| 摘要 |
The process consists in manufacturing, in a single operation a polystyrene container of variable size but of defined shape, coated in its concave part with a composite film consisting of three layers: polystyrene - ethylene/vinyl alcohol (EVOH) copolymer - polyethylene. After the meat is introduced a controlled atmosphere containing oxygen, nitrogen and carbon dioxide is introduced before the package is sealed with a heat-welded cover consisting of a three-layer film: polyethylene - ethylene/vinyl alcohol (EVOH) copolymer - polyethylene terephthalate (PET). The porosity to the gases, oxygen, nitrogen and carbon dioxide, of the package thus formed is lower than 1 cm<3> per square metre per 24 hours. The shape of the container is fully defined in order to enable the process to be used, namely in that all the corners are rounded and their radius is smaller than half the thickness of the expanded polystyrene wall at the point in question and in that the width of the outer surround is between 4 and 8 mm.
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