A European scientific panel has given its approval to a pair of industry proposals related to recycling PET into food packaging.
In one opinion, the “Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids” (CEF), a panel of the European Food Safety Authority (EFSA), approved the use of two chain-extender additives in recycled PET destined for food packaging. Specifically, the panel concluded the use of a mix of tetraethyl orthosilicate (TEOS) and hexamethyldisilazane (HMDS) “does not raise a safety concern for the consumer” if limited amounts are used.
In a different decision, the CEF approved the use of Starlinger & Co. technology to recycle post-consumer PET containers into drink bottles and food trays at up to 100 percent recycled content.
In the European Union, recycled plastics and additives in those plastics can only be used in food packaging if the EFSA says they’re safe. Under EU law, recycling companies submit applications to individual countries, which apply to the EFSA on their behalf.
Chain-extender additives
CEF approved the use of TEOS and HMDS when mixed at a ratio of 97:3 and when limited to a maximum of 0.12 percent by weight in recycled PET.
The TEOS/HMDS additive mixture extends the polymer chains and increases molecular weight in recycled PET. Recycled PET has a lower molecular weight than virgin PET.
The review request came from Czech Republic-based company Plastics Technologies and Products (PTP Group) and was passed through the Netherlands government. PTP Group intends to use the technology in packages holding food at room temperature or up to about 160 degrees Fahrenheit.
In reaching their decision, scientists analyzed the residual content of the substances in recycled PET and the substances were not detected in a test that would have been able to find 4 one-thousandths of a milligram per 6 square decimeters, according to the EFSA. And, in a migration study, recycled PET incorporating the additives was compared to virgin PET without the additives and they were found to be identical.
PTP Group was founded in 2002 with the goal of commercializing a proprietary PET recycling process, according to the company. Recycled resins created by the company’s technology are used in the U.S., Europe and Asia, and they’re molded into bottles and thermoforms at up to 100 percent recycled content levels. California-based Verdeco Recycling was the first to begin licensing and using the technology, called PET-M, in the Americas.
Starlinger IV+ technology
CEF also gave the nod to a proposal to use Starlinger IV+ technology to recycle PET into beverage containers and other packaging.
Germany submitted the application on behalf of two companies: Morocco-based Sumilon Eco PET and Bulgaria-based ITD. The companies propose to take washed and dried PET flake from containers collected curbside and through deposit systems and recycle the material into pellets ready for molding into new packaging.
In the Starlinger IV+ system, flakes are dried and crystallized in a reactor under air using high temperature at atmospheric pressure. Next, they’re extruded into pellets under vacuum at high temperature and then re-crystallized. Lastly, the crystallized pellets are pre-heated before they’re sent to a continuous-running solid state polycondensation reactor at high temperature and under vacuum.
CEF found those steps reduce contaminants to below 0.1 billionth of a kilogram per kilogram of food. It also noted the stream should contain no more than 5 percent PET from non-food containers, which could include soap and mouthwash bottles.