, due to the interstices, fewer carbon fibers as compared to a same-diameter pultrusion rod. This results in a slightly lower rated strength, but the important advantages are:
  • Structural redundancy: Multi-stranded design avoids single-point-of-failure
  • Flexibility: Multi-stranded design allows greater bending before damage
  • Less bending stiffness
  • Much better damage tolerance
  • Practical handling characteristic
  • Compatibility with conventional compression type fittings
7 free moving strands → Stress distribution → Increased flexibility
Avoids single-point of failure
Figure 1: Close-up of Bent CFCC®
Figure 2: Stress Distribution on CFCC®
CHARACTERISTICS OF CFCC®
Lightweight:
About 1/5 weight of steel strands.
Flexible:
Flexible and structurally redundant.
High Corrosion Resistance:
CFCC's added corrosion resistance is superior to steel and the alkali corrosion resistance is the same as steel. After 3 years+ exposure in acidic soil with pH range or 2.25-2.5 at 60-100°C, no reduction of tensile strength of CFCC, nor visual deterioration, was observed whereas conventional steel wire deteriorated severely.
The acid resistance of CFCC® exceeds that of steel wire, and the alkali resistance is equivalent to that of steel wire. As a result of conducting an exposure test on CFCC® (12.5 mm diameter) and steel wire for three years in an acidic soil environment with a pH value of 2.25-2.50 (60-100℃), it was found that the steel wire had a noticeable decrease in tensile strength due to corrosion. However, no deterioration in appearance or decrease in strength was observed in CFCC.
Non-Magnetic /No Iron Loss:
CFCC is made from carbon fibers and thermoset epoxy resin, thus, it is non-magnetic (not magnetically permeable). Unlike steel core, since a magnetic field is not created, no iron loss occurs at the core when the conductor is energized
CFCC® is a non-magnetic composite cable made of carbon fiber and epoxy resin, and because it is not magnetic like steel, it does not generate iron loss (electrical energy lost when magnetized) when energized.
Material Relative magnetic permeability
CFCC Below 1.000
Non-magnetic PC steell wire (18Mrs steels) 1.002
Steel wire 1,200,000
*Values less than 1,000 were immeasureble due to limitation on equipment.
Low Coefficient of Linear Thermal Expansion:
The coefficient of linear thermal expansion for CFCC is less than 1/10 of steel, resulting in much lower sag when the line is energized and the conductor is running hot (The resin used for CFCC can resist up to 200°C)
The coefficient of linear expansion of CFCC is approximately 1/10 that of steel, and it does not elongate even in high-temperature environments, so CFCC suppresses the slack of ACFR wires due to thermal expansion. The resin used in CFCC® can be used in a temperature environment of ~200℃.
Material Coefficient of linear expansion
CFCC 1.0 × 10*/°C
Steel wire 11.5 × 10*/°C
High Tensile Strength and Modules of Elasticity:
Specimen:   Stranded CFCC 1×7-12.5mm dia.(for Civil Eng.)
Tensile strength:   1.4 - 2.1kN/mm2(Equal or greater than steel.)
Modulus of Elasticity:   137kN/mm2
High Tensile Fatigue Resistance:
The graph shown below indicates that CFCC is durable after 2 million stress cycles. The fatigue limit of CFCC is 300N/mm2 whereas it is 100N/mm2 for steel wire
Low Relaxation:
Expected relaxation for initial tension (65% RTS) of CFCC after 10^7 = 10.000,000 hours = 114 years is less than 3%. Increase in sag of the conductor by relaxation of CFCC core is minimum.
Specimen:   Stranded CFCC 1×7-12.5mm dia.
Load:   92.4kN(65% Rated tensile strength)
Temperature:   22°C
Small Creep Elongation:
CFCC‘s creep elongation is almost equal to the low creep type steel wire. Creep elongation of CFCC under the following load after 1,000 hours is 0.068%
The creep elongation of CFCC® loaded for 1,000 hours under the following conditions is 0.068%. It is smaller than other FRPs such as glass fiber and aramid fiber, and is comparable to steel cables.
Specimen:   Stranded CFCC 1×7-12.5mm dia.
Load:   92.4kN(65% Rated tensile strength)
HISTORY OF CFCC® AND DEVELOPMENT OF ACFR®
Tokyo Rope International is globally the first company to develop the "stranded" carbon fiber composite material as a tension bearing member. Our CFCC® was initially developed as a non-corrosive reinforcing member for civil construction, such as prestressed concrete piles, ground anchors and external cable for bridges in corrosive environments. After years of extensive R&D, the world's first carbon fiber composite conductor developed by TRI was installed in 2002 in Japan. Our objective was to develop a conductor that could be used to upgrade existing transmission corridors without structural modifications as to provide solutions to the utilities common constraints of ROW and the time-consuming process of building a whole new line. Incorporation of highly sophisticated stranding technologies and materials science enabled us to develop CFCC®, a new higher-strength, flexible, lighter-weight, and structurally-reliable tension bearing component of high-temperature Low-sag conductor that could incorporate additional conductive aluminum without a weight or diameter or handling characteristic penalty.
Tokyo Rope is the world's first company to develop carbon fiber composite stranded cables. CFCC® was originally developed for non-corrosive reinforcement applications in civil engineering applications such as prestressed concrete piles, ground anchors, and bridge external cables in corrosive environments. After many years of extensive research and development since the 1980s, in order to apply CFCC®, which has features superior to conventional cables, to overhead power transmission lines, in 2002 we developed the world's first cable using CFCC® as a core material. Carbon fiber core overhead power transmission line ACFR® has been put into operation in Japan, and since 2012 it has also been adopted in transmission lines in countries overseas where demand for electricity is increasing significantly. Our goal was to create a new generation power transmission line that would allow for upgrades in power transmission efficiency while retaining the same wire support structure, as well as a new generation of power transmission lines that were lightweight and had increased aluminum properties, and that could be applied using conventional construction methods. ACFR® - CFCC® was developed using "Total Cable Technology" which combines our long-cultivated twisted wire technology with the latest materials science.

CFCC® was initially developed as non-carrasize low-relaxation reinforcing member for civil construction in 1980's

Kitakami CFCC® Production facility
Michigan CFCC® Production facility (USA)
Standard Characteristics & Specification of CFCC®