Food or edible material: processes – compositions – and products – Packaged or wrapped product – Having specific electrical or wave energy feature
Patent
1990-01-04
1991-10-22
Czaja, Donald E.
Food or edible material: processes, compositions, and products
Packaged or wrapped product
Having specific electrical or wave energy feature
426113, 426126, 426234, 426243, B65D 8500
Patent
active
050594362
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to packaging and more particularly to packaging which facilitates microwave heating of certain foodstuffs.
The invention will herein be described with reference to packaging for pies but it will be understood that the invention is useful for packaging a variety of pastry products and other foodstuffs and is not limited to use with any particular food.
BACKGROUND ART
Meat pies have hitherto been packaged in paper bags or in individual transparent film packs manufactured by folded web packaging machinery. When it is desired to heat a pie it is removed from the package and placed in an oven. However if heated in a microwave oven the pie filling tends to become excessively hot and/or the pastry tends to become soggy during heating. It has been suggested to avoid or lessen this problem by heating the pastry in contact with a microwave interactive surface, which browns or toasts the pastry surface.
Some microwave interactive surfaces form part of a utensil which needs to be washed after use. Brastad (U.S. Pat. No. 4,267,420) described a disposable microwave interactive plastic film for wrapping crumbed fish piece and the like. We have found that the Brastad wrapping has a tendency to overheat, shrink and even melt in regions which are subjected to microwave energy while not in contact with the wrapped foodstuff, especially when the film is in overlapping layers each of which is heated by microwaves.
Moreover some pastry products become soggy if heated with all surfaces in contact with a plastic film without air circulation.
Other microwave interactive materials have been employed for example as a thin flat tray or sheet in the base of a carton. In that case overlapping thicknesses of microwave interactive layers are avoided and air circulation is permitted resulting in a crisp pastry. However cartons are a relatively expensive means of packaging and have other well know disadvantages.
An object of the present invention is the provision of a package in which a pie pastry product or the like may be handled in commerce, which facilitates heating of the content in a microwave oven, and which avoids or ameliorates at least some of the disadvantages of prior art.
DISCLOSURE OF THE INVENTION
According to one aspect the invention consists in a package for heating contained food in a microwave oven said package comprising:
at least one web; a package seam wherein at least one thickness of the web is affixed to a second thickness of the, or another, web in overlapping or overlying relationship; and wherein the web or webs of the seam comprise a dielectric layer, a microwave interactive layer adapted for heating the contained food when subjected to microwave energy and a structural layer.
Preferred embodiments of the invention are paper bags or folded web packages manufactured on conventional machinery utilizing a laminate in which the dielectric layer is a polyester film, the microwave interactive layer is a vacuum deposited thin layer of aluminium and the structural layer is paper. The metallized polyester is adhesively laminated to the paper. In the preferred embodiment the polyester layer is provided with an amorphous surface layer or face and seams are formed by heat sealing the polyester face of one seam web to the polyester face of the other seam web.
It is surprising that a bag of this construction can be heated in a microwave oven without excessive temperature build up at a seam and at parts of the package not in contact with food and indeed that the two sides of the seam remain adhered one to the other after microwave heating.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be more particularly described with reference to particular embodiments by way of example only with reference to the accompanying drawings wherein:
FIG. 1 shows a laminate according to the invention (not to scale).
FIG. 2 shows a package according to the invention.
FIG. 3 shows the package of FIG. 2 in end view when viewed on line A--A.
FIG. 4 shows in cross section a package acc
REFERENCES:
patent: 2881078 (1959-04-01), Oritt
patent: 3615711 (1971-10-01), Markus et al.
patent: 4122324 (1978-10-01), Falk
patent: 4190757 (1980-02-01), Turpin et al.
patent: 4230924 (1980-10-01), Brastad et al.
patent: 4267420 (1981-05-01), Brastad
patent: 4351997 (1982-09-01), Mattisson et al.
patent: 4363851 (1982-12-01), Mishina et al.
patent: 4590349 (1986-05-01), Brown et al.
patent: 4592914 (1986-06-01), Kuchenbecker
patent: 4594492 (1986-06-01), Maroszek
patent: 4626641 (1986-12-01), Brown
patent: 4641005 (1987-02-01), Seiferth
patent: 4735513 (1988-04-01), Watkins et al.
patent: 4742203 (1988-05-01), Brown et al.
patent: 4890439 (1990-01-01), Smart et al.
Aberle Jean L.
Czaja Donald E.
Leigh-Mardon Pty. Limited
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