NON-STICK COOKWARE AND MATERIALS AND METHODS OF MANUFACTURING AND USING - Patent application

Abstract

To provide heat-resistant and / or nonstick polymer materials and composites, and cookware including a food support surface comprising an integrated or attached cooking surface formed of the materials and composites.SOLUTION: The cookware can include a melt-processible fluoropolymer surface or insert. The cookware can further include a laminate material with structural rigidity, where the laminate material includes a flexible substrate impregnated with the heat-resistant polymer material, coated with a nonstick coating, and pressed or molded into shaped cookware or other nonstick items or components. Various cooking devices as well as oven or vehicle components can be pressed from the material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Application No. 62 / 719,799, filed August 20, 2018, U.S. Provisional Application No. 62 / 829,706, filed April 5, 2019, and U.S. Provisional Application No. 62 / 834,189, filed April 15, 2019. Each of these co-pending provisional applications is incorporated herein by reference in its entirety and made a part hereof, including, but not limited to, those portions specifically described below. [Background technology]

[0002] TECHNICAL FIELD OF THE PRESENT APPLICATION The present invention is directed to heat resistant polymeric materials and products using same, including cookware, particularly non-stick polymeric cooking surfaces, materials, composites and coatings, and / or replaceable and / or recyclable inserts / covers.

[0003] (Discussion of Related Art) Non-stick cookware, including but not limited to pots, pans, baking sheets, cake / bread pans, etc., have been accepted for commercial and residential use for many years. A common exemplary cookware is a metal cookware coated with a fluoropolymer, e.g., polytetrafluoroethylene. Over time, the polymer coating tends to flake off the metal or accumulate residue and become ineffective. Residential users tend to simply replace the entire cookware item, while commercial / industrial users often send the cookware out for recoating. There is a continuing need for improved non-stick cookware, and cookware that does not use metals that retain heat and cause uneven cooking after removal from the oven.

[0004] Polymer-coated non-metallic cooking sheets and baskets are known for heating foods and toasting sandwiches in ovens. Such temperature-resistant sheets or baskets are particularly useful for quickly toasting sandwiches in high-speed or rapid-cook ovens, such as those commercially available from TurboChef Technologies, Inc. (Carrollton, Texas) and / or Welbilt, Inc. (UK). High-speed ovens typically incorporate several cooking elements, such as those selected from hot air, infrared, radiant, conductive, steam, and / or microwave heating elements.

[0005] While convenient for toasting and cooking food items, known polymer-coated cooking sheets and / or cooking baskets / cooking trays often lack the desired food support, durability, cleanability, heat dissipation (for proper cooking and / or worker safety), and / or appearance in commercial restaurants, especially when food is prepared in view of customers. Also, these known sheets and baskets are typically removed from the oven using a pizza paddle or the like, which generally does not provide the completely desired stability of the removed sheet or basket. U.S. Patent No. 8,857,652, incorporated herein by reference, discloses a cooking support to remedy these problems. Also, there is a continuing need for improved cooking utensils and materials for flexibility in cooking various food items in high temperature / high speed ovens. Summary of the Invention

[0006] An overall object of the present invention is to provide improved non-stick materials and products thereof, particularly cookware, such as pans, baskets, trays, sheets, baking molds and accessories (e.g., lids, covers, oven or counter racks, etc.) for use in fast ovens, quick cook ovens and / or conventional ovens. Embodiments of the appliances allow for easy insertion and removal from the oven, provide structure to hold and support removable cooking inserts of various shapes and sizes, cool quickly, do not retain heat (e.g., contain little or no metal), and can withstand temperatures indefinitely in excess of 375°F (191°C), and more preferably 500°F (260°C).

[0007] Another general object of the present invention is to provide a non-stick, reusable cookware / baking pan that includes at least one polymeric cooking surface. The cooking surface may be formed of a "non-stick" polymer, contain a non-stick additive as part of the polymer matrix, be dip or spray coated with a non-stick polymer, and / or be coated with a removable non-stick polymeric on-surface insert. A variety of polymers are available for these applications.

[0008] Exemplary polymeric materials having a non-stick surface according to embodiments of the present invention include melt-processable fluoropolymers such as perfluoroalkoxyalkanes (PFA), TFE / perfluoromethylvinylether copolymers (MFA), or fluorinated ethylene propylene (FEP). Additionally, mixtures of fluoropolymers such as MFA, PFA, FEP, ECTFE, and PTFE, as well as non-stick silicone-containing materials may also be utilized.

[0009] The present invention provides an improved woven / plastic / non-adhesive laminate material with structural advantages that can be pressed or molded in a forming process to provide a cookware or other non-adhesive item / component with a shape. Exemplary plastics for these embodiments include engineering resins. Engineering resins and thermoplastics are used today in fabrics and conveyor belts. These are typically resins mixed with fluoropolymers and / or silicones. The incorporation of fluoropolymers or silicones generally precludes the use of engineering resins in structure, so the engineering resins are used for barrier or abrasion resistance rather than structure. Composites of the material of the present invention may be infused with 100% engineering resin until the woven glass substrate is fully saturated, so that the engineering resin is consolidated during molding to create the structural elements. Another feature is that the present invention combines 100% engineering resin with non-adhesive materials such as fluoropolymers or silicones. This results in good bond strength.

[0010] The invention includes a composite material including a flexible substrate impregnated with a heat resistant polymeric material and having a non-stick coating, the composite material having structural rigidity upon curing. The composite material is pressable or moldable into a predetermined configuration prior to or during curing, and retains the predetermined configuration having structural rigidity upon curing. The predetermined configuration is a consumer product, preferably a cooking item or a mechanical (e.g., vehicle) component.

[0011] An embodiment of the invention includes surface coatings, such as those applied by spray or dip coating, or those applied as a film or coated fabric. In another embodiment of the invention, the cooking surface is first dip or spray coated and then covered / laminated with a cast or laminated film or coated fabric, for example, formed of one or more of the following materials: silicone materials and / or fluoropolymers, such as melt processable fluoropolymers or blends of PTFE and melt processable fluoropolymers. Spray coatings, cast films, and the like desirably interlock with each other during curing, providing a stronger bond to the underlying cookware surface.

[0012] The present invention further provides a woven / plastic / non-adhesive laminate material with structural advantages that is pressable or moldable in a forming process to provide a cookware or other non-adhesive item / component with a shape. Composites of the material of the present invention may incorporate flexible and / or fibrous materials impregnated with 100% engineering resin, whereby upon molding, the engineering resin compacts to produce a structural component that maintains its molded shape.

[0013] An embodiment of the present invention includes an individually formed on-surface insert that is applied over the cooking / grilling surface of a cooker, and is preferably replaceable and recyclable. The insert may be applied by suitable means such as clipping, snapping, press-fitting, or nesting onto the cooker at the cooking surface. The insert may be applied to a new type of cooker, or may be retrofitted to refresh the non-stick surface of an existing household, commercial, or industrial cooker. When the on-surface insert approaches the end of its life, it can be removed and replaced, or preferably returned to the manufacturer for recycling. The present invention includes a subscriber service method for routine replacement and recycling of the on-surface insert.

[0014] Another general object of the present invention is to provide an improved cooking support device, such as a basket, tray or sheet, particularly for use in high speed, rapid cooking microwave ovens and / or conventional ovens. Embodiments of the device provide easy access to and from the oven, provide a structure to hold and support removable cooking inserts of various shapes and sizes, cool quickly, do not retain heat (e.g., contain little or no metal), and can withstand temperatures indefinitely in excess of 375°F (191°C), more preferably 500°F (260°C), and most preferably up to 600°F (315°C), and in some applications up to 800°F (426°C). The cooking inserts may themselves be non-stick, may be coated, or may desirably have a removable on-surface insert as described above.

[0015] An embodiment of the present invention includes a food support apparatus for holding food items during cooking in an oven. The food support of the present invention includes a reinforcing structure, such as a support frame. One or more fixed or movable and / or removable cooking inserts extend across the support frame and are designed for one or more different types of cooking and / or food. Many, and preferably all, of the components of the apparatus are formed of or at least include a high temperature resistant material, such as a high temperature resistant or heat resistant polymer.

[0016] Embodiments of the present invention may also support a flexible sheet-like insert on the bottom support surface of the support frame, which may be held at the periphery or may be a mesh or solid film substrate, such as a stone, metal, porcelain and / or ceramic sheet or pan insert.

[0017] The support frame, cooking insert, and / or mesh / solid substrate can be formed of materials including mica, wollastonite, fiberglass, nylon, polyester, aramid, polyethylene, polyolefin, ceramic, metal, liquid crystal polymer (LCP), polysulfone, polyketone, polyphenylene sulfide, polyphenylene sulfone, polyimide, polyamideimide, fluoropolymer, or combinations thereof. The support frame, its components, and / or frame inserts can be thermoformed, extruded, molded, or 3D printed with or including a heat-resistant polymer. "Heat-resistant" as used herein refers to the ability of a material to withstand continuous use temperatures of about 400° F. (about 204° C.) or greater. The heat resistant polymer may be pure or reinforced and may include, for example, fluoropolymers (e.g., PTFE, FEP, PFA, MFA®, ETFE), fluoroelastomers, silicone rubbers, silicone resins, urethane rubbers, urethane resins, polyketones, polyetheretherketones (PEEK), polyamideimides (PAI), polyphenylene sulfide (PPS), polyphenylsulfones (PPSU), liquid crystal polyesters (LCP), polyethersulfones (PES), epoxies, or combinations thereof.

[0018] In an embodiment of the present invention, the cooking inserts may also be made of disposable or single-use materials made from pulp materials such as bagasse, straw, paper, wood, hemp and / or bamboo, etc. These inserts are capable of withstanding one cooking cycle and are therefore considered highly relevant for certain uses.

[0019] The food support of the present invention may be configured as, for example, a cooking basket or tray, or a cooking sheet, and is convenient for transferring food items to and from an oven, and for holding food items while in the oven. The food support of the present invention desirably withstands multiple heating cycles, is high temperature and water resistant, is easy to clean, is stain resistant, and dissipates heat quickly, desirably with no or little effect on the cooking of the food. The food support may include a base sheet having a solid bottom, such as to prevent liquids from dripping onto the heating element, or may include a meshed base sheet. Multiple cooking inserts that can be used with the support frame can cook different food items, for example, to obtain desired browning, toasting, and / or cooking characteristics of the food.

[0020] Other objects and advantages will become apparent to those skilled in the art from the following detailed description when considered in conjunction with the appended claims and drawings. [Brief description of the drawings]

[0021] [Figure 1] 1 shows a cooking surface insert for a pan according to one embodiment of the present invention. [Diagram 2] 1 illustrates a composite material in accordance with one embodiment of the present invention. [Diagram 3] 3 shows the composite layers and shapes of FIG. 2. [Figure 4] 3 shows the composite layers and shapes of FIG. 2. [Diagram 5] 3 shows the composite layers and shapes of FIG. 2. [Figure 6] 1 illustrates a laminated composite material in accordance with one embodiment of the present invention. [Figure 7] 1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 8] 1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 9] 1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 10]1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 11] 1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 12] 1A-1D each illustrate an exemplary shaped cooker in accordance with an embodiment of the present invention. [Figure 13] 1 illustrates a panini press surface according to an embodiment of the present invention. [Figure 14] A molded cooker component according to an embodiment of the present invention is illustrated, preferably as a component of a cooking appliance. [Figure 15] A molded cooker component according to an embodiment of the present invention is illustrated, preferably as a component of a cooking appliance. [Figure 16] A molded cooker component according to an embodiment of the present invention is illustrated, preferably as a component of a cooking appliance. [Figure 17] A molded cooker component according to an embodiment of the present invention is illustrated, preferably as a component of a cooking appliance. [Figure 18] 1 shows a support frame for a cooking appliance according to one embodiment of the present invention. [Figure 19] 1 shows a support frame for a cooking appliance according to one embodiment of the present invention. [Figure 20] 1 shows a support frame for a cooking appliance according to one embodiment of the present invention. [Figure 21] 21 illustrates a cooking insert within the support frame of FIGS. 18-20 according to one embodiment of the present invention. [Figure 22] 21 illustrates a cooking insert within the support frame of FIGS. 18-20 according to one embodiment of the present invention. [Figure 23] 18-20 illustrate the use of a cooking insert within the support frame of FIGS. 18-20 in accordance with one embodiment of the present invention. [Figure 24] 1 illustrates stacked support frames according to one embodiment of the present invention. [Diagram 25] 1 shows a support frame for a cooking appliance according to one embodiment of the present invention. [Figure 26]1 illustrates a lid for a support frame according to one embodiment of the present invention. [Figure 27] 1 illustrates a solid backed insert within a support frame in accordance with one embodiment of the present invention. [Figure 28] 1 illustrates a mesh insert in accordance with one embodiment of the present invention. [Figure 29] 1 illustrates a mesh insert in accordance with one embodiment of the present invention. [Diagram 30] 1 illustrates a cooking insert within a support frame according to one embodiment of the present invention. [Diagram 31] FIG. 31 is an assembly diagram of the cooker of FIG. 30. [Diagram 32] 1 shows an insert on a cooking surface according to one embodiment of the present invention. [Diagram 33] 1 shows an insert on a cooking surface according to one embodiment of the present invention. [Diagram 34] 1 illustrates a cooker appliance according to one embodiment of the present invention. [Diagram 35] 1 illustrates a cooker appliance according to one embodiment of the present invention. [Diagram 36] 1 illustrates a cooker appliance according to one embodiment of the present invention. [Figure 37] 1 illustrates a cooker appliance according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The present invention provides heat-resistant and / or non-stick materials and products thereof, including cookware comprising at least a non-stick polymeric cooking surface. Cookware, as used herein, includes, but is not limited to, various pots, pans, sheets and baskets, as well as baking pans such as cake / bread pans and cooking sheets, and components for cooking devices / appliances. The cookware comprises a non-stick cooking surface formed of a polymeric material or coated / covered with a polymeric material. Suitable polymeric materials include, but are not limited to, silicone and fluoropolymeric materials.

[0023] The present invention includes improved heat-resistant materials and products, including those for use in vehicle components and cookware, particularly in high speed ovens, quick cooking ovens, and / or high temperature conventional ovens. In some preferred embodiments, the products are made entirely of polymeric materials and contain substantially or no metal, and are therefore non-metallic. As explained above, any suitable high heat resistant polymer may be used. When referring to "non-metallic," it is meant that the entire product and / or each layer or element is free of metal.

[0024] In an embodiment of the invention, the polymeric material of the cookware and / or cooking surface is a heat-resistant polymer. "Heat-resistant," as used herein, refers to the ability of a material to withstand continuous use temperatures of about 400° F. (about 204° C.) or greater. Heat-resistant polymers may be pure or reinforced and may include, for example, fluoropolymers (e.g., PTFE, FEP, PFA, MFA®, ETFE), fluoroelastomers, silicone rubbers, silicone resins, urethane rubbers, urethane resins, polyketones, polyetheretherketones (PEEK), polyamideimides (PAI), polyphenylene sulfide (PPS), polyphenylsulfones (PPSU), liquid crystal polyesters (LCP), polyethersulfones (PES), epoxies, quartz, fluorinated materials such as fluorinated mica, combinations thereof, and / or other non-stick, easy-to-clean materials.

[0025] To form the products of the present embodiments, the pelletized glass filler material or other polymeric material may be melted in a screw extruder and then formed by any suitable molding process to obtain the shape of the cooker. Exemplary molding processes include, but are not limited to, injection molding, stamping, and / or thermoforming, desirably forming a one-piece molded article of the cooker. Additives may also be included to promote desirable properties. Exemplary additives include materials that reduce thermal mass and allow for rapid cooling, such as hollow glass spheres, chopped glass fibers, mica, and the like.

[0026] In an embodiment of the invention, the product is formed from or includes a melt-processable fluoropolymer. Exemplary melt-processable fluoropolymers include, but are not limited to, perfluoroalkoxyalkanes (PFA) or fluorinated ethylene propylene (FEP), homopolymers or copolymers of PTFE, or combinations thereof. In an embodiment of the invention, the entire cooker, or at least the cooking portion / surface thereof (e.g., a coating on the cooking surface, or an attachable handle, etc.), is molded from a melt-processable fluoropolymer. Exemplary embodiments have a thickness of 20 mils or more and are capable of retaining their molded shape during a cooking cycle in a high-temperature oven.

[0027] Embodiments of the present invention are particularly directed to cookware items and provide or include a lid or insert having a polymeric surface, desirably formed of a melt-processable fluoropolymer, for example, because melt-processable fluoropolymers are expensive, and the on-surface insert provides a thin, snap-on and / or drape-on (cap-on) covering material to provide non-stick properties to metal or polymer cookware and / or to restore aged cookware.

[0028] FIG. 1 illustrates a polymeric on-face insert (20) for covering a food support surface (31) of a pan (30). The pan (30) may be a metal mold or, for example, a PTFE pan that has lost its non-stick surface (e.g., due to flaking or charred deposits). The on-face insert (20) includes a cooking surface (21) that conforms to the shape of the pan and corresponds to the support surface (21). The on-face insert (20) includes clip or snap structures (24) along an upper perimeter edge (22). The snap structures (24) in FIG. 1 are designed to removably snap around the upper edge (32) of the pan (30).

[0029] The cooking surface inserts of the present invention are applied, such as by clipping, snapping, press fitting, or nesting, onto the food support surface of a cooking / grilling cooker and are desirably replaceable and recyclable. The inserts may be applied to new cookers (e.g., FIG. 30) or may be retrofitted to refresh the non-stick surfaces of existing household, commercial, or industrial cookers. When the polymeric cooker or surface insert of the present invention approaches the end of its life (e.g., due to buildup of fouling), it can desirably be returned to the manufacturer for recycling. The present invention includes methods for installation and removal of the surface inserts and / or methods of subscriber service with the distributor / manufacturer for regular routine replacement and recycling of the cooker and / or inserts.

[0030] The present invention further provides an improved woven / plastic / non-adhesive composite or laminate material with structural advantages, which is pressable or moldable in a forming process to provide a cookware, cooking surface insert, or other non-adhesive item / component with a shape. The composite embodiment of the material of the present invention may incorporate 100% engineering resin as the plastic material until the woven glass substrate is fully saturated, so that upon molding, the engineering resin will consolidate to produce the structural component. Another feature is that the present invention desirably bonds 100% engineering resin with fluoropolymer or silicone. This is easily accomplished and provides good bond strength.

[0031] An embodiment of the present invention provides a formable composite that is resistant to high temperatures (≧375° F). As shown in FIG. 2, the composite (50) may be formed by impregnating and / or coating one or more substrates (52) with a plastic material (54). Exemplary flexible substrates include woven substrates, nonwoven substrates, open mesh / leno substrates, braided substrates and / or unidirectional fabrics, including those made with fiberglass or other suitable fibrous materials such as Kevlar, Nomex, carbon fiber, quartz fiber, PEEK, PAEK, PPS, PES, PPSU, LCP and / or PAI fibers, or combinations of such fibers or yarns. Exemplary resin materials include engineering thermoplastic materials and blends thereof. When molded, the engineering thermoplastics desirably act as the support and structure of the composite.

[0032] A variety of alternative sizes, shapes and configurations of plastic impregnated / coated substrates are available. For example, multiple substrate layers may be impregnated. Additionally, multiple individually impregnated substrates may be laminated together prior to topcoating. The multiple layers may be of the same or different substrate material, for example, a coated woven fabric may be laminated to one or both sides of a coated nonwoven fabric. The type and number of layers may be adjusted for stiffness as needed. For example, FIG. 6 shows a laminated composite having 10 resin impregnated substrate layers, which may provide the desired stiffness for applications such as the oven components of FIGS. 14-16. The desired number of layers, greater than 3, preferably greater than 5, more preferably greater than 8, and preferably at least 10, may be laminated without a non-stick coating, and then coated, if necessary, with a non-stick fluoropolymer film or coated fabric, etc., on one or both sides of the multi-layered product.

[0033] A non-stick coating (56), such as those of the materials disclosed herein, is applied over the engineering thermoplastic coating (54). The non-stick coating (56) is desirably easily cleanable, chemically resistant, abrasion resistant, and stain resistant. Exemplary non-stick materials include fluoropolymers and silicone rubbers and resins. Once formed, the composite material is capable of withstanding temperatures desirably in excess of 375°F (191°C) and up to 800°F (426°C) continuously, depending on the engineering resin utilized.

[0034] The non-stick coating (56) may be applied over the engineering resin (54) by, for example, dip coating, spray coating, curtain coating or powder coating. The surface of the non-stick coating (56) may be applied by casting, extruding, skiving or laminating a PTFE-coated woven fabric onto the surface of the engineering resin. The non-stick coating (56) may be applied before or after formation of the molded part, as described in more detail below.

[0035] In embodiments of the present invention, a microwave absorbing material or coating 58 may be applied prior to application of the non-stick coating 56 or as a component of the application on the non-stick surface. As with the application of the non-stick coating 56, it may be applied as a coating or laminate material in the same manner as described above.

[0036] The composite materials of the present invention are useful for forming molded articles such as consumer goods and cookware. In accordance with some embodiments of the present invention, the forming method begins with a substrate, such as a woven fiberglass substrate, which may include a layer of coated straight strand fiberglass. The substrate is saturated coated with a solution of dissolved or suspended plastic, such as PAI, PPS, PEEK, PPSU, PES, or combinations thereof, or other suitable plastics known for high temperature use. Multiple passes of the coating may be used to sufficiently saturate the fibers and build up the appropriate weight for flow and forming. The plastic coated substrate is dried and processed, preferably to a prepreg (pre-impregnated) state similar to that done with fiberglass epoxy resins used in printed circuit boards.

[0037] A topcoat of PTFE or other non-stick material is applied to one or both sides. A coating of fluoropolymer provides release function during forming and provides a high performance release finish for cooking (similar to coating a pan). Coatings may be applied, for example, by a single layer of heavy coating and / or by multiple layer layups of lighter weight woven or straight strand fiberglass.

[0038] The dried but uncured composite material may be wound into rolls and stored for further processing from the rolls in an automated forming press, or may be sheeted into individual sizes for manual entry into the press. Forming presses typically include heated platens fitted with male and female forming dies and generally have adjustable temperatures above 600°F (315°C). The material is formed at a temperature above the glass transition temperature (Tg) of the mixed engineering resins. Pressure is also generally adjustable and varies with size. Testing has shown reasonable results of 30 psi in a pneumatic press capable of 3 tons of total applied pressure. Larger part sizes and multiple part molds may require significantly greater pressures. Matched secondary molds or coining are forms of compression molding that require higher pressures, and for the purposes proposed in this invention, a hydraulic press of 30 to 50 tonnes would likely be required.

[0039] After forming, the edges may be trimmed with a die cutting device such as a "steel rule die" or a "clicker press." The formed parts are post cured in a batch oven with a stepped temperature cycle to obtain higher service temperatures and to harden the PTFE and improve its bond to the tray. Post-molding processes may be used to crosslink, chain extend, or otherwise cure the engineering polymer. The engineering polymer may also be post cured to temperatures capable of fusing the fluoropolymer.

[0040] In an embodiment of the invention, the material may be cured during the molding process if molding is done at a high enough temperature. Another option is to post cure in an in-line process such as a hot air oven on a conveyor or an infrared oven. In an embodiment of the invention, molding is done between 640°F (338°C) and 800°F (426°C). At these temperatures, the process is complete and no post cure is required. Higher temperatures allow the fluoropolymer to be cured simultaneously with molding, thus reducing the need for post cure.

[0041] In an embodiment of the invention, a composite is formed, a woven substrate of high temperature thermoplastic material (e.g., capable of continuous use at temperatures of 375°F (191°C) or greater), such as PEEK, PAEK, PPS, PES, PPSU, LCP, and / or PAI, which may be coated with another compatible thermoplastic material, the coating may include chopped glass fiber or other reinforcing materials, and the material may then be topcoated with a non-stick surface.

[0042] Additionally, for added dimensional strength, the thermoplastic woven material may be laminated, either prior to or during the separate coating passes described above, with a nonwoven, woven, or unidirectional fabric of reinforcing material capable of withstanding continuous service temperatures of 375°F (191°C) or greater.

[0043] The composites of the embodiments of the invention preferably have or include a rigid molded shape, are inherently insulating (i.e., do not conduct heat), durable, non-sticky, low friction, cleanable, chemically resistant, corrosion resistant, heat resistant, and / or capable of rapid heat extraction. Also, the weave of the substrate is preferably capable of conforming to a shape during the compression or thermoforming process so as not to tear, wrinkle, or break. The composites and formations of the invention are useful for components of cookers and cooking appliances, including but not limited to baking pans, microwave applications, and oven cooking (conventional, conveyor, quick cook, brick / stone, fast cook, etc.). The composites and formations of the invention are useful for other consumer or industrial products / applications, and / or automotive applications, including but not limited to providing corrosion resistance and / or chemical or heat resistance or insulation to components such as tubes, fluid containers, oil pans, and / or exhaust system components. These properties also make the material useful for forming aerospace and / or defensive parts.

[0044] Exemplary cookware pressed or molded from laminated materials include cooking sheets or trays such as those shown in FIG. 7, bread or cake molds such as those shown in FIG. 8, and / or baskets, trays, egg cooking molds or cups such as those shown in FIGS. 30-37. Other exemplary cookware include bowls, cookie sheets, pizza pans, panini presses or grill pans, muffin molds, croissant molds, cake molds, pie plates, plates, covers, or other cookware accessories. FIG. 9 shows an embodiment of a pressed basket including multiple perforations. FIG. 10 is a pressed bread proofing tray or proofing mold including multiple grooves for proofing. FIG. 11 is a taco tray including a pressed uneven surface, each of which is a V-shaped recess for holding a taco. Although a tray with side walls is shown, a tray without side walls or with any side configuration may be formed. FIG. 12 shows a pressed pizza pan including an exemplary ribbed cooking surface. FIG. 13 shows a panini press surface including a contoured or other ribbed surface. The panini press surface may be built into the panini press for added non-stick benefits.

[0045] The cooker of the present invention further includes cooking components, including but not limited to appliance components, preferably oven, fryer, or toaster components. Figure 14 shows an oven rack or other shelving structure. Figure 15 shows a rail or bar that may be used in an oven, but does not necessarily come into direct contact with food. By using the materials of the present invention to form oven components, ovens and the like can be provided with easier cleaning due to non-stick surfaces. Figure 16 shows an oven rack or toaster rack, and Figure 17 shows a typical oven rack.

[0046] Thus, the present invention provides a laminated composite material that can be formed by hot press molding or other stamp / press molding, which may be coated with a non-stick coating prior to forming, thereby providing an efficient forming process and allowing for storage and transportation of material prior to pressing, stamping, or molding.

[0047] 18 and 19 illustrate a cooking device according to an embodiment of the invention, such as a cooking basket, including a cooking support frame (120). The support frame (120) includes a perimeter frame (122) formed in a square shape. The perimeter frame (122) has a lower edge or end (124) connected to an upper edge or end (126) by a sidewall (128). Cross bars (130) (e.g., rails, etc.) extend from the lower end (124) across the interior space. The support frame (120) is desirably formed as a single piece, such as by thermoforming, injection or compression molding, 3D printing, stamping, cutting, etc. Alternatively, the support frame (120) may be assembled from one or more separate side and / or cross bars.

[0048] A variety of alternative sizes, shapes, materials and configurations are available for the support frame of the present invention. For example, the support frame may be circular, rectangular or any suitable shape. The length, width and / or height of the support frame may vary as needed. In one embodiment of the present invention, the length and / or width is about 4 inches to 20 inches, more desirably about 12 inches to 15 inches, and preferably between about 13 inches and about 14 inches. For example, the food support or base may be 4, 6, 12, 13, 14, 15 or 16 inches square, or rectangular, such as 6 inches by 12 inches. Also, the spaces between the cross bars may facilitate cooking, but may be replaced in whole or in part with a solid bottom. Also, alternative cross bar patterns are within the scope of the present invention, if desired.

[0049] The support frame (120) includes an internal support structure for receiving and supporting / holding the removable cooking insert, the internal support structure being desirably spaced apart over the cross bars (130). In the embodiment of Figs. 18 and 19, the side wall (128) includes a plurality of support openings (125). Each opening (125) is aligned and positioned along an imaginary centerline from a corresponding opening (125) in the opposing side wall (128) and / or opposing side of the support frame (120). As shown in Fig. 20, the supports of the insert, shown as support bars (140), extend through the correspondingly aligned paired openings (125). Each of the opposing ends (142) of one of the support bars (140) is positioned in one of the aligned openings (125), such that the support bar (140) extends the length or width of the interior of the support frame (120). The support bar ends (142) and openings (125) that fit together to secure the support bar (140) desirably have matching shapes. For example, the ends shown have circumferential grooves or edges that fit into or out of notches in the bottom of each opening (125).

[0050] A plurality of support bars (140) are positioned within the support frame and spaced apart as necessary to receive and support the cooking insert. FIG. 21 shows one embodiment in which a cooking insert (150) is suspended by being seated between a pair of parallel support bars (140). Each cooking insert (150) includes a cooking surface (152) that is desirably surrounded by one or more insert side walls (154) depending on the shape for receiving food items for cooking, heating, etc. Each cooking insert includes opposed, outwardly extending ridges (156) on each support bar for suspending the insert (150). The ridges (156) desirably have a shape that partially wraps around the outer periphery of the support bar (140) and may include a partial hook shape and / or a semicircular groove at the bottom that matches the outer diameter of the support bar (140). If desired, the cooking insert (150) may be seated, snapped or hooked onto the support bar (140). A variety of alternative sizes, shapes, materials and configurations are available for the support bar of the present invention. The support bar may be formed of the same or different materials as the frame, including the polymers or composites described above, or metals, ceramics, porcelain, natural fibers, or combinations thereof. The support bar may also include a non-slip coating to inhibit movement of the cooking insert.

[0051] The cooking inserts of the present invention are removable for cleaning and / or substitution of other inserts. The inserts provide a food preparation system with a base frame and, for example, separately purchased inserts, allowing for the preparation of various food shapes, sizes, and / or types. FIG. 22 shows a cooking insert configuration in which the support bar (140) has been reduced and repositioned to a different opening (125) to allow for the use of a larger sized cooking insert (150). Various alternative sizes, shapes, materials, and configurations are available for the cooking inserts of the present invention. The illustrated cooking inserts are shown as circular, but any shape can be used (square, rectangular, etc.). Non-parallel shapes (e.g., triangular) can also be used by providing suitable ridges. The movable support bar allows for different sizes and can support large square or rectangular baking sheets or griddles. Each cooking insert can be single or multiple, for example, the flat surface can have integral wall portions or attachable / detachable wall elements. The cooking inserts may also optionally be interlocked with each other to inhibit movement during use and / or may be clipped or otherwise semi-permanently secured to the support shaft. The cooking inserts may be formed of the same or different materials as the frame, including the polymers or composites described above, or metal, ceramic, porcelain, or combinations thereof. The cooking inserts may have a solid or mesh-like and / or flat or contoured bottom, and may include a non-stick or easy-to-clean coating, such as a fluoropolymer (PTFE, PFA, MFA, FEP, ETFE, etc.) or silicone (silicone rubber, silicone resin, silicone oil, etc.), and / or a cooking surface or on-surface insert as described above with respect to Figures 1 and 2. The materials or coatings may also include microwaveable subcategory materials or coatings to enhance cooking.The cooking insert may be designed for cooking food items such as, but not limited to, eggs, omelets, pancakes, pizza, bread, cookies, bacon, soup, fries, or for steaming vegetables, eggs, rice, etc. Figure 23 illustrates a cooking insert in place for cooking eggs.

[0052] As shown in FIG. 24, the support frame (120) of FIG. 18 is stackable with one or more other such support frames (120). Various configurations of the top end (126) and / or bottom end (124) can allow the support frames (120) to be securely stacked. In an embodiment of the invention, the cooker includes a matching or nesting arrangement of corresponding or matching parts (e.g., male / female parts) to allow for stacking. In the illustrated embodiment, the support frame includes a plurality of stacking elements (145), which are formed in the sidewalls (128) and extend between the bottom end (124) and the top end (126). The illustrated stacking elements (145) are implemented as ridges extending outwardly from the sidewalls (128), which allow the bottom end (124) of the frame (120) to rest on the wider edge of the top end (126), as shown in FIG. 24. The stacking elements (145) that extend the height of the side walls provide the desired support for the side walls (128) and form notches in the upper ends (126) to receive the bottoms of other stacking elements (145) and secure the baskets in a stacked configuration. Figure 25 shows the support frame (120) without the stacking elements.

[0053] 26 illustrates an optional lid (155) for placement over the support frame during cooking, which may be molded from the materials described above. The lid (155) may include an internal ridge that fits into a notch in the top end (126) of the support frame (120), an internal lip that fits within the inner periphery of the top end (126), or any other suitable structure to retain the lid on the top end (126).

[0054] As shown in Figure 27, the support frame receives a removable base plate (165), which is desirably sized and shaped to fit within the base plate placement area (i.e., food support surface) of the support frame (120), fit within the base plate placement area, and attach to the cross bars (130). The sheet-type base plate insert (165) of Figure 27 is sized to cover the bottom of the base plate placement area, and optionally extend over the side walls (28), as shown in Figure 27.

[0055] For example, the support frame (120) of Figures 18, 19 and 27 may include optional fastening elements or mechanisms for securing individual substrates (165) within the support frame (120). Figure 25 shows an embodiment without these structures. The fastening elements may be or include any suitable clips, hooks, slots, snaps, pins, or similar elements. In the illustrated embodiment, the fastening elements include a number of hooks or clips (160) spaced along and extending inwardly from the top end (126). As shown in Figure 27, the edges of the basket-shaped substrate insert (165) fit under the downwardly facing hook fastening elements (160).

[0056] The support frame (120) can receive and secure a substrate insert (165) that seats on the cross bars (130) to form a food support. The substrate can be semi-rigid or flexible, such as a thermoformed fluoropolymer sheet or fluoropolymer membrane insert of PPS or PPS and fiberglass, and the support frame (120) provides the desired rigidity to hold the food while being moved in and out of the oven. The support frame can be used to provide a more pleasing appearance, allow for easy cleaning and replacement of used substrates as needed, and / or provide rapid heat dissipation, which can be an advantage for proper cooking and improves operator safety. Rapid heat dissipation is particularly desirable in embodiments of the present invention to avoid extended cooking times on conventional baking sheets or baskets.

[0057] A blend of materials such as PPS / PAI / PTFE, PPS / PAI / PFA / PTFE, LCP / PTFE, LCP / PTFE / PFA, or even PTFE, PFA, FEP, PPS, or LCP alone can provide non-stick, stain resistant, and / or other easy-to-clean or heat dissipation properties. The support frame and substrate are both desirably formed from high temperature or heat resistant materials that are also resistant to steam and water, thereby providing durability to multiple heating and cleaning cycles. The support frame, insert, and substrate are desirably formed from one or more polymers that have low thermal conductivity and / or microwave transparency, thereby maximizing cooking energy applied to the food product. Additives may be included to promote desirable properties. Exemplary additives include materials that can reduce thermal mass and cool quickly, such as hollow glass spheres, chopped glass fibers, mica, and the like.

[0058] The substrate for placement within the support frame (120) may be solid, as shown in FIG. 27, or may be meshed with openings, as shown in FIGS. 28 and 29. Meshed substrates of the present invention may be formed, for example, from threads, threads and / or wires connected by folding or other methods, or may be films with openings. A variety of materials may be used to form the meshed substrate, including, but not limited to, fiberglass, nylon, polyester, aramid, liquid crystal polymers (such as liquid crystal polyester), polyethylene, polyolefin, ceramic, polysulfone, polyketone, polyphenylene sulfide, polyimide, or combinations thereof. A variety of alternative mesh materials may be used for use within the food support of the present invention, as will be understood by those skilled in the art following the teachings herein. Meshed substrate inserts of the present invention may also be, for example, injection molded or thermoformed, and then die-cut or otherwise structurally separated. The coating desirably includes a heat-resistant polymer, such as those described above. To facilitate extending the mesh over the vertical sides of the frame (120), the corners of the mesh may be machined with slits or notches, as shown in Figure 28. Over the mesh substrate, a coating is applied.

[0059] The meshed substrate (165) includes a plurality of openings having lengths and / or widths of about 0.10 inches to about 0.65 inches, preferably about 0.2 inches to about 0.3 inches, and more preferably about 0.22 inches to about 0.28 inches. The openings generally have a square shape, although alternative shapes such as rectangular, circular, or irregular shapes may be used. It will be appreciated that forming a web of threads or threads may result in, for example, openings that are not perfectly square. Thus, in one embodiment of the present invention, the length and width across the openings may vary by small differences, but at least at some point, include the measurements set forth above.

[0060] Thus, the present invention provides a food support, specifically a cooking basket, tray, pan or sheet, useful for transferring food items to and from an oven and for holding food items while in the oven. The food support of the present invention is high temperature resistant and can be used in ovens having heat retention temperatures of 600° F. The variable insert allows different food items to be cooked and provide the desired browning and cooking characteristics. The support frame allows for the use of inserts and / or substrates in a manner that is rigid, durable, and aesthetically pleasing.

[0061] Figures 30 and 31 illustrate a cooking support system according to one embodiment of the present invention, including a support frame (120) as described above. The perimeter frame (122) has a lower edge or end (124) connected to an upper edge or end (126) by side walls (128). Cross bars (130) extend from the lower end (124) across the interior space. As previously shown in Figure 21, this embodiment may also include an insert or accommodate supports extending through correspondingly aligned mating openings to support a cooking insert.

[0062] As an alternative to the cooking insert of FIG. 21, the cooking surface insert of FIG. 30 and FIG. 31 is designed to snap or nest or press fit onto the tray (170). The tray (170) includes a plurality of cooking surfaces formed as recesses (172) within the tray (170). The tray (170) includes curved edges (174) that snap or clip onto the top edge (126). Corner cutouts (176) can further facilitate installation of the tray (170). The tray (170) further includes a central spillway (175) connected to each recess (172) for collecting any liquid that spills out of the recesses (172).

[0063] Also, the trays of Figs. 30 and 31 may be used with conventional cookware, such as metal baking sheets or pans, as new food support surfaces, or may be formed as separate sheets or pans, etc. A variety of alternative sizes, shapes, materials, and configurations are available for the cooking inserts and cooking recesses therein of the present invention. While the illustrated cooking inserts and recesses are shown as circular, any shape may be used (square, rectangle, etc.). Non-parallel shapes (e.g., triangular) may also be used. Each cooking insert may be single or multiple. Also, the individual cooking inserts may optionally be interlocked with each other and / or clipped or otherwise semi-permanently secured to the support shaft to inhibit movement during use. The cooking inserts may be formed of the same or different materials as the frame, including polymers as described above, or metals, ceramics, porcelain, materials described above for Figs. 1 and 2, or combinations thereof. The cooking insert may have a solid or meshed and / or flat or contoured bottom and may include a non-stick or easy to clean coating, such as a fluoropolymer (PTFE, PFA, MFA, FEP, ETFE, etc.) or silicone (silicone rubber, silicone resin, silicone oil, etc.). The material or coating may also include a microwaveable subcategory material or coating to enhance cooking. The cooking insert may be designed for cooking food items such as, but not limited to, eggs, omelets, pancakes, panini, pizza, bread, cookies, bacon, soup, fries, or steaming vegetables, eggs, rice, etc.

[0064] The systems of Figures 30 and 31 further include a cooking surface insert (180), shown separately in Figures 32 and 33, having a corresponding shape to snap, clip or press onto or around the cooking insert (170). As described above for Figure 1, the cooking surface insert (180) may be a non-stick surface that is removable and preferably recyclable. The cooking surface insert (180) is preferably a thinner material, such as a more expensive and / or recyclable non-stick material, that is rigid enough to snap onto the cooking insert, but is generally supported by the cooking insert and by a frame for ease of installation / removal from the oven.

[0065] The support frame and cooking / surface inserts are all formed from high temperature or heat resistant materials that are also resistant to steam and water, thereby providing durability to multiple heating and cleaning cycles. The support frame and inserts are formed from one or more polymers with low thermal conductivity and / or microwave transparency, thereby maximizing cooking energy delivered to the food. Blends of materials such as PEEK / PTFE (or other fluoropolymers / blends), PAEK / PTFE, PPS / PAI / PTFE, PPS / PAI / PFA / PTFE, LCP / PTFE, LCP / PTFE / PFA, or even PTFE, PFA, FEP, PPS, or LCP alone provide non-stick, stain resistant, and / or other easy-to-clean or heat dissipating properties. In a preferred embodiment, the surface inserts are formed from pure melt processable fluoropolymers such as those described above. Additives may be included to promote desirable properties. Exemplary additives include materials that can reduce thermal mass and cool quickly, including hollow glass spheres, chopped glass fibers, mica, and the like.

[0066] FIG. 34 illustrates a cookware appliance (240) according to another embodiment of the present invention, preferably formed entirely of a heat-resistant polymer or composite material as described above to add high heat resistance. FIG. 34 shows a non-metallic support frame (242) raised on two parallel side walls (243) for securing at least one, and preferably multiple, food preparation inserts (244), such as trays, baskets, pans, cups, etc. The food preparation inserts (244) are secured to the top surface of the frame (242) by any suitable fastening mechanism, such as the post (246) and hole (248) arrangement shown in FIG. 34. The cooking insert (244) includes a food dish, container, or bowl (250) for receiving and holding the food items to be cooked. The food tray (250) is surrounded by a rim (252) that sits on top of the frame (242), and the food tray (250) extends through an opening (245) in the frame (242). The food tray (250) is shown in FIG. 34 as round, such as for cooking pancakes or eggs, but may be any suitable shape. Various alternative sizes, shapes and configurations are available for the frame, cooking insert and fastening mechanism of FIG. 34, as desired. For example, the insert may include snap-on, clippable or push-fit ends similar to those described above, or the support frame may include one or more openings or slots along its upper surface to receive the posts, extensions or downwardly curved clip-like ends of the insert.

[0067] 35 and 36 illustrate a cooker appliance (260) according to another embodiment of the present invention, preferably formed from a heat-resistant polymer or composite as described above to add high heat resistance. The appliance (260) is thermoformed from a plastic sheet or composite / laminate and includes a food support surface embodied as a cooking tray (262). The cooking tray extends between the upper edges of peripheral sidewalls (264) that hold the tray (262) apart above the cooking surface. The tray (262) includes a pattern of intersecting rib channels (266) that provide rigidity and facilitate the flow of hot air around the food. The tray (262) includes a plurality of openings (268) to allow the hot air to pass through the tray (262). Various alternative configurations are available for the support area, sidewalls, rib channels and openings. There is a central opening, at least one opening at some or each of the rib channel intersections, and at least one opening at some or each of the support surfaces formed between corresponding rib channels, as shown in Figures 35 and 36. The size, shape and arrangement of the channels and / or holes may be varied as desired, and a mesh substrate as described above may be used on the tray to inhibit debris from falling through.

[0068] FIG. 37 illustrates an alternative cooking support embodiment for receiving cooking inserts (300). The cooking support includes a support frame (320), preferably made from any one or more of the polymers described herein. The support frame (320) includes a sidewall (322), a tray top (324), and a bottom having an opening in the peripheral edge (326) of the bottom and between the sidewalls (322). The tray (324) includes openings (328), each of which receives one of the inserts (300). Each opening (328) has a diameter smaller than the top edge (304) of the insert (300) so that the insert (300) can be seated therein. The openings (328) further include opposing and / or peripheral opening extensions (330) for allowing the insertion of a finger or tool to remove each of the inserts (300) after cooking. Again, it will be appreciated that various sizes, shapes and configurations are available for the inserts, trays and openings of the present invention depending on the needs and items being cooked / baked. For example, the base and opening patterns can also be used for the sidewalls and inserts of FIG. 18 to provide a versatile device.

[0069] In an embodiment of the invention, the cooking insert (300) is at least partially formed of disposable or single-use materials made from natural or pulp materials such as bagasse, straw, paper, wood, hemp, bamboo, etc. These inserts are capable of withstanding one cooking cycle and are therefore considered highly relevant for certain uses. For example, the cooking insert (150) of FIG. 21 may be formed of such pulp material and supported on a corresponding multi-use platform or ring-like holder extending between the rods (140).

[0070] In some embodiments of the invention, single-use pulp cooking inserts are typically pre-packaged, sealed, and shipped to restaurants for cooking prior to cooking at a remote location. FIG. 37 illustrates an exemplary cooking insert (300) formed of natural pulp material. The insert (300) contains a food product to be cooked, including but not limited to eggs or batter (e.g., batter for soufflés, pancakes, cupcakes, muffins, donuts, etc.). For storage and / or shipping, the insert is sealed with a lid (302), preferably also with paper. Alternatively, the empty insert cup (200) can be filled by the user at the cooking location. Exemplary inserts and / or materials include Rigid Containers available from Chef Pack and / or may be made in accordance with U.S. Patent Application No. 2018 / 0346228, incorporated herein by reference.

[0071] Thus, the present invention provides cooking equipment or components, such as cooking baskets, trays or sheets, and materials thereof, that are convenient for transferring food items to and from an oven and for holding food items while in the oven. The cookers and materials of the present invention are non-stick and high temperature resistant and can be used in ovens having heat retention temperatures as high as 600°F (about 316°C). The variable cooking inserts allow different food items to be cooked and provide the desired browning and cooking characteristics. The support frame allows for the use of the inserts and / or substrates in a rigid, durable, and aesthetically pleasing manner. The on-surface inserts allow for an improved, replaceable / recyclable non-stick surface.

[0072] It should be understood that the details of the above embodiments are provided for illustrative purposes and are not intended to limit the scope of the present invention. Although only a few exemplary embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that modifications can be made in the exemplary embodiments without substantially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention as defined in the appended claims and all equivalents thereof. Furthermore, it should be recognized that while many embodiments may not achieve all the advantages of some embodiments, particularly preferred embodiments, the absence of a particular advantage does not necessarily mean that such an embodiment is outside the scope of the present invention.

Claims

1. A cooker for holding food items during cooking, the cooker comprising: having a food support surface, including an integral or attached cooking surface, formed of a heat resistant polymeric material; the cooking surface is snapped or press fitted onto the cooker over the food support surface; The heat-resistant polymer material is at least one selected from the group consisting of fluorinated materials such as fluoropolymers, fluoroelastomers, silicone rubber, silicone resins, urethane rubber, urethane resins, polyketones, polyetheretherketones (PEEK), polyamideimides (PAI), polyphenylene sulfide (PPS), polyphenylsulfones (PPSU), liquid crystal polyesters (LCP), polyethersulfones (PES), epoxy, quartz, and fluorinated mica. A cooking appliance characterized by:

2. The cookware of claim 1, wherein the heat-resistant polymeric material comprises a melt-processable fluoropolymer, preferably perfluoroalkoxyalkane (PFA), TFE / perfluoromethylvinylether copolymer (MFA), or fluorinated ethylene propylene (FEP), a homopolymer or copolymer of PTFE, or a combination of such fluoropolymers.

3. A cookware as described in claim 1 or 2, wherein the cooking surface comprises a polymer spray coating or polymer dip coating, the polymer spray coating or polymer dip coating being coated or laminated with a cast or laminate film of the heat resistant polymer material, and the polymer spray coating or polymer dip coating and the cast or laminate film bond to each other during curing.

4. The cooker further comprises a laminate material having structural rigidity, the laminate material including a flexible substrate impregnated with the heat resistant polymeric material, having a non-stick coating thereon, and pressed or molded into a shape of the cooker or other non-stick item or component; The flexible substrate comprises a woven substrate, a nonwoven substrate, an open mesh / leno substrate, a braided substrate and / or a unidirectional fabric formed of fiberglass, Kevlar, Nomex, carbon fiber, quartz fiber, PEEK, PAEK, PPS, PES, PPSU, LCP and / or PAI fibers, or a combination of such fibers or yarns; the heat resistant polymeric material comprises an engineering thermoplastic material, preferably PAI, PPS, PEEK, PPSU, PES or combinations thereof; The cookware according to any of claims 1 to 3, wherein the non-stick coating applied over the heat resistant polymeric material is PTFE or other non-stick material.

5. The cooker of claim 4, wherein the cooker is pressed or formed into the shape of a basket, tray, sheet, pan, bowl or cup, plate or cover, wherein the cooker or the food supporting surface is completely free of metal, and wherein the cooker is capable of withstanding temperatures indefinitely in excess of 375°F (191°C), more preferably 500°F (260°C), and most preferably up to 600°F (315°C) and up to 800°F.

6. The cooker of claim 1, wherein the cooking surface includes an individually formed cooking surface insert of the heat resistant polymeric material applied as or onto the food supporting surface of the cooker, the cooking surface insert being replaceable, and the cooking surface insert including a snap on non-adherent cover.

7. A replaceable cooking surface or insert for a food supporting surface of the cooker, said cooking surface or insert being formed of a heat resistant polymeric material selected from one or more of the group consisting of fluoropolymers, fluoroelastomers, engineering resins, silicone rubber, silicone resins, urethane rubber, urethane resins, polyketones, polyetheretherketones (PEEK), polyamideimides (PAI), polyphenylene sulfide (PPS), polyphenylsulfone (PPSU), liquid crystal polyesters (LCP), polyethersulfones (PES), epoxies, quartz, fluorinated materials such as fluorinated mica, etc. Cooking device according to any one of claims 1 to 6, characterized in that it has an exchangeable cooking surface or insert for the food supporting surface.

8. Use of a cooker as described in claims 1 to 6, or a replaceable cooking surface or insert as described in claim 7, comprising removing and replacing the cooking surface or insert.

9. A method comprising the step of providing a removable and replaceable cooking surface or insert as described in claim 7 for a cooker, said cooking surface or insert being separate from said cooker and adapted to be removably secured within said cooker to hold food items in an oven during cooking, said cooking surface or insert being formed of a heat resistant polymer.

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