Mon, Mar 13th 2017 04:45 pm
AURORA, Ill., February 20, 2017 - Processing Technologies International (PTi), a leading global manufacturer of high-performance sheet extrusion machinery,has released the findings of an
independent study which reaffirms FDA guidelines for the use of virgin PET cap
layers as functional barriers over Post-Consumer Recycled Non-Letter of No
Objection (hereinafter referred to as PCR) PET flake materials for direct food
packaging use at room temperature. The
study, which was completed in conjunction with Plastic Technologies Inc.,
Holland, Ohio, and Container Science Inc., Atlanta, Georgia, found that a
1-mil-thick virgin PET cap layer meets the necessary functional barrier
requirements, eliminating surface contaminates within multilayer food packages
made of PCR PET materials for room temperature (70°F/21°C) applications. PTi presented these
findings in December at the Extrusion 2016 conference, sponsored by Plastics
This study was prompted by a recent 2016 European industry report by Dr.
Frank Welle of the Fraunhofer Institute, "Assessment of Recyclates behind
Functional Barriers", that questioned the efficacy of an ABA structure with PET
recyclates behind a functional barrier and suggested that the virgin cap layer may
become contaminated during extrusion, rendering the functional barrier
inadequate. The European report findings were based on
testing of recycled PET packaging at elevated use temperatures as high as 212°F/100°C (Welle, 2016), which is not in keeping with guidance stipulated
by the FDA recommendation (i.e.; room temperature and below) using a minimum of 1 mil thick virgin PET cap layer
to encapsulate the PCR PET materials for direct food contact packaging
applications (FDA, 2006).
set out to examine the elevated application temperature relevance used as part
of the Fraunhofer Assessment and reaffirm virgin PET for suitability as a functional
barrier and its corresponding FDA guidelines.
Our simulation results demonstrate that a 1-mil virgin cap layer is
adequate protection for a PET food package when used at room-temperatures,"
said Sushant Jain, Senior Scientist - Applications and Technology, for PTi. In co-extruded multilayer PET structures, the
FDA recommends a 1-mil-thick virgin cap layer for room temperature applications
and 2 mil for higher temperature use (up to 150°C) to prevent permeation of
contaminants migrating from the PCR PET regrind core layer of the packaging
material into the contained food (FDA, 2006). The virgin cap layer provides protection from
unhealthy contact or transfer of inks, adhesives, chemicals, or other materials
not meant for consumption.
performed several simulations as part of this study. Table 1, Functional Barrier Layer Simulation
Results For 40 Mil Sheet, summarizes data from four (4) different simulations
that modeled the production of a 40-mil-thick PET sheet with a 10/80/10%
virgin/regrind/virgin layer structure at a combined rate of 2000 pph. The first simulation assumed a conventional
single screw extruder (i.e.; no devolatilization capability) processing the 80%
core layer using only PCR PET flake. The
second simulation changed the formulation to a 50% PIR and 30% PCR PET flake
blend. The third simulation repeated the
formulation used during the first simulation while adding the devolatilization
benefits of the high vacuum twin screw extruder using a Bandera co-rotating
twin screw (HVTSE®). And
finally, the forth simulation repeated the formulation of the second simulation
while also adding the benefits of the HVTSE® process.
of these four (4) simulations the results demonstrate the virgin cap layers maintained
its suitability as a functional barrier since the resultant uncontaminated
virgin cap layer thicknesses exceed the 1 mil FDA recommendation (FDA, 2006). The third
and fourth simulations further demonstrate the devolatilization benefits using the
HVTSE® dryer-less process which is shown to increase the resultant
uncontaminated virgin cap layer thicknesses (i.e.; the resultant functional
barrier layer thickness) due to a significant reduction of contaminant
concentration levels in the core layer.
In summary, this study was effective in demonstrating
the importance of various factors with regard to contaminant migration with the
most significant being the correlation of higher migration rates at increased
application temperatures. In the Fraunhofer Assessment, the relative
permeation rate at 212°F(100°C) used as a point of origin (Welle, 2016), is
several orders of magnitude higher than the rate at room temperature, according
Other conclusions from this study indicate that
exposure time during extrusion processing has some impact with the simulation
models showing primary contaminant migration occurring in the feed block and die
area. However, at this point migration
is found primarily at the interface and not through the virgin cap layer,
according to Jain. Furthermore, this study
demonstrates that virgin cap layers can remain uncontaminated at a layer
thickness greater than 1 mil, proving the functional barrier remains intact
during the extrusion process and reaffirming FDA guidelines for use as an effective
barrier. "Our study eliminates any doubt
regarding virgin PET's effectiveness as a functional barrier," Jain concludes.
(August 2006). Guidance for
Industry: Use of Recycled Plastics in Food Packaging: Chemistry
- Welle, Frank, Dr. (March 3, 2016). Assessment of Recyclates behind
Functional Barriers. PET Recycling
for Food Contact Conference.
Fraunhofer Institute for Process Engineering and Packaging
About Plastic Technologies, Inc.
Plastic Technologies, Inc. (PTI) is recognized worldwide as
the preferred source for preform and package design, package development, rapid
prototyping, pre-production prototyping, and material evaluation engineering
for the plastic packaging industry. For more information, visit www.plastictechnologies.com
Container Science, Inc. was founded in January
2002 to offer materials science expertise for improving the basic performance,
quality and economics of PET and other plastic container materials. The
corporation provides a fundamental knowledge of the chemistry and science
associated with plastic containers, and we translate that understanding into
practical solutions that address the needs, issues and opportunities for this industry.
company's clients are suppliers and customers throughout the value chain of the
PET plastic packaging industry across the world. These clients include resin
producers, package designers, package developers and converters, as well as
bottlers and other end-users.
and President, Dr. Mark Rule, earned his Ph.D. in physical-organic chemistry
from Yale University. He spent 16 years with Eastman Chemical Co. and six years
with The Coca-Cola Co. before founding Container Science, Inc. His knowledge of
materials science and the plastic container value chain has been acquired
through leadership roles in basic and applied research, new product development
and commercialization, negotiations, strategic alliances and licensing,
strategy development, and new business development. Dr. Rule is the
author/co-author of over 85 U.S.
patents ranging from technologies for raw material synthesis to methods to
improve package shelf life. His expertise covers not only the fundamental
science of plastics, but also the economic and market forces at work in the
industry. For more information, visit www.containerscience.com.
Technologies International LLC (PTi)
International LLC, based in Aurora, Ill., is a leading global manufacturer of
high-performance sheet extrusion machinery, serving more than 20 countries.
Established in 1988, PTi produces and services single-screw extrusion equipment
for many end-use markets including packaging, construction, automotive, lawn
and garden, office products, signage and displays, and appliances. PTi's
extrusion systems are engineered to exacting standards and offer an exceptional
range of design features which result in superior equipment performance. More
information is available by calling (630) 585-5800 or visit www.ptiextruders.com.