BLOW MOLDING: Foamed PET Bottles for Beer

 WEB EXCLUSIVE: Now the foam isn’t just on top of the beer, it’s all around it.


WEB EXCLUSIVE: Now the foam isn’t just on top of the beer, it’s all around it. Plastic Technologies, Inc. (PTI), Holland, Ohio, is making its novel oPTI lightweight foamed PET blow molding process available for beer bottles. The process can be used to produce monolayer PET foam bottles (gray bottle in picture) or a combination of a foamed layer and a standard solid PET layer. The blue bottle in the picture has a foamed layer inside and solid, pigmented layer outside. The brown bottle has a solid, amber PET layer inside and foamed layer outside. Dual layers allow customization of barrier properties: For example, oxygen barrier could be added to the inner layer and a carbon dioxide barrier to the outer layer. The foaming process reportedly allows up to 5% lightweighting without significant loss of performance, and it opens the door to new optical and tactile effects.
            Launched at NPE 2009, PTI’s oPTI process is based on preforms injection molded with the MuCell microcellular foam process from Trexel, Inc., Woburn, Mass. It involves injecting pressurized nitrogen gas into the injection barrel. The preforms reportedly can be blow molded on standard, unmodified stretch-blow machines. The oPTI process can also be used with PEN and PLA resins.

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NPE 2009 Wrap-Up: New Machinery for Blow Molding

Several new developments include a brand-new compression blow process, the first foamed PET bottles, and a preform decontamination approach for aseptically filled products sold at ambient temperature. Attendees also saw a new stack-mold Multi-Parting Line concept that doubles bottle output within the same machine footprint. (Additional NPE blow molding news appeared in May and June—see Learn More box.)