PARTIALLY SHIELDED MICROWAVE CARTON

摘要

PARTIALLY SHIELDED MICROWAVE CARTON A carton is di.sclosed having a paperboard receptacle and a cover fitting over the same; the cover being adapted to shield the top and sides of food material within the receptacle from microwave radiation, but allowing radiation to be admitted through the unshielded bottom of the receptacle. A surface of the cover is formed of a conducting metal which substantially inhibits the passage of microwave radiation therethrough. The depending cover wall which surrounds the side edges of the receptacle is constructed such that adjacent portions of the panels forming the cover wall are provided with a low impcdance electrical connection at microwave frequencies to inhibit arcing between such panels during heating. The cover may be formed from a unitary, flat paperboard blank, in which case all corners of the various cover wall panels which will be in proximity to the surface on which the carton is supported durinq heating are rounded to minimize the electric field intensity created at these corners -- thus reducing the likelihood that arcing will occur bctween various portions of the cover, or between the cover and the surface on which the carton is supported.