Quality Control of Barrier-Enhanced Plastic Bottles
MBAA TQ vol. 44, no. 4, 2007, pp.
278-280 |
VIEW ARTICLE Roland Folz and Roland Pahl. Research Institute for Engineering and
Packaging, Research and Teaching Institute for Brewing in Berlin (VLB), Seestr.
13, 13353 Berlin, Germany.
Abstract
Plastic containers and closures have taken on an increasingly important role
as packaging materials for the brewing industry. Along with the many well-known
advantages of plastic bottles, however, there is the problem of plastic�s
inherent permeability to gases (O(2) and CO(2)). To enhance the barrier
properties of plastic materials, different bottle systems (multilayer, internal
coatings, and blends) have been developed. The quality of these systems can be
evaluated through the measurement of permeation. Since an increasing number of
breweries are using plastic bottles and measuring permeation, novel methods for
permeation measurement have been developed. The diversity of these measurement
systems has led to a situation in which measurement results from different
sources cannot be compared with each other. This paper describes experiences
with existing and novel methods and presents an evaluation of the latest
developments in barrier-enhanced plastic bottles and closures. The existing VLB
real-time method for the measurement of O(2) and CO(2) permeation is discussed,
and a new nondestructive, noninvasive measurement method is introduced. The
methods are compared.
Keywords: barrier, closure, permeation, PET, plastic
bottles, scavenger
S�ntesis
Recipientes y tapas pl�sticas son cada d�a de mayor importancia como
materiales de envasado en la industria cervecera. Como contrapartida a las
m�ltiples ventajas de las botellas pl�sticas, existen problemas serios en cuanto
a la permeabilidad inherente del pl�stico al paso de gases (O(2) y CO(2)). Se
han desarrollado diferentes sistemas (multicapa, capas internas y mezclas) para
mejorar las propiedades de barrera de los materiales pl�sticos. La eficacia de
estos sistemas puede ser evaluada mediante la medici�n de la transmisi�n de
gases a trav�s del pl�stico. Dado que muchas cervecer�as est�n comenzando a
utilizar botellas pl�sticas y midiendo esta permeabilidad de gases, se han
desarrollado m�todos novedosos para esta medici�n, pero los resultados de
diferentes mediciones no son siempre comparables entre s�. Aqu� se describe las
experiencias con m�todos existentes de medici�n y se presenta una evaluaci�n de
los �ltimos desarrollos en botellas y sellos pl�sticos con barreras mejoradas.
Se discute el m�todo VLB para la medici�n en tiempo real de la permeabilidad de
O(2) y CO(2), y se presenta un m�todo nuevo no invasiva y no destructiva. Se
hace una comparaci�n de los diferentes m�todos.
Palabras claves: barrera,
botella pl�stica, permeabilidad, PET, �scavenger,� tapa
