A peelable package is defined as a packaging system that consumers
are able to open themselves without assistive devices. The
opening process consists of holding the packaging firmly in one
hand whilst using the other to pull on a tear tab in order to peel off
the foil lid along the sealed seam. The design of an easy-to-open,
consumer-friendly package must take into account not only
packaging-related parameters but also consumer-related factors
that affect the handling of peelable packaging. First, the principle
behind opening the package must be recognized and understood.
This depends partly on the visibility of the opening mechanism but
also on the consumer's knowledge and capability. The process itself
should be easy. The opening force therefore plays a very important
role: it is influenced by the size and material of the tear tab, by the
sealing parameters, and by the tear contour. Furthermore, the
consumer's physical abilities, such as hand strength and grip,
determine whether the package can be opened (Berns, 1981;
Schreib and Liebmann, 2011). Two finger-tip sized notches, placed
laterally in the bottom plastic foil, simplify the opening process by
providing more space for the fingers and allowing consumers to use
the key grip. With notches placed on both sides of the packaging,
the key grip can be used by both right- and left-handers. Guidelines
for the development of consumer-friendly packaging recommend
that 95% of the healthy consumer population and 80% of people
with hand disorders should be able to open the packaging (Berns,
1981; Marks et al., 2012; Schreib and Liebmann, 2011; Yoxall
et al., 2006). For healthy female consumers between 61 and 80
years this threshold is 11N for a 14 mm long tear tab (Schreib and
Liebmann, 2011). For patients with hand disorders an opening
force not higher than 8N is recommended for this specific tab
(Marks et al., 2012).