Valtion Teknillinen Tutkimuskeskus

Espoon Paineilma Oy

Raija Ahvenainen

Eero Hurme

Matti Siika-Aho

Maria Smolander

Timo Pullinen

Eero Heikkinen

Package (,) for decayable foodstuffs (,), consisting of a package material (,) and forming a mainly closed package space (,) and a mainly closed indicator space (,) for an indicator (,). The indicator space (,) forms an exterior wall (,) adjoining the environment (,) and made of a material (,) with a controllable gas permeability so that gas can penetrate through the exterior wall into the indicator space in a controlled manner as the package,) is aging, so that the indicator (,) will indicate the entry of gas into the indicator space and therefore the aging of the package upon the lapse of a certain time after the package was exposed to the environment; and an interior wall (,) of the indicator space (,), adjoining the package space,) and made of a material controllably permeable to gas so that gas entering into and/or generated in the package space can penetrate from the package space into the indicator space in a controlled manner and the indicator will indicate that gas has entered into the package space.

Package for decayable foodstuffs

A method for detecting a leak in a resilient, semi-hard and hard package includes a test gas supplied to the package to subject the contents of the package to a first pressure. The package is then maintained for a predetermined time in a chamber having a gas pressure, and the presence of gas is detected in a measuring space in gas flow relationship with the chamber by a detection apparatus. In order for the method to be rapid enough to be suitable for detecting very small holes in packages and for use in production plants without a change in their operating rate, a hydrogen gas having a hydrogen gas concentration from 0.0001-6% by volume is used as the test gas supplied to the package, and the hydrogen gas concentration of the gas within the chamber is maintained below a reference concentration that is lower than the hydrogen gas concentration in the package immediately after the addition of hydrogen gas to the package. If hydrogen gas that has leaked outside the package into the chamber is detected and the package is considered defective, if the detected hydrogen gas content is higher by a predetermined value than the reference concentration after the predetermined time. The method also improves the shelf life of the quality of a product in the form of a foodstuff.

Method for treating a product and a leak-detection device

Growing community of inventors

Espoo, Finland

Raija Ahvenainen