A HEAT TREATED PACKAGE FORMED FROM FIBRE BASED PACKAGING MATERIAL

摘要

The invention relates to a package intended for thermal treatment comprising a fibre-based packaging material treated with a hydrophobic size and comprising one or more layers for reduced water penetration outside and/or inside the fibre substrate. The package of the invention is characterised by the fibre substrate being treated with a combination of a wet-strength size, a hydrophobic size and an aluminium and/or calcium compound for increased heat resistance of the packaging material, and in that the ratio of hydrophobic size to the aluminium and/or calcium compound is 1:1-1:10.