Cable materials--the competitive edge
George Kotelly
Senior Editor/Features
Buried in trenches, laid along the ocean floors, strung behind walls or hung on poles, fiber-optic cables are being installed worldwide in record numbers. For example, a study from Electronicast Corp. projects that the North American market for fiber-optic cables is expected to increase strongly, from $2.2 billion in 1994 to $4.8 billion in 1999, a 17% annual growth rate (see page 54). Another market study from Kessler Marketing Intelligence Corp. claims that during the past eight years, undersea cable suppliers have installed an amount of fiber-optic cable nearly equal to all of the copper cable installed over the 37 years from 1950 to 1987 (see page 56). Moreover, by 1998, almost 129 countries are expected to be connected to submarine lightwave networks.
And to meet the surging demand for fiber-optic cable, cable suppliers are increasing their investments in optical fiber and fiber-cable production plant expansion (see Lightwave, September 1995, page 1). More important, though, suppliers are also constantly researching and improving cable products and materials to stay market-competitive and to accommodate ever-changing optical communication technologies.
The operational characteristics of fiber draw accolades, but the unheralded cabling materials provide mechanical and environmental protection, ease optical fiber handling, promote connection and splicing access, and link the transmitter and receiver end-points.
Moreover, fiber-optic cable materials are constantly being formulated and strengthened to meet the challenge of enduring expected lifetimes of several decades of active and inactive usage. Forming layers of protection around the optical fibers, these materials comprise a range of plastics, coatings, gels, flame and water retardants, yarns, jackets, armors and dielectrics. Not surprisingly, therefore, each cable product material has evolved into a design specialty.
In recognition of these expert disciplines, the 44th International Wire and Cable Symposium in Philadelphia this month is initiating a third technical session track wholly dedicated to cable materials and their associated processing methods.
Likewise this month, Lightwave focuses its special report section on fiber and cable, covering a range of related topics. For instance, engineers from Siecor Corp. describe an outdoor dry-core loose-tube fiber-optic cable design that excludes the use of applying flooding compound but still prevents water penetration.
An advanced buffer-tube material made of a special thermoplastic resin blend that can withstand tighter bends, provide less stiffness and alleviate cable entry has been produced by investigators from Alcatel Telecommunications Cable.
Corning Inc. researchers are producing dispersion-shifted and non-zero dispersion-shifted fiber to accommodate both the building of new networks and the upgrading of existing ones.
And, lastly, scientists at Ericsson Cables AB have overcome the shortcomings of existing polarization-maintaining fiber alignment and splicing techniques by designing an advanced azimuth and transverse alignment method and incorporating them into an automatic-operating fusion splicer.
For fiber-optic cable manufacturers, material formulations and their distinctive processing procedures often constitute the core technologies that help gain competitive market advantage.