New PET grade good for extrusion blowmolding and recycling

By MPW Staff
Published: January 21st, 2010

A new grade of PET from supplier Invista is said to successfully straddle multiple challenges for the material: it can be extrusion blowmolded and also is suitable for recycling via the standard clear PET recycling stream. Jeff Wardat, business development manager at the supplier, will officially introduce the new grade at the Nova-Pack 2010 Conference on PET Containers for Food & Beverages in two weeks

What’s the big deal? Well, the preferred material for clear containers with handles today is glycol-modified polyethylene terephthalate (PET-G), an amorphous polyester sufficiently different from PET that it can present a challenge to the regrind and clear PET recycling process. Standard PET is fine for blowmolding of transparent containers via single-or two-stage stretch blowmolding, but does not have the melt strength required for extrusion blowmolding. If handleware need not be transparent, then it usually is extrusion blowmolded from high-density polyethylene.

Invista says its new material provides the required melt strength for extrusion blowmolding, and that containers processed from the material can be tossed into standard transparent PET recycling streams.

The new, modified PET can be processed at temperatures and conditions similar to standard PET and simultaneously provides the required melt strength. It has a higher melt temperature that standard PET, so processors may need to make some modifications to existing extrusion blowmolding equipment. The ability to recycle the new grade in the clear PET stream has been demonstrated according to the APR Critical Guidance protocol.

Crystal-clear containers with handles, which can be recycled in the clear PET stream, could be attractive to brand owners who have stood with HDPE for these applications, sacrificing clarity for a material that is easily recycled.

Wardat will spell out the details and benefits of this new development at the conference, to be held February 9-10, 2010 at the Waldorf Astoria Orlando Hotel in Orlando, Florida. More information on the event can be found here. —mpweditorial@cancom.com Source plasticstoday.com

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