Abstract: A microwave heating material is formed of a micromesh conductive coating on a substrate. The micromesh includes a plurality of closely spaced, fine lines of a conductive material such as aluminum. The conductive material may have a resistivity of about 1-50 &OHgr;/□. The microwave heating material may include electrically and physically discontinuous islands of micromesh, each of which may optionally be connected to another only by a susceptor fuse region. The microwave heating material is laminated to a supporting material which may be incorporated into wraps, bags, boxes, trays, and other food containers.

Abstract: A laminate structure of a retroreflective film includes one layer of a prismatic plastic film laminated to a heat sealable, white polyester film having a pattern of aluminum deposited such that the resulting laminate is very cost effective to produce and has superior whiteness properties when compared to conventional films.

Abstract: Materials from which metal film capacitors with plastic or other dielectric films are formed include a plurality of regions or segments defining plates of a capacitor, the regions electrically interconnected by fuse regions which separate a region containing a short circuit fault from the capacitor. The plurality of regions or segments are circular. The fuse regions may be circular or may alternatively be high resistivity regions filling spaces between the plurality of regions or segments. A capacitor having a higher energy storage density and safer construction is wound from these materials using conventional techniques.

Abstract: A security device includes two plastic layers and a metal layer. The plastic layers may be embossed or surface cast with contrasting surface relief diffraction patterns. A second metal layer may be provided including a pattern of voids through which the first metal layer may be seen by a human observer.

Abstract: Security devices which are difficult to reproduce include a grid screen metallization pattern. The grid screen metallization pattern may be laid down over a hologram or diffraction grating formed as a surface relief pattern on a substrate, to form a visually identifiable, semi-transparent security device. Additionally, the metallization pattern may include resonant structures in which information about the security device is encoded. In some embodiments of these security devices, the metallization pattern is disposed in accurate registration with the underlying hologram or diffraction grating. These security devices are made by methods which include printing an oil pattern on the substrate. Areas on which oil is deposited do not receive metal during a metallization step. Since these methods do not use caustics, metallization patterns including features which would otherwise trap and hold caustics are possible.

Abstract: Security devices which are difficult to reproduce include a grid screen metallization pattern. The grid screen metallization pattern may be laid down over a hologram or diffraction grating formed as a surface relief pattern on a substrate, to form a visually identifiable, semi-transparent security device. Additionally, the metallization pattern may include resonant structures in which information about the security device is encoded. In some embodiments of these security devices, the metallization pattern is disposed in accurate registration with the underlying hologram or diffraction grating. These security devices are made by methods which include printing an oil pattern on the substrate. Areas on which oil is deposited do not receive metal during a metallization step. Since these methods do not use caustics, metallization patterns including features which would otherwise trap and hold caustics are possible.

Abstract: A security device includes a holographic image observable in ambient light and through which a covert image is observable in a focussed beam of bright light, such as a flash light. The holographic image is coated with a metal layer of low optical density, while the covert image is produced by a metal layer of high optical density disposed away from an observer relative to the holographic image. The covert image may itself be amplified by positioning the high optical density layer on a layer of micro prisms.

Abstract: A conductive structure for use in microwave food packaging which adapts itself to heat food articles in a safer, more uniform manner is disclosed. The structure includes a conductive layer disposed on a non-conductive substrate. Provision in the structure's conductive layer of fuse links and base areas causes microwave induced currents to be channeled through the fuse links, resulting in a controlled heating. When over-exposed to microwave energy, fuses break more readily than the conductive base areas resulting in less absorption of microwave energy in the area of fuse breaks than in other regions where fuses do not break. The arrangement and dimensions of fuse links compensate for known uneven stresses in the substrate, giving uniform fuse performance. In addition, by varying the dimensions of the fuse links and base areas it is possible to design and fabricate different fused microwave conductive structures having a wide range of heating characteristics.

Abstract: A bag for heating food products in a microwave oven and a blank for forming the bag are disclosed. The bag is formed of a dielectric substrate having a laminated layer including at least one microwave interactive patch. The microwave interactive patches are positioned to avoid overheating at creases and seams formed in the bag. At least one of the microwave interactive patches includes a heat sensitive fuse.

Abstract: A conductive structure for use in microwave food packaging which adapts itself to heat food articles in a safer, more uniform manner is disclosed. The structure includes a conductive layer disposed on a non-conductive substrate. Provision in the structure's conductive layer of fuse links and base areas causes microwave induced currents to be channeled through the fuse links, resulting in a controlled heating. When over-exposed to microwave energy, fuses break more readily than the conductive base areas resulting in less absorption of microwave energy in the area of fuse breaks than in other regions where fuses do not break. In this way the fused microwave conductive structure compensates for the uneven microwave field within a microwave oven and at the same time provides a safer conductive structure less likely to overheat.

Abstract: Microwave diffuser films are describe that provide a modified microwave energy field on one side of the diffuser film and on the other side. The films include an insulative substrate having a first side upon which is deposited a metallic coating capable of selectively reflecting a portion of incoming microwave energy. A coating is formed in a plurality of discrete areas having a predetermined reflectivity. The shape and spacing of the areas may be varied so that energy emission from noncoated surfaces of the substrate is spatially distributed in one or more ways; i.e. the energy emission more uniform than the energy impinging on the coated surface, the energy emission is focused on one or more particular location and/or the energy emission is shielded. A food packaging system for microwave cooking, which includes the microwave diffuser film of this invention, is also described.

Abstract: Shelf stable packaging films and packages which are microwaveable yet are substantially impermeable to gases and ultraviolet energy and selectively permeable to microwave energy are described. The films include a water vapor and oxygen barrier substrate having a first side upon which is deposited a metallic coating capable of selectively transmitting a portion of a microwave energy field through the substrate. The coating is formed in a plurality of discrete, microwave reflective areas separated by non-reflective gaps. The shape and spacing of the areas is varied so that the microwave energy transmission through non-coated areas of the barrier is sufficient to avoid arcing and heat the object but not cook the object. A food packaging system for storing and heating food by microwave energy, which includes the microwave barrier film of this invention, is also described.

Abstract: A selectively permeable membrane microwave susceptor for use in food packaging is disclosed. The susceptor comprises a substrate having at least one absorbing coating and at least one reflecting coating deposited thereon. Either one or both of the absorbing coating or the reflecting coating can be varied to control the amount of microwave energy reaching the absorbing coating, thereby controlling the overall amount of susceptor heating.

Abstract: A susceptor composite and related packaging devices employing the susceptor composite comprising a plurality of heat sealable layers is disclosed. The susceptor composite is adhesiveless and is used in food packages for heating and cooking food products in a microwave oven. In one preferred embodiment, a first substrate of amorphous polyester has a metallic microwave absorptive layer deposited on one of its surfaces. A dimensionally stable layer that includes a heat sealable material is heat sealed to at least one of the first substrate and microwave absorptive layer. The heat sealable film can be applied in a pattern and can also be applied using different heat-sealing temperatures to provide selective microwave absorption to the susceptor composite of the invention.

Abstract: A selectively permeable membrane microwave susceptor for use in food packaging is disclosed. The susceptor comprises a substrate having at least one absorbing coating and at least one reflecting coating deposited thereon. Either one or both of the absorbing coating or the reflecting coating can be varied to control the amount of microwave energy reaching the absorbing coating, thereby controlling the overall amount of susceptor heating.

Abstract: An etchless patterning method for depositing material patterns upon substrates. The method involves providing substrate to be patterned, immobilizing a patterned physical mask upon a mask carrier, transferring the mask from the carrier to contact the substrate, immobilizing the mask upon the substrate while removing the mask carrier, exposing the masked substrate to vapor phase pattern material in a vacuum, reimmobilizing the mask upon the mask carrier and removing the mask from the substrate in a manner that allows the mask to remain immobilized on the mask carrier. The process is particularly well suited for the production of circuit boards or electronic applications.