E-glass fibre meets electrical industry demands

Edited by the Engineeringtalk editorial team Apr 6, 2005

A new single-end Type 30 roving meets demanding electrical requirements for such pultruded FRP applications as medium- and high-voltage transmission and distribution long-rod insulators.

At the JEC Composites Show, Owens Corning introduced SE 8400 LS, a new single-end Type 30 roving to meet the demanding electrical requirements for such pultruded FRP applications as medium- and high-voltage transmission and distribution (T and D) long-rod insulators.

SE 8400 LS combines the anticorrosion, electrical and mechanical benefits of boron free Advantex E-glass manufactured using state-of-the-art glass melting technology and advanced low-seed filament technologies, ensuring seed levels well below 0.5 seeds per gram.

Minimising microscopic bubble voids or "seeds" in the glass avoids the formation of hollow filaments, which increase conductance, offering the path of least resistance to the electrical energy, and causing system failure.

The properties of SE 8400 LS single-end Type 30 roving offers not only the required exceptionally high electrical resistance from low seed production but also: higher corrosion and temperature resistance of Advantex over conventional E-glass, reducing brittle fracture failure; quicker processing than alternatives owing to fast wet-out in polyester, vinyl ester and epoxy resins; low migration for improved wet-out and glass to resin bonding; improved flashover resistance in highly polluted areas; high mechanical strength (weight ratio); and greater design flexibility and overall system costs reduction.

"While the industry has been working with nonceramic insulators for several years, developing and ensuring the consistent manufacture of a noncorrosive, boron-free glass with seed counts well below 0.5 seeds per gram has been the 'tipping point' level this marketplace needs to transform to a new technology and SE 8400 truly delivers that solution", said Wisdom Dzotsi, Owens Corning Global Product Manager, T30 Direct Roving.

After extensive beta testing, customers agree.

"Avoiding moisture ingress has been and will continue to be the first line of defense in preventing brittle fracture".

"Brittle fracture is a primary concern of the utility engineer when evaluating the use of composite insulators", said James Schmiedeknecht, VP International Sales and Marketing at MacLean Power Systems.

"The major insulator manufacturers have paid particular attention to sealing the end fitting of the FRP rod, silicone rubber housing junction and several have designed redundant seal systems".

"The use of boron free glass fibres has been a long acknowledged means of preventing brittle fracture if an insulator's housing has been breached".

"However, earlier generations of boron free fibres had seed count levels that were too high and wouldn't consistently pass qualification tests mandated by insulator standards", continued Schmiedeknecht.

"Owens Corning has solved that problem with their Advantex corrosion resistant E-glass fibre that is low in seed count".

"Insulator manufacturers like MacLean Power Systems can now take full advantage of boron free glass fibres and also have wicking performance comparable to standard E-glass".

"MacLean Power Systems can now offer the utility engineer that extra margin of safety at a relatively low incremental cost", Schmiedeknecht concluded.

Owens Corning SE 8400 LS roving is available in 113 yield (4400 TEX), 103 yield (4800 TEX), and 52 yield (9600 TEX).

The 52 yield requires fewer ends of roving to produce a part of equal glass content, a significant advantage for pultrusion manufacturers with building or creel sise restrictions, who wish to produce larger parts.