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October 1, 2006

3 Min Read
GE produces virgin PBT from recycled PET

GE Plastics (Pittsfield, MA) has announced a new chemical process for breaking down PET waste and incorporating it as a primary feedstock into virgin polybutylene terephthalate (PBT) and polycarbonate (PC)-PBT compounds.

GE says the Valox iQ (PBT) and Xenoy iQ (PC-PBT) resins are composed 85% by volume from recycled PET, and in terms of broader environmental impact, the materials would reduce CO2 emissions by 1.7 kg per kg of resin; save up to 8.5 barrels of crude oil per 1000 kg/resin; and offer an outlet to 562,000 tonnes/yr of PET waste.

GE’s Tim Dummer, market director for automotive new market business, told MPW the technology is far removed from traditional recycling, and the materials it creates are equally divergent from existing reclaim resins.

Largely a mechanical process, traditional recycling involves the sorting, cleaning, shredding, and pelletizing of PET, a process which can degrade mechanical properties, forcing PET used in bottles, for example, to devolve to lower-tier applications like strapping in its next life.

GE’s process breaks the PET back down to its original building blocks on a chemical level, creating materials with equivalent performance to first-generation petroleum or natural gas plastics.

Full circle

PBT is normally composed of two different chemical feedstocks: butanediol (BD) and dimethyl terephthalate (DMT) or terephthalic acid (TPA). In the iQ resins, the DMT or TPA is replaced with the post-consumer PET feedstream, so that GE starts with primarily scrap and ends up with a virgin resin. Dummer said to think of it as a new way to make PBT, not a new PBT, which means the iQ portfolio can seamlessly replace PBTs in the field.

For now, the post-consumer PET will be processed from one Asian location and distributed globally to Xenoy and Valox compounding and manufacturing sites. GE won’t discuss production volumes, but did say the materials are viable replacements for PBT in automotive, with Japanese supplier Denso showing interest. Applications could include connectors, bumper energy absorbers, and possibly aesthetic parts like instrument panels. Dummer puts the total global market for PBT at 600,000 tons, with automotive making up one-third of that total.

Given the sector’s potential size, Dummer said GE only moved forward when it was clear an adequate PET supply stream existed.

“It’s only really today that we see the availability of a feedstream like PET in a way that we feel comfortable enough to go out and build a significant business on it,” Dummer says. “You can go back as little as five years, and that just wouldn’t have been possible.”

GE has agreements with a number of undisclosed post-consumer PET vendors for that supply, which should be ample. In 2005, according to the National Assn. for PET Container Resources (NAPCOR; Sonoma, CA), 1.003 billion lb of PET were collected in the U.S., the largest PET market globally, representing a recycling rate of 21.6%.

GE didn’t address pricing, but said the materials offer environmental and engineering advantages, which will be reflected in its cost while still being competitive with traditional PBT and PC-PBT blends. In terms of further recycling, GE officials said if a clean stream of the Xenoy and Valox iQ materials was created, the materials could be regenerated multiple times.

GE is also working with its other proprietary polyester chemistries to create a thermoplastic elastomer (TPE). Using a thermoplastic polyether polyester copolymer structure, the iQ-based TPEs would have high-heat and continuous-temperature performance. The company is also considering pairing the iQ PBT with a biobased resin like polylactic acid, and eventually using a corn-derived chemistry to create the BDO used in PBT for a material that is 100% green.

Tony Deligio | [email protected]

Contact information

GE Plastics www.geplastics.com

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