Packages materials for shielded food containers used in microwave ovens
US4894503A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 23, 1987 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Oct 23, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S99/14
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A package for heating food in a microwave oven is disclosed. The package includes metal shielding or other metal components which cause a gain in electric field strength which is greater than 3. The present invention also involves low load microwave environments where the electric field strength is greater than 10 volts per centimeter. A rigid, dimensionally stable dielectric support is provided in close proximity to a conductive sheet, being spaced less than 0.5 inch from the conductive sheet. The dielectric support is composed of material selected to avoid failure of the dielectric support in high electrical fields which may exist near the conductive sheet during microwave irradiation. The dielectric support material has a dielectric loss factor less than 0.005, and a failure temperature greater than 101.degree. C. The present invention relates to intrinsically nonarcing packages. A method for selecting packaging material for use in a shielded microwave container having a gain greater than 3 is also disclosed. A package material is selected having a combination of dielectric loss factor, heat capacity, density, and failure temperature, such that during microwave heating for a pre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.