Polyester resins resist fires

A Sabic Innovative Plastics product story

Edited by the Engineeringtalk editorial team Jun 20, 2007

GE Plastics' Valox thermoplastic polyester resin delivers better ductility and strength than other environmentally responsible flame-retardant PBT materials.

GE Plastics has released a new family of flame-retardant Valox thermoplastic polyester resins aimed at helping electrical/electronics (E/E) manufacturers and suppliers comply with regulations restricting use and disposal of hazardous substances.

Valox ENH resin meets the requirements for nonbrominated partsand is based on polybutylene terephthalate (PBT), delivering better ductility and strength than other environmentally responsible flame-retardant PBT materials, and better electrical properties than standard brominated flame-retardant PBT materials.

The European Union's (EU) Restriction of Hazardous Substances (RoHS) directive restricts the use of polybrominated diphenyl ether (PBDE), as well as other hazardous substances.

The Waste Electrical and Electronics Equipment (WEEE) directive requires OEMs and suppliers to remove plastic containing brominated flame retardants and treat it separately at end of life.

There are widespread concerns about the release of corrosive and/or toxic gases from brominated flame retardants during a fire.

GE's Valox ENH resins offer best-in-class flame retardance without the use of brominated or chlorinated additives, meeting the requirements of these and other environmental regulations.

"The development of this new Valox resin family is the result of our strong focus on environmentally responsible materials, particularly for the E/E industry, to help our customers to meet current and emerging regulations covering brominated additives, said Estelle Cheret, GE Plastics' global Valox Resin Platform Product Manager".

"GE's Ecomagination initiative continues to produce innovative solutions that support environmental protection while helping our customers deliver competitive products".

The first product in the Valox ENH resin family is ENH4550, a 25% glass-filled grade that will be commercially available in Q3 2007.

In addition to providing flame retardance that meets the UL94 V0 standard at 0.8mm, Valox ENH4550 resins will deliver excellent mechanical properties.

Improved ductility and strength mean fewer rejects during assembly and reduced breakage during use.

GE Plastics' new Valox ENH resin has a CTI (comparative tracking index) - the behaviour upon short circuiting or overheating - of 325V, compared to 200V for standard glass-filled brominated PBT.

The GE material also surpasses standard PBT in GWIT performance (glow wire ignition temperature), which measures the effect of heat from malfunctioning electrical equipment to determine at what temperature a material will ignite.

Valox ENH resins have a GWIT of 775C at 3mm versus 700C for standard glass-filled brominated PBT grades.

This new material is a good candidate for such applications as electrical connectors, relays, lamp sockets, and consumer appliances.

Another possibility is combining this new nonbrominated, nonchlorinated flame retardant technology with GE Plastics' existing Valox iQ resin, which would provide a full environmentally responsible solution for customers.

Valox iQ resins are derived from 85% post-consumer waste.

They consume less energy and yield less carbon dioxide (CO2) in their manufacturing than traditional resins.

This new nonbrominated flame retardant technology helps customers comply with WEEE and other environmental regulations.

This product will be commercially available in Q3 2007.