THE S.H.E.S. SYSTEM

TECHNICAL AND HYGIENIC ASPECTS OF METALLIC CONTAINERS

Metallic containers are used for packaging of drinks. These containers are made of a funneled body (aluminum, steel, and/or these alloys) and a lid, with "easy-opening" (typically in aluminum or its alloys).
Coupling between body and lid is done through clinging.
To date there are two main types of easy-opening lids. The first type uses a closed weakening section, which defines both the opening and the operculum. A pull-off ring is connected to that portion of lid that forms the operculum. Pulling the ring causes the lid to lacerate along the weakening line, the operculum to separate from the lid, and a consequent opening to be formed on the can lid.
This type of lid has the disadvantage that when the can is opened, both the operculum and the attached ring get completely separated from the can body, and for this reason they can dispersed separately in the environment.
In order to overcome this disadvantage a second lid type (so called "ecological" or "environmentally friendly") was designed and widely adopted. With this lid, a lever, with its fulcrum connected to the fixed portion of the lid, causes the lid to lacerate along an open weakening line, which defines the edge of an operculum and corresponding opening, with a displacement of the operculum toward the interior of the can.
With this second type of opening, the operculum, following the laceration and displacement, remains solidly connected to the can by means of an attachment included between the end portion of the laceration line and precludes its disposal in the environment as a separate entity.

Both systems are affected by the hygienic limitations discussed above and consumption of drinks packaged in such containers do not offer any protection in terms of preventing the contamination of the drink itself. The product, in fact, either directly consumed from the can or poured in a glass, flows on the lid and its clinged edge thus defeating all care taken during its production and packaging to guarantee its sterility. The second system has another disadvantage due to the operculum that is immersed into the liquid after the displacement action, this representing another source of hygienic limitation. In addition, whenever one drinks from the can, other risks come from the lips contacting directly the edge of the lid and the opening profile.