Processes and systems that enhance the heating of packaged foodstuffs and other items in various microwave heating systems are described herein. The foodstuffs may be contained in a package including one or more energy control elements that interact with microwave energy in order to alter the effect that microwave energy has on the foodstuff. These energy control elements can enhance or inhibit microwave energy and a single package may include one or more energy control elements. In some cases, the energy control element may respond differently to different types of microwave energy. As a result, some packages described herein may exhibit different absorption or reflectance characteristics when exposed to microwave energy while being pasteurized or sterilized in a larger-scale microwave heating system than when the package is reheated in an at-home microwave oven prior to consumption or use.

A zipper tape includes a pair of belt-shaped bases bondable to a film of a bag body, and mutually engageable engagement portion each integrally provided to corresponding one of the belt-shaped bases. One of the belt-shaped bases includes at least two portions having different bonding strengths to the film on a side opposite a side provided with the engagement portion and between an edge of the one of the belt-shaped bases in a width direction orthogonal to a longitudinal direction to a point at which the engagement portions are provided. A bonding strength of a first portion of the at least two portions to the film may be larger than a bonding strength of a second portion to the film.

A bag includes: a bag body at least having a first surface and a second surface facing each other with a storing space formed between the first surface and the second surface; and a tape member provided between the first surface and the second surface and defining one side of the storing space. The tape member includes, in a cross section, a first portion formed of a first resin composition and a second portion formed of a second resin composition different from the first resin composition. The first portion is bonded to both the first surface and the second surface at a first section of a longitudinal direction of the tape member while bonded to only the second surface at a second section of the longitudinal direction, and the second portion is bonded to the first surface at the second section.

A packaging device including a breathable or non-breathable, microwavable composite film structure in the form of a bag, a tray or other type of container is disclosed. The device may include atmospheric control attributes in the form of microperforations, and steam venting mechanisms in the form of precision cuts or channels. The microperforations may form atmospheric conditions within the device for the storage of perishable and/or respiring food products, and the steam venting mechanisms may regulate the pressure and/or heat within the device during microwave cooking of the food products within.

A zipper tape includes a pair of belt-shaped bases bondable to a film of a bag body, and mutually engageable engagement portion each integrally provided to corresponding one of the belt-shaped bases. One of the belt-shaped bases includes at least two portions having different bonding strengths to the film on a side opposite a side provided with the engagement portion and between an edge of the one of the belt-shaped bases in a width direction orthogonal to a longitudinal direction to a point at which the engagement portions are provided. A bonding strength of a first portion of the at least two portions to the film may be larger than a bonding strength of a second portion to the film.

A packaging bag composed of a multilayer film and having a steam releasing mechanism. The multilayer film has at least a base layer and a welding layer and has a moisture content of not more than 1.0% in a state in which the packaging bag is filled with a content. The steam releasing mechanism has at least a steam releasing portion formed to have a maximal width of 3 to 20 mm. The internal pressure of the packaging bag is kept to be not more than 115 kPa during a period from the time the internal pressure is released through the steam releasing portion as a result of an increase in the internal pressure caused by heating in a microwave oven to the time the heating in the microwave oven finishes.

The presently disclosed subject matter is directed to a pouch for cooking a food product and a method of making a pouch for cooking The pouch for cooking a food product may have a film, a longitudinal seal so as to form a sealed tube, a first transverse seal at a first end of the pouch, and a second transverse seal at a second end of the pouch. The pouch may have a surface area to food product volume ratio from 3:1 to 9:1. The pouch may have at least one layer with at least 5% polybutylene. The longitudinal seal may extend from the first end of the pouch to the second end of the pouch. The longitudinal seal may seal the film to itself.

A food container includes a case including a food storage space, a peripheral flange on tops of the case, a first heat joining area on the peripheral flange, and a first less adhesive area on the first heat joining area; a closure device including a heat sealing layer, an outer layer attached to the heat sealing layer, a second heat joining area on a peripheral edge of the closure device and corresponding to the first heat joining area, and a second less adhesive area on the second heat joining area and corresponding to the first less adhesive area; and a non-sticky after heated lacquer layer disposed between and at the first and second less adhesive areas. After heating the container, the non-sticky after heated lacquer layer is softened and does not adhere to the second less adhesive area to form an exit for releasing both steam and pressure.

The invention comprises an ovenable packaging structure having an integral one-way valve. The laminate structure comprises an outer layer having a cut line which defines a flap that is separable from the outer layer, wherein the outer layer is adhered to an inner layer having a cut line which is offset from the outer cut line and defines a portion that is separable from the inner layer along the inner cut line and defines an opening into the packaging structure. The adhesive between the layers comprises, in an embodiment, a channel of pressure sensitive adhesive which surrounds both the outer cut line and the inner cut line, wherein the channel of pressure sensitive adhesive defines the perimeter of at least one adhesive-free valve chamber within said channel. The valve chamber comprises at least a portion of the outer cut line and the inner cut line.

A closable cooking pouch includes a heat resistant pouch body with a flap attached to it. The flap is tuckable into an opening the permits access to the pouch's interior. To close the pouch, the flap is tucked into the pouch's interior and a hook portion that forms part of the flap is inserted through a slot on the pouch body. Once through the slot, the hook portion retains at least a portion of the flap in the slot when the pouch is closed and typically provides sufficient retaining force to keep the pouch closed if it is flipped while being used for cooking. The pouch may be manufactured from a single sheet of material.