| 摘要 |
<p>A refrigerated food is packaged in a paperboard tray covered by a plastic film bonded to upper edges of the tray sidewalls in provision of a barrier against contamination of the food. The film and the tray are transparent to microwave energy for heating the food, and automatic venting of the covered tray, while heating, is afforded by a relatively small strip of electrically conductive material on the film and absorptive of microwave energy in an amount sufficient to heat the same and melt a vent opening in the film.</p> |
