MXPA97001153A - Laminate of metal laminilla that brings a patron and method to prepare the mi - Google Patents

Abstract

The present invention relates to a method for forming a metal foil laminate with pattern / substrate comprising the steps of: (a) laminating a sheet of metal foil to a substrate, applying an adhesive between the foil and the substrate, a predetermined pattern defining areas where adhesive is present and areas where the adhesive is not present, (b) cutting the metal foil in a pattern corresponding to the boundaries of the areas containing adhesive, and (c) removing the areas from the metal foil that does not they are adhered with adhesive to the substra

Description

LAMINATE OF METALLIC LAMINATE THAT LEADS A PATTERN AND METHOD TO DEVELOP THE SAME BACKGROUND OF THE INVENTION Cross reference with related applications This application is a continuation request in part of the pending application Serial No. 08 / 602,576, filed on February 14, 1996.

FIELD OF THE INVENTION This invention relates in general to laminates containing metal foil and to methods of making these laminates, more specifically to metal foil laminates / substrates useful, among other applications, to form containers for food suitable especially for packaging food intended to be heated in microwave ovens and, more particularly, to metal foil laminates with pattern / substrate and methods to make these laminates.

DESCRIPTION OF THE PRIOR ART The increasing popularity of microwave ovens for cooking a food, in whole or in part, has led to the development of a wide variety of food products that can be cooked in an oven.

P-.073 / 97 MX microwaves, directly in the packaging of the food in which they are stored. The convenience of being able to cook food without removing it from its packaging attracts a large number of consumers. Unfortunately, the packages that are currently available for food products that are heated in microwave ovens suffer from certain considerable disadvantages. A major disadvantage is that the package can not control the amount of microwave energy received by different areas of the food contained therein. A particular problem is that the edges as well as the thinner areas of a food are dried and overcooked while the central or thicker areas can be practically uncooked. Frozen foodstuffs, particularly those of relatively large volume, and more particularly foodstuffs having a thick central section and thin end sections, are examples of foodstuffs that will most likely be cooked unevenly in the packages that today they are available from the freezer-type to the microwave oven. Similarly, frozen food products consisting of several different prepared foods, each of which requires varying degrees of microwave heating, are food products in which some of the P1073 / 97 MX Prepared foods will most likely be overcooked while others will probably go uncooked, using the freezer-type microwave-type packaging available. The metal foil, for example the aluminum foil, in contrast to the thin metallized coatings, reflects the microwave energy instead of transmitting or absorbing it. Therefore, instead of being partially or completely transparent to microwave energy, the metal foil is opaque. This characteristic of the metal foil and its use as protection against microwaves are widely known and used in microwave food packaging. For example, in U.S. Patent No. 3,615,713 and in U.S. Patent No. 3,936,626 a microwave cooking appliance is disclosed which comprises a tray having several cuts of different sizes and a plurality of individual containers that they are dimensioned to be supported in the cuts of the tray. Each container is designed to fully and adequately cook the product contained therein, simultaneously with food products from other containers, so that a complete meal can be prepared simultaneously. The containers include variable amounts of aluminum foil for P1073 / 97 MX control the amount of microwave energy that reaches each of the food products. For example, the containers that are intended to contain food products that require little or no heating, for example for ice cream, are formed of aluminum foil to fully protect the product against microwave energy. Other containers are formed in the same way with microwave-opaque material, for example with aluminum foil, but have holes or openings formed in them to allow a selected amount of microwave radiation to penetrate the container and cook the contained food products in them, within the prescribed time. The number and size of holes is determined according to the normal cooking requirements of the food product inside the container. U.S. Patent No. 4,351,997 discloses a food package consisting of a tray that includes a bottom wall, transparent to microwave radiation, and a peripheral structure, which includes a peripheral wall and a peripheral ring that extends outwardly. of the peripheral wall, in its outer part, wherein at least a portion of the peripheral structure incorporates a material opaque to microwaves such as for example a metal foil, namely aluminum foil. The metal foil can be coated F1073 / 97 MX advantageously on the peripheral wall substrate or laminate thereto. Food packages, where the metal foil is selectively located or a pattern is formed to cover the selected portions of the tray against microwave energy, contribute to the uniform microwave cooking of the food product they contain. The same beneficial result is achieved in U.S. Patent No. 5,370,883 wherein a microwave heating tray is exposed which includes a cover having portions thereof formed of aluminum foil laminates, to protect selected portions of the tray. The metal foil in which a pattern formed by the selective removal of predetermined areas has been provided, is currently made for microwave packaging applications by the caustic demetalization of the metal foil in the predetermined areas. For example, according to the methods disclosed in U.S. Patent Nos. 4,552,614 and 5,340,436, the polyester film is vacuum-metallized or laminated with aluminum foil and then selectively coated or printed with a standard mask of material resistant to caustic chemicals, placed on the areas of the aluminum foil that will be protected. Subsequently, the laminate P1073 / 97 MX Masked is sprayed with a caustic material or passed through a caustic bath, where the unmasked areas of the aluminum foil are selectively removed by chemical reaction with the caustic product. The resulting laminate of the patterned / film laminate can also be laminated with a paper or a cardboard substrate in the conventional manner. However, the process of de-maltication is slow, problematic and quite expensive. Also, it is equally important to consider that the chemical reaction generates hydrogen, which represents treatment problems, and creates the need to recover aluminum from the caustic bath. Other methods for producing patterned metal foil for microwave packaging applications, which have been proposed, are equally unsatisfactory for reasons peculiar to the proposed methods or because they are unattractive in the economic sense. To date the efforts developed in this field have not been fruitful and to provide an economically attractive and commercially practical method for the elaboration of a laminated metal foil laminate which, among other uses, is particularly effective as a packaging material for foodstuffs. those who want a selective microwave heating, of a wide variety of food products. P1073 / 97 MX SUMMARY OF THE INVENTION Therefore, a primary object of this invention is to provide a method for manufacturing a patterned metal foil laminate that is essentially useful as a microwave package for food and that is commercially practical and economically attractive. It is also an object of the present invention to provide a method for making a patterned metal foil laminate, which is especially useful as electrical circuitry and which is commercially practical and economically attractive. Another object of the present invention is to provide a method that allows the formation of a wide variety of patterns in a regular or irregular manner, to selectively control the amount of microwave energy that passes through the laminate and is received by different foods or the different areas of food product contained within the microwave packaging formed from laminate. Still another object of the invention is to provide a method for manufacturing a metal foil laminate with pattern / substrate wherein an adhesive is applied between the metal foil and the foil.

P1073 / 97 MX substrate, in a predetermined pattern corresponding to the desired pattern in the metal foil of the laminate. Still another object of the invention is to provide a method for manufacturing a metal foil laminate with pattern / substrate, where an adhesive is applied between the metal foil and the substrate in selected areas forming a predetermined pattern, the metallic foil is cut in a pattern corresponding to the boundaries of the areas in which the adhesive was applied and the non-adhered areas of the adhesive. The metal foil is removed to provide a laminate, wherein the pattern of the metal foil corresponds to the application pattern of the adhesive. Still another object of the present invention is to provide a method for manufacturing a metal foil laminate with pattern / substrate, wherein an adhesive is applied between the metal foil and the substrate in the selected areas, in a predetermined pattern, and the The metallic foil is cut with a rotating die, without cutting or degrading the substrate in an unacceptable way, forming a pattern that corresponds to that of the limits of the areas in which the adhesive was applied. Still another object of the present invention is to provide a method for making a foil laminate with pattern / substrate, where it is applied P1073 / 97 MX an adhesive between the metallic foil and the substrate, in selected areas in a predetermined pattern, and the metal foil is cut with a laser beam, without cutting or degrading unacceptably to the substrate, forming a pattern corresponding to that defined by the limits of the areas in which adhesive was applied. Still another object of the present invention is to provide a method for making a container for packaging foods intended to be heated in a microwave oven; According to this method, a metal foil laminate with pattern / substrate is formed to form a container, wherein the areas containing the metal foil of the laminate form sections of the containers that are opaque to microwave energy, in order to avoid the excessive cooking of the food products in these areas of the container and favor the uniform cooking of the food. Still another object of the present invention is to provide a metallic foil laminate with pattern / substrate for a microwave heating package and other applications, wherein the pattern is formed by laminating a metal foil sheet with a substrate, applying a adhesive between the metal foil and the substrate, in selected areas in a predetermined pattern; cutting the metal foil, by P1073 / 97 MX example with a cutting tool such as a rotating die or a laser, in a pattern corresponding to the boundaries of the areas where adhesive was applied, and removing the non-adhered areas from the metal foil in order to provide the laminate, in where the metallic lamellae pattern corresponds to the adhesive application pattern. Still another object of the present invention is to provide a method for making a metal foil laminate with pattern / substrate wherein an adhesive is applied between the metal foil and the substrate, in order to form a laminate, and the metal foil is irradiated with a laser beam in a predetermined pattern, to vaporize the irradiated metal foil, without degrading the substrate in an unacceptable manner. Still another object of the present invention is to provide a method for making a metallic foil laminate with pattern / substrate, wherein the metallic foil pattern comprises a plurality of islands separated by free spaces; the method comprises the steps of applying an adhesive between the metal foil and the substrate to form the laminate, and irradiating the metal foil with a laser beam in a predetermined pattern, in order to vaporize the irradiated metal foil without unacceptably degrading the substrate. The above objects and others will be achieved, P1073 / 97 MX according to the present invention, providing a method for forming a metal foil laminate with pattern / substrate, comprising the steps of: laminating a sheet of metal foil to a substrate, applying an adhesive between the foil and the substrate in a pattern predetermined that defines areas where the adhesive is present and areas where there is no adhesive present; Cut the metal foil in a pattern that corresponds to the boundaries of the areas that contain adhesive; and removing the areas of the metal foil that did not adhere with the adhesive to the substrate. In one embodiment, the method includes the additional step of laminating a sheet of barrier layer material, preferably polymer film, to the metallic lamella layer with patterned laminate formed of metallic lamella with pattern / substrate. Preferably the metal foil is cut using a rotating die, which desirably is a machined rotating die, or a laser beam. Advantageously, the metal foil is an uncoated aluminum foil, the substrate is cardboard and the polymer film is a polyester film. In another embodiment, the present invention provides a metal foil laminate with pattern / substrate wherein the pattern is formed by: laminating a sheet of metal foil to a substrate, by applying an adhesive between the foil and the foil.

P1073 / 97 MX substrate in selected areas in a predetermined pattern; cutting the metal foil in a pattern that corresponds to the limits of the areas applied with adhesive; and removing the non-adhered areas from the metal foil, whereby the pattern of the metal foil corresponds to the adhesive application pattern. In still another embodiment, the present invention provides a container for packaging food, intended to be heated in a microwave oven, and a method for making said container, in accordance with which a metal foil with pattern / substrate is made to form a container , wherein the areas containing the metal foil of the laminate form sections of the container that are opaque to microwave energy, in order to avoid overcooking of food in those sections of the container. The objects are also achieved, according to another embodiment of the present invention, by providing a method for manufacturing a foil laminate with pattern / substrate that includes the steps of: laminating a sheet of metal foil to a substrate, applying a adhesive between the metal foil and the substrate; and irradiating the metal foil in a predetermined pattern with a laser beam, in order to vaporize the irradiated areas of the metal foil. Fit P1073 / 97 MX advantageous, the metallic foil is an aluminum foil and the substrate is paper or cardboard. Depending on the application intended for the laminate, the method may include the additional step of laminating a sheet of barrier layer material, preferably polyester film, to the metallic foil layer with the pattern of the laminate formed of metallic foil with pattern / substrate BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagrammatic representation of a laminate comprising a patterned metal foil formed according to the present invention. Figure 2 is a schematic representation of a first method for manufacturing a patterned metal foil laminate, according to the present invention; Figure 3 is a schematic representation of a second method of laminating metallic foil according to the present invention; Figure 4 is a diagrammatic representation of a laminate including a patterned metal foil formed according to the present invention; Figure 5 is a plan view of a blank or blank for the formation of a container for packing food, intended to be heated in an oven.

P1073 / 97 MX microwave, which includes an illustrative embodiment of microwave pattern packaging, according to the present invention; Figure 6 is a plan view of another blank or blank to form a food packaging container, intended for heating in a microwave oven, which includes a second illustrative embodiment of the microwave pattern package, according to the present invention; Figure 7 is a plan view of yet another blank or blank for a food packaging container intended to be heated in a microwave oven, which includes a third illustrative embodiment of microwave pattern packaging, according to the invention. present invention; Figure 8 is a schematic representation of a third method for the production of patterned metal foil laminates, according to the present invention; Figure 9 is a schematic representation of a fourth method for the production of patterned metal foil laminates, according to the present invention; Figure 10 is a fragmentary view, on the upper floor, of a metal foil laminate form P1C73 / 97 MX with pattern, made according to the present invention, comprising a plurality of metal foil islands separated by dielectric substrate spaces; Figure 11 is an enlarged sectional view taken along line 11-11 of Figure 10; Figure 12 is a graphical representation of the relationship between free space separation and center-to-center separation of the islands, for water, separated more than free space separation from an island grid; Figure 13 is a graphic representation of the relationship between free space separation and center-to-center separation of the islands, for meat, separated more than the separation distance of the free space of an island grid; Figure 14 is a graphical representation of the relationship between free space separation and center-to-center separation of the islands, for bread, separated more than the separation distance of the free space from an island grid; Figure 15 is a graphical representation of the relationship between free space separation and center-to-center separation of islands, for water, positioned adjacent to an island grid; Figure 16 is a graphic representation of the P1073 / 97 MX relation between the separation of free space and the center-to-center separation of the islands, for meat, placed adjacent to an island grid; Figure 17 is a graphical representation of the relationship between free space separation and center-to-center separation of the islands, for bread, positioned adjacent to an island grid; Figure 18 is a sectional view of a typical resonant circuit containing an electronic monitoring tag, developed by a method of the present invention.

DESCRIPTION OF THE PREFERRED MODALITY Most of the packages for food products that are currently on the market and intended for cooking by microwave energy, have a global configuration of a three-dimensional rectangular solid and the food product is contained within the walls . This configuration is easily formed from blanks or two-dimensional blanks, flat, made of cardboard and the like, which can be folded or pressed to produce a three-dimensional container of the desired size. When the food product has a relatively large volume or pronounced areas thinner or thicker, the result more P1 73/97 MX Probably the microwave cooking is that the edges and / or the thinner areas are overcooked while the central and thicker areas will be frozen or very undercooked. To eliminate or, at least, reduce this undesired effect, the blank pieces or blanks may include portions formed of a metal foil laminate / substrate to define in the package areas transparent to microwaves and areas opaque to microwaves, which can be placed in proximity to the selected foods or portions of food inside the container, to selectively protect them from microwave energy. The present invention provides metal foil laminates / substrates which are particularly useful for food packaging and are intended for microwave heating, and also for economical and advantageous methods for manufacturing these laminates. According to one embodiment of the present invention, predetermined selected areas of metal foil are removed, allowing these portions of the laminate to be transparent to microwave energy while the areas of the laminate where the metal foil is still present are opaque to energy of the microwave. When designing the metallic foil patterns with the heating requirements of the food product, P1073 / 97 MX containers made from the laminate can be formed, wherein the areas containing the metal foil form the sections of the container that will be opaque to the microwave energy, thus preventing the overcooking of the food products in those sections of the container and promoting the uniform cooking of the food. the food products. The metallic foil patterns can be easily and conveniently designed for food products and shaped in such a way as to avoid unwanted heating areas in the food package. In addition, the heating activity of the microwave energy can be selectively reduced in different portions of the container to heat several portions of a food product, at different speeds or at different degrees. Figure 1 illustrates a metal foil laminate with pattern / substrate 10 having areas in which it contains a metal foil and areas in which the metal foil has been removed and which was made according to the method of the present invention. The relative sizes of the layers shown have been exaggerated for purposes of illustration. The laminate 10 includes a substrate 12, which also functions as one of the walls of the container comprising the food packaging. A layer of metal foil 14 adheres to substrate 12 and, preferably, P-073/97 MX it is placed between the substrate and a barrier layer 16, for example polymer film, to which it is attached. As will be evident from the following description, the laminate 10 can be formed by applying adhesive, in a predetermined pattern, on a substrate 12, adhering a metal foil 14 to the substrate 12, cutting the metal foil 14 in a pattern corresponding to the pattern of the applied adhesive, removing the unbonded metal foil and, for some applications, by laminating a polymer film 16 on the adhered metal foil 14, in contact with the substrate and the metal foil. In another embodiment of the invention, the laminate 10 can be formed by applying adhesive on a substrate 12, adhering a metal foil 14 to the substrate 12, vaporizing the metal foil in a predetermined pattern, without damaging the substrate, and for some applications, laminating a film of polymer 16 on the adhered metal foil 14, in contact with the substrate and the metal foil. The metal foil layer 14, shown in Figure 1, represents the portion of the applied metal foil remaining after cutting and removal of the non-adhered portions thereof, or after removal of the metal foil by laser vaporization. . The barrier layer 16 is preferably made of a heat-stable and stable material, which functions as P1073 / 97 MX barrier to separate the food product contained in the container from the metal foil layer. The layer 16 must be transparent to the microwave energy and sufficiently stable at high temperatures, when it is laminated to the metal foil, so that it is suitable to be in contact with food at the temperatures reached while the food is cooked in a microwave. The layer 16 can be formed from a wide variety of stable materials having barrier properties, for example polymeric film and paper, including polyesters, polyolefins, nylon, cellophane, paper and polysulfones. Polyester is the preferred film material for food containers because of its thermal stability and the smooth characteristics of its surface. The thickness of the plastic film can preferably be 0.003 inches (0.076 mm) to 0.002 inches (0.051 mm), and is desired to a greater extent than is approximately 0.0005 inches (0.0127 mm). The metal foil 14 is preferably aluminum foil, but can be of any known type, such as metal foil opaque to microwaves, laminable, thin, like the foil of aluminum alloy. In a preferred embodiment of the invention, the metal foil is a non-annealed or annealed sheet, less malleable, ie, more brittle,. An example of P1073 / 97 MX This annealed sheet is a relatively brittle aluminum alloy that is designed to be cut with die. This sheet is obtained commercially as Alumax 8145. However, the use of uncoated aluminum lamella is particularly preferred. Desirably, the metal foil used in the laminate of the present invention has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm) and, more preferably, is relatively thin having a thickness in the range from 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). The substrate is preferably a flexible material that is transparent to microwave energy and has a relatively high insulating capacity and sufficient thermal stability to withstand cooking temperatures in a microwave oven. Suitable materials and substrate include paper, coated and uncoated cardboard, plastic films such as polyester films, and composite materials such as fiber / polymer composites. For microwave applications, the preferred substrate materials are paper, coated and uncoated cardboard and polymer films. The metal foil laminate with pattern / substrate 10 is profitably processed according to the present invention, in accordance with the P1-.73 / 97 MX method illustrated schematically in Figure 2, where the adhesive is applied to the metal substrate-lamella interface, only in those areas of the laminate where the microwave reflection is desired. Subsequently, the metallic foil is cut, without deteriorating, cutting or else significantly damaging the substrate, in a pattern corresponding to that of the boundaries of the areas applied with adhesive. The areas of the metal foil to which they do not adhere to the substrate are removed and desirably sent to a clean recycle stream. As a final step, particularly for microwave heating food packaging applications, a barrier layer, for example a layer of polymer film, may be applied on the patterned metallic foil layer, to act as a barrier between the laminate metal foil / substrate and the food product. The resulting laminate, comprising a substrate with metallic foil pattern areas, microwave reflecting, laminated thereto, is particularly useful for forming blanks or blanks of boxes and folding or press trays, for microwave heating. Referring to Figure 2, a sheet of substrate material 30, for example cardboard, is fed to the feed roller 32. Adhesive is distributed to P1073 / 97 MX starting from a deposit of adhesive 34, on a roll engraved with a pattern 36 which transfers the adhesive, in the predetermined pattern of the roll, onto a sheet of metal foil 38 as it passes over the rolling pin 40, towards rolling contact with the substrate sheet 30. Alternatively, adhesive can be applied using a flexographic rubber roller having a raised pattern formed thereon. The resulting metal foil laminate / substrate passes between a rotating die 42 and the anvil 44, wherein the metal foil layer is cut in a pattern corresponding to the boundaries of the areas applied with adhesive, without significantly damaging or degrading the substrate . The metal foil that does not adhere with adhesive to the substrate is vacuum removed in a vacuum clipping collection station 46 and sent to a clean metal foil recycling station (not shown). The clipping collection station, in one embodiment, comprises a combination of rotary vacuum / pressure drum / vacuum bell, or simply a vacuum hood to remove the metal foil cutout, scrape and blow the cutout and bring it to a station of recycling. Subsequently, a barrier layer by, for example, a thin layer of polymer film, as a film of P1073 / 97 MX polyester, can be applied on the metal foil with pattern. Various techniques can be employed to coat or laminate polymer film 48 on the metal foil. For example, a polymer film having on the surface thereof a heat sealable layer, such as amorphous polyester, is intended to be brought into contact with the metal foil layer and can be laminated thereto by hot contact lamination. According to this technique, the polymer film 48 passes over the heated film rolling roll 50 to melt the heat sealable layer so that, when the molten layer is pressed to contact the metal foil layer, the polymer film heat to the metal foil and the substrate (in the areas where the metal foil has been removed). Other well known coating or lamination techniques, for example lamination of dry-mount adhesive, extrusion lamination, lamination using solvent-free adhesives and extrusion coating, may also be used in the method of this invention. The cutting of the metal foil by rotary die contact is the preferred method to cut it in a pattern that corresponds to that of the applied adhesive. A problem found in the cutting of aluminum foil / cardboard substrates when using a die is that the P1073 / 97 MX aluminum metal foil is very malleable. The blade undergoes great stresses of shear stress out of the plane, without being sectioned. In order to cut the metal foil, the die has to penetrate deeply into the soft and thick substrate of the cardboard. In the process, depending on the die, the cardboard can be cut unacceptably and be damaged. In accordance with the present invention, it has been found that machined rotary dies are the preferred cutting tool for die cutting aluminum. More particularly, the marginally rotated dies are typically precision-machined solid, solid and sharp steel pieces. The machined rotary data are especially effective die cutting tools, since they are able to make a cut in the metal sheet in a precise, sharp and clean way, without cutting the underlying substrate. Rotary steel rule data also produces satisfactory results in many applications. Dies with steel rule teeth seem to produce better results than straight steel rule dies. In addition, the cut improves with steel rule dies when the substrate is corrugated cardboard, for example corrugated corrugated cardboard, or when soft anvils are used during die cutting. Soft anvils can be soft anvils P1073 / 97 MX conventional, corrugated cardboard or paper substrate, which have been wetted to make the anvil soft. Better results are obtained when the metal foil is an uncoated aluminum foil. It is believed that the superior results observed with the uncovered metal sheets are due to the fact that these metal sheets are more brittle and easier to cut with die. For example, in one case, particular results are obtained by using a non-annealed aluminum foil with a thickness of 0.0003 inches (0.0076 mm), which is commercially obtained as Alumax 1145 H19, laminated to a coated 18 pt board. No significant difference was observed when it was replaced by an uncoated cardboard. When using uncovered metal sheets care should be taken that the lubricants used in the rolling of the aluminum foil do not interfere with the bonding of the metal foil to the substrate. The uncovered metal sheets still have superficial layers of lubricant and these can interfere with the joint. Consequently, the surface lubricants on the non-annealed metal foil can be treated, for example, with a corona treatment or with a soft flame treatment sufficient to remove the surface lubricants but insufficient to anneal the foil, in order to increase the adhesion. Alternatively, P1073 / 97 MX Special adhesives can be used to form an effective bond even when surface lubricants are present. It will be appreciated that the method of rolling described above can be practiced on various types of rolling equipment and all those equipment having the ability to effect the method of the present invention are contemplated in connection therewith. A suitable attachment of rolling equipment is the flexographic press with individual platforms on which different steps of the method can be carried out. Another suitable equipment of the laminating equipment uses a central printing drum, such as the one shown schematically in FIG. 3. The method illustrated schematically in FIG.

Figure 3 is essentially identical to that illustrated in Figure 2, except that the adhesive pattern is applied to the substrate, rather than to the metal foil, prior to lamination of the metal foil to the substrate, and that the Metal foil is cut with a laser beam instead of with a rotating die. In the practice of the present invention it is not important if the adhesive is applied to the metal foil or the substrate. Specifically with reference to Figure 3, a sheet of substrate material 60 is fed between a drum of P1073 / 97 MX central print 62 and a feed roller 64. The adhesive is distributed from an adhesive reservoir 66, onto a roller engraved with a pattern 68, which transfers the adhesive with the predetermined roll pattern, onto one side of the substrate sheet, as it passes between the substrate roll 70 and the engraved roll 68. Alternatively, adhesive may be employed using a flexographic rubber roll having the predetermined pattern formed thereon. A foil sheet 72 is brought into rolling contact with the substrate sheet bearing the adhesive pattern, as the foil sheet passes over the foil roll 74. The resulting foil laminate / substrate is moved beyond a laser cutting station 76, wherein the metal foil is cut in a pattern corresponding to that of the boundaries of the areas applied with adhesive, without damaging or significantly degrading the substrate. It has been found that the laser beam pattern that cuts the metal foil is very precise and highly desirable, particularly when cutting with the laser beam is achieved using an Nd: YAG laser. The laser can be easily adjusted to different patterns and different thicknesses of metal foil, simply by adjusting the scanning pattern of the laser beam and / or changing software. Cutting with laser beam burns P1073 / 97 MX effectively removes the metal foil while carefully preserving the substrate. In many applications, the advantages of laser beam cutting outweigh the cost disadvantages and the disadvantage that, for large patterns, laser beam cutting is slower than die cutting and the laminate production line must decrease its speed. After cutting, the metal foil which does not adhere with adhesive to the substrate is vacuum removed in a vacuum clipping collection station 78 and sent to a clean metal foil recycling station (not shown). Subsequently, a barrier layer, such as a layer of thin polymer film, for example a polyester film, can be applied to the patterned metal foil. Various techniques can be used to coat or laminate the polymer film 80 on the metal foil. For example, a polymer film having a heat-sealable layer, for example an amorphous polyester layer, on the surface thereof, which is attempted to be contacted with the metal foil, can be passed over the heated rolling roll 82. of film to melt the heat sealable layer and press it into contact with the metal foil, to heat-seal the polymer film with the metal foil and the substrate by hot contact lamination.

P1073 / 97 MX Alternatively, lamination or coating techniques such as lamination of dry-mount adhesive, extrusion lamination, lamination using solvent-free adhesives, and extrusion coating can be used. The objective to be achieved by the method of the present invention, regardless of the materials and / or equipment selected, is the production of a laminate, such as the laminate 10 of Figure 1, which includes a metal foil with pattern 14. that reflects the microwave energy to avoid the overcooking of the foods contained in the container and that are adjacent to the areas where the metallic foil is present. In this way, the areas selected for microwaved microwave heating, ie, microwave reflecting areas, can be placed as required in a food package, so that different areas of the food product can be heated at different speeds and at different degrees. In another embodiment of the invention, the barrier layer polymer film can be metallized with a thin metal foil by conventional techniques, for example vacuum metallization, before lamination of the polymer film to the patterned metal foil. As seen in Figure 4, the P1073 / 97 MX laminate 90 includes the metallized layer 92, positioned between the metal foil layer 94 with pattern / substrate 96, (in areas where the metal foil has been removed) and a surface of the barrier layer polymer film 98 and adheres with adhesive to the metal foil layer with pattern 94 / substrate 96. The relative sizes of the layers shown have been exaggerated for purposes of illustration. It will be better to observe that metallized films having a surface continuity of approximately 0.01 Mhos, on a substrate transparent to microwaves, like a polymer film, will absorb some of the microwave energy and convert it into thermal heating energy that can be used to brown or toast food products that are adjacent to the metallized layer. The laminate 90 especially has all the attributes of laminate 10 since it improves the uniform cooking of the food products by the effect of the microwaves, by means of the selectively protected portions of the food products. Further, in those areas of the laminate 90 where the patterned metal foil layer 94 has been removed, the laminate 90 has the attributes of a microwave interactive layer. It will be appreciated that when the laminate 90 forms a food package for microwave cooking, the proper selection of a lamellae pattern P1073 / 97 MX metallic and the selective positioning of the metallic foil with pattern, allow not only the selective protection but also the selective toasting and browning of the food contained in the package. The representation of one embodiment of a metal foil laminate with pattern / substrate, according to the present invention, for packaging food intended to be heated in microwaves, is shown in the blank or blank 100 for a tray, of Figure 5 The tray blank 100 will eventually be passed to a press where it is given the shape of a container for microwave heating. The configuration of the microwave reflecting areas 102 and the transmitting areas of the microwave 104 in the blank 100 is illustrative of an effective configuration for food products of a particular size, shape and dielectric constant. As can be seen, the portion of the tray blank 100 that will form the bottom portion 106, when the blank 100 conforms to the shape of the tray, does not contain areas having metal foil. In contrast, the portion of the tray blank 100 that will form the side panels 108, 110 when the tray is formed, comprises areas that are essentially completely formed of metal foil. The peripheral rim 112 of the tray is completely free of metal foil, in order to ensure that there is no formation P1073 / 97 MX of arc with the walls of the microwave oven. The formation of the metallic foil pattern and the resulting selective positioning of the areas containing the metal foil 102 prevent excessive heating of the food product by the effect of the microwaves in these areas and promotes uniform cooking. Figure 6 is an example of another tray blank 120 that is formed from a patterned metal / foil laminate of the present invention. The tray blank 120 is finally folded to form a microwave heating vessel. As with the tray blank 100, the blank 120 includes areas that contain metallic lamella 122, which will reflect the microwave energy, and areas 124 where the metallic lamella has been removed according to the method of the present invention, which will transmit microwave energy. Once again, the peripheral rim 126 of the tray is completely free of metal foil, in order to ensure that there is no arcing with the walls of the microwave oven. The resulting pattern and selective placement of the metallic lamella 122-containing areas promotes uniform baking of the food product. Figure 7 is a further example of a tray blank 130 that is formed from the metal foil P1073 / 97 MX with pattern / substrate of the present invention. The blank of tray 130 will finally pass to a press where it will be given the shape of a container for microwave heating. As with the tray blanks 100 and 120, the blank 130 includes areas that contain metal lamella 132, which will reflect the energy of the microwave, and area 134 where the metal foil has been removed according to the method of the present invention, that will transmit the energy of the microwave. Once again, the peripheral rim 136 of the tray is completely free of metal foil, in order to ensure that there is no arcing with the walls of the microwave oven. The metallic lamellate areas on which the bottom 138 will be formed when the blank 130 is pressed to form a tray, include generally concentric and spaced rings. The portion of the tray blank 130 that will form the side panels 140, 142 when the blank 130 is pressed, comprises areas that are substantially made entirely of metal foil. The resulting pattern and the selective positioning of the metallic lamella containing areas 132 avoids the overcooking of the food product in the areas containing metallic lamella and promotes the uniform cooking thereof. The types of patterns that can be used for this purpose are essentially unlimited and can be varied Fl 073/97 MX as desired according to the microwave heating requirements of a particular food product. Ideally, to ensure uniform cooking, each type of food product should be packaged in a container that has a pattern of areas containing metal foil, designed specifically for that type of food product. The present invention achieves this objective and facilitates the provision of patterned metal / foil laminates designed to produce the desired uniform cooking of a particular food product, when the product is heated in a microwave oven. According to still another embodiment of the present invention, the laminate formed by metal foil with pattern / substrate 10 can be advantageously processed according to the methods illustrated schematically in Figures 8 and 9, where adhesive is applied to the interface of the Metallic foil substrate to form the laminate, after which the metal foil is removed in selected areas, in a predetermined pattern, by vaporization with a laser. As in the embodiments already described, particularly for food packaging applications for microwave heating, a barrier layer, for example a layer of polymer film, can be applied on the layer of P-973/97 MX metallic lamella with pattern in order to act as a barrier between the metal foil laminate / substrate and the food product. The resulting laminate comprising a substrate, with areas of a microwave reflecting metal foil pattern laminated with adhesive to the substrate, is particularly useful for making blanks for press forming or folding trays or boxes for microwave heating. Referring to Figure 8, a sheet of substrate material 30, for example cardboard, is fed to a feed roller 32. The adhesive is distributed from an adhesive reservoir 34 onto a distribution roller 36a, which transfers the adhesive onto a metal foil sheet 38, as the metal foil passes over a laminating roll 40 towards rolling contact with the substrate sheet 30. The resulting foil laminate / substrate moves past a laser cutting station 76 , wherein the metal foil is irradiated in a predetermined pattern, without damaging or significantly degrading the substrate. As already described with respect to the embodiment of Figure 3, irradiation is desirably achieved using a Nd: YAG laser that is capable of easily adjusting to different patterns and different thicknesses of metal foil. Subsequently, a P107 / 97 MX barrier layer, for example a thin film layer of polymer, such as a polyester layer, on the patterned metal foil, using any of the techniques already described above, for coating or laminating the polymer film 48 on the metal foil. Without intending to be limited to the different types of laminating equipment that can be used to effect the method of the present invention, another suitable laminating equipment addition utilizes a central printing drum, such as the one shown schematically in FIG. 9. The method illustrated schematically in Figure 9 is practically identical to that illustrated in Figure 8, except that the pattern adhesive is applied to the substrate instead of being applied to the metal foil. In the practice of this invention, it does not matter whether the adhesive is applied to the metal foil or the substrate. Specifically in relation to Figure 9, a sheet of the substrate material 60 is fed between a central printing drum 62 and a feeding roller 64. The additive is distributed from an adhesive reservoir 66 on a distribution roller 68a which transfers to the adhesive on one side of the substrate sheet, as it passes between a support roller 70 and a distribution roller 68a. A sheet of metal foil 72 is brought into rolling contact with the substrate sheet which P1073 / 97 MX it carries the adhesive, as the metal foil sheet passes over the rolling roller 74. The resulting metal foil laminate / substrate moves past a laser cutting station 76, where the metal foil is irradiated in a pattern default, without degrading or significantly affecting the substrate. Subsequently, the barrier layer 80, for example a thin layer of polymer film, such as a polyester film, can be applied to the patterned metal foil using one of the various techniques already mentioned herein. Regardless of whether a laser cut or die cut is used, or whether the adhesive is applied in a predetermined pattern or not, the important objective of the invention is to provide a method for manufacturing low cost food packaging that improve the uniformity of cooking in a microwave oven. This is achieved by providing a package that is opaque to microwaves in some regions and transparent to microwaves in other regions. In this way, the different areas of a food product can be heated at different speeds and in different degrees. In a particularly advantageous form of the invention, a metallic foil laminate with pattern / substrate according to the present invention, for P1073 / 97 MZ pack food that will be heated by microwaves, is formed with transparent regions to microwaves without the need to completely remove the metal foil in these regions that demand transparency to microwaves. Instead of this, in relation to Figures 10 and 11, the metal foil 202 of the laminate 200 is gridded into a plurality of conductive metal foil islands or patches 204, separated by spaces or strips 206. Desirably, the metal foil 202 is aluminum foil having a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm) and, more preferably, in a thickness of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). The substrate 208 that is most desired is coated or uncoated paperboard or paper. The resulting array of conductive metal foil islands comprises islands that are electrically separated from each other. Although, due to its thickness, the metallic islands are reflective and do not transmit the microwave energy through them, it has been found that the adequate selection of the dimensions of the island and the free space will cause the lamella of Normally reflecting aluminum is essentially transparent to microwave energy. The object of the islands-space pattern is to deactivate locally, that is to say functionally eliminate, a layer of lamella P1073 / 97 MZ metallic aluminum that would ordinarily be a protection against microwaves, without completely removing the aluminum metal foil. According to the present invention, the reflection and heating of the fringe field are diminished and the thermal heating and the expected browning and roasting are negligible. In other words, by selectively gridding the aluminum foil, a laminate can be made, which preferably passes the energy of the microwave in regions difficult to heat while keeping the regions of easy heating protected. This is significantly different with the grille disclosed in U.S. Patent No. 4,230,924 to Brastad et al, wherein the aluminum foil islands are intended to have a tangible influence on the food, ie to brown or change the color of the food that is inside the package. According to the present invention there is provided a method for making a metal foil laminate with pattern / substrate for packaging foods that are to be heated by microwaves, comprising: laminating a foil sheet to a substrate, applying an adhesive between the foil metal and the substrate, and irradiate the metal foil with a laser beam in a predetermined pattern, to form a plurality of individual islands of conductive metal foil, separated PlC 3/97 MX by spaces of dielectric substrate material. The islands can have regular geometric shapes, for example squares, or they can be of irregular shapes or patterns. It has been found that a suitably adjusted sweep laser beam from an Nd: YAG infrared laser will vaporize the aluminum foil away from the laminate without damaging the paper or board that is the substrate. By scanning the laser beam, for example in a square pattern, on the regions that are going to be transparent to the microwaves, a plurality of islands of conductive metallic foil having a square shape can be formed, which are separated by relatively wide spaces, from the Dielectric substrate material made with laser. The dimensions of the grid (separation from center to center of the islands (W) and the width of the space (w)), which are necessary for the deactivation of the aluminum foil, depend on the dielectric constant of the food to be placed in the packaging and the proximity of the grid with the food. The grids can be defined in terms of a degree of grating intensity, A, expressed as Wln (2W / pw). It will be appreciated from this expression that the grids with the smaller A's are gridded in a finer form, ie the W's are smaller, or have a greater separation or spaces P1073 / 97 MX between the islands, the largest w. The electric field is concentrated in the spaces between the islands and there is a high intensity volume of the microwave field that extends at a distance approximately equal to the separation of the free space, w, perpendicular to the grid. The reflectivity of a grid depends to a large extent on the dielectric constant of matter, such as food, in this volume of high field strength. When the dielectric constant in this volume of high field strength is large, the grid is more reflective. The transmission of microwave energy is greater when the grid separates from the surface of the food at a distance much greater than the separation w. In this case, the dielectric constant in the high field intensity volume is small. The grille intensity, ie the fineness or opening of the grid, necessary for the transmission of at least 90% of the energy would be transmitted in the absence of the grid, decreases as the dielectric constant of the food in the high volume Field strength decreases. In other words, it is easier to make the metal foil transparent, separated from foods that have a high dielectric constant. Even when the well-entangled metal foil is near food with high dielectric constant, it is reflective since the dielectric constant in the volume of P1073 / 97 MX High field strength is great. However, when the grid is immediately adjacent to the food, the situation reverses. It is easier to make the metallic foil transparent near foods of low dielectric constant. To illustrate the above, refer to Figures 12 to 17, where each is a graph of the values of w (separation of the free space of the islands), in centimeters, as the function of (center-to-center separation of the islands) ), in centimeters, necessary to achieve at least 90% of the energy transmission through the grid, which would have been transmitted in the absence of any grid. Figures 12, 13 and 14 illustrate the relationships of three different foods, water, meat and bread, respectively, for the proximity condition where the food is placed at a distance greater than the separation, w of the grid, ie outside of the high intensity field volume. Figures 15, 16 and 17 illustrate the same relationship for the same foods, respectively, for the proximity condition where the food is placed adjacent the grid, ie within the high field strength volume.

INDUSTRIAL APPLICABILITY Laminates of metal foil with P1073 / 97 MX.

The pattern / substrate of the present invention are mainly useful in the production of packages for food products that are to be heated in a microwave oven, in order to ensure uniform cooking of the food product. However, these laminates also have applications in cooking without microwaves, for example in applications where laminates having metal foil patterns designed on request are desired. In particular, the metallic lamella laminates with pattern / substrate of the present invention have wide applications in electronic circuitry, particularly, where laminates are formed using laser beams to cut the pattern. To date, the conductive circuitry has been manufactured either chemically or by caustic etching, or using laser beams, for example by depositing a very thin film metal layer, such as a metallized layer, on the surface of an insulating substrate.; irradiating the metallized layer with a laser in a predetermined pattern to remove the metal layer in the parts where it was irradiated and, subsequently, forming a thicker conductive metal layer over the remaining metallized layer. This multilayer procedure was needed because of the inability to irradiate with a laser beam the metal layers that have a sufficient thickness to exhibit P1073 / 97 MZ satisfactory conductivity in a circuit, without using sufficient laser output power with which the underlying synthetic resin substrate is irreparably damaged. It will be appreciated that both caustic etching and multi-deposition lasers are laborious, troublesome and costly processes. In accordance with the present invention, the metal foil laminate with pattern / substrate can be made and used for electrical circuitry, by laminating a dielectric substrate to a layer of metal foil and irradiating the foil layer with a laser beam in a predetermined pattern for remove the metal foil by vaporization, in the places where it was irradiated. The circuit includes extended areas that are functionally non-conductive, instead of using a laser beam to vaporize the entire extended area it has been found that it is advantageous to grid the area by cutting a plurality of individual, conductive metal foil islands, separated by spaces of material dielectric. A laser beam can be used to achieve the grid, as disclosed above in relation to microwave packaging. Alternatively, in some applications, the grid can be achieved by mechanically cutting the gap in the metal foil, according to the cutting techniques with P1073 / 97 MX already mentioned. As with the applications for microwave packaging for the laminates of the present invention, the metal foil used is preferably aluminum foil having a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm), preferably 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). The dielectric substrate is preferably a material, such as the one just described in relation to microwave packaging applications, which has a relatively high insulating capacity. Most desirably, the substrate is selected from coated and uncoated paper and cardboard. The preferred laser is a Nd: YAG laser that can be easily adjusted for different patterns and different metal sheets of different thicknesses. One application of the electronic circuitry for the laminates and methods of the present invention, which is very promising, is the tagging and tagging circuitry for electronic item monitoring to prevent theft of merchandise at retail. As is well known, these tags comprise inductive and capacitive elements placed in series and supported on a dielectric substrate. The tags are typically used by attaching them to the items. When the client presents the articles for P1073 / 97 MX pay them, the tags are removed and deactivated. Typically, at each exit from a retail establishment that uses electronic monitoring tags on their merchandise, buyers leaving the establishment have to pass through radio transmitter and receiver units. When a monitoring tag 220 employing circuitry made in accordance with the present invention is subjected to a radio frequency signal at the resonant frequency of its resonant circuitry, an electronic anti-theft system is activated which sounds an alarm to indicate that an item of Merchandise that carries the tag intact is being removed from the establishment. Referring to Figure 18, an electronic monitoring tag 220 is illustrated. The tag 220 comprises a metal foil laminate with pattern / substrate 222 having metallic lamella containing areas and areas from which the metal foil has been removed by laser beam vaporization. The laminate 222 includes a dielectric substrate 223, preferably formed of paper or cardboard, to which a spiral strip 224 is adhered on the upper surface 226 and the lower surface 228 of the substrate 223. The spiral strip 224 functions as an inductor of the resonant circuit of the tag 220. Connected Pl 3/97 MX in series with the induced strip 224 is a capacitor 230 which is formed with two conductive plates 232 and 234 adhered, respectively, to the upper surface 226 and the lower surface 228. There is a conductive connection (not shown) through the substrate 223 between the spiral strip 224 and the capacitor plate 234. The laminate 222 is formed by adhesively bonding the metal sheets to the opposite surfaces of the substrate 223 and cutting the metal sheets using a laser beam in the patterns required to establish the spiral strip 224 and the capacitor plates 232 and 234 on the substrate 223. The spiral strips 224 and the capacitor plates 232 and 234, which are not shown in Figure 18, represent the portions of the applied metal sheets that remain after laser irradiation. , to vaporize the irradiated portions of the metal sheets.

Pl- ~ 3/97 MX

Claims (98)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1. A method for forming a metal foil laminate with pattern / substrate comprising the steps of: (a) laminating a metal foil sheet to a substrate, applying an adhesive between the metal foil and the substrate, in a predetermined pattern defining areas where adhesive is present and areas where the adhesive is not present; (b) cutting the metal foil in a pattern corresponding to the boundaries of the areas containing adhesive; and (c) removing the areas of the metal foil that are not adhered with adhesive to the substrate. A method according to claim 1, characterized in that it includes the additional step of laminating a sheet of barrier layer material to the metal foil layer with laminate pattern. 3. A method according to claim 2, characterized in that the barrier layer material is a polymer film. P1 73/97 MX 4. A method according to claim 3, characterized in that the polymer film is a polyester film. A method according to claim 3 or 4, characterized in that the polymer film is metallized on a surface thereof and the metallized surface is adhesively bonded to the patterned metal foil layer. 6. A method according to claim 2, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, by hot contact lamination. A method according to claim 2, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, by extrusion lamination. A method according to claim 2, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, applying a layer of solvent-free adhesive to the film, prior to lamination. A method according to claim 2, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, by lamination with adhesive by mounting on Pl 73/97 MX dry. A method according to claim 2, characterized in that the sheet of barrier layer material is coated by extrusion on the metal layer with laminate pattern. 11. A method according to claim 1 or 2, characterized in that the cutting step comprises a cut with rotating die. 12. A method according to claim 11, characterized in that the step of rotary die cutting is achieved using a machined rotary die. A method according to claim 11, characterized in that the step of cutting with a rotating die is achieved using a rotating steel rule die. A method according to claim 13, characterized in that the die acts against a soft anvil. 15. A method according to claim 14, characterized in that the soft anvil is corrugated cardboard. 16. A method according to claim 14, characterized in that the soft anvil is wet cardboard. 17. A method according to claim 1 or 2, characterized in that the cutting step comprises cutting with a laser beam. 18. A method according to claim 17, characterized in that the cutting step with laser beam is P1 73/97 MX achieved using a Nd: YAG laser. 19. A method according to claim 1 or 2, characterized in that the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard and polymeric film. 20. A method according to claim 19, characterized in that the polymeric film is a polyester film. 21. A method according to claim 1, characterized in that the substrate is a polymer film and includes the additional step of adhesively laminating a sheet of paperboard to a layer of metallic foil with laminate pattern. 22. A method according to claim 19, characterized in that the metal foil is aluminum foil. 23. A method according to claim 22, characterized in that the metal foil is un-annealed aluminum foil. A method according to claim 23, characterized in that it includes the corona treatment step of the uncoated aluminum foil surface, before laminating the aluminum foil to the substrate. 25. A method according to claim 23, characterized in that it includes the treatment step with P1073 / 97 MX soft flame from the surface of the uncoated aluminum foil, before laminating it to the substrate. 26. A method according to claim 22, characterized in that the metal foil is a die-cut aluminum alloy foil. 27. A method according to claim 1, characterized in that the non-adhered metal foil areas are removed by vacuum cleaning. 28. A method for forming a container for packaging food to be heated in a microwave oven, the container has at least one section that is opaque to microwave energy to protect the food that is adjacent to the opaque section, and at least one section that is sufficiently transparent to microwave energy, the method comprises the steps of: (a) laminating a sheet of metal foil to a substrate, applying an adhesive between the metal foil and the substrate, in a pattern predetermined defining areas where the adhesive is present and areas where the adhesive is not present; (b) cutting the metal foil in a pattern corresponding to the boundaries of the areas containing adhesive; and (c) removing the areas from the lamella Pl -73/97 MX metal that are not bonded with adhesive to the substrate; (d) laminating a sheet of barrier layer material to the patterned metal foil layer; (e) forming the barrier / metal foil laminate with pattern / substrate as a container in which the barrier layer is adjacent to the food contained in the container; the areas of the laminate from which the metal foil was removed form the sections of the container that are transparent to microwave energy and the areas containing the metal foil form the sections of the container that are opaque to microwave radiation. 29. A method according to claim 28, characterized in that the metal foil is aluminum foil, the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard and polymeric film and the barrier layer material is polymeric film. 30. A method according to claim 29, characterized in that the metal foil is aluminum foil not annealed. 31. A method according to claim 30, characterized in that it includes the corona treatment step of the surface of the uncoated aluminum foil before laminating the aluminum foil to the substrate. P1073 / 97 MX 32. A method according to claim 30, characterized in that it includes the step of treating the surface of the uncoated aluminum foil with a soft flame before laminating the aluminum foil to the substrate. 33. A method according to claim 28, characterized in that the cutting step comprises a rotating die cut with a machined rotary die. 34. A method according to claim 28, characterized in that the cutting step comprises laser beam cutting. 35. A method according to claim 28, characterized in that the barrier layer material is polymer film, the polymer film is metallized on a surface thereof and the metallized surface adheres with adhesive to the patterned metal foil layer . 36. A method according to claim 28, characterized in that the non-adhered metal foil areas are removed by vacuum stripping. 37. A metallic foil laminate with pattern / substrate, wherein the pattern is formed by laminating a sheet of metal foil to a substrate, applying an adhesive between the foil and the substrate in a predetermined pattern, defining areas where it is present the adhesive and areas where it is not present P1073 / 97 MZ adhesive; cutting the metal foil in a pattern that corresponds to the boundaries of the areas that contain an adhesive; and removing the metal foil areas that are not bonded with adhesive to the substrate. 38. A metallic foil laminate with pattern / substrate according to claim 37, characterized in that it also includes a barrier layer material laminated to the patterned metal foil layer. 39. A metal foil laminate with pattern / substrate according to claim 38, characterized in that the barrier layer material is polymer film. 40. A metal foil laminate with pattern / substrate according to claim 37, 38 or 39, characterized in that the metal foil is aluminum foil and the substrate is selected from the paper substrate, coated paperboard, uncoated cardboard and polymer film. 41. A metal foil laminate with pattern / substrate according to claim 40, characterized in that the metal foil is aluminum foil not annealed 42. A foil laminate with pattern / substrate according to claim 39, characterized in that the polymer film is metallize on a P1Q73 / 97 MX surface of the same and the metallized surface is attached with adhesive to the patterned metallic foil layer. 43. A container for packaging foods to be heated in a microwave oven, the container has at least one section that is opaque to microwave energy to protect the food that is adjacent to the opaque section, and so minus a section that is sufficiently transparent to microwave energy; the container is formed from a barrier / foil layer laminate with pattern / substrate, the barrier layer being adjacent to the food contained in the container, wherein the barrier / foil layer laminate with pattern / substrate is form by laminating a metal foil sheet to the substrate by applying an adhesive between the metal foil and the substrate, in a predetermined pattern defining areas where adhesive is present and areas where the adhesive is not present; cutting the metal foil in a pattern that corresponds to the boundaries of the areas containing adhesive; removing the areas of the metal foil that are not bonded with adhesive to the substrate; and laminating a sheet of barrier layer material to the patterned metal foil layer, whereby the laminate areas from which the metal foil was removed form the sections P1073 / 97 MX of the container that are transparent to the microwave energy and the areas containing the metal foil form the sections of the container that are opaque to microwave radiation. 44. A container according to claim 43, characterized in that the metal foil is aluminum foil, the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard and polymer film and the barrier layer material is foil. polymer. 45. A container according to claim 44, characterized in that the metal foil is uncovered aluminum foil. 46. A container according to claim 43, characterized in that the barrier layer material is polymer film, the polymer film is metallized on a surface thereof and the metallized surface is adhesively bonded to the patterned lamella layer. 47. A method for forming a metal foil laminate with pattern / substrate comprising the steps of: (a) laminating a metal foil sheet to a substrate, by applying an adhesive between the metal foil and the substrate; (b) irradiate the metal foil with a P1073 / 97 MZ laser beam in a predetermined pattern to vaporize the irradiated areas of the metal foil. 48. A method according to claim 47, characterized in that it includes the additional step of laminating a sheet of barrier layer material to the metallic lamella layer with laminate pattern. 49. A method according to claim 48, characterized in that the barrier layer material is a polymer film. 50. A method according to claim 49, characterized in that the polymer film is a polyester film. 51. A method according to claim 49 or 50, characterized in that the polymer film is metallized on a surface thereof and the metallized surface is adhesively bonded to the patterned metal foil layer. 52. A method according to claim 48, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, by hot contact lamination. 53. A method according to claim 48, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with lamination pattern, by extrusion lamination. P1073 / 97 MX 54. A method according to claim 48, characterized in that the sheet of barrier layer material is laminated to the metallic lamella layer with laminate pattern, applying a layer of solvent-free adhesive to the film, before lamination. 55. A method according to claim 48, characterized in that the sheet of barrier layer material is laminated to the metal foil layer with laminate pattern, by lamination with dry-mount adhesive. 56. A method according to claim 48, characterized in that the sheet of barrier layer material is coated by extrusion on the metallic layer with laminate pattern. 57. A method according to claim 47 or 48, characterized in that the irradiation step with laser beam is achieved using a Nd: YAG laser. 58. A method according to claim 47 or 48, characterized in that the substrate is selected from the group consisting of paper, coated paperboard and uncoated cardboard. 59. A method according to claim 58, characterized in that the metal foil is aluminum foil. 60. A method according to claim 58, P1073 / 97 MZ characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 61. A method according to claim 60, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 62. A method according to claim 59, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 63. A method according to claim 62, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 64. A method according to claim 59, characterized in that the metal foil is uncoated aluminum foil. 65. A method according to claim 64, characterized in that it includes the step of the corona treatment of the surface of the un-annealed aluminum foil, before the lamination of the aluminum foil to the substrate. 66. A method according to claim 64, characterized in that it includes the step of the treatment of P1073 / 97 MZ soft flame on the surface of the uncoated aluminum foil, before laminating it to the substrate. 67. A method according to claim 47 or 48, characterized in that the predetermined pattern is a plurality of conductive islands separated by spaces. 68. A method according to claim 47, characterized in that the predetermined pattern is an electrical circuit. 69. A method for forming a container for packaging foods to be heated in a microwave oven, the container having at least one section that is opaque to microwave energy, to protect the food that is adjacent to the opaque section, and at least one section that is essentially transparent to microwave energy, the method comprises the steps of: (a) laminating a metal foil sheet to a substrate, applying an adhesive between the metal foil and the substrate; (b) irradiating the metal foil with a laser beam in a predetermined pattern to vaporize the irradiated areas of the metal foil. (c) laminating a sheet of barrier layer material to the patterned metal foil layer; and (d) forming the barrier / foil layer laminate with pattern / substrate as a P1073 / 97 MX container, the barrier layer being adjacent to the food contained in the container; the areas of the laminate from which the metal foil was removed form the sections of the container that are transparent to microwave energy and the areas containing the metal foil of the laminate form the sections of the container that are opaque to microwave radiation . 70. A method according to claim 69, characterized in that the metal foil is aluminum foil, the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard and the barrier layer material is polymeric film. 71. A method according to claim 70, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 72. A method according to claim 70, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 73. A method according to claim 70, characterized in that the metal foil is uncoated aluminum foil. 74. A method according to claim 73, characterized in that it includes the corona treatment step P1073 / 97 MX of the non-annealed aluminum lamellae surface, before lamination thereof to the substrate. 75. A method according to claim 73, characterized in that it includes the step of the treatment with soft flame of the surface of the uncoated aluminum foil, before the lamination thereof to the substrate. 76. A method according to claim 69, characterized in that the barrier layer material is polymer film, the polymer film is metallized on a surface thereof and the metallized surface is adhesively bonded to the patterned metal foil layer. 77. A method according to claim 69 or 70, characterized in that the predetermined pattern is a plurality of conductive islands separated by space. 78. A metallic foil laminate with pattern / substrate, where the pattern is formed by laminating a sheet of metal foil to a substrate, applying an adhesive between the metal foil and the substrate, and irradiating the foil with a laser beam, in a predetermined pattern for vaporizing the irradiated areas of the metal foil. 79. A metallic foil laminate with pattern / substrate according to claim 78, characterized PÍO1- "MZ because it further includes a sheet of barrier layer material laminated to the patterned metal foil layer. 80. A metallic foil laminate with pattern / substrate according to claim 79, characterized in that the barrier layer material is polymer film. 81. A metal foil laminate with pattern / substrate according to claim 78, 79 or 80, characterized in that the metal foil is aluminum foil and the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard. 82. A method according to claim 81, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 83. A method according to claim 81, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 84. A metal foil laminate with pattern / substrate according to claim 81, characterized in that the metal foil is aluminum foil not annealed. 85. A metal foil laminate with P1 73/97 MX pattern / substrate according to claim 80, characterized in that the polymer film is metallized on a surface thereof and the metallized surface is adhesively bonded to the patterned metal foil layer. 86. A metal foil laminate with pattern / substrate according to claim 78 or 79, characterized in that the predetermined pattern is a plurality of conductive islands separated by spaces. 87. A container for packaging foods to be heated in a microwave oven, the container having at least one section that is opaque to microwave energy to protect the food that is adjacent to the opaque section, and at least one section that is essentially transparent to microwave energy; the container is formed from a barrier / metal foil laminate with pattern / substrate, the barrier layer being adjacent to the food in the container, wherein the barrier / foil layer laminate with pattern / substrate is formed laminating a metal foil sheet to the substrate by applying an adhesive between the metal foil and the substrate; irradiating the metal foil with laser beam in a predetermined pattern, for vaporizing the irradiated areas by metal foil, and laminating a sheet of barrier layer material to the foil layer P1073 / 97 MZ with pattern, whereby the areas of the laminate from which the metal foil has been removed form the sections of the container that are essentially transparent to microwave energy, and the areas containing the metal foil form the sections of the container that They are opaque to microwave radiation. 88. A container according to claim 87, characterized in that the metal foil is aluminum foil and the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard and the barrier layer material is polymer film. 89. A container according to claim 88, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 90. A container according to claim 88, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 91. A container according to claim 88, characterized in that the metal foil is un-annealed aluminum foil. 92. A container according to claim 87, characterized in that the barrier layer material is polymer film, the polymer film is metallized P1 73/97 MZ on a surface thereof and the metallized surface is bonded with adhesive to the patterned metallic foil layer. 93. A container according to claim 87 or 88, characterized in that the predetermined pattern is a plurality of conductive islands separated by spaces. 94. An electronic monitoring label for merchandise, to set off an alarm in case merchandise marked with the tag is removed from a commercial establishment, the tag comprises a resonant circuit tuned to a given radio frequency to produce a detectable resonant condition which activates an anti-theft alarm, the resonant circuit is formed from a metal foil laminate with pattern / substrate, wherein the metallic foil laminate with pattern / substrate is formed by the lamination of a sheet of metal foil to a substrate, by applying an adhesive between the metal foil and the substrate and irradiating the metal foil with a laser beam in a predetermined pattern, to vaporize the irradiated areas of the metal foil, whereby the non-irradiated areas of the laminate formed of the metallic foil comprise elements of a conductor circuit to form the circumference resonant uito. 95. An electronic monitoring label according to Pl 073/97 MX claim 94, characterized in that the metal foil is aluminum foil and the substrate is selected from the group consisting of paper, coated cardboard, uncoated cardboard. 96. An electronic monitoring tag according to claim 95, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.002 inches (0.051 mm). 97. An electronic monitoring tag according to claim 95, characterized in that the metal foil has a thickness in the range of 0.0002 inches (0.0051 mm) to 0.0006 inches (0.0152 mm). 98. An electronic monitoring tag according to claim 94, characterized in that the metal foil is aluminum foil not annealed. P1 73/97 MZ