| 摘要 |
Perishable goods containing water, especially foodstuffs, are packed aseptically in packages formed from impervious but flexible film and furnished with vents adequate for the escape of vapor during treatment at bake or part-bake temperatures at which goods in the package are pasteurized, the vents remaining open throughout the heating and subsequent cooling thereafter to prevent the package collapsing on the goods. The vents are positioned for security of subsequent closure in a closure seam first made to enclose the goods in the package and are constituted by interruptions in the seam providing a total cross-sectional venting area of more than 2.5 mms2. The vents are sealed after cooling. The invention is particularly applicable to the packaging of bakers' goods which are baked or part-baked in the package, which is preferably made from laminated polymeric film material. Preferably the vents, at least two in number, extend through a seam sealing a lid to a container forming the package, the seam being interrupted to provide the vents, by forming the seam over spacing members which are either subsequently withdrawn or are tubular to provide the vents. |
