www.packworld.com/chemicals
Vented cap
liners cure
container woes
High-altitude plastic bottle collapsing
problems solved and product safety and
brand image preserved.
Judy Rice | Contributing Editor
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 Extensive evaluations
Prior to choosing the induction liner system best suited
to its universal needs, Bayer performed several comparison
tests over the course of about 26 weeks.
The company concluded that the optimum choice for prevention of container collapsing was the GORE® vented pulp
induction liner from W. L Gore (www.gore.com).
Gore technicians huddled with Bayer to discuss off-gassing
problems and container pressure equalization problems
related to the Central American geographic locations, with
their varying altitude and temperature conditions, where the
products are marketed. The trials evaluated the behavior of
Bayer’s various agrochemical formulations in combination
with the Gore vented pulp induction liner and a reducedweight one-liter container.
The Gore circular liners have an attached membrane
made of ePTFE (expanded polytetrafluoroethylene) and can
be customized for different porosity levels. They can be
integrated with a broad range of caps and closures. These
liners are designed to provide a liquid-tight barrier with
high levels of venting air flow for pressure equalization for
increased safety and sustainability of products. Without the
free exchange of air provided by the liner, a vacuum is created that can cause container collapse.
The liners are well-suited for a range of typically hardto-package products such as powerful cleaning chemicals,
disinfectant formulations, and other caustic household and
agricultural/gardening chemicals. The addition of the vented
liners allows the containers to attain a pressure balance
by letting them breathe through the ePTFE membrane in
combination with another mechanism, such as a perforation
in the cap top and/or cap thread. W.L. Gore notes that its
Bayer S.A. (Guatemala) produces agricultural
chemicals and packages them in plastic bottles
for distribution to farming and gardening supply outlets and other retail stores.
The company had been experiencing some
container collapse problems. Bayer had been
using thick-walled HDPE containers and nitrogen purge to avoid collapsing, but with less
than satisfactory results for some product
formulations due to the altitudes above sea
level. To enhance product safety and preserve
their brand image, Bayer began to evaluate
packaging improvement options.
A key corrective packaging option was the
addition of vented induction cap seal liners
which allow gas transfer without permitting liquid leakage. Bayer S.A. first implemented this
measure in 2004 for selected products with
great success in Guatemala. Consequently,
the vented closures are now universal to the
STAYING IN SHAPE. Customized induction cap liners (above) incorporate a
company’s entire line of bottled agrochemicals
venting feature that can work in conjunction with a perforation in the cap top
or cap thread to prevent container distortion.
filled in Amatitlan, Guatemala.
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NOT FOR DISTRIBUTION.
technicians strive to custom-engineer airflowcontrol solutions to meet a full range of specific product and package requirements.
 Positive results
According to Bayer, the Gore vented liner
solution defeated Bayer’s container failure
problem on a cost-neutral basis. Bayer’s original strategy of using heavier, thicker-walled
containers meant that the containers were
more expensive to produce and ship. And
the nitrogen gas purge required the ability
to have precise control of the nitrogen purge
application.
By using the GORE liners with uniquely designed vents, Bayer has been able to
STAYING IN SHAPE. Without proper venting, container collapse can occur (above).
reduce container weight by more than 25%,
and the company has improved its overall
25% which helps balance out the cost increase for the
sustainability performance. For example, the
vented cap liners.”
one-liter HDPE containers, currently supplied by Matriceria
Bayer Guatemala salutes the sales and technical support
Industrial Roxy S.A., (www.matriceriaroxy.com), San
provided by W.L. Gore and recognizes the important brandSalvador, El Salvador, weigh approximately 80 g versus the
protection and packaging integrity benefits provided by the
previous container weight of about 100 g.
Gore-lined caps.
Roxy also supplies the caps with the vented liners preSazo emphasizes, “The most important environmental
installed. The vented liner allows gas egress through the
benefit is that, with the bottle weight reduction, we have
closure threads. Bayer uses cap application equipment from
averted more than 90 tons of plastic packaging materiMewes (www.mewes-gmbh.de).
als going into the waste stream during the period of 2008
Estuardo Sazo, Head of Quality Control for Bayer S.A.,
through 2009.” pw
says, “We estimate a bottle weight reduction of more than
(#72709) Copyright 2011 Summit Media Group. Reprinted with permission from the October 2011 issue of Packaging World.
For more information about reprints from Packaging World, contact PARS International Corp. at 212-221-9595.
W. L. Gore & Associates, Inc.
401 Airport Road
P.O. Box 1550
Elkton, MD 21922-1550
Phone: 410-392-4440
Toll free: 1.800.637.4449
Fax: 410.506.8749
Email: [email protected]
gore.com/packvents
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NOT FOR DISTRIBUTION.
FOR INDUSTRIAL USE ONLY. Not for use in food, drug, cosmetic or medical device manufacturing, processing, or packaging operations.